PSU's can't decide...
Hi
This was a thread that lead to this very very interresting design of janneman, which I think is the most beautiful yet simple made serial regulator I have seen. (sorry I didn't saw that you where the author from the beginning
)
From the beginning (my beginning), in my DIY start about 30 years ago, I had dreams about a good hifi preamp with tubes. I gathered all about it under several years....
Then came family and other work stuff and also other hobbies. Finally I thought, some years ago, I would, at last, build that aftersought homemade preamp and then... I learned some more ... and some more ...
Now I'm almost there, where the light comes from when you have the near death sight, I guess 🙄 😀
I mean, along the way to build the really good stuff you learn a lot and then you realise you have to start all over again...
I'm the person who won't have 20 halfmade projects around but just a few well done. So, thats why I have built all my amps in the head and not a real one, exept one guitarramp 5w EL84, when I was 16. Before I got this high demand on quality on myself. (Some transistorstuff though, that not counts in )
To the point. I have finally learned that the most important part of the amp project is the PSU.
janneman's PSU seems beautiful in it's simplicity and elegant design but.....
I have also bought two cards in a group buy from another project at this forum. I'm in the progress of testing that one out, maybe next week. Thats a shunt regulator though.
This is the thread
Maybe we can soup this thread up with some opinions and schematics on shunt vs serial regulator's? I have no references but serials yet. Are a well designed shunt reg all that much better and superior the serial reg's? Everyone whos a descent "hotshot" in the electronics say they are. Is the "sound" all that much better?
Thanks for interresting reading along the way. 😎
Hi
This was a thread that lead to this very very interresting design of janneman, which I think is the most beautiful yet simple made serial regulator I have seen. (sorry I didn't saw that you where the author from the beginning
)From the beginning (my beginning), in my DIY start about 30 years ago, I had dreams about a good hifi preamp with tubes. I gathered all about it under several years....
Then came family and other work stuff and also other hobbies. Finally I thought, some years ago, I would, at last, build that aftersought homemade preamp and then... I learned some more ... and some more ...
Now I'm almost there, where the light comes from when you have the near death sight, I guess 🙄 😀
I mean, along the way to build the really good stuff you learn a lot and then you realise you have to start all over again...
I'm the person who won't have 20 halfmade projects around but just a few well done. So, thats why I have built all my amps in the head and not a real one, exept one guitarramp 5w EL84, when I was 16. Before I got this high demand on quality on myself. (Some transistorstuff though, that not counts in )
To the point. I have finally learned that the most important part of the amp project is the PSU.
janneman's PSU seems beautiful in it's simplicity and elegant design but.....
I have also bought two cards in a group buy from another project at this forum. I'm in the progress of testing that one out, maybe next week. Thats a shunt regulator though.
This is the thread
Maybe we can soup this thread up with some opinions and schematics on shunt vs serial regulator's? I have no references but serials yet. Are a well designed shunt reg all that much better and superior the serial reg's? Everyone whos a descent "hotshot" in the electronics say they are. Is the "sound" all that much better?
Thanks for interresting reading along the way. 😎
Re: power
Hi Panos,
Those MPSW transistors will work, but they are a bit low on the minimum gain spec.
If you have them already, I would just use them and if you're happy, then your done. The transistors I used are not expendsive but you need to find them. I got mine from farnell, and they have a min order of 50 euro I believe so it would work if you can combine orders.
I'll check with my board maker on the prices and will update my website on the availability of boards tomorrow.
Jan Didden
panos29 said:
Hi Panos,
Those MPSW transistors will work, but they are a bit low on the minimum gain spec.
If you have them already, I would just use them and if you're happy, then your done. The transistors I used are not expendsive but you need to find them. I got mine from farnell, and they have a min order of 50 euro I believe so it would work if you can combine orders.
I'll check with my board maker on the prices and will update my website on the availability of boards tomorrow.
Jan Didden
Re: PSU's can't decide...
In ideal cases there's no oscillation and the high frequencies wil sound normal. At low frequencies the error amplifier has to cope with the current waveform introduced by the musical signal. Because of the HPF slope bass notes will be influenced (both in amplitude and phase).
I've tried to power a 20W PP amplifier from shunt regs but it produced too much heat to call it a success. That's the problem with shunt regs when currents are getting large: it must dissipate at least two times the maximum current need for the amplifier to give low Z SOURCE.
Which regulator sounds best? I guess it depends on many aspects like current, amplifier stage PSRR, power source and other things I can't think of at the moment. Whatever you choose, remember it's only a tool (which must be small for my toolbox) and good reproduction does not solely depend on it.
We all started with one well done... 😉Radioman62 said:
An amplifier supplied from whatever regulator forces its error amplifier to track the musical waveform. Although regulators have low Z SOURCE the response towards DC must fall rapidly because of the error amplifiers' need for stability. Because Z SOURCE is inductive and rises with frequency, it's possible the regulator suffers from HF instability.
In ideal cases there's no oscillation and the high frequencies wil sound normal. At low frequencies the error amplifier has to cope with the current waveform introduced by the musical signal. Because of the HPF slope bass notes will be influenced (both in amplitude and phase).
