audio-talk

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But I wonder if its worth trying a NPN for Q1 and taking the feedback back to Q1's base. Oh wait, sorry I misunderstood - forgot where 'Q1' was - I know what you mean now - I shall have a ponder..... back shortly ... "I have a cunning plan my lord" http://livinginthepast-audioweb.co.uk/im...

Ah found a picture ...
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This is cobblers and do this better is my kind of self-encouragement! :lol: I was part-paid (aka "take them please before I dump them on eBay") for a repair job a while back in a few OC35s! Matched pairs apparently back in the 60s or 70s and stored in these polystyrene boxes. Shiny shiny!...

Ray P wrote: ↑Mon Mar 11, 2024 7:32 pm Warmer weather is on the way Mike, soon be working on your geranium amplifier...

As usual, the last few days I've been down a different rabbit hole...

Just a couple of thought, you are never going to be able to use much in the way of negative feedback in that amp (at least by comparison with a modern direct coupled circuit. That interstage is going to add so much group delay and general phase shifting nastyness that the most you can manage is PP ...

andrew Ivimey wrote: ↑Sat Mar 09, 2024 7:32 am PNP oc35s ( never heard of them) I always thought oc28s were the swanky ones!

I'd like to hear them.

And these are ex-RAF military ones, so even swankier.

I concur with Nick.

I even use 100k pots on transistor amp front-ends (with large value bias resistors for the first stage) just in case the source clutches its pearl necklace and faints if presented with anything much lower

Nice Steve. Does aluminium work-harden at all or can it be bent "in one"? It does work harden so you probably have only the one chance to get it right. Steel is more forgiving but harder to get moving in the first place. Copper would be a brilliant option for bending. My experience has be...

I always assume a unexpected short term power outage could happen, so I either make sure that the startup control is automatic, or not needed. I had exactly one of these yesterday - Western Power have been 'fiddling about' with the underground network over the road for weeks, but this was the first...

Germanium Amp Revisited This below ... wow it's now 12 years old! 12 years ago I made this... - Germanium Amp 2024-01.jpg - It's been to Owston a couple of times and got at least one or two favourable comments as I remember. However it always had a few issues. I was looking at it again recently (for...

Re the PSU, wow what a story.

I like it!

andrew Ivimey wrote: ↑Thu Feb 29, 2024 9:00 pm Yep but worth it!

It's giving me lots of pies to scoff, if that's what you mean.

simon wrote: ↑Wed Feb 28, 2024 8:13 am Hey, it wasn't obvious on my phone! Honest! And my attention was drawn to Dave's tidy manicure which appeared to me to be pointing at the two soldered joints!

Sorry, that was me seeing it for the first time as well, after you.

Not a criticism.