| wytco0 |
Following Lars suggestion in the UCD400 thread, this thread is suggested as a discussion place for the LC Audio ZAPpulse amps.
Although I have not used the LC Amps I have used their Predator power supply to power my UCD modules. I believe others have done the same.
We are extremely lucky to have the people involved in designing and building the LC and UCD modules in this forum and I for one would like to thanks them all for their assistance.
So first question about ZAPpulse, are there any new higher power versions planned? |
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| Lars Clausen |
Hi
At this point we have no plans to release our high-power version of ZAPpulse.
However you might have noticed that we have upgraded the power of the newest verion of ZAPpulse 2.2SE to 360 W in 8 Ohms and 720 W in 4 Ohms. |
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| Duck-Twacy |
| Is that a newer version (or the same as the model sold a few months ago)? The cookbook and website still mention 286 watt@ 8 ohm at 69V DC. |
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| Lars Clausen |
Duck Twacy: Same as sold a few months ago, as long as it's the SE version you can run it up to 80 V rails and get the 360 W in 8 Ohms / 720 W in 4 Ohms.
The non-SE version however is limited by the 63V MKT caps.
LC |
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| mrsito |
For Lars:
I have just ordered 2 modules, and I see that you believe a modification to input resistors for LM6172 can change hiss coming from the Zappulse modules.
I would like to try this in my modules, if you can be more specific.
If you want to reply privately, please email at address
"mrsito AT yahoo.com"
Regards,
mrsito |
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| Henrik Juhl |
Hi Lars,
(Vi kunne snakke Dansk, men så går de andre glip af guldkornene..... :D )
| quote: | Originally posted by Lars Clausen
The non-SE version however is limited by the 63V MKT caps.
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Does this mean that one could replace the caps of the non SE version with caps of higher voltage rating and get the same power for the non SE modules - or are there any other limitations :confused:
The reason I'm asking is that I would like to use some toroids I allredy have rated at ±50 V AC (± 69 V rails) for subwoofer use - and me thinks not me needs the claimed extra quality of the mid and treble.
Possible ? |
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| bambadoo |
| Yes You can, but bevare of soldering/desoldering issues on the Zappulse boards, because of the 4 layer pcb's. |
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| Lars Clausen |
Bambadoo: Thanks for answering that one for me. Exactly right ;-)
About the hiss issue, i have not had the time to test out the best way to do this yet, and also i have not had the time to make an instruction for you, so i am not going to expand on that particular issue just yet. Sorry :bawling: |
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| bambadoo |
Thanks Lars.
I have after trying all of your comercial zappulse modules (from v1.0 to 2.2se) and become quite familiar with them. I have had my problems (with the v4p), but now they only play beautiful music. I have posted my system setup in several forums. The version that surprised me the most was infact the versjon zappulse 1.2, where I tried different mosfets. I ended up using the STP19nb20 and the music flowed with ease :D
Of course the 2.2se is better, but as an early design, the 1.2 impressed me.
Now I am using the 2.2se (with black gate) and some Elna cerafine psu caps. Diode bridges and 1 trannie /channel. In monoblock. Havent got any problems with hum or hiss.
One day I actually tried them with some 94db speakers I have in my basement. Audio Note AN/J (they are being upgraded), and the combination performed quite good actually. I heard some hiss from the
speakers, but it wasn't much. I am using an audio note dac, one ss preamp, and tried a Kora Eclipse valve pre, with good result. I have some problems with a ground loop or something with the valve pre, but the combination is very interesting. The Kora (upgraded with silver cable, mcap silver caps etc.) is like a pre with turbo. Very dynamic and the combination is extremely lifelike. The earlier zappulse modules didn't like the cable-spaggetti that was behind the amp, but the 2.2 is better here.
Btw. I am planning another pre. for my setup, however one of those I have in mind has got quite high output impedance. The zappulse modules have 17 k input impedance. Is there an easy way of making that input impedance higher?
Best Regards bambadoo
Greetings from Norway. It is snowing now, and it is almost weekend. :) |
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| Lars Clausen |
Bambadoo: Thanks for using all my products ;-)
The input of the 2.2SE goes to a virtual ground coupled op-amp, so the best way to increase the input impedance is simply add a resistor in series with the input, say 100k.
Of course your gain will drop from this also, but can be increased again by lowering the value of R4 to say 4k99.
Also here in Denmark it's snowing, it's beautiful, and it's also almost weekend ;-) |
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| michaelab |
I made a power amp using the LC Audio 2.2SE modules (see here) and I'm very happy with it. It sounds fantastic!
However, I just have a couple of questions about 2 strange things that it does, allthough neither affects it during use:
1. When I switch the amp off, as the power drains from the PSU caps I get a sort of "weeeeiiiiiiuuuuuu" sound rather like tuning a SW radio. It's quite quiet and only lasts for maybe 2-3 seconds before there's a light "thud" in each speaker as each module powers off presumably. It's not annyoying but I just wanted to know what might be causing it.
2. If I switch the amp off and then turn it back on again with a relatively short timeframe (say 2-3 minutes) it appears to be dead. If I put my ear to the tweeters I can't hear the usual quiet hiss that I usually do and if I play music there's just silence. If I continue to play music then each module does kick in eventually and works normally. Sometimes there can be a difference of 15-30 seconds between each module kicking in! If I leave the amp switched off for a long time (more than 15 minutes or so) then it powers up normally and there's no issues.
Again, neither problem is annoying, just confusing :)
Michael. |
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| bambadoo |
| Hi michaelab. I have exactly the same issues. You described them very well. I leave my amps on 24/7, that should do the trick ;) |
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| michaelab |
Thanks bambadoo - great to know that I'm not the only one with these issues. I do usually leave the amp on 24/7 but the other day I was experimenting with some speaker cables and, being a good little boy, I was turning off the amp whilst swapping cables ;)
Michael. |
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| Lars Clausen |
Michealab: I have some explanations for you:
1..When the voltage starts to drop, the switching frequency changes, and same time the zener regulators go out of their saturated mode, opening for a better transmission of power rail noise. This means modulation of the two different sw ferq's from the two ch's will interfere.
2..This problem comes from the DC servo. When you have just switched it off, the DC servo will be out of tune, because it just tried to maintain 0 mV on the output even with changing power rails at power off. Now when you switch the amp back on again, the integrator can not start because it is offset by the DC servo for maybe 5 to 20 seconds.
Cheers
Lars |
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| michaelab |
Lars, thanks for the quick explanation. It's nice to know that it's normal behaviour :)
Michael. |
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| Raoul |
Hi,
I have an Adire Brahma 15" subwoofer that I want to use in my home. I have read that the Zappulse 2.2SE can drive difficult loads, but can it drive a 1 ohm load (Brahma with voice coils wired in parallel)? Also, the specification sheet lists response at 20Hz to 20KHz. Will this present a problem when used as a sub amp?
Thanks for any advice you can offer. |
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| Andrew Steele |
I live in Australia and it isn't snowing outside, we're actually having 35C days. Nice and hot.
Cheers
Andrew |
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| richie00boy |
| I don't know which spec sheet you looked at but all the ones I saw listed response as DC to over 20kHz. Ideal for a subwoofer :D |
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| Raoul |
| I guess I am worried about material below 20Hz (movies, etc.) |
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| Raoul |
Whoops! I must have been looking at the output power rating for 1 ohm (20Hz-20kHz). Frequency response +0-3 dB: DC-140.000 Hz
Thanks richie00boy |
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| Lars Clausen |
| Raoul: if you reduce the rail voltages it will drive 1 Ohms load without any problem. Say +-45V will give you full freq response of 800 W / 1 Ohms RMS |
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| Raoul |
| Thanks Lars, that's exactly what I was looking for. Is the Predator PS a good choice for this application, or would it be better to build up a power supply? |
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| Pierre |
A simple question about Zap Pulse.