I've tried to power a 20W PP amplifier from shunt regs but it produced too much heat to call it a success. That's the problem with shunt regs when currents are getting large: it must dissipate at least two times the maximum current need for the amplifier to give low Z SOURCE.
Which regulator sounds best? I guess it depends on many aspects like current, amplifier stage PSRR, power source and other things I can't think of at the moment. Whatever you choose, remember it's only a tool (which must be small for my toolbox) and good reproduction does not solely depend on it.
Re: Re: PSU's can't decide...
I think it also depends on the design most. I design my regulators for stability 😉
Jan Didden
disco said:
I think it also depends on the design most. I design my regulators for stability 😉
Jan Didden
Re: Re: Re: PSU's can't decide...
Agreed, the most important goal is stability, from DC to a certain frequency. Would an abbriviated bandwith of say 30KHz have impact on amplification of noise?
On comparison of regulator sound, it must be understood that lots of people compare results by ears only. The unfortunated misunderstanding can arrise that distortion is interpreted as 'extra detail' which might be welcomed.
Agreed, the most important goal is stability, from DC to a certain frequency. Would an abbriviated bandwith of say 30KHz have impact on amplification of noise?
On comparison of regulator sound, it must be understood that lots of people compare results by ears only. The unfortunated misunderstanding can arrise that distortion is interpreted as 'extra detail' which might be welcomed.
Re: Re: Re: Re: PSU's can't decide...
You couldn't be more right. Thats why we see the never ending threads on how different preposterous tweaks would change tone.
Put a scope on the signal or the supply lines and watch the radio carrier wave 😀
Having sayed that, I can also hear differences when tweaking a good circuit, just by changing OP's, even though they both have good figures on the paper. Very subtle tone differences though.
Some clami they here differences when they compare same sort of cable but different color on the isolation
disco said:
You couldn't be more right. Thats why we see the never ending threads on how different preposterous tweaks would change tone.
Put a scope on the signal or the supply lines and watch the radio carrier wave 😀
Having sayed that, I can also hear differences when tweaking a good circuit, just by changing OP's, even though they both have good figures on the paper. Very subtle tone differences though.
Some clami they here differences when they compare same sort of cable but different color on the isolation
Re: Re: PSU's can't decide...
Why? Where have you learned that? Can you please elaborate or show some theory.
The design I refer to above, the shuntregulator on this forum says 0.2 times the load.
I recently read somewhere at John Broskies Tubecad that it's a misunderstanding that the shunt needs to draw more then the load. Can't find it right now though.
disco said:
Why? Where have you learned that? Can you please elaborate or show some theory.
The design I refer to above, the shuntregulator on this forum says 0.2 times the load.
I recently read somewhere at John Broskies Tubecad that it's a misunderstanding that the shunt needs to draw more then the load. Can't find it right now though.
Re: Re: Re: PSU's can't decide...
The important thing is the *variation* of the load current, not the absolute value. The shunt current must be at least as large as the variation in load current to maintain a current at the highest load current. The thing you set is the CCS feeding the shunt and load, the shunt regulates itself.
Suppose you have a load that varies between 800mA and 1200mA. Then make your CCS feeding the shunt and load to deliver 1300mA. Then at 800mA load current, the shunt absorbs 500mA, and at max load of 1200mA, the shunt takes the remaining 100mA. So, the shunt always stays in control.
Jan Didden
Radioman62 said:
The important thing is the *variation* of the load current, not the absolute value. The shunt current must be at least as large as the variation in load current to maintain a current at the highest load current. The thing you set is the CCS feeding the shunt and load, the shunt regulates itself.
Suppose you have a load that varies between 800mA and 1200mA. Then make your CCS feeding the shunt and load to deliver 1300mA. Then at 800mA load current, the shunt absorbs 500mA, and at max load of 1200mA, the shunt takes the remaining 100mA. So, the shunt always stays in control.
Jan Didden
It's possible I am the source of the idea that shunt current must be at least equal to that drawn by the load. I say this quite strongly in my "Tube preamp CookBook" in the chapter on current sourced shunt regs. And as there are over 2000 copies of this book out there, mayhbe the idea has gotten around.
Since writing that, I have found you can get away with much less shunt current than what the load draws, but never so low that the shunt never has any shunt current left on peaks of current in the load.
In our big RTP3D preamp, each channel draws 75 mA, and I set the shunt current to 20mA. Works just fine and there's no sonic advantage in having more shunt current than this.
Regards, Allen (Vacuum State)
Since writing that, I have found you can get away with much less shunt current than what the load draws, but never so low that the shunt never has any shunt current left on peaks of current in the load.
In our big RTP3D preamp, each channel draws 75 mA, and I set the shunt current to 20mA. Works just fine and there's no sonic advantage in having more shunt current than this.
Regards, Allen (Vacuum State)
Great,
The layout looks nice. The first one I will try is a above 700V
6C33C regulator with the board some centimeters below the socket. Will come back when I have the boards.Allen Wright said:
I see. Nice of you to admit that. It could very well be so. I thought I understood the shuntregulator before and now I feel even better.
