No-global-loop amplification

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Cresnet

Cresnet

Member
Joined 2012
micro-audio.com
My personal attempt at building an amplifier for the bench.

This amplifier is simply a superb amplifier when it comes to sonics.

We have more than one amplifier here, but this one is the best from all.
 

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jwilhelm

Member
Joined 2014
vzaudio.com/
After almost a year of drastic changes in life and a relocation of my lab I hope to get back at testing the AX3 version of the Simpelstark soon. The lab still has boxes of parts heaped up so working in it is still a rough go.

I tested some modifications to the ODNF circuit using high speed op amps but they didn't go well. As usual high speed op amp in audio bring on high speed oscillations. This will be revisited at some point, but not now. The goal is to extend the frequency range that the ODNF circuit is effective in to the full audio frequency range.

Next step will be to to do some formal measurements and some proper listening tests on some better speakers. The test speakers I used to use died a horrible death in some other testing so that's a bit of a hurdle right now too.

Due to the power output levels of this design it will likely be a good candidate for SMPS, otherwise this will weigh a lot in stereo / dual-mono configuration. This is why I'm curious how others are making out with SMPS.
 
Last edited:
Cresnet

Cresnet

Member
Joined 2012
micro-audio.com
jwilhelm said:
Did you do a stereo version or just a mono-block? I'm interested to see how people are making out with dual-mono designs with SMPS. It sounded like Pinocchio was having some noise / ground loop issues, but gave up and went to conventional supplies.
Click to expand...

I am doing it as Mono-Block, I don't have parts for the other channel to build.

I don't know which SMPS was used by Pinocchio indeed, Pinocchio also used the new version of my SMPS with other amplifiers and everything was super quiet.

I have many SMPS options that may fit perfectly with this amplifier.

Thanks
 
T

thimios

Member
Joined 2009
jwilhelm said:
After almost a year of drastic changes in life and a relocation of my lab I hope to get back at testing the AX3 version of the Simpelstark soon. The lab still has boxes of parts heaped up so working in it is still a rough go.

I tested some modifications to the ODNF circuit using high speed op amps but they didn't go well. As usual high speed op amp in audio bring on high speed oscillations. This will be revisited at some point, but not now. The goal is to extend the frequency range that the ODNF circuit is effective in to the full audio frequency range.

Next step will be to to do some formal measurements and some proper listening tests on some better speakers. The test speakers I used to use died a horrible death in some other testing so that's a bit of a hurdle right now too.

Due to the power output levels of this design it will likely be a good candidate for SMPS, otherwise this will weigh a lot in stereo / dual-mono configuration. This is why I'm curious how others are making out with SMPS.
Click to expand...

Hi Jeff, i hope that everything is good for you now:)
 
R

rhythmsandy

Member
Joined 2012
jwilhelm said:
After almost a year of drastic changes in life and a relocation of my lab I hope to get back at testing the AX3 version of the Simpelstark soon. The lab still has boxes of parts heaped up so working in it is still a rough go.

I tested some modifications to the ODNF circuit using high speed op amps but they didn't go well. As usual high speed op amp in audio bring on high speed oscillations. This will be revisited at some point, but not now. The goal is to extend the frequency range that the ODNF circuit is effective in to the full audio frequency range.

Next step will be to to do some formal measurements and some proper listening tests on some better speakers. The test speakers I used to use died a horrible death in some other testing so that's a bit of a hurdle right now too.

Due to the power output levels of this design it will likely be a good candidate for SMPS, otherwise this will weigh a lot in stereo / dual-mono configuration. This is why I'm curious how others are making out with SMPS.
Click to expand...

when using high speed opamps do put an output resistor take 51ohm in series after the feedback resistor of the high speed opamp in the ODNF circuit and see if it stabilizes. Im curious to know that if it stabilizes. Pls let me know.
 
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