Please, could anyone tell me what the typical ripple level at the output is for, say, +/-60v supplies?
Thanks! |
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| mrsito |
What is the frequency of the peak created by the filter choke network?
What values of R and C would you recommend for a Zobel network applied to the Zappulse output? |
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| bambadoo |
As far as I know, there is already a Zobel network installed on the output of the zappulse modules (from v2.0). The values are 2.2 ohm and 100nf.
Regards |
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| richie00boy |
| The resonant peak is described in one of the PDFs for the ZAPpulse on LC Audio website. I think it's either 85kHz or 113kHz. Check out the website to be sure, there's lots of useful info there. |
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| robomatique |
Hello,
My first post here, but I am a synth and recording studio DIY guy with lots of experience and absolutely no understanding of what I am doing :D
I am planning to build two channels of Zap Pulses powered by the predator PSU.
1. I have access to 1000VA power transformers, but what voltage do you think I should go for. I don't really need a lot of power, but do you think it sound a lot better in a higher power set up? I could go for whatever, but I just want to hear some thoughts about pros and cons.
I am also a bit worried about working with high voltage... I am planning to use a separate 15V transformer for the Gate Drive.
2. How big does it have to be?
3. Can I just split the power after the IEC input connector to both transformers?
I will connect this amp to a Yamaha DSP-E800 pre amp that also has center and rear amplifiers as well as DTS/DD decoders. They go dirt cheap at ebay for the moment :) and the specs seems good with 70W/channel in 8ohm and 24,000F capacitance in the power supply. And it is only for the effect channels anyway... the zaps will power my setup for music :)
Anyway, the amp has a power output that is controlled of the standby button of the unit. I wouldn't really like to power my Zap Pulse from it, but I thought I could build a relay circuit inside my zap that is controlled from this output which controls the zap's standby feature. In other words I would put my zap pulses in standby mode from the standby button on my preamp and remote :)
4. In that case I suddenly have three power transformers in my chassi, one power, one gate driver and one for the relay circuit. Would this be a problem?
Thanks for any help!
Robert |
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| sven-ake |
Picture of my Zappulse not finished cabinet but playing.And yes Lars Clausen there is an Zapsolute under it(beautiful sounding amp).I´m using a 2*50V 1000VA trafo and you soldered bigger capacitors to me on the Predator PSU to handle the bigger voltage 2*15000 80V and it works just fine and the amp sound fantastic at its price. Unfortunally as you know (i mailed you about it)the right module got some shorting or something it just blinks very heavily.I have returned it to you,i have mailed about the problem when i shut the amp down it give the speakers a real "puff" that`s what happend with the modul.It also took one of my sub in the Martin Logan SL3 speaker to the grave.Is there any easy solution to this "puff" when im shutting down the amp,because the sub`s in my speakers are expensive?Some people have no problems at all with this fenomen i seem to be the only one that really get a "puff" in the speakers have i done something wrong,or is it the bigger trafo and capacitors that makes this"puff"?
/ Sven-Åke |
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| LaKrissen |
Hello everyone ..
well since this happens to be the post of zappulse I would like to share my current idea that i have been having lately
allthough 3-phase is not legal use in diy in denmark .. as far as i know ... here is the idea, with 3 phases using 3 trannies each 2x42V 500Vac supplying 6 sets of circuits of the neverconnected kind ( 3 positive and 3 negative ) with a total of 180.000 uF's , connected to 2 High-Q. El's with short leads to the ZapModules
All together a very stable supply in my mind .. given that it would now be a tiny 300Hz ripple without any noise from the mains *SSSS*
And Lars .. Thanks a great many times for sending the Zapfilter replacement so quick .. *S* it's been implemented with great care in the Pioneer and works Super ( connected according to the PCM1716 scheme ... but the filter caps connected to EXTL-R should be removed, no problem then )
:smash: still tweaking on : |
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| gpapag |
Hellow Mr. Clausen
I need your help.
A friend of mine bought (through the Greek distributor) three ZapPulse 2.2SE modules (he needs four more).
He set up a monoblock with one of them in a half steel, half aluminum enclosure using a 250 W 2x50 V AC X-former (+/- 69V DC), a 30 A bridge and 2x 15000uF with very sort thick wiring throughout following the directions of the data sheet. He phoned me saying the amp had a bright sound, not much of power and it was becoming warm quite a lot (aluminum bloch attached to massive aluminum plate). I asked him not to operate it and bring to me for testing with the osciloscope. I was suspecting self oscilation.
When he brought it home, I connected a dummy 6 Ohm load and shorted the input.
The output with stand-by ON was quite acceptable (short bursts of 3MHz 1.5mVpp oscilations repeating with a frequency of 50 KHz, superimposed on +3 mV DC).
The output with stand-by OFF was a continuous 6.5Vpp 500KHz sinusoid (~1W RMS/6 Ohm).
The same picture when i connected a 50 Ohm signal generator to the input. The audio signal was simply modulating the 6.5Vpp 500KHz sinusoid.
The 2.2 Ohm Zobel resistor was becoming hot within 5 minutes (with no input signal). I tried different connections to ground, but no difference.
I asked he bring the second module. I connected a 100pF across the + and - input. Then i connected this module to:
A) my workbench regulated PSU (+/-24V DC).
B) a 2x24V AC (+/- 34V DC)100W x-former with a 10A bridge and 2x2200 uF
C) the initial 250 W 2x50 V AC x-former (+/- 69V DC), a 30 A bridge and 2x 15000uF
all ouside of any box, with very short leads. Same picture, only the oscilation amplitude followed the PSU voltage (2.1Vpp for the +/- 24V DC, 3.2Vpp for the +/- 34V DC, 6.5Vpp for the +/- 69V DC).
We havn't tested the third module, but chances are it will perform the same.
Please advise
Regards
George Papageorgiou |
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| ghemink |
| quote: | Originally posted by gpapag
Hellow Mr. Clausen
I need your help.
A friend of mine bought (through the Greek distributor) three ZapPulse 2.2SE modules (he needs four more).
He set up a monoblock with one of them in a half steel, half aluminum enclosure using a 250 W 2x50 V AC X-former (+/- 69V DC), a 30 A bridge and 2x 15000uF with very sort thick wiring throughout following the directions of the data sheet. He phoned me saying the amp had a bright sound, not much of power and it was becoming warm quite a lot (aluminum bloch attached to massive aluminum plate). I asked him not to operate it and bring to me for testing with the osciloscope. I was suspecting self oscilation.
When he brought it home, I connected a dummy 6 Ohm load and shorted the input.
The output with stand-by ON was quite acceptable (short bursts of 3MHz 1.5mVpp oscilations repeating with a frequency of 50 KHz, superimposed on +3 mV DC).
The output with stand-by OFF was a continuous 6.5Vpp 500KHz sinusoid (~1W RMS/6 Ohm).
The same picture when i connected a 50 Ohm signal generator to the input. The audio signal was simply modulating the 6.5Vpp 500KHz sinusoid.
The 2.2 Ohm Zobel resistor was becoming hot within 5 minutes (with no input signal). I tried different connections to ground, but no difference.
I asked he bring the second module. I connected a 100pF across the + and - input. Then i connected this module to:
A) my workbench regulated PSU (+/-24V DC).
B) a 2x24V AC (+/- 34V DC)100W x-former with a 10A bridge and 2x2200 uF
C) the initial 250 W 2x50 V AC x-former (+/- 69V DC), a 30 A bridge and 2x 15000uF
all ouside of any box, with very short leads. Same picture, only the oscilation amplitude followed the PSU voltage (2.1Vpp for the +/- 24V DC, 3.2Vpp for the +/- 34V DC, 6.5Vpp for the +/- 69V DC).
