Joe's Pye R33.

[Yorkie]

I'm probably stating the obvious Joe, but have you tried any substitute valves?

[Joe]

No, David, but after checking I see that my Little Maestro has a UCH81 and a UCH83, though I'm sure the latter is fine. Obviously the filaments are OK and I can megger the UBF89 for H-K shorts.

My money is still on a dodgy connection somewhere, or possibly one of those resistor-like capacitors has failed without going bang.

I've been otherwise distracted for the last few days so hopefully I'll be able to concentrate on it better soon.

It's certainly grown on me stylistically and before it went off was sounding very nice through the Roberts speaker. The charms of PCBs still elude me though.

- Joe

[Joe]

Thanks, David. I tried the Little Maestro's UCH81 and it's working. I've even got a spare as I was given one in an attempt to sort that set out.

The next issue is the speaker.

Thanks for the help everybody

- Joe

[Joe]

I had it on for over an hour during which it played fine while I was fiddling with the speaker.

I've greatly improved it by bending the frame a bit but the Roberts one is still better, though it's probably a better quality one.

I'd be interested to hear what Alan thinks re the shrillness if he tries his through a different speaker when he's next working on it.

- Joe

[AlanBeckett]

Joe,

Unfortunately I'm not in a position to try mine at the moment.
I'll report when I get to it.

Alan

[Joe]

I got a 3W 330Ω resistor yesterday which means that bit is now properly finished.

This morning I added a tone control, mainly out of interest. Getting rid of the excess top has revealed that the speaker is still a bit distorted so hopefully I'll be able to find something on Sunday.

   

- Joe

[Yorkie]

I'm sure it must be the speaker Joe - my R33 sounds fine, as does the one that I fettled up for my son. I thought that from a design point of view, they did well to get a decent sized elliptical speaker into a small cabinet. Larger in fact than many TV speakers! If you don't see a suitable speaker at the GF Swapmeeet, you're almost certain to see plenty of scrapper sets for a couple of sovs that you could cannibalise, but I always fail miserably in that department and end up wanting to fully restore the donor set rather than pulling it to bits:-/

[Joe]

I thinks it's a bit of both. It sounds fine through the Roberts speaker but through the ten inch Richard Allen one it was setting my teeth on edge.

It will certainly be interesting to see and putting the tone control on was as much a bit of fun as anything and it's a completely reversible mod as it's fixed to pre-existing holes.

I know just what you mean about wanting to fix things you've got for parts.

- Joe

[Mark R]

Joe
what resistance speakers are you using?
It should only be 3ohms or so.

cheers Mark

[Joe]

All three are 3Ω.

Through the big speaker with the tone trimmed it sounds fantastic - as good as anything I've got.

- Joe