Anyone done this? I just completed a build and got some strange things going on - a bit distorted...cannot tell if its SMPS or something else...
Thinking of just putting in a pack of caps between the SMPS and amp or just going to conventional linear power supply...
But any reason why it would not work?
The new ESP forum is horrible (old, very good forum long gone and deleted)....
Thinking of just putting in a pack of caps between the SMPS and amp or just going to conventional linear power supply...
But any reason why it would not work?
The new ESP forum is horrible (old, very good forum long gone and deleted)....
Yes, I know / understand it not the standard application for power on these amps - just trying the understand why it would not work...other than possibility it is the reason it isn't working in my case...
The recommended linear power supply shows six 4300uf caps - not exactly a Class A type, high capacitance power supply...
The recommended linear power supply shows six 4300uf caps - not exactly a Class A type, high capacitance power supply...
Assuming you have other amplifiers with conventional power supplies, either commercial or DIY, why not tap off the rail supplies of one of these to prove whether or not there's a problem. As long as the supply rails don't exceed the limits of the P101 and its capacitors as you built it, that should work fine for the purpose and you won't need the full, maximum supply voltage or current capability of the P101 to do this.
Often, I just use scrap 3-wire power cable to couple a power module direct to a cheap dual bench supply (+/-30V) and test the amplifier that way before assembling any PSU or even building/buying a case for the amplifier. It's really the same as an inbuilt supply but take care and use secure connections rather than clips because most supplies are big enough to do damage if the supply wiring can loosen and fly off, shorting to things that it shouldn't.
It's also wise to continue monitoring the idling current when testing any new amplifier. That often indicates whether there is a problem somewhere and likely sources if it can't simply be adjusted correctly.
Often, I just use scrap 3-wire power cable to couple a power module direct to a cheap dual bench supply (+/-30V) and test the amplifier that way before assembling any PSU or even building/buying a case for the amplifier. It's really the same as an inbuilt supply but take care and use secure connections rather than clips because most supplies are big enough to do damage if the supply wiring can loosen and fly off, shorting to things that it shouldn't.
It's also wise to continue monitoring the idling current when testing any new amplifier. That often indicates whether there is a problem somewhere and likely sources if it can't simply be adjusted correctly.
Adding capacitors to the output of a SMPS is often not good, as the SMPS will balk at the current required to charge them and shut off. The spec sheet for most supplies have a maximum output capacitance, which you can’t mess with.
If your SMPS is causing distortion, my guess is it’s undersized, and going into current limit.
Agree with the idea to run your amp off a bench supply. I do this with all my amps for initial smoke test and setup, before going to the real supply to test under load.
If your SMPS is causing distortion, my guess is it’s undersized, and going into current limit.
Agree with the idea to run your amp off a bench supply. I do this with all my amps for initial smoke test and setup, before going to the real supply to test under load.
Maybe understressed is a better term. If for example, the supply was a large but cheap dual 36V type, it may not regulate smoothly with such a light load. I have one if these that I used once and didn't like its noise level or regulation behaviour. Also, I can't think why such a dual polarity supply would be classified with LED lighting types but that's what the sales brief said.
Did you say that the Chinese supply is classed with LED lighting types Ian ---OMG!
Over 2000 complaints so far on my previous website of -- our LED bulbs will last XXXXXXX hours but they last --XX hours .
Reason ? -after a professor and I opened up around 10 each of various makes --absolutely cr@p components making up the smps,s that's right -cheap & nasty .
This is a major issue in the UK importers selling "built to a price " lamps and some are well known makes but actually made in China -check it out yourself .
Over 2000 complaints so far on my previous website of -- our LED bulbs will last XXXXXXX hours but they last --XX hours .
Reason ? -after a professor and I opened up around 10 each of various makes --absolutely cr@p components making up the smps,s that's right -cheap & nasty .
This is a major issue in the UK importers selling "built to a price " lamps and some are well known makes but actually made in China -check it out yourself .
A 500W supply might be rated for optimum performance at around 65% maximum load. That's 7A, both rails and a bit too much bias for any P101 amplifier. I'd only be guessing what you actually have there, john65b but you might tell us a little bit more about it.
Regarding lousy SMPS LED lighting units, isn't this just symptomatic of slack purchasing procedure? If someone is going to buy large volumes of any imported products, they owe it to their company and customers to ensure all said products will meet local quality standards and assurance requirements for legal liability reasons. No excuses there. If your supplier can't demonstrate adequate quality levels for your customers and you aren't equipped to do it on their behalf, as a business, you're headed for trouble.
