Had not got any notifications of posts here the last couple of weeks - sad how we get dependent on that kind of thing. I was worried no one was paying attention to this.
Good to see Vunce's work. HEARING forward to what he thinks of how they perform.
Mine continue to please me, to say the least.
My only regret is that there are not more folks giving this circuit a try
Another thanks to Tombo.
Good to see Vunce's work. HEARING forward to what he thinks of how they perform.
Mine continue to please me, to say the least.
My only regret is that there are not more folks giving this circuit a try
Another thanks to Tombo.
Vunce knows how they perform as he has R21 supplies in one amplifier. It is hard to evaluate PS performance in amplifier with supply that is there from the beginning. Any impressions other than how amplifier performs are unlikely.
Your case was different, as amplifiers were listened for a time with the different supplies. So it was possible to evaluate the difference.
Anyway, I’m sure that this supply enables any amplifier to show truly what is it capable of, but I know as well that it can’t bring audible improvement to the absolutely any amplifier.
Purpose of publishing this design was fulfilled when first forum member, apart from me, found better sound by using it. So, I’m good. 🙂
There is or will be more builds but not everyone is comfortable with showing/discussing their results.
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Your correct Tombo, I didn’t compare the R21 equipped power supply against any other psu in the same amp.
I’d like to be able to use the R25 bipolar ‘modules’ in my current build as swappable units into other amps. At least that’s my thought going in, but when music sounds right from the beginning it takes incentive away from digging in again to move components around. That was the case with Bliss😊.
I’ve had wonderful sound/listening results from three projects of yours so far (Input buffer, R21, Bliss), I fully expect to be 4 for 4 when R25 is in service. Thanks Tombo!
I’d like to be able to use the R25 bipolar ‘modules’ in my current build as swappable units into other amps. At least that’s my thought going in, but when music sounds right from the beginning it takes incentive away from digging in again to move components around. That was the case with Bliss😊.
I’ve had wonderful sound/listening results from three projects of yours so far (Input buffer, R21, Bliss), I fully expect to be 4 for 4 when R25 is in service. Thanks Tombo!
Finally got around to transferring my SIT OPT amp into dedicated monoblocks, which gave me the opportunity to use the R21 PSUs. Everything performs as expected in comparison to the modules. I really like the soft start - plays perfectly with the depletion parts.
Well done, Tombo!
Well done, Tombo!
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No, a few months ago I ordered a pair of custom output transformers that are spec'd more toward use with solid state, and I've been creating circuits for them. Using the same board dimensions, which makes it easy to swap out and test. So far I've got a common source output stage with buffer in front (Singing Bush inspired), a two stage circuit with SE SIT CS front end and SE SIT CS output, and am currently working on a SE SIT CS FE with common drain SIT output. Basic circuits, but they sound pretty amazing and this PSU plays a big part in that (inherently bad PSRR with these circuits). Hope to make a post soon to share findings, measurements, files, etc.
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Very cool project for these VFET unicorns, Cody.
Look forward to reading more.......when you're ready of course.
Look forward to reading more.......when you're ready of course.
In tha way, wouldn't the upper one be heated by the lower one so ending up in different temperature zones... is that wise?
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Yes, I've had them for a couple months. I ordered the version that is modeled after the Tango FG-50S. The only change I made was to use a 50W core, allowing for higher bias current. Primary taps are 64/32/16 and secondary are 16/8/4. The quality and performance of these J&K transformers appear to be top notch.
@rickmcinnis: See also Susan Parker's 20+ year old and still going thread: Zero Feedback Impedance Amplifiers.
Almost certainly not the intended use case, but let’s say I want to use this transformer:
In operation, the peak current draw would be below the example 0.58 A scenario. (let’s say ~ 300 mA at quiescent state)
Can I expect 57V of regulated output?
Can I/should I use 10 mF @ 100VDC for C2?
Replace R8 & R9 with 4K7 & 3K9 values.
Use onboard heat sinks as in BOM?
I realize this is designed to deliver much more current, but I have an unusual use case at as close to 60V of regulated output as possible, with up to .5 A of draw.
In operation, the peak current draw would be below the example 0.58 A scenario. (let’s say ~ 300 mA at quiescent state)
Can I expect 57V of regulated output?
Can I/should I use 10 mF @ 100VDC for C2?
Replace R8 & R9 with 4K7 & 3K9 values.
Use onboard heat sinks as in BOM?
I realize this is designed to deliver much more current, but I have an unusual use case at as close to 60V of regulated output as possible, with up to .5 A of draw.
Juice for Ra7’s preamp perhaps?
60V output is OK, but without RF filter as Murata declared it for 50V max. Another limit comes, as Vunce pointed out, from the LT4320 allowed voltage range.
But, there are no obstacles (except price) to connect two supplies in series and get 100V. Noise will be slightly worse at 3 uV total, but that is still exceptionally low.
☺️
You caught me.
I am assessing returning to a single supply board to power all the things (preamp board and headphones buffer board in my case).
My current supply boards use 4 X 33R balancing resistors and with a 55-60V target and at least 0.2 A of draw, things get complicated fast, in terms of transformer options and dissipation.
I almost thought I had found a silver bullet here.