We havn't tested the third module, but chances are it will perform the same.
Please advise
Regards
George Papageorgiou |
Hello George,
That 500kHz signal that is modulated by the input signal is exactly what you should see. The ZAPpulse self-oscillates at that frequency, this is exactly as it should be. The 500kHz signal's amplitude also should follow exactly the power supply voltage since before the output LC filter, the signal would be a squarewave with an amplitude equal to the power supply voltage. The amplitude of that signal is quite large, this is because the output LC filter on the ZAPPulse has a high cut-off frequency in the order of 150kHz or so. Therefore, that 500kHz signal is not so very well suppressed. I have worked with the ZAPpulse a bit as well. That zobel network resistor becomes quite warm, this is because that 500kHz signal that is at the output will result in a current flowing in that resistor and will therefore heat up that resistor.
So bottomline: I think there is nothing abnormal with your modules, this is as axpected and I had similar experience with the ZAPpulse.
Best regards
Gertjan |
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| gpapag |
At first i wish a prosperous 2005 to all of you.
Gertjan thank you for your reply. It eased my worries a lot, at least you informed me that the modules behave "as expected".
Yesterday night i was thinking that i should give them a try. So today evening after the traditional New Years Eve family meeting , i went to the lab, i switched on the Zappulse
monoblock and an inverted LM 1875 amp, connected both to dummy loads, fed them through a cd player in repeat mode and i went for a double espresso with my wife. Two hours later i returned for a listening test. The Zappulse (at low power levels to match the LM) was more controlled, faster and more transparent than the LM amp. At higher levels it was performing great. Very good control and detail. The loudspeaker was a DIY sealed 70 lt B139/ sealed 7 lt B110/T33 replaced by a cheap 1.5" cone tweeter for this test. The temperature of the Zap did not raise a lot (ferrite ~42 d.C, Zobel resistor ~60 d.C, FETs~40, X-former ~45 d.Celsius.
So the module behaves OK acoustically. The problem (as i see it ) is that electrically it is "dirty": At the coil's input there is an almost rail to rail 500KHz square wave (130 Vpp for 138V supply). At the coil's output there is a 7.6 Vpp 500KHz sinusoidal wave.
Problem no 1. This sinusoidal signal feeds directly and continuosly the tweeter. 7.6 Vpp is 0.9WRMS in 8 Ohms, 1.8 W RMS in 4 Ohms. Not a good thing. I wonder what would happen to the sound if the output LC filter on the ZAPPulse had a lower cut-off frequency, say 50kHz. The tweeters would love it.
Problem no 2. It seems that a big part of the energy that the output coil has to dissipate is radiated around. I probed with my scope (20 MHZ only bandwith) the input socket; a 50mVpp 500KHZ square wave.On the upper and lower flats there was a decaying 100mVpp 5Mhz signal, resulting in a nasty signal of 250mVpp. This, inside the enclosure. Outside the enclosure at the input plug, there was a 180mVpp 5MHz signal left . Half a meter apart, at the output of my 50 Ohm signal source which was feeding the module, the 5MHz signal was 140mVpp. Some way of more efficient electromagnetic shielding is required.
Problem no 3. On the 15000 uF per rail PSU caps i probed an equally nasty 350mVpp 500KHZsquare wave /5MHz 200mVpp signal. Through the bridge at the x-former secondary there was a 450mVpp 500KHZ square wave/5MHz 50mV signal. It seems that a lot of experimentation with type/size of caps is required for trimming off this dirt. Also the temperature rize at the x-former's core manifests eddy currents in the core induced by this high freq. signal. Again good quality x-former is required (a C type will work also as a low pass filter toward the primary side).
Problem no 4. On the 2.2 Ohm Zobel resistor there is a 1.2Vpp voltage drop of the 500KHz sinusoidal signal. By Ohms law this is 0.08W RMS power dissipation. This resistor becoming quickly very hot (indicating that there are in addition a lot of harmonics passing through) and located between the two electrolytic caps, will probably dry them out sooner or later. A possible remedy is to have it raised higher, above the caps with ceramic spacers.
It seems that the "Nothing comes free" applies to the PWM amps as well. The laws of physics...
Regards
George |
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| ghemink |
| quote: | Originally posted by gpapag
At first i wish a prosperous 2005 to all of you.
Gertjan thank you for your reply. It eased my worries a lot, at least you informed me that the modules behave "as expected".
Yesterday night i was thinking that i should give them a try. So today evening after the traditional New Years Eve family meeting , i went to the lab, i switched on the Zappulse
monoblock and an inverted LM 1875 amp, connected both to dummy loads, fed them through a cd player in repeat mode and i went for a double espresso with my wife. Two hours later i returned for a listening test. The Zappulse (at low power levels to match the LM) was more controlled, faster and more transparent than the LM amp. At higher levels it was performing great. Very good control and detail. The loudspeaker was a DIY sealed 70 lt B139/ sealed 7 lt B110/T33 replaced by a cheap 1.5" cone tweeter for this test. The temperature of the Zap did not raise a lot (ferrite ~42 d.C, Zobel resistor ~60 d.C, FETs~40, X-former ~45 d.Celsius.
So the module behaves OK acoustically. The problem (as i see it ) is that electrically it is "dirty": At the coil's input there is an almost rail to rail 500KHz square wave (130 Vpp for 138V supply). At the coil's output there is a 7.6 Vpp 500KHz sinusoidal wave.
Problem no 1. This sinusoidal signal feeds directly and continuosly the tweeter. 7.6 Vpp is 0.9WRMS in 8 Ohms, 1.8 W RMS in 4 Ohms. Not a good thing. I wonder what would happen to the sound if the output LC filter on the ZAPPulse had a lower cut-off frequency, say 50kHz. The tweeters would love it.
Problem no 2. It seems that a big part of the energy that the output coil has to dissipate is radiated around. I probed with my scope (20 MHZ only bandwith) the input socket; a 50mVpp 500KHZ square wave.On the upper and lower flats there was a decaying 100mVpp 5Mhz signal, resulting in a nasty signal of 250mVpp. This, inside the enclosure. Outside the enclosure at the input plug, there was a 180mVpp 5MHz signal left . Half a meter apart, at the output of my 50 Ohm signal source which was feeding the module, the 5MHz signal was 140mVpp. Some way of more efficient electromagnetic shielding is required.
Problem no 3. On the 15000 uF per rail PSU caps i probed an equally nasty 350mVpp 500KHZsquare wave /5MHz 200mVpp signal. Through the bridge at the x-former secondary there was a 450mVpp 500KHZ square wave/5MHz 50mV signal. It seems that a lot of experimentation with type/size of caps is required for trimming off this dirt. Also the temperature rize at the x-former's core manifests eddy currents in the core induced by this high freq. signal. Again good quality x-former is required (a C type will work also as a low pass filter toward the primary side).
Problem no 4. On the 2.2 Ohm Zobel resistor there is a 1.2Vpp voltage drop of the 500KHz sinusoidal signal. By Ohms law this is 0.08W RMS power dissipation. This resistor becoming quickly very hot (indicating that there are in addition a lot of harmonics passing through) and located between the two electrolytic caps, will probably dry them out sooner or later. A possible remedy is to have it raised higher, above the caps with ceramic spacers.
It seems that the "Nothing comes free" applies to the PWM amps as well. The laws of physics...
Regards
George |
Hello George,
You may want to try the Hypex UcD400 modules, I expect those to be a lot cleaner with respect to EMI and power supply noise. They have a LC filter that filters at a lower frequency, so less high frequencies at the output and they don't need a zobel network.
