Don't worry, Gertjan. I was not saying that we want you to purchase BP4078's, just pointing out that the same advantages that you are finding using our SPS80 with UcD's can be found with our modules, that also have, IMHO, great value for the money.
The aux. supply you mention is very useful for powering preamps, input stages of Class-D amplifiers, etc, but can also be used (not at the same time) to power the gate drive circuit, reducing around 3-3.5W of idle dissipation in each BP4078. I don't know if I mentioned this before, just in case. I think this is also possible with ZAPPulse 2.3 but UcDs don't offer this option to my knowledge.
The SPS30 is still in pre-production. Yes, we know, it should be already in the market, but sincerely we are a bit overflown with the orders, etc and cannot find the time to definitely launch it, although we have some units up and running fine.
We don't plan to make a 2nd version of SPS30 as we are incorporating all the improvements to SPS80 into this from the start.
Best regards.
The aux. supply you mention is very useful for powering preamps, input stages of Class-D amplifiers, etc, but can also be used (not at the same time) to power the gate drive circuit, reducing around 3-3.5W of idle dissipation in each BP4078. I don't know if I mentioned this before, just in case. I think this is also possible with ZAPPulse 2.3 but UcDs don't offer this option to my knowledge.
The SPS30 is still in pre-production. Yes, we know, it should be already in the market, but sincerely we are a bit overflown with the orders, etc and cannot find the time to definitely launch it, although we have some units up and running fine.
We don't plan to make a 2nd version of SPS30 as we are incorporating all the improvements to SPS80 into this from the start.
Best regards.
Hi KeithC, can you tell anything more about the differences in performance between the UCD and the BP4078 (with LPS or SMPS) on your Lowther system (if you haven't already done that, could not find it). Can you tell me what other kind of amps you have used before.
Reason for asking is that I'm still very curious about the classD subject, haven't got any chance to listen to them myself. I'm really curious about the performance in my setup wich at the moment consist of a active 3-way open baffle system with DEQX and a mix of amps (class AB for lows, classA for mids, 300B SET for highs) I'm wondering if there might be any gain by using the same amps for all the drivers.
Sorry if I'm asking the same question as other might have done allready.
well that's just one off the problems I'm having in trusting the whole class D issue, it's the use of the poor performing opamps. In all of my years in diy amplifiers cq modding cd players etc I ALWAYS had a BIG improvement in every area when swapping those NE5532 opamps for something better and preferably discrete circuits and tube stages, so to me it's kind of confusing that all of you class D folks rave the performance of the amps while these are still based on thos (poorly) performing opamps. Wouldn't it be time that a firm like Hypex comes out with an audiphile grade version of their class D amps with discrete/tube buffer stages (wich I will be willing to pay for) As far as I read all of the class D threads I remember that even Bruno Putzeys is not using any opamps in his own class D amps at home.
Seems almost that since this whole gaincard/clone movement everyone is back in believing that opamps are the best way to go. I have heard the gaincard several times in different setups and was initialy impressed by them but after a direct compare with a Welborne Labs DRD 300B SET the gaincard sounded very mediocre, dull, liveness, lacking dynamics etc (by the way, the Welborne Labs also sounded better than my own 300B SET amps but not with the HUGE margin as it did compared to the Gaincard) That's one of the reasons I'm still sceptical about the class D amps (yes, the opamps) but I'm also very curious in hearing (and judging) it myself.
Opamps can sound good when propably taken care of their enviroment in wich they are used, my experience is that they are very sensitive to the power supply used with them (the opposite as all the datasheets would want you to believe) and as for now I don't see this taken care propably in the class D amps I have seen so far.
Just remember that the only time I have heard Class D amps was in a B&O system, this sytem with the two dishes sitting on top of a conical bass cabinet and unfortunatly it was one of the worst so called "High End" speaker systems I have listened to in a long time, although it had rave reviews in several magazines I could not back that up.
Still thinking of buying some class D amps to start for my subs wich defenatly are in need of some better amps then the old fashioned NAD2200pe wich I'm still using at the moment but can't decide to go for the Hypex or the Coldamp with SMPS, any recommendations on that would be nice. I can always try them full range than and judge myself.
I'm sorry if this is a bit off topic and I really don't want to offend anyone but I have asked before in other threads about the absolute sound quality of those class D amps and not in compare with budget amps or receivers. I'm not in for the best value for money, I'm only in for the best value
Seems almost that since this whole gaincard/clone movement everyone is back in believing that opamps are the best way to go. I have heard the gaincard several times in different setups and was initialy impressed by them but after a direct compare with a Welborne Labs DRD 300B SET the gaincard sounded very mediocre, dull, liveness, lacking dynamics etc (by the way, the Welborne Labs also sounded better than my own 300B SET amps but not with the HUGE margin as it did compared to the Gaincard) That's one of the reasons I'm still sceptical about the class D amps (yes, the opamps) but I'm also very curious in hearing (and judging) it myself.
