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?
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?
Zappulse input resistor mod
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
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
Hi Lars,
(Vi kunne snakke Dansk, men så går de andre glip af guldkornene.....
)
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
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 ?
(Vi kunne snakke Dansk, men så går de andre glip af guldkornene.....
)Lars Clausen said:
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
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 ?
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
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.
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
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.
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 ;-)
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 ;-)
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.
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.
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
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
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.
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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