Sorry have to go, wife and kids are waiting
Gertjan |
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| gpapag |
Hi Gertjan
Thank you again. If you or anyone else has a PWM amp module and can do some measurements to determine EMI/PSU noise, please post in this forum. Also any mods to aleviate the problem.
Regards
George |
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| richie00boy |
| For your problem no. 1, Lars has already explained that this is not a problem as tweeters do not have 8 ohms impedance at 500kHz, more like 50 ohms or so. So the power in the tweeter is negligible. |
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| ghemink |
| quote: | Originally posted by gpapag
Hi Gertjan
Thank you again. If you or anyone else has a PWM amp module and can do some measurements to determine EMI/PSU noise, please post in this forum. Also any mods to aleviate the problem.
Regards
George |
Hi George,
Have done only a few measurements in the past on ZAPpulse modules. You have to be very carefull with the scope probes. The short GND cable (10cm or so) of the scope easily picks up noise (I guess from the electromagnetic field generated by the filter coil) so what you measure may not be the actual signal on a certain node. If you move that GND wire a bit, the signal strength changes. I have not measured my UCD180 modules yet (have to bring a scope from work) but I think the UcD180 coils have less EM stray field.
Best regards
Gertjan |
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| gpapag |
Gertjan
You are right. In high frequency circuits, test leads can induce noise. I have been fooled again in the past. But now, after the initial measurements, i try to scope in the differential mode using the scope probes of both channels but having their ground leads not connected to circuit under test.
In this particular case (Zappulse) the noise seems to be not related to ground problems or test leads.
Today i tried a very good quality 2x38V AC/3.5A x-former with the module. The temperature of the x-former did not go higher than 35 d. Celcius.
richie00boy
Thank you for this very important information. So practically speaking , problem No 1 is non-existent. Or is this very optimistic?
Off topic: Today it was the third day i was unable to connect to diyaudio.com. What was it all about? I realised that i am a bit adicted to it.
Regards
George |
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| Raoul |
Hi,
Does anyone know where I can find information on the damping factor of the ZAPpulse SE module, specifically driving a 1ohm or 4ohm load? I have looked over the LC Audio site several times and did not come up with anything...
Thanks
Steve. |
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| michaelab |
Raoul, if you download the ZAP Pulse 2.2SE cookbook (pdf file) it has many spec details including damping factor. From memory I think it's something like 250.
Michael. |
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| richie00boy |
| quote: | Originally posted by gpapag
richie00boy
Thank you for this very important information. So practically speaking , problem No 1 is non-existent. Or is this very optimistic? |
Well, your measurement results in less than 0.3W peak in a 50 ohm load. I would count that as non-existent unless you keep a pet bat :)
| quote: | Originally posted by gpapag
Off topic: Today it was the third day i was unable to connect to diyaudio.com. What was it all about? I realised that i am a bit adicted to it. |
I had withdrawal symptoms as well :D I believe there was a Denial of Service attack. |
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| Joep Zonnebloem |
Hello,
Would anyone (with more electronical knowledge than me...) consider the Zappulse module suitable for amplifying a bassguitar on stage? The power seems OK (> 700 W in 4 Ohm on a creditcard sized IC!) and the idea of building a bass instrument stage amplifier with this module is very appealing to me. However, at the same time I realize that home audio systems have considerably different requirements than stage gear, especially when it comes to bass amplification, which requires very robust lows and mid-lows and crunchie/crispy softened highs. I read on this forum that the bass is a little thin, which would make the module not usable. On on the other hand, on the LCAudio site the module is said to have an almost tube-like high frequency response, which is ideal for bass.
What do you think, would it be worth a try?
Thanks in advance,
Joep |
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| richie00boy |
| Everything I have read about the ZAPpulse says that the bass is fantastic and the UcD400 is possibly less able in this area. |
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| GregD |
| From the experiments I've done so far, bass from the Zappulse is fairly dependent on the robustness of your power supply, i.e., bigger transformers and bigger capacitors = more bass and it's tight too. Not so sure about the effect of the bigger tranformers and capacitors on the mids and highs though, some things seem better, some worse, more experimentation required. :) |
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| tim pattinson |
| UCD's have phenominal bass and controlled at that. Also, this is irrespective of the speaker. i'm sure they would work well- after all, Hypex is a PA company... |
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| sven-ake |
| quote: | Originally posted by Joep Zonnebloem
Hello,
Would anyone (with more electronical knowledge than me...) consider the Zappulse module suitable for amplifying a bassguitar on stage? The power seems OK (> 700 W in 4 Ohm on a creditcard sized IC!) and the idea of building a bass instrument stage amplifier with this module is very appealing to me. However, at the same time I realize that home audio systems have considerably different requirements than stage gear, especially when it comes to bass amplification, which requires very robust lows and mid-lows and crunchie/crispy softened highs. I read on this forum that the bass is a little thin, which would make the module not usable. On on the other hand, on the LCAudio site the module is said to have an almost tube-like high frequency response, which is ideal for bass.
What do you think, would it be worth a try?
Thanks in advance,
Joep |
I`m not sure about "on stage" but i`ve tried mine Zappulse at home With my bass guitar and it was really something else.Tightness , details and power that`s what its all about,you need to buy a very expensive bass guitar amplifier to beat this. |
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| Joep Zonnebloem |
Thank you all for your encouraging replies. I am pleased that nobody thinks it is a silly idea. I have been playing with the thought for some time know and I am just so curious whether a small thing like this module is able to drive one or more heavey bass cabinets whith a good sound. For those who know about bassguitar; I am currently playing on an SWR redhead combo with an Eden 4 Ohm 2x12 inch extension cabinet or a Trace Elliot AH300 whith 4 x 12 inch 4 Ohm, so I would like to test the module on the preamps of the SWR and the Trace Elliot and on those cabinets.
I am going to search some more information on the electronical stuff (any suggestions?) and I will keep you informed on the "project". |
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| km |
hi.
joep feel free to mail me if you want more info about class-d amplifiers and the usage in bass systems.
best rgds - karsten madsen - cadaudio.dk
ps. bear in mind that the amp board is only a small part of the weight in a complete amplifier, specially when using traditional power supply ;) |
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| tgb |
I finally completed the 2 channel version of the amp with the 2.2SE modules (PS parts procurement problems + finding the time). We are currently using a conventional power supply at the 42.5 VAC windings that Lars recommended.
Both channels work in the respect that they amplify the signal. I brought the amplifier to a trusted high quality service center to verify specifications.
The tech tested both channels and found each channel producing a noticeable 100K oscillation on each respective output with loading at both 4 and 8 Ohm loads.
Channel 1's oscillation level measured 3.399RMS and Channel 2's oscillation level measured 4.20RMS.
Output power was less than what was stated on the specifications but it is probably due to the oscillation issue causing early clipping.
We tried to isolate the problem without success. We feel confident that the problem is occurring in the 2.2SE modules and not from the PS/input/output wiring or power supply.
The tech's findings and notes are as follows:
Technical Service Time - Scope and evaluate supplied amp 0.5 65.00 32.50T
MALFUNCTION FOUND There is a 100kHz oscillation on both
channels. The power supply is stable. The oscillation is present
even with inputs shorted.
Output wattage specs:
449 into 4 ohms
Oscillation level is 3.399 -Channel 1 - 8 ohms
4.20 - Channel 2 - 8 ohms
No abnormal DC offset.
The oscillation would modulate on low frequency waveforms and
exaggerate as amp approached peak output.
Bench tested a QSC RMX2450 as a control comparison amp.
We would appreciate Lar's, Henrik's, or anyone in the forum's response and possibe resolution.