Opamps can sound good when propably taken care of their enviroment in wich they are used, my experience is that they are very sensitive to the power supply used with them (the opposite as all the datasheets would want you to believe) and as for now I don't see this taken care propably in the class D amps I have seen so far.
Just remember that the only time I have heard Class D amps was in a B&O system, this sytem with the two dishes sitting on top of a conical bass cabinet and unfortunatly it was one of the worst so called "High End" speaker systems I have listened to in a long time, although it had rave reviews in several magazines I could not back that up.
Still thinking of buying some class D amps to start for my subs wich defenatly are in need of some better amps then the old fashioned NAD2200pe wich I'm still using at the moment but can't decide to go for the Hypex or the Coldamp with SMPS, any recommendations on that would be nice. I can always try them full range than and judge myself.
I'm sorry if this is a bit off topic and I really don't want to offend anyone but I have asked before in other threads about the absolute sound quality of those class D amps and not in compare with budget amps or receivers. I'm not in for the best value for money, I'm only in for the best value
Sjef said:
Hi Sjef,
The UcD amps use the opa2134 or the AD8620 in the high-end version. There are many UcD owners in Holland, so maybe you can listen to them somewhere. I can tell you I was surprised when I heard the first Class D amp in one of my systems. I started with a Tripath based Marantz, I found it better sounding than my Accuphase E407 which is , or at least was, considered by many as high-end. Then I tried ZAPpulse 2.3SE and UcD. UcD performs best in my case. It has an extremely low noise level, much lower than the Tripath and the ZAPpulse and comparable or maybe slightly better than the Accuphase. One point that I found in common with all those Class D amps is that they play more effortless than the Class AB amp. Imaging seems better and you will find quickly that you turn up the volume much higher. I guess because the sound stays cleaner at high levels. For me there is no way back, although I have to admit I never tried tube amps.
Best regards
Gertjan
Sjef said:
OK, you asked for it:
Through the 80s I used Quad 405 & Celestion SL6 with matched
Volt dual voice coil sub. Replaced the Quad with Velleman 4000, which I stopped using as it tended to blow the biasing resistors when the EL34s required replacement.
For the past 10 years my systems have been front-ended by computer, for the last 5(ish) with CDs ripped to disk, DAB radio (stopped using a Troughline due to appalling over-modulation of virtually all analogue transmissions), analogue & digital TV). All media available across a 6 PC house LAN.
Got obsessed about minimal components in the signal path, and moved to Lowther single driver and JLH 15 Watt Class A 4 years or so ago. Ran the Lowthers in TQLT and OB (Lowthers are exceptional in OB, but no bottom end, and it's nigh on impossible to match a sub). Lowthers are now in rear horn.
My listening environment has << 20db ambient noise, and the most recent obsession became irradication of residual noise from the speakers (I used to get pick up of my mobile phone switching cells). So started to play with balanced input. My first use of OP amps.
Got a DR amp a year or so ago, it's class D with a socket to enable use of different op amps. Rapidly progressed through Charlize to Hypex.
General issues with Class D: Tripath have good bass extension, poor soundstage, high residual noise. All Class D are sensitive to power supply changes (especially capacitance) regardless of whether or not they are front-ended with an op-amp.
Major scare stories are alarming dc offsets on the output, and enough emi to classify as a local transmitter. Not something I've personally encountered - and I have yet to encase one of these things.
I have both UcD180AD (in general use since March) & 400AD (only ever used in comparison tests). Sound from these is identical to my ear. 180s use a vanilla Hypex HG/100A dual mono psu. I originally used a single psu for both 180s, and upgraded after 3 months. Prefer the 180s tonally when both driven from a single psu, but the soundstage is improved with one per channel.
Hypex amp/psu/softstart gives a dead silent amp with comprehensive over and under everything protection. Good stable soundstage, and good - and well defined - bass extension.
Health warning though - the Lowthers are not typical speakers. 30hz - 22Khz (if mounted & driven properly), emphasis on upper-mids, extremely dynamic (max voice coil excursion of 1mm), 98db/watt - I typically bounce around in the bottom 0.5 watts of any amp, and have run for extended periods using a high current headphone amp. The differences between Hypex and Coldamp combinations that are very audible on the Lowthers are hardly noticable on my wifes Quad C22s.
Bought a Coldamp amp/smps combination in June mainly to evaluate the SMPS, and have spent the time until now comparing combinations of Hypex UcD400 & Coldamp BP4078, Coldamp LPS30, Each combination has been subjected to at least 100 hours continual use at normal listening levels before evaluation, and I don't do high output level tests - the Lowthers will (theoretically) handle 100 watts, but this would be tantamount to assualt with a deadly weapon.
