Transformer Failure on Classic 30??

[tubeswell]

Does anyone know if they make a modded or upgrade board or kit for these amps that might fix my troubles and make it better at same time??

Well PV have a 'custom shop' concept but I don't quite think they have got to that stage yet.

The best collection of PV C30 mods to date are on www.blueguitar.org - IMHO the tone stack mod is the best one - followed by the cathode bias mod. I have also done an 'SLO100 pre-amp' mod on my C30 that I came up with after discussion with Amp Kat a while back. It makes for a much-improved killer overdrive channel (at the expense of somewhat changing the tone of the clean channel).

[tsmilliner]

You definitely have my interest, I rarely use the clean side of the amp, so a little sacrifice for a better overdrive would not be a problem. I have already done a tube upgrade through Eurotubes, and a speaker swap using a greenback clone from warehouse speakers. With those mods it already nails the ACDC type tone I was looking for, and I love the tone, but there's always room for better. What does the slo100 mod give you for tone?? I play mostly ACDC style blues rock occasionally straying into a little Metallica and other old school 80's Metal stuff. Thanks.

[tsmilliner]

Of course all that depends on getting the problem fixed first. otherwise upgrades aren't even worht talking about.

[52 Bill]

Of course all that depends on getting the problem fixed first. otherwise upgrades aren't even worht talking about.

If you have access to an ohmmeter check the value of R58. I think it should be around 400 ohms. I've seen these open up from overheating and would cause the problems that you describe.

[tsmilliner]

Thanks, I will check it out. I found it in the schematic, hopefully just as easy to find on the board itself. The schematic notatres 400 so you are correct.

[tubeswell]

What does the slo100 mod give you for tone??

Something like a middy-snarly growl which is definitely better than buzzing mosquitoes. Would suit a pair or quad of 20-25W Greenbacks. The one thing I might yet further do to it is take out the 1M to ground before stage V2A (because it is just in parallel with the previous wiper, which in-fact attentuates more signal than necessary when that pot is open)

Story of the mod is here

http://music-electronics-forum.com/s...ht=c30+SLO+mod

[tsmilliner]

Thanks, to all you guys, you are all awesome.

I pulled my amp apart tonight which was a pain in the butt as I expected. Anyhow, I checked r58 and it tested fine, checked jumpers, and not one but two were broken at the board. I broke out the desoldering braid, cleaned up the eyelet and resoldered.
Buttoned amp back up, and as near as I can tell it is back to normal.

I am too whipped after all my other weekend projects to play for very long, but tomorrow will let it heat up real good and see what happens. having found what I did, I don't expect any issues.

I guess the vibration of the amp must wreak havoc on solder connects the same way it does to the tubes (Tube tamer was first upgrade).

Anyhow, now that I know a little more about that board config, I am going to look further into the mods.

Thanks again,
Peace,
Tom

[Chuck H]

Thats interesting. Since different metals can shift or warp slightly at different temperatures. Thats how most "meat thermometers" work. They use "bi metal" technology. Perhaps the componant leads would shift as the amp warmed up. Just enough that it worked when cool but then failed with temperature rise.

Chuck