Also what is the status on the availability of a SMPS for these modules?
tgb |
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| ghemink |
| quote: | Originally posted by Joep Zonnebloem
Thank you all for your encouraging replies. I am pleased that nobody thinks it is a silly idea. I have been playing with the thought for some time know and I am just so curious whether a small thing like this module is able to drive one or more heavey bass cabinets whith a good sound. For those who know about bassguitar; I am currently playing on an SWR redhead combo with an Eden 4 Ohm 2x12 inch extension cabinet or a Trace Elliot AH300 whith 4 x 12 inch 4 Ohm, so I would like to test the module on the preamps of the SWR and the Trace Elliot and on those cabinets.
I am going to search some more information on the electronical stuff (any suggestions?) and I will keep you informed on the "project". |
Hi Joep,
You may also want to take a look at ICEpower modules. The ASP series gives you modules with output power ranging from 200 to 1000W. These modules have on board switching power supply, have the possibility to use balanced input and have all kinds of protections on board and were designed for professional applications. You may want to check out the icepower web-site.
http://www.icepower.bang-olufsen.com/sw1022.asp
You can download PDF files with documentation there as well. I don't have them, but for your on-stage application they maybe the right thing. They probably don't sel for DIY, but you maybe able to get some somewhere? One way to get them is to check out the acoustic reality web-site. These guys built these modules in a case (that you probably don't need) and put some extra electronics in there it seems.
http://www.acoustic-reality.com/
Best regards
Gertjan |
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| ghemink |
| quote: | Originally posted by tgb
I finally completed the 2 channel version of the amp with the 2.2SE modules (PS parts procurement problems + finding the time). We are currently using a conventional power supply at the 42.5 VAC windings that Lars recommended.
Both channels work in the respect that they amplify the signal. I brought the amplifier to a trusted high quality service center to verify specifications.
The tech tested both channels and found each channel producing a noticeable 100K oscillation on each respective output with loading at both 4 and 8 Ohm loads.
Channel 1's oscillation level measured 3.399RMS and Channel 2's oscillation level measured 4.20RMS.
Output power was less than what was stated on the specifications but it is probably due to the oscillation issue causing early clipping.
We tried to isolate the problem without success. We feel confident that the problem is occurring in the 2.2SE modules and not from the PS/input/output wiring or power supply.
The tech's findings and notes are as follows:
Technical Service Time - Scope and evaluate supplied amp 0.5 65.00 32.50T
MALFUNCTION FOUND There is a 100kHz oscillation on both
channels. The power supply is stable. The oscillation is present
even with inputs shorted.
Output wattage specs:
449 into 4 ohms
Oscillation level is 3.399 -Channel 1 - 8 ohms
4.20 - Channel 2 - 8 ohms
No abnormal DC offset.
The oscillation would modulate on low frequency waveforms and
exaggerate as amp approached peak output.
Bench tested a QSC RMX2450 as a control comparison amp.
We would appreciate Lar's, Henrik's, or anyone in the forum's response and possibe resolution.
Also what is the status on the availability of a SMPS for these modules?
tgb |
Hi TGB,
That's indeed a mall-function, they should oscillate at around 400kHz. Are you sure they oscillated at 100kHz???? Because the output filter on the ZAPpulse rolls-off with 12dB/Oct from 150kHz or so, that 4V output oscillation sounds about right in amplitude if it were at 400-450kHz.
Best regards
Gertjan |
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| vroum90 |
hi,
i want to test the BHC T-network caps ( 10.000uF/63V) on ma 2.2SE.
Do you know this product ?
Which are the best caps for use on the power supply ? ( the blackgate are a little expensive for me:smash: )
Seb |
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| tgb |
Gertjan,
Thanks for the reply! I checked with the Tech at the service center and he assured me that the oscillation was centered at 100KHz. He agrees with you that if it were at 400-450K and with the 12dB filter scheme this would knock it down to an acceptable level but that is not the case in this situation.
I had emailed Lars last week and I am waiting for a reply. He may be out of town, as I know that the CES trade show ended early last week.
At this point I would ask to exchange the modules to see if I get the same conditions (which I expect when retesting it would not happen).
I talked to DIY Cable, the U.S. dealer and he deferred me Lars. I hope I can get this worked out very soon as I have a few possible projects that I would like to use these modules for. From the forum it seems that Lars and LC Audio have an excellent rap and following.
Anybody else have any problems like this?
Again thank for the reply,
tgb |
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| vroum90 |
Hi,
I Read on www.lcaudio.dk that the new version of zappulse 2.3 is soon ready.
Is it excatly ?
Do you have informations ?
thanks
Sebastien |
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| michaelab |
From the little amount of Danish I can read it seems the 2.3SE was launched on the 15th of Jan and you can already order one - in fact, the order form for ZAPPulse already says 2.3SE :)
I'd love to know what the changes from 2.2 to 2.3 are...
Michael. |
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| vroum90 |
Hi,
In fact, the changes are new protections which were added.
But, i'm not sure that the 2.3SE are already available.
With which frequency do you use the 2.2SE?
At 1MHz the 2.2SE functions better. Already noticed the difference ?
Seb |
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| michaelab |
| quote: | Originally posted by vroum90
With which frequency do you use the 2.2SE?
At 1MHz the 2.2SE functions better. Already noticed the difference ? |
Are you asking me? I let my modules run at their natural frequency which is I think is about 400kHz. Are you sure they can be run as high as 1Mhz?
Michael. |
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| Joep Zonnebloem |
richie00boy, tim pattinson : Maybe I will try the ucd module too, I don't know; I have to study some more on electronics first, if I find the time. At the moment I feel like ordering all kinds of modules but I know that by the time they arrive I maybe all consumed by, say, jet engines, or the stone age, or Dutch politics (which is not very likely.. :) ). Anyway, for the time being I am just orientating.
GregD : Could you please tell me more about your experiments? And what speakers did you use? I had thought that the bigger en more solid the power supply, the better bass performance you get, but other people say that this factor should not be overrated.
sven-ake : I believe you instantly, after all, the best bassplayers live in Scandinavie :) I think tightness is essential in a bass tone, but it must be able to move a lot of air too, through rigid heavey bass speakers, and still keep its warmth... Btw, what bassguitar do you play?
km : Thanks, I visited your website cadaudio and sent you an email.
ghemink (hallo): I had found the ICEpower modules earlier, but the B&O website said that they were not to be sold to private persons. When you go to the "request information" page, your company website appears to be a mandatory field... However, on cadaudio.dk (see km's message) they apparently can be purchased. On http://www.classd.org/indexold.html I found a very negative review on them, though.
Bottomline: I don't know and I will not know before I have tried and heard, so that is going to be my next step. I will try and just see what comes on my way... |
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| robomatique |
About the ZAP 2.3:
I ordered the 2.2 about a week ago but never got any reply so I called them last friday. They told me that the new module would be delivered to them this monday and be shipped to me late this week.
In other words the new module is what is shipped opn all orders from the last week or so.
And now the important thing, the difference! No idea sorry ... :rolleyes: |
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| GregD |
| quote: | Originally posted by Joep Zonnebloem
GregD : Could you please tell me more about your experiments? And what speakers did you use? I had thought that the bigger en more solid the power supply, the better bass performance you get, but other people say that this factor should not be overrated. |
I have Wilson Audio Watt/Puppy 6 speakers and my usual amp is a Threshold S/500 II. I wrote a short review about my experiences so far with the Zappulse amps and various PSU configurations here:
http://www.diyaudio.com/forums/show...4984#post554984 |
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| sven-ake |
| Joep Zonnebloem> I have a Washburn RB2000, did try it trough my son`s Marshall 4*10 and it sounded really good but i don`t know what the sound would be trough some 4*15 inch speakers or so but it would not be any less. |
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| m.parigi |
I'm in the process of building a 6-channel power amp (or maybe 2 three-channel blocks) for my monster speakers (see my thread on dipole line arrays).
