In these power supply discussions, the question I have not seen addressed before ... would this or one of the offspring amps benefit from a dual mono PSU - meaning the use of two Meanwell 36V bricks, one for each channel ?
Using same or lower wattage rating if there's two of them ?
Best regards, Claas
I’m not among lucky winners, but was contemplating the same just in case.
As OS is biased through CCS there is zero current change through PS while there is AC output signal. So, no intermodulation between channels due PS voltage variation. Single PS seems perfect.
Though I have at ready design of super regulator PS with measured 2uV total noise, 200 µΩ impedance, > 120 dB PSRR, 5-10 A output etc.
If I join lucky bstrds club
in the next lottery round, I will use super regulator PS.
ask your self why the smps is outer of the kit case
and yes sound good we start using when born the first Tamp
ask your self why the smps is outer of the kit case
and yes sound good we start using when born the first Tamp
I think the main reason is to ensure an inexperienced builder does not get exposure to mains voltage.
It might also be that the linear power supplies might be too complex & time consuming to build?
The kit seems to be prepared primarily for ease of assembly in mind, where all one has to do is to connect the boards - wire them up with minimum soldering skills required.
What is your take?
Yep, sure, easy to build for beginners... simple... non expensive... BUT aren't we missing here the main point? Quite a few knowledgable and experimented posters have outlined, as Papa in his paper, that this SMPS was performing extremely well and had sonic qualities.
Before tweaking anything (...and I love tweaking), shouldn't we first have a listen to it and see if it is really a potential bottleneck? My bet is it has been chosen so as not to compromise this artwork poweramp. Not to mention that we might get even an additional option in form of Mark's SMPS filter, should we really need it. Should this filter materialize, given Mark' credits, it is likely to be a performing item (be it only because he wouldn't probably chose to release it otherwise).
I wouldn't throw the SMPS away: I am eager to plug my cheap scope on it and my old ears on the amp with suitable speakers ;-)
Just thinking out loud
Claude
Before tweaking anything (...and I love tweaking), shouldn't we first have a listen to it and see if it is really a potential bottleneck? My bet is it has been chosen so as not to compromise this artwork poweramp. Not to mention that we might get even an additional option in form of Mark's SMPS filter, should we really need it. Should this filter materialize, given Mark' credits, it is likely to be a performing item (be it only because he wouldn't probably chose to release it otherwise).
I wouldn't throw the SMPS away: I am eager to plug my cheap scope on it and my old ears on the amp with suitable speakers ;-)
Just thinking out loud
Claude
In these power supply discussions, the question I have not seen addressed before ... would this or one of the offspring amps benefit from a dual mono PSU - meaning the use of two Meanwell 36V bricks, one for each channel ?
Using same or lower wattage rating if there's two of them ?
The benefit is minimal for a circuit biased by a constant current source as this one is. The ac signal is not significantly seen by the supply.
A guess. Its cheaper & simplier? And likely having bought many similar for the ACA, volumes may be adding together for better pricing yet.
dave
Also, I’ve heard theories that two SMPS PSUs supplying the same box can interfere with each other since any radiated frequencies are probably slightly different, so might “beat”, plus getting a PSU in a separate chassis has to only be good regarding any radiated “noise”, so it should be a feature, not a bug. If you prefer the PSU inside the case because you think it’s “better” why not just shorten the cable from the external brick and leave it external, but close.
There are always lots of observations and theories posted. Often conflicting! It’s up to the builder who to believe. I tend to believe Nelson.
While ease of construction has been a consideration, it wouldn’t make sense for Nelson to compromise the performance of an amp which is clearly a high end product it he weren’t confident that it was equal if not better. And we have reports from experienced builders saying the amps are the quietest they’ve seen.
It appears that over time some SMPS supplies have improved. Not surprising. And these PSU’s are quite expensive! They certainly have the budget to make them good
There are always lots of observations and theories posted. Often conflicting! It’s up to the builder who to believe. I tend to believe Nelson.
While ease of construction has been a consideration, it wouldn’t make sense for Nelson to compromise the performance of an amp which is clearly a high end product it he weren’t confident that it was equal if not better. And we have reports from experienced builders saying the amps are the quietest they’ve seen.
It appears that over time some SMPS supplies have improved. Not surprising. And these PSU’s are quite expensive! They certainly have the budget to make them good
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Biggest advantage of external SMPS “brick” is that it has been safety certified and approved by almost every possible organization. CE, UL, CSA, FCC, etc...
The amp itself is inherently safe from electrical-mains shock hazard. It allows a product development cycle to save a lot of $ in CE/UL certification fees.
As a side benefit, it’s cost effective and contributes less radiated noise when outside.
A 36v 4.44A capable SMPS really can do a lot of things. Imagine two in series would be a great +/-36v PSU for a multitude of 50w Class AB amps.
More than a side benefit is noise performance benefit. Here is the FFT of the noise floor of an amp I recently built using a SMPS from Micro-Audio. This is with the inputs to the preamp stage shorted. The preamp used a small Mean Well PCB mounted DCDC converter (another tiny SMPS) to generate +/-15v from the 12v auxiliary output of the 51V SMPS. The SMPS is capable of supplying 600w continuously. I don’t know about you guys, but I have never been able to get the noise floor of any linear PSU to be this clean. Full scale output is referenced to -10dB. So the noise floor (not including the little blips) is very very low - inaudible. Cannot tell the amp us turned on - a similar comment I heard 6L6 say about the VFET - and that’s a great thing to say about any amp. So both preamp and main power amp were powered by SMPS’s. Result is absolutely quiet amp.
FFT of amp output into 10ohm load, inputs to preamp shorted. Ref to max signal at -10dB so noise floor is -130dB:
With my ear pressed (touching the driver), I cannot tell the amp is turned on.
The amp itself is inherently safe from electrical-mains shock hazard. It allows a product development cycle to save a lot of $ in CE/UL certification fees.
As a side benefit, it’s cost effective and contributes less radiated noise when outside.
A 36v 4.44A capable SMPS really can do a lot of things. Imagine two in series would be a great +/-36v PSU for a multitude of 50w Class AB amps.
More than a side benefit is noise performance benefit. Here is the FFT of the noise floor of an amp I recently built using a SMPS from Micro-Audio. This is with the inputs to the preamp stage shorted. The preamp used a small Mean Well PCB mounted DCDC converter (another tiny SMPS) to generate +/-15v from the 12v auxiliary output of the 51V SMPS. The SMPS is capable of supplying 600w continuously. I don’t know about you guys, but I have never been able to get the noise floor of any linear PSU to be this clean. Full scale output is referenced to -10dB. So the noise floor (not including the little blips) is very very low - inaudible. Cannot tell the amp us turned on - a similar comment I heard 6L6 say about the VFET - and that’s a great thing to say about any amp. So both preamp and main power amp were powered by SMPS’s. Result is absolutely quiet amp.
FFT of amp output into 10ohm load, inputs to preamp shorted. Ref to max signal at -10dB so noise floor is -130dB:
With my ear pressed (touching the driver), I cannot tell the amp is turned on.
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Normally building a good linear PSU for a power amp is expensive, time consuming and makes the amp very heavy (and large).
Maybe a good designed SMPS with good filtering is perfect for "constant current" amps like KL. A amps.
For class A/B a linear PSU with a large cap. bank is probably needed to deliver fast peak currents.....
Maybe a good designed SMPS with good filtering is perfect for "constant current" amps like KL. A amps.
For class A/B a linear PSU with a large cap. bank is probably needed to deliver fast peak currents.....
