Guys, let's keep the arguments to the technical and NOT to personal characterizations.
haha, you certainly have a taste for irony. I did not say anything against transformers, I objected to your massive and derogatory sweeping statement, even bringing class into it. all because I suggested that removing the PCB entirely from a surface mount amp, that is ALL about the PCB was a very strange choice and expecting it might perform better was folly
then you choose to say that IM the one talking down to people? comedy, pure comedy
anyway i'm buying out of this conversation, dont expect further comment
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thats not what got my back up pieter, well not totally. what got my back up was his reaction to my initial suggestion including classifying the whole group buy of the power supply as penny pinching paupers; simply because it doesnt fit with his view and because he didnt like me questioning him. go back and look at my initial post and see if its actually rude?
this provoked a characterization and a personal attack against not just me and heres me with an infraction? sorry i'm at a loss here
SY:
I'm not seeing anything of value to the DIY community from post 1590 to 1603 if you want to blow away a few pages of angry fighting.
To address Ian's original questions:
Yes, I have enough left to send you 4. I'll send you a PM.
Absolutely, but that would have to be a regulated 95V or you could easily creep over the maximum values under high-line conditions. It is not recommended to mount the LME to the same heatsink as the output devices, so you would need a larger separate sink for the LME
Depending on how good your point to point skills are, this might work. I've never done it myself with the LME, but I'm sure it's possible. You already know that the compensation cap is critical, so just solder it carefully between the required pins.
I've seen people do this (and have done it myself) with chip amps, so I would imagine it might work here too. I would guess, and it's only a guess, that you'll end up with a slightly higher noise floor without the ground plane, and I would imagine decoupling would also be slightly worse since lead length is almost guaranteed to be longer.
The bias and voltage/current is definitely for the output devices and not the LME. There are some charts showing the LME performance at different supply voltages in the datasheet, so you can see what you get there.
The higher voltage would probably help to an extent, but the real benefits in terms of distortion reduction comes from the current. It would be safe to say that you'd probably see a slight improvement at 80V and 400mA versus 30V and 400mA, but it's not like the 80V version is going to measure better than the 30V version at 1A bias.
Cheers,
Owen
I'm not seeing anything of value to the DIY community from post 1590 to 1603 if you want to blow away a few pages of angry fighting.
To address Ian's original questions:
Yes, I have enough left to send you 4. I'll send you a PM.
Absolutely, but that would have to be a regulated 95V or you could easily creep over the maximum values under high-line conditions. It is not recommended to mount the LME to the same heatsink as the output devices, so you would need a larger separate sink for the LME
Depending on how good your point to point skills are, this might work. I've never done it myself with the LME, but I'm sure it's possible. You already know that the compensation cap is critical, so just solder it carefully between the required pins.
I've seen people do this (and have done it myself) with chip amps, so I would imagine it might work here too. I would guess, and it's only a guess, that you'll end up with a slightly higher noise floor without the ground plane, and I would imagine decoupling would also be slightly worse since lead length is almost guaranteed to be longer.
The bias and voltage/current is definitely for the output devices and not the LME. There are some charts showing the LME performance at different supply voltages in the datasheet, so you can see what you get there.
The higher voltage would probably help to an extent, but the real benefits in terms of distortion reduction comes from the current. It would be safe to say that you'd probably see a slight improvement at 80V and 400mA versus 30V and 400mA, but it's not like the 80V version is going to measure better than the 30V version at 1A bias.
Cheers,
Owen
That will be a difficult affair; PCB layout is fixed; P-P can be done in different ways.
I'd be more interested (and more on topic here) in a good comparison between hiqh quality SMPS and linear supply options, since you guys seem not to be far off building/finishing the amps.
Could you define 'good comparison' please pieter?
Was Owen's evaluation not sufficient to make a good comparison? Since his first set of measurements was with linear supply earlier in the thread and the most recent with a variety of smps configurations isn't that enough for us to draw our own conclusions already? My money went with the smps so you can see what my decision was ...
Do you have any vested interest in starting yet another debate whereby you can promote the virtues of a transformer based linear power supply? What value does it add to bring it up again now? At this stage I think the debate has been had plenty of times and Owen has given his evaluation, no one even has a smps other than Owen yet and I doubt anyone is in a better place to make the comparison than he is.
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Apparently it is enough for you to conclude, which is perfectly OK.
However I know that not all linear supplies are equal in quality, and besides the requirements can be quite different (class AB or class A for example).
In my opinion a stock toroidal transformer with a huge bank of capacitance is not a high quality supply for a class AB amplifier.
No, I have no interest in restarting the power supply debate
If you want to follow the leader by choosing for a SMPS, please do so
I guess that not all Wire Amp builders will use the SMPS, so I expect comments from SMPS users and linear supply builders, and that's what I am interested in.
Ok, but you have to prove it. I think I asked you kindly enough weeks ago to do so in a pm, before I made my decision on the DPS600, I unfortunately did not get any reply from you.
Ok, but you have to prove it. I think I asked you kindly enough weeks ago to do so in a pm, before I made my decision on the DPS600, I unfortunately did not get any reply from you.
You mean this one (my reply to you May 9th)?
Re: Wire Amp
Quote:
Originally Posted by lolo
Hi Peter,
I saw you came up with a few interesting comments on the Wire amp thread. I am on the GB for 10 boards as I am multi amping my system.