Coldamp SPS80. Hypex amp/Coldamp psu combinations are silent in operation, but have low-level switch on/off noise. Coldamp only combinations have around 20db residual psu noise, typically more for the SPS80 than the LPS30, although I have recently fitted chokes to both +ve & -ve rails (as per recent recommendations) which has reduced the SPS residual noise to levels that can only be heard by my ear within 0.5m of a speaker cone. There is no switch on/off noise in Coldamp only configurations. I did not notice any other significant differences in performance between LPS30 & SPS80, but I have not used the LPS30 for long periods of time - large toroids are mechanically a pain.
Coldamp v Hypex amps - the BP is much warmer than the UcD, with a busier soundstage. Fuller bass, but not quite as extended as the UcD. An example. The 2005 Cream Royal Albert Hall concerts. The BP sounds as if one was really there, but with the UcD you can pick out every note Jack Bruce plays on his bass guitar.
I intend to revert the UcD 180ADs to run off a single HG supply - which will free up a Hypex supply for further combinations. I am currently using the Coldamp BP/SPS combination as my normal amp of choice, but will probably swap back to the 180s from time to time. The 400ADs will go to power my wifes system.
Meanwhile, I have a pair of Brian's 10 watt mono kits on order, and will probably get a brace of NCDs when the dust settles.
Sjef said:
I'm old'n reactionary enough to think that ANY ic should be expunged from the signal path. I was pleasantly surprised by Class D though - even with the Tripath based systems, which started me off down this road to ruin.
I can confirm what Gertjan states - the sound from good Class D amps is so clean that you do have to be careful about listening levels.
Myself, for subs I would use Hypex amps and smps psu.
Regards,
Keith
KeithC said:
I did a test with the BP's vs UCD's some while ago, using the same housings/PSU/grounding and had, while testing it with"John Williams- Concerto for 2 mandolins(guitars), strings and basso in G major, RV532 - III, Allegro" about the same verdict.
If you switch(switch only the speakers from 1 amp. to the other) the power amps. (both connected to a passive pre)while playing the concerto you'll hear an instant difference. This is very confronting because you have no mind/emotion twisters here.
You'll here that the UCD's have indeed an extended high range while the BP's have a fuller sound and are more forgiving for bad source material. So its up to you what you'ld prefer. Bass extension...........could not find a difference.
playing "John Williams - 3 Valse Venezolanos - Natalia" gives a slightly different picture. Here the guitar play is very much the same on both amps. Because there is no orchestra the music is not so busy.
Changing over to "Andreas Volleweider's Book of Roses - Hirzel" changes the picture. The harp here is extremely revealing. The BP is way too loud here. The UCD is more layed back.
Playing level is average loud, no conversation possible.
The UCD's used here are the 180AD&400AD's.
"Paco de Lucia - Live in America" shows the extended bass response(bass slew rate) of the UCD with no input caps.
I have no caps at all in the signal path from DAC to power output(if used with the UCD's).
Changing over to "Andreas Volleweider's Book of Roses - Hirzel" changes the picture. The harp here is extremely revealing. The BP is way too loud here. The UCD is more layed back.
Playing level is average loud, no conversation possible.
The UCD's used here are the 180AD&400AD's.
"Paco de Lucia - Live in America" shows the extended bass response(bass slew rate) of the UCD with no input caps.
I have no caps at all in the signal path from DAC to power output(if used with the UCD's).
Sjef said:
The B&O amp you heard was never actually designed for audio, believe it or not, and is why it used some of the worst components going. Maybe it wasn't the speaker that sucked?
I honestly wonder how often Bruno gets a request to custom design an amplifier with a fancy tube input stage and auxiliary supplies all around tightly regulated and well filtered..... for a subwoofer.
Aside from that I think you're allowing your judgements to be clouded in order to allow yourself to not research the matter properly. I think you'll find most manufacturers are more interested in a viable product that has mass appeal both cost and performance wise, and whatever balance they come up with between the two is for them to decide, and you to modify. Otherwise if money is no object and it's a signature series input stage you want, give 'em a call, they'll make you one.
There's now a few decent amps out there to choose from ( and one really very good one), so do your research and roll the dice, that's my advice.
BTW, for those who commented on the sound of coldpower, I won't be at all shocked to see you find it very similar to NCD. Kind of smoothed, kind of euphonic, smooths out alot of source flaws in a bed of silk..yet perfectly pleasing to listen to.
Vs:
An amp so true to the source that it often hurts to listen to because of such poor recording/mix quality ... you just never knew how bad recordings sucked before.
So, you're on a desert island and you can only have one amp.. and any one of the red hot chili pepper albums... call me shark bait but I'm going swimming before the smokes run out.
