Retro Amp 50W Single Supply

[Blujay]

I like single supply. I use diff pair in feedback and current limit protection. This design reminds me of my old Lafayette 30 watt in '70's. Output stage failed a fe times.

 

[Joel Wesseling]

I'm trying to debug Autona AL125

I have high DC at the output and input terminals

Whats the purpose of the DC rail dropped across R1,R2 and R3? - circled in red

I'm not sure why the input Caps are not blocking DC?

 

[wahab]

The purpose is to set the output DC voltage before the output cap such that the amp clip symmetricaly.
To make mesurements connect a 1k resistance fom VOUT to GND, otherwise the output capacitor will never be charged.

 

[chermann]

Can someone tell, if this amp will work with modern more easily available devices? Just an exercise towards curiosity!😀.

regards
Prasi

did somebody test this penfold amp FX4- with LAT_FETS´s??
post 286

kr
chris

 

[gannaji]

Dear chermann,
Please check this out.

Thread 'Retro TGM8 with TMC, Laterals and 80db OLG @ 20 KHz'

2024-10-30 2:28 pm

Dear friends,

There was a thread by Nico Ras, (6) Another thread regarding CCS vs BOOTSTRAP | diyAudio . There was a lot of discussion about CCS vs Bootstrapping. In post https://www.diyaudio.com/community/...egarding-ccs-vs-bootstrap.134046/post-1674672 , MJL21193 suggested “We need a compromise Nico - a bootstrapped CCS!”

I remember that Dadod used it in his GEM amplifier. Also, Hugh used it in his Fetzilla. I used Hugh’s idea in my latest iteration, in toto.

When I checked the distortion products, the FFT @ 1 KHz is as below. Not very useful. Hence, I...

• gannaji
• Replies: 2
• Forum: Solid State

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