audio-talk

Why not indeed. Well, the 40k ra of the first triode would need about 1000H to get a good FR.

The valve Andrew I used has a better looking small triode, but less gain.

I wonder if a CCS would improve the first triode.

I used the zener for simplicity, again trying to use valves that were currently, available, and no more than needed. The two supplies was (as you say) to avoid a RC dropper for the driver stage, and also to avoid the driver supply moving as the 300b B+ was altered.

If the master tapes are good dunno how much 'reemastering' can be done TBH, maybe reduce the noise floor further Don't think they were in that good a shape, the program on the radio talked about using modern trickery to remove things like drop out. They played a example where there was audible drop...

pre65 wrote:Thought you knew all about guitars Davey me lad ?

http://www.mavenpeal.com/sag.html

Yep, but not 10k !!!

I would also check if its actually 10k, seems a big value, but then again, it may be to help the supply sag. I would have expected the first two stages to pull about 2ma or so, so thats not much left for a class A output stage.

Its a close thing I think, the origin of the design was for someone who wanted a amp building, so I tried to use common valves, having said that I found I like the 5687 anyway. as to if its better/worst than 6em7 hard to say, I suspect I prefer the 5687 to the first triode in the 6em7. It would be a...

I am not going to be able to make the Sunday, Alex is on his way to uni on that day, so I can't not help.

It was the "Trawler" after NK clamed 6c33c had been used in Russian trawlers/spy ships/whatever.

They will get hot, running 5W resistors at 2.5W seems to stress them more than you would expect.

Are the transformers toroid?

Here is the supply I used (well, almost, couple of little tweeks)

Yep, Colin noticed the typo, I just forgot to change it, sorry.

There you go, no huge surprises.

Phil, Nick hasn't officially published the design schematics for this amp. Though I have them plus a MS Excel spreadsheet partslist. I could email these to you, but would rather wait until Nick replies to your request first. Last I was over Nick's he commented he should really update the schematics...

Possibly, what does the getter look like?

How are the voltages around it, I would expect grid current if its starting to get gassy.