As Chinese manufacturing quality goes, I think most DIYaudio folk are aware that it varies widely between good and reputable quality to something that escaped from a school kid's desk. Meanwell for example, produce some very competitive, high quality SMPS units in many grades from qualified, high reliability types down to basic, single duty, economy models. Their reputation has been very good and they've built up quite an enviable global customer base over many years now.
For my part with SMPS, I bought an adjustable voltage and current limited pair of "Gophert" SMPS benchtop units about 6 years ago. They aren't pro. quality but they're small, neat, stackable and supply a cool 32V/5A max. I haven't used these with P101 but did run a stereo pair to Rod's P3A design with them regularly for a year without discernible problems. Nice sound quality, actually.
Regarding lousy SMPS LED lighting units, isn't this just symptomatic of slack purchasing procedure? If someone is going to buy large volumes of any imported products, they owe it to their company and customers to ensure all said products will meet local quality standards and assurance requirements for legal liability reasons. No excuses there. If your supplier can't demonstrate adequate quality levels for your customers and you aren't equipped to do it on their behalf, as a business, you're headed for trouble.
As Chinese manufacturing quality goes, I think most DIYaudio folk are aware that it varies widely between good and reputable quality to something that escaped from a school kid's desk. Meanwell for example, produce some very competitive, high quality SMPS units in many grades from qualified, high reliability types down to basic, single duty, economy models. Their reputation has been very good and they've built up quite an enviable global customer base over many years now.
For my part with SMPS, I bought an adjustable voltage and current limited pair of "Gophert" SMPS benchtop units about 6 years ago. They aren't pro. quality but they're small, neat, stackable and supply a cool 32V/5A max. I haven't used these with P101 but did run a stereo pair to Rod's P3A design with them regularly for a year without discernible problems. Nice sound quality, actually.
I have tested P101s (as well as many other amps even class A) on a dual lab psu made of two MeanWell 50V 5A SMPS set to 54V followed by DSP5005 modules.
Apart from a few cases where the amp would oscillate, I never encountered any problem with this SMPS. This oscillation has nothing to do with the psu and can be cured easily with a proper Zobel & output inductor.
Apart from a few cases where the amp would oscillate, I never encountered any problem with this SMPS. This oscillation has nothing to do with the psu and can be cured easily with a proper Zobel & output inductor.
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Just thinking aloud, I´d leave amp alone (meaning build and bias it as recommended) and add a smallish filament lamp , a few Watts end to end, so as to load SMPS with something more ... ummm ... "meaty".
Won´t hurt anything and warm orange glow (undervolt tha lamp meaning choose one with higher rated voltage than available, say an easy to find 120V lamp for 70V end to end rails or so) emanating from cabinet openings may even improve sound (as many tubeheads believe
). To boot, PTC tungsten filament behaviour means they will show an even more important load at startup, precisely when SMPS is waking up and deciding on turning on (finding a worthy load) or not.
The only other "variance" I had on this particular P101 build was I added about 3" of wire leads to the output transistors to be able to mount them and pcb onto a more narrow heatsink.
Already changed the output transistors from 2SJ162 / 2SK1058 (bought from member on DIYAudio) to Profusion Exicons, thinking maybe the transistors were fake...with Exicons I can dial in 34mv where before with the j162/k1058 I could not get under 60mv...
I have built these before with no issues following the design instructions...
Also, I would not say its oscillating - more of a sharp crackle on transients in music - early "premature" clipping....
The SMPS:
500W +/-60V amplifier dual-voltage PSU audio amp switching power supply board | eBay
Already changed the output transistors from 2SJ162 / 2SK1058 (bought from member on DIYAudio) to Profusion Exicons, thinking maybe the transistors were fake...with Exicons I can dial in 34mv where before with the j162/k1058 I could not get under 60mv...
I have built these before with no issues following the design instructions...
Also, I would not say its oscillating - more of a sharp crackle on transients in music - early "premature" clipping....
The SMPS:
500W +/-60V amplifier dual-voltage PSU audio amp switching power supply board | eBay
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you might want to take a look at the meanwell smps thread: Mean well vs generic power adapter vs audio oriented smps
I used a passive filter plus capacitance multiplier to good effect after the SMPS. The schematic is in post #51, and if you scroll up there are measurements shown as well.
I used a passive filter plus capacitance multiplier to good effect after the SMPS. The schematic is in post #51, and if you scroll up there are measurements shown as well.