I've already bought 6 2.2SE modules through the Italian distributor and I was waiting for a suitable sync module before starting the actual building of the amp.
From what I've been able to see on the LC site, if you use more than a couple of modules in the same enclosure (or even in the same house, for that matter!) you are "strongly recommended" to use some sort of synchronization of the modules.
For a short time LC had a module for sale on their site but, besides the cost being outrageously high, apparently it created more problems than it solved (some high-frequency ringing or harshness of sound), so that it has been withdrawn.
However, I definitely need to find a way to synchronize the modules (at least so I'm told) before even starting to build my amp.
Has anybody here a good solution for it?
Lars, what is the status of LC on designing the new module?
What are the issues of using a "traditional" oscillator like the one that is suggested somewhere on the LC documentation?
While I wait for this issue to be solved, I'll start experimenting with Karsten Madsen's (CadAudio) modules. I have to build a small amp for my kids, I'll give them a try. |
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| Joep Zonnebloem |
Hi Greg, I read your findings and my jaws hurt from smiling, you're really a freak! I like the way you talk about sound. And so far I had only read about capacitors for the Zap module of around max 33000 mF, so you decided that it had to be some 10 times as much, that is cool, same as the 1500VA PSU's. And, while I think of it : the only thing a digital "amplifier" has to do is to control the power by means of the processed signal (sound); it has nothing to do with amplifying the signal itself.
So it makes sense to look at a PSU as a basic starting point, instead of just a component. |
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| tgb |
| quote: | Originally posted by GregD
I have Wilson Audio Watt/Puppy 6 speakers and my usual amp is a Threshold S/500 II. I wrote a short review about my experiences so far with the Zappulse amps and various PSU configurations here:
http://www.diyaudio.com/forums/show...4984#post554984 |
| quote: | Originally posted by Joep Zonnebloem
Hi Greg, I read your findings and my jaws hurt from smiling, you're really a freak! I like the way you talk about sound. And so far I had only read about capacitors for the Zap module of around max 33000 mF, so you decided that it had to be some 10 times as much, that is cool, same as the 1500VA PSU's. And, while I think of it : the only thing a digital "amplifier" has to do is to control the power by means of the processed signal (sound); it has nothing to do with amplifying the signal itself.
So it makes sense to look at a PSU as a basic starting point, instead of just a component. |
In the project that I am working on (using the 2.2SE modules for subwoofer power) it was recommended by Lars at LC that for low frequency and low impedance loads (2-4 Ohms) that the PS be able to handle 400VA per module and large caps. I used 82,000mF for the caps. I haven't been able to put the amp through a serious work out due to a mysterious 100K oscillation in the modules but it seems like it can produce an output and sound that will make anyone smile.
Now if we only get a SMPS to replace the boat anchor torroidal transformer and the beer can size caps we would really have something.
tgb |
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| ericpeters |
| quote: | Originally posted by Joep Zonnebloem
Hi Greg, I read your findings and my jaws hurt from smiling, you're really a freak! I like the way you talk about sound. And so far I had only read about capacitors for the Zap module of around max 33000 mF, so you decided that it had to be some 10 times as much, that is cool, same as the 1500VA PSU's. And, while I think of it : the only thing a digital "amplifier" has to do is to control the power by means of the processed signal (sound); it has nothing to do with amplifying the signal itself.
So it makes sense to look at a PSU as a basic starting point, instead of just a component. |
Jaap, modify/upgrade any audio equipment....90% of the upgrades involve the power supply section. Also plenty of commercial available upgrades concentrate on power supply. This is the case with digital sources, amplifiers, phono pre's....anything.
Class D is not a Digital amplifier, it is analog! (a TACT milenium is an example of a digital amplifier) |
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| robomatique |
I recently ordered two zap pulse modules and a predator power supply that I am still waiting for... and now I am getting worried.
I was thinking of using two 40V 500VA transformers which should be ok?
Could I add four capacitors after the predator supply? Two on each channel? Do you think it would make any difference?
I am not the biggest hi-fi guy, but I have been working in recording studios for quite a while and been building my own high end compressors and mic preamps, so I know what sounds good.
I love good sound, but my stereo is not the best, but it still sounds good. That is bassically what I am looking for in the zap as well, a good sound without spending too much money.
So, what is worth investing in :xeye:
Thanks
Robert |
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| GregD |
A couple of things that I am sure of at this point are to separate the modules and give each one its own power supply. Since you already plan to use two transformers, all you'd need is four bridge rectifiers, say 4 10,000uf electrolytics, and if you like, 16 68nf capacitors for the bridge rectifiers for noise reduction. All of this combined should cost much less than one Predator power supply, and is pretty easy to wire up point to point. The 4 electrolytics aren't too expensive, will give you double the capacitance of the Predator PSU, and are at least a good place to start. You can always parallel more capacitors later.
I'd also stick each Zappulse in its own box as well. I really didn't like having the two modules next to each other on the Predator power supply. Channel separation was poor, and they made annoying whiny noises when turning off.
Beyond that, hopefully I'll have a better idea in the next couple of weeks. |
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| sven-ake |
| quote: | | and they made annoying whiny noises when turning off. |
Having same problem ,did it dissapere when you separated them? LC audio recommend that they shuold be placed so close to each other as possible to avoid hum and noise. |
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| GregD |
| quote: | Originally posted by sven-ake
Having same problem ,did it dissapere when you separated them? LC audio recommend that they shuold be placed so close to each other as possible to avoid hum and noise. |
Yes, the noise disappeared when I put them in separate cases and the channel separation is much, much, much better, although some of that might be due to each module having its own power supply. I have absolutely 0 audible hum in my Zappulse amps. :) |
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| GregD |
| quote: | Originally posted by Joep Zonnebloem
Hi Greg, I read your findings and my jaws hurt from smiling, you're really a freak! I like the way you talk about sound. And so far I had only read about capacitors for the Zap module of around max 33000 mF, so you decided that it had to be some 10 times as much, that is cool, same as the 1500VA PSU's. And, while I think of it : the only thing a digital "amplifier" has to do is to control the power by means of the processed signal (sound); it has nothing to do with amplifying the signal itself.
So it makes sense to look at a PSU as a basic starting point, instead of just a component. |
I'm happy that you enjoyed my post. :) |
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| michaelab |
| quote: | Originally posted by GregD
and they made annoying whiny noises when turning off. |
That's completely normal behaviour and nothing wrong with that. See below (from earlier in the thread):
| quote: | Originally posted by michaelab
1. When I switch the amp off, as the power drains from the PSU caps I get a sort of "weeeeiiiiiiuuuuuu" sound rather like tuning a SW radio. It's quite quiet and only lasts for maybe 2-3 seconds before there's a light "thud" in each speaker as each module powers off presumably. It's not annyoying but I just wanted to know what might be causing it. |
...and in response:| quote: | Originally posted by Lars Clausen
When the voltage starts to drop, the switching frequency changes, and same time the zener regulators go out of their saturated mode, opening for a better transmission of power rail noise. This means modulation of the two different sw ferq's from the two ch's will interfere. |
In fact, Lars recommends you don't build monoblocks at all:
From this page on the LC Audio site:
| quote: | Traditionally monoblocks are popular because that way you are sure the channels don't interact with one another, keeping a good clean perspective of sound stage. With ZAPpulse modules it can be very hard to electrically separate two channels. The input GND's are connected through the preamplifier or signal source, and most probably the power GND's can see each other, noisewise through the mains transformer's internal capacitance of typically 1-2 nF. You can isolate the way modules can see each other if you make a good effort of HF filtering the mains, but it is not the best way to go.
