The Newton 300B

[Thermionic Idler]

This amp which you may have seen ended up similar https://www.diyaudio.com/community/thre ... ll.271081/

Unsurprisingly, it seems a great idea to me to drive the finals balanced from a Tx.

It's an interesting thread.

Cheers,
Stephen

Thanks for posting that Stephen, that's a good point of reference, especially with Lynn Olson's contributions.

I have about 440 or so volts of B+ to play with on the input and driver stages, it occurred to me looking at the first 'option 2' circuit that with suitably deployed CCS's I might have enough B+ there to direct couple the first two stages, and do away with caps in the signal path completely. I haven't yet read deeply enough into the thread to find out which option they ended up with in the end though.

EDIT - I see they went with cap-coupling in the end. I'm aware that direct coupling brings its own issues, especially in push-pull circuits.

[Thermionic Idler]

Decided to plug in the JJ 6V6S tubes this afternoon to give them a try - I got them as a platinum matched quad from Karltone. First thing I noticed was the complete absence of short periods of hum on warmup, suggesting they are all coming up to temperature in perfect sync.

And the sound... is fine, on first impressions. It hasn't had the life sucked out of it like it seemed with those Russian-made ones. I'm going to let them bed in for a bit before giving them a serious listen, but it certainly doesn't seem to have gone backwards from the Tung Sols, if anything it's a little more 'fleshed out'.

If I only have to deal with NOS for the 12SN7, then I'm a happy camper.