I would be very interested to see what's your take on this debate with Roberto's SMPS. What is your opinion?
Cheers
Laurent
Hi Laurent,
I have no experience with Roberto's SMPS, so it is not possible to comment on that one apart from the fact that of course it should function flawlessly without the risk to blow speakers.
OPC was quite enthusiastic with the SMPS some months ago, and at that time I questioned the superiority of a SMPS over a high quality linear supply.
Until now (I just had a post in that direction) there has not been a comparison.
I would start with the good linear supply, also because it seems a more logical combination with a class A/B amplifier, and I have more expectations from linear supplies as fas as reliability and life expectancy is concerned.
Multiple power supplies in multi amp systems will be very good (but quite expensive of course), but in a dedicated system you should have great results when worked out well.
For example low bias high power supply voltage amps for bass, and higher bias / lower supply voltage amps for mid and treble.
It's all in optimizing a given concept; no need for SMPS to do that IMO.
Regards,
Pieter
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No, I have no interest in restarting the power supply debate
If you want to follow the leader by choosing for a SMPS, please do so
From your contact details on your profile:
Tribute - The final word in audiotransformers
Sounds to me like keeping transformer sales flowing is at least part of your interest. Happy for me to be corrected on this matter, but for a transformer manufacturer to be continually questioning the quality of an alternative power supply technology without disclosing their commercial interest raises some concerns.
I look forward to hearing about others results, but subjective evaluation in totally different systems holds little value to me and my purchasing decisions.
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no Pieter, I was referring to my reply on the 10th May, naively maybe asking for a good linear design as you seemed to know a lot on the subject, but since then I've done my own research and found my own conclusion. no ill feelings, I can understand you were busy and you don't owe me anything!
I also think you should have mentioned your commercial interest, even if you did not trully promote anything, Roberto was clearly showing his colours and contradicting him fiercely without mentioning your background is not very fair play.. it's basically called lobbying, the evil of this world.. I don't see why you are asking moderators protection really..
I also think you should have mentioned your commercial interest, even if you did not trully promote anything, Roberto was clearly showing his colours and contradicting him fiercely without mentioning your background is not very fair play.. it's basically called lobbying, the evil of this world.. I don't see why you are asking moderators protection really..
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I do not have any interest in promoting the use of transformers here.
I am an audio guy; I post in threads on loudspeakers, DA converters, tube and SS electronics, and of course transformers (where I can contribute quite a lot without the intention to promote...).
When I need the forum for promotion I can simply open threads myself in a commercial sector or Vendors Bazar, but as stated before, I don't need it.
I always have been very keen on separating my commercial activity from my contribution at the forum.
When that turns out to become a problem it seems better for the moderators to change rules in that respect.
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Not that anyone here is interested in my findings (findings not opinion) but I agree with this statement. Having been involved with the design and prototype development of a commercial class AB integrated stereo amplifier in 1997, samples of several makes of 500VA toroid were used to supply the low cost 8 x 10,000uf 63V caps. Each Tx performed differently. One radiated a field that a simple home made sensor was picking up a couple of meters away. Mechanical hum, a lot of variance. Effect on the sound from the speakers; varied from one Tx to another.
Throughout the 1990's I personally used many Tx of a wide span of qualities to drive the DAC and output stage on my CD player. PSU was 20 x Nichicon KZ 1000uF 50V, discrete regs, black gates and Oscons after them. Very wide variation is sound quality and tonal balance from the loud speakers. Even between different good grade Tx's. Lacking any proper measuring gear to make it make sense, it seemed like I was making just random shots in the dark. One special and secret configuration Tx someone brought around, apparently a C core in a potted can, had by far the sweetest treble but caused a boomy bottom end and we preferred the tonal balance of one of the others, even though the top was inferior. Frustrating.
I was interested to read in a Super Teddy reg thread where Teddy Pardo said that with his regs in place you could get rid of all those large PSU transformers and parts as they no longer made a difference. I'm keen to try it. Just as I'm keen to try a suitable SMPS, except my concern over very long term reliability. If the linear caps need replacing in 15 or 20 years, probably not a problem. However if the fancy SMPS goes, may have to scrap the whole amp. A linear supply won't fit in the box and another suitable SMPS will have to be available. as they're more likely than not, unrepairable.
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Sure, there must be variations out there, I myself have two similar amps at home, one has a very noisy trafo the other don't, same production batch, same trafo..
but your "findings" look more like capacitor sound competition rather then proper documented facts.. unless you could show us something? Tonal balance is mesurable, so is dynamic behaviour, distorsion and so on..
Yes if you have the tool to do it. We had only our ears plus a spectrum analyser which I don't have any results from. All scrapped over a decade ago. And to be honest, what matters is how it sounds on your system in your lounge. For that amplifier, as far as I know, not one single buyer anywhere asked for wave analysis prints. They just listened to it and then mostly bought one as they were such a good sound for the money.
What I'm saying is you have try these things for yourself, such as juxtaposing the mains wires to the transformer, I now know that has an effect and have been around to some people and swapped theirs back and forth and I think in all cases there was a preferred way around. Even if I had good data from my experiments they might not translate to a good sound on your system.
Perhaps what you'd like is if I could help to provide some meaningfully measured clarification as to what's going on but alas all I have is anecdotal evidence.
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