If you try to separate two channels, and the run off each others frequency by just a few hundre HZ, you may experience a slight background tone, of high or low pitch.
The best solution is to not build monoblocks. Better place the modules closely together, and connect the two ground planes together with a short heavy wire, so shorting out the source of the switching noise. |
Michael. |
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| m.parigi |
Michaelab is right, the LC site strongly discourages from building separate monoblocks and/or using separate non-synced modules on the same power line.
They say that the interference could travel through the live/neutral/earth wires and that there's no sure way to prevent this from happening.
Hence my previous post about synchronization modules: they claim that the best s/n ratios are obtained when all the modules work in sync.
The added benefit of using an external synchronization module is that it is possible to change the oscillating frequency of the module from the approx. 400KHz standard setup up to almost 1MHz. I' would be interested in finding out what are the sonic effects of such a change.
Has anybody tried it? |
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| GregD |
| quote: | Originally posted by m.parigi
Michaelab is right, the LC site strongly discourages from building separate monoblocks and/or using separate non-synced modules on the same power line.
They say that the interference could travel through the live/neutral/earth wires and that there's no sure way to prevent this from happening.
Hence my previous post about synchronization modules: they claim that the best s/n ratios are obtained when all the modules work in sync.
The added benefit of using an external synchronization module is that it is possible to change the oscillating frequency of the module from the approx. 400KHz standard setup up to almost 1MHz. I' would be interested in finding out what are the sonic effects of such a change.
Has anybody tried it? |
I also read the posts by Lars about not building monoblocks, but when I had the two modules right next to each other I found the channel separation to be unacceptable with a very flat soundstage. Connecting the ground planes together on the modules made no difference for separation, and I don't remember if there was any difference regarding the whiny noise on shutdown. Also, even though the whiny noise is normal, it still bothered me a bit.
To prevent the power line issues, I put Schaffner FN9222 IEC filter sockets on the amps primarily to prevent switching noise from getting out of the amps as well as any noise from getting in. I figured that we're basically trying to filter out the same kind of noise that switching power supplies generate.
I would also be curious about the sonic effects of moving the oscillating frequency up to 1MHZ, but without changing the output filter to take advantage of this, I don't see why the sound would change. |
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| michaelab |
| quote: | | when I had the two modules right next to each other I found the channel separation to be unacceptable with a very flat soundstage |
In my amp I use an 800VA transformer and the LC Audio V4P PSU board (expensive) and run both 2.2SE modules off it (GND planes connected) in a single enclosure. I have no issues with channel separation and the soundstage is outstandingly deep and wide.
Michael. |
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| richie00boy |
There is no need to change the output filter as it will 'take advantage' of the increased switching frequency by having more attenuation of the switching frequency.
However, increasing the switching frequency is not automatically a good thing as it results in more losses and the driving stage has to be up to the task of the increased charge/discharge requirements. I believe Lars recommends to leave well alone here. |
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| GregD |
| quote: | Originally posted by michaelab
In my amp I use an 800VA transformer and the LC Audio V4P PSU board (expensive) and run both 2.2SE modules off it (GND planes connected) in a single enclosure. I have no issues with channel separation and the soundstage is outstandingly deep and wide.
Michael. |
How far apart are the modules from each other? When I tried this the modules were only separated by a few millimeters to a couple of centimeters. Or maybe the difference is in the power supply. I only tried the Zaps in this configuration with the Predator PSU. A couple of other people who listened to the amps weren't bothered by the lack of separation, but it bothered me from the moment I started listening. |
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| GregD |
| quote: | Originally posted by richie00boy
There is no need to change the output filter as it will 'take advantage' of the increased switching frequency by having more attenuation of the switching frequency. |
Good point, I didn't think of that. Do you or anyone else know what the attenuation of the switching frequency in standard configuration, and with the higher switching frequency?
I think I'm tired. Time to go to bed. |
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| richie00boy |
As a fair approximation, as the filter is 12dB/oct and you are roughly doubling the frequency, the attentuation will be roughly 12dB more than at the original frequency.
I say again however, that increasing the frequency could actually worsen performance due to increased losses and tighter rise/fall time requirements. |
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| Duck-Twacy |
| quote: | Originally posted by michaelab
From the little amount of Danish I can read it seems the 2.3SE was launched on the 15th of Jan and you can already order one - in fact, the order form for ZAPPulse already says 2.3SE :)
I'd love to know what the changes from 2.2 to 2.3 are...
Michael. |
Well, maybe somebody can translate this:
Hvad er nyt på ZAPpulse 2.3SE i forhold til 2.2SE?
1..Sikring imod Load Dumping (se nedenfor).
2..Sikring mod DC på indgangen.
3..Blop ved tænd og sluk helt elimineret.
4..Interferens mellem kanaler reduceret væsentligt.
5..Kortslutningssikring hævet til højere strøm.
6..Modulator forbedret til lavere forvrængning i mellemtone/diskant.
7..Signalvej afkortet 30% med forbedret gengivelse i diskantområdet.
8..Low Noise option. 2.3SE kan leveres i low-noise version med -120 dBa S/N men til gengæld er indgangsimpedansen 2k0 i stedet for 17k som er standard.
Vi anbefaler til dette formål en forforstærker med low impedance drive, som f.eks. Sidewinder.
http://www.lcaudio.dk/index.php?page=70 |
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| UrSv |
| quote: | Originally posted by Duck-Twacy
Well, maybe somebody can translate this:
Hvad er nyt på ZAPpulse 2.3SE i forhold til 2.2SE?
1..Sikring imod Load Dumping (se nedenfor).
2..Sikring mod DC på indgangen.
3..Blop ved tænd og sluk helt elimineret.
4..Interferens mellem kanaler reduceret væsentligt.
5..Kortslutningssikring hævet til højere strøm.
6..Modulator forbedret til lavere forvrængning i mellemtone/diskant.
7..Signalvej afkortet 30% med forbedret gengivelse i diskantområdet.
8..Low Noise option. 2.3SE kan leveres i low-noise version med -120 dBa S/N men til gengæld er indgangsimpedansen 2k0 i stedet for 17k som er standard.
Vi anbefaler til dette formål en forforstærker med low impedance drive, som f.eks. Sidewinder.
http://www.lcaudio.dk/index.php?page=70 |
What's new on the 2.3SE in comparison with the 2.2SE?
1..Protection against Load Dumping (see below).
2..Protection against DC on input.
3..Thump at power-on and power-off eliminated completely.
4..Interference between channels reduced considerably.
5..Short-circuit protection current increased.
6..Modulator improved for lower distortion in mids and highs.
7..Signal path shortened by 30% with improved response in the treble range.
8..Low Noise option. 2.3SE can be delivered in a low noise version with -120 dBa S/N but the penalty is an input impedance of 2k0 instead of the 17k for the standard module.
For this we recommend a preamp capable of driving a low impedance e.g. Sidewinder. |
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| robomatique |
Today I received two zap 2.3 SE modules :D
Robert |
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| sven-ake |
| quote: | Originally posted by robomatique
Today I received two zap 2.3 SE modules :D
Robert |
Lucky you! I have been waiting since long before Christmas to get my broken 2.2SE fixed or replaced by LC audio.By the time (whenever that will be)i get it back it`s already obsolete.There is no idea to mail them either i have done it several times and they just dont answer.
:dead: |
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| tgb |
| quote: | Originally posted by sven-ake
Lucky you! I have been waiting since long before Christmas to get my broken 2.2SE fixed or replaced by LC audio.By the time (whenever that will be)i get it back it`s already obsolete.There is no idea to mail them either i have done it several times and they just dont answer.