Thanks for all the reply's, that's some answers I was looking for.
In answer to the last post. No I'm not looking for a sub amp only, I was only saying that my current amp for the lows are in desperate need of replacement because they are the weakest link in the system so far, not enough control and my woofers really are in need of tight amplifier control or else they bottom out to easily. The woofers are JBL2205H in a w-frame configuration and they where actually not designed to operate this way. (they are not really subs anyway but the woofers of my active three-way setup). This way I would be able to try the class D amps on mids and highs as well. And yes I'm stll very open minded to the whole question.
And yes I also want my system to be a bit forgiven for badly recorded albums. I'm not listening to audiophile recordings all day, I listen to music I like, well recorded or not.
Anyway, this is getting a bit too much off topic and I don't want the be accused of thread hijacking. I think I'll just follow Keith's reccomendation about the SMPS with UCD to try with my woofers for a start.
In answer to the last post. No I'm not looking for a sub amp only, I was only saying that my current amp for the lows are in desperate need of replacement because they are the weakest link in the system so far, not enough control and my woofers really are in need of tight amplifier control or else they bottom out to easily. The woofers are JBL2205H in a w-frame configuration and they where actually not designed to operate this way. (they are not really subs anyway but the woofers of my active three-way setup). This way I would be able to try the class D amps on mids and highs as well. And yes I'm stll very open minded to the whole question.
And yes I also want my system to be a bit forgiven for badly recorded albums. I'm not listening to audiophile recordings all day, I listen to music I like, well recorded or not.
Anyway, this is getting a bit too much off topic and I don't want the be accused of thread hijacking. I think I'll just follow Keith's reccomendation about the SMPS with UCD to try with my woofers for a start.
ssanmor
Thank you for your reply about Coldamp is using NE5532 at buffer stage. I do argree with you that it may not be easy to distinguish between different op-amp. BTW, do you think there's significant improvement if this op is powered by discrete supply like audiophiloe using UCD? If so, where can I find further info to modify the module?
Thank you for your reply about Coldamp is using NE5532 at buffer stage. I do argree with you that it may not be easy to distinguish between different op-amp. BTW, do you think there's significant improvement if this op is powered by discrete supply like audiophiloe using UCD? If so, where can I find further info to modify the module?
hmdiy,
Yes, the BP4078 module is prepared for separate feeding of the modulator stage (not only the input opamp).
For that, you have to remove two solder blobs near Q13 and Q12, then please check that the blob is correctly removed using a multimeter before applying power. Then you can use a symmetric supply with that voltage connected to two holes labelled "+8-25V" and "-8-25V" (we recommend +/-12V, for example. GND can be connected to the "Fback" connector, only to the pin farthest the input connectors)
Please refer to the BP4078 datasheet and app.notes for more details.
You may gain something in background noise, although it is already too low to hear the difference, but for sure you will reduce the module idle power dissipation in about 2.5-3W. (at +/-60V).
If you want to power ONLY the input opamp, you can do it by removing two resistors, Rc1 and Rs1 near the NE5532, and soldering the +V and -V directly to their pins going to pins 8 and 4 of the NE5532, respectively (use a multimeter). We don't see any reason to do this, anyway.
In case you use the SPS80 aux +/-12V output to power the input stage, use ferrite chokes in series to decouple switching noise in both + and - 12V rails for quiet operation.
Yes, the BP4078 module is prepared for separate feeding of the modulator stage (not only the input opamp).
For that, you have to remove two solder blobs near Q13 and Q12, then please check that the blob is correctly removed using a multimeter before applying power. Then you can use a symmetric supply with that voltage connected to two holes labelled "+8-25V" and "-8-25V" (we recommend +/-12V, for example. GND can be connected to the "Fback" connector, only to the pin farthest the input connectors)
Please refer to the BP4078 datasheet and app.notes for more details.
You may gain something in background noise, although it is already too low to hear the difference, but for sure you will reduce the module idle power dissipation in about 2.5-3W. (at +/-60V).
If you want to power ONLY the input opamp, you can do it by removing two resistors, Rc1 and Rs1 near the NE5532, and soldering the +V and -V directly to their pins going to pins 8 and 4 of the NE5532, respectively (use a multimeter). We don't see any reason to do this, anyway.
In case you use the SPS80 aux +/-12V output to power the input stage, use ferrite chokes in series to decouple switching noise in both + and - 12V rails for quiet operation.
some of the opamps in a class D runs in switching mode / comparator mode so I am not sure how audiable swapping them out to be.
Not to mention that I have not seen a single non-refutable research where anyone can demonstrate the audiability between reasonable good opamps (for example 5532 vs. others).
Not to mention that I have not seen a single non-refutable research where anyone can demonstrate the audiability between reasonable good opamps (for example 5532 vs. others).
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