One thought. Is it maybe overkill to use such a shuntregulator on a Constant Current Draw Grounded Cathode amplifier? I mean it doesn't tug alot on the powerline, even though it's PSRR isn't the best of the tube circuits. Maybe it's best on such an amp because of the low PSRR figures?
Radioman,
If your common cathode stage uses a CCS as a anode load, then adding CCS fed shunt reg may not help much, but if it is a regular resistive loaded CC stage, or is a SRPP (or similar) then it will GREATLY help. By actual test.
I believe a CCS fed Shunt reg is VITAL in all signal handling stages, that's why we have been selling our "SuperReg" kit for over 10 years now!
Regards, Allen (Vacuum State)
If your common cathode stage uses a CCS as a anode load, then adding CCS fed shunt reg may not help much, but if it is a regular resistive loaded CC stage, or is a SRPP (or similar) then it will GREATLY help. By actual test.
I believe a CCS fed Shunt reg is VITAL in all signal handling stages, that's why we have been selling our "SuperReg" kit for over 10 years now!
Regards, Allen (Vacuum State)
janneman said:
Sorry, missed a topic, which resistors are you talking about? Is it about DN2540 or tube version?
LinuksGuru said:
DN2540 or DN2470. For the tube versions you can use up to 1k since the grid capacitances are much less than the gate caps.
Jan Didden
Allen Wright said:
Although regulated stabilized power supply will certainly benefit tube gear from the point of view of engineering, I have not seen any blind listening tests which will confirm that regulated PS does really improve sonic performance, especially when it comes to tube pre-amps, which draw very little constant current. Better characteristics on oscilloscope do not necessarily translates in something audible.
I have to admit I plan to use regulated PS for power amp, but for purpose of better preservation of output tubes.
I would just throw in a comment here: blinded tests don't work.
Non-blinded tests don't work, either, but there's a caveat to that:
educated testing works, depending upon who's ears you're trusting.
There are a few ears I trust. Wright's. Pimm's. Broskie's. a few others.
You'll find this hard to understand, I know. For an explanation, you can read:
http://www.transformationaudio.com/blog/TheNeuroacousticsofAudio
Important note: this is an explanation only, containing a hypothesis. It is not a proof. There is no proof, yet. Until we can free ourselves of the belief that engineering understands neuroacoustics - it doesn't, it only understand electronics (barely), an entirely different matter - and figure out how to do valid psychoneurologically-based neuroacoustic testing of audio components, the only foundation we have are educated ears that have done this work for many years. See above.
50 years ago, music was fun. I didn't really care about hifi, I just enjoyed.
20 years ago I thought I knew something, but it was all baloney; I had been tricked by the illusion of specifications.
5 years ago I realized most of what engineers said about audio was also baloney, but the field of audio is filled with landmines, placed there by both engineers, frauds, con-artists, lunatics, and people who must be from other universes, so it took me some time to parse out who's ears I could trust and who were nutcases. Mind you, the best educated ears are also good engineers, but the reverse doesn't follow at all.
Now, I trust the judgment of a very select few educated ears. There is a consensus: for preamps, CCS'd Shunt Regulation is the way to go. Period. For a preamp, I'd use Allen Wright's power supply kit in a heartbeat. It's a no-brainer. For power amps, I'm starting to lean in the judicious application of CCs's also, as Pimm is demonstrating.
Being a DIY'er, I waste time and money designing my own, but I take very careful lessons from those who've done the work for a long time, and emulate them.
Best, Charlie
Non-blinded tests don't work, either, but there's a caveat to that:
educated testing works, depending upon who's ears you're trusting.
There are a few ears I trust. Wright's. Pimm's. Broskie's. a few others.
You'll find this hard to understand, I know. For an explanation, you can read:
http://www.transformationaudio.com/blog/TheNeuroacousticsofAudio
Important note: this is an explanation only, containing a hypothesis. It is not a proof. There is no proof, yet. Until we can free ourselves of the belief that engineering understands neuroacoustics - it doesn't, it only understand electronics (barely), an entirely different matter - and figure out how to do valid psychoneurologically-based neuroacoustic testing of audio components, the only foundation we have are educated ears that have done this work for many years. See above.
50 years ago, music was fun. I didn't really care about hifi, I just enjoyed.
20 years ago I thought I knew something, but it was all baloney; I had been tricked by the illusion of specifications.
5 years ago I realized most of what engineers said about audio was also baloney, but the field of audio is filled with landmines, placed there by both engineers, frauds, con-artists, lunatics, and people who must be from other universes, so it took me some time to parse out who's ears I could trust and who were nutcases. Mind you, the best educated ears are also good engineers, but the reverse doesn't follow at all.
Now, I trust the judgment of a very select few educated ears. There is a consensus: for preamps, CCS'd Shunt Regulation is the way to go. Period. For a preamp, I'd use Allen Wright's power supply kit in a heartbeat. It's a no-brainer. For power amps, I'm starting to lean in the judicious application of CCs's also, as Pimm is demonstrating.
Being a DIY'er, I waste time and money designing my own, but I take very careful lessons from those who've done the work for a long time, and emulate them.
Best, Charlie
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