:dead: |
sven-ake
I am another one left high & dry with problems on LC Audio 2.2SE amp modules. I had a hard to almost impossible time get responses prior to my purchase and now NO RESPONSE from LC Audio when I have a problem with 2 of their modules.
My only hope is the US Distributor, DIY Cables, has promised satisfaction or a refund my money. At this point I am looking for a refund.
This whole event is very discouraging as I was looking to use this company for an ongoing vendor for a new product that would have yielded a sale for hundreds of modules per month!
I guess when you read all the good stuff in this forum about LC Audio you must take it with a grain of salt. BUYER BEWARE
:att'n: :dead:
Who else has been bitten by LC?
tgb:( |
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| sven-ake |
| quote: | Originally posted by tgb
sven-ake
I am another one left high & dry with problems on LC Audio 2.2SE amp modules. I had a hard to almost impossible time get responses prior to my purchase and now NO RESPONSE from LC Audio when I have a problem with 2 of their modules.
My only hope is the US Distributor, DIY Cables, has promised satisfaction or a refund my money. At this point I am looking for a refund.
This whole event is very discouraging as I was looking to use this company for an ongoing vendor for a new product that would have yielded a sale for hundreds of modules per month!
I guess when you read all the good stuff in this forum about LC Audio you must take it with a grain of salt. BUYER BEWARE
:att'n: :dead:
Who else has been bitten by LC?
tgb:( |
I think it`s very strange when a company that manufacture things just leave customers with problems out high&dry,they could at least answer mail.There is nothing more important to have support if you want to sell anything.This kind of problems can end any company ,things like this is spreading like a fire and will eventually damage their name and credability forever.
:mad: |
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| ericpeters |
| I just want to add that I have good experience with the LC audio support. It takes sometimes a few days but the service and support is good in my opinion. |
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| tgb |
| quote: | Originally posted by ericpeters
I just want to add that I have good experience with the LC audio support. It takes sometimes a few days but the service and support is good in my opinion. |
To ericpeters,
Is there any magic you use or secret you have to get LC Audio to respond in a timely manner?
2+ weeks ago was my first post on the forum about this concern but I emailed LC twice before that with a week in between each email!
I had originally contacted them back in MAY 2004 and had nothing but dribbles of info or contacts. If it wasn't for DIY Cables I wouldn't have purchased their products for R & D. In addition to the cost of the 2.2SE modules we have $330.00 in P/S, chassis, I/O connectors, etc. not to mention the $500+ dollars in labor. So you can see this is an expensive business lesson.
I did get scolded by LC about complaints that he is emailed by Clients not getting to their reason for contacting him. My email was as direct as possible!
tgb:hot: |
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| Duck-Twacy |
I have experienced the people from LCaudio to respond sometimes (very) slow to emails. However after some time they do deliver (at least for me).
I think they have a problem with to many things to do and to few people to do it: lots of sales (I guess), new modules, problems with website, lots of emails with questions, xmass.
I hope they can get things in order again, because in itself I like their products and ideas. |
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| sven-ake |
| quote: | Originally posted by ericpeters
I just want to add that I have good experience with the LC audio support. It takes sometimes a few days but the service and support is good in my opinion. |
A few days i could accept,but a couple of months and not respond to e-mail that is unacceptebel.
| quote: | Originally posted by Duck-Twacy
I have experienced the people from LCaudio to respond sometimes (very) slow to emails. However after some time they do deliver (at least for me).
I think they have a problem with to many things to do and to few people to do it: lots of sales (I guess), new modules, problems with website, lots of emails with questions, xmass.
I hope they can get things in order again, because in itself I like their products and ideas. |
I have a lot of components from them and i also like their products,but if you want to stay in buissness you have to support as well,there is no excuse not to do. |
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| ghemink |
| quote: | Originally posted by sven-ake
A few days i could accept,but a couple of months and not respond to e-mail that is unacceptebel.
I have a lot of components from them and i also like their products,but if you want to stay in buissness you have to support as well,there is no excuse not to do. |
There are other vendors that have good if not better Class D modules, you can find them in other threads on this board, hint, the name of these modules starts with an U :-)
Best regards
Gertjan |
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| sven-ake |
| Today they finally responded to my e-mails (asking me to write in English)maybe that`s the problem,i dont know.Anyway i look forward to read my mail tomorrow to see what answer i get.Maybe they been reading this forum and felt a little bit guilty. |
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| tgb |
| quote: | Originally posted by sven-ake
Today they finally responded to my e-mails (asking me to write in English)maybe that`s the problem,i dont know.Anyway i look forward to read my mail tomorrow to see what answer i get.Maybe they been reading this forum and felt a little bit guilty. |
Yes indeed, possibly a little guilty but I would hope more concerned for their Clients' needs, concerns and LC Audio's future existence in business.
We want to give them some respect but LC Audio makes it very hard. If they can't provide good short turn-around support for defective products how can you want to do business with them?
If they can't provide the product or have engineering problems it is much better to post the issue rather than be blasted with negative comments. This is where advertising can hurt not help them in their future.
I haven't heard from them as of yet, I hope I have my resolution or at least contact today.
tgb :( |
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| ericpeters |
| quote: | Originally posted by tgb
To ericpeters,
Is there any magic you use or secret you have to get LC Audio to respond in a timely manner?
tgb:hot: |
As said, they are slow, and I admit I tend to be very comitted to get an answer if I need one.
First of all I always ask for a delivery and a read receipt when sending mails. If no answer within 2 days I start calling.
Service has a particular email adress, the owner an other email adress. If no answer within a week I'm normally on the phone with the owner.
And as said as soon as I got answers they were always satisfying. |
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| sven-ake |
| quote: | Originally posted by tgb
Yes indeed, possibly a little guilty but I would hope more concerned for their Clients' needs, concerns and LC Audio's future existence in business.
We want to give them some respect but LC Audio makes it very hard. If they can't provide good short turn-around support for defective products how can you want to do business with them?
If they can't provide the product or have engineering problems it is much better to post the issue rather than be blasted with negative comments. This is where advertising can hurt not help them in their future.
I haven't heard from them as of yet, I hope I have my resolution or at least contact today.
tgb :( |
Try : Brenda@lcaudio.dk she did respond quickly,at least told me to write in English.They are alive,nice to know.I hope for some news about my module i sent them long before Christmas.It could be difficult if they can`t fix it and have to replace it.I can`t have a 2.2SE on the left channel and a 2.3SE (the new model) on the right channel.If so i hope they let me change both modules to the new model.Feel`s like i`m going to have trouble here. |
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| robomatique |
I emailed them a few weeks ago and didn't hear anything from them at all... BUT...
Last week I emailed them again and they got back to me within 2 days with good explanations to all my questions.
I wonder what happened to the first email? Server problems?
Robert |
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| sven-ake |
| Got mail today,they will send me a new 2.2SE today and i will probably have it already tomorrow, they promised????Well not all the way from Denmark but in this week it will keep me satisfied anyway. |
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| Duck-Twacy |
Somebody on a Dutch forum experienced a (big) difference in soundquality between balanced (xlr) and unbalanced (rca) connection. He prefered unbalanced, because the bass wat better, tighter, more controled etc.
Does anybody have simular experiences? |
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| Jan-Peter |
....hm, I have a much better experience;
My amplifiers are INCREADIBLE silent without ANY white noise when they are switched off........:cool:
Jan-Peter |
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| Duck-Twacy |
| quote: | Originally posted by Jan-Peter
....hm, I have a much better experience;
My amplifiers are INCREADIBLE silent without ANY white noise when they are switched off........:cool:
Jan-Peter |
I understand you are also using a Zappulse? :D |
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