Mr. Foxen

If they've lost the glow, but haven't turned white, maybe they are fine, but they aren't getting power any more, maybe a fuse somewhere. Easy enough to swap them out to check.

These things haven't been powered up for 20+ years, should be good to go. Replacing all the electros an other criticals before I even try turning it on. Been suggestions I switch out the diodes, sound like a goer, they are cheap, and apparently new ones won't need the snubber caps.

Overkill filter capacitors (modern ones are laods smaller, same value equivalents in 35mm don't even poke out the top of the clamps, I figured more is more so these are more than double value of originals, more punch or something. I'm told it is a worthwhile upgrade for my purpose, of bass, and the guitarist I lent my Burman with overkill filter caps in was loving it, so think it should be happy.

Because the thread is about valve heads.

[quote name='Toasted' post='1271208' date='Jun 16 2011, 11:17 AM']How many of these do you have? [/quote] Nine SC120, although at least one has had the preamp gutted out of it and replaced. That one and another are with a tech I trust. Am fairly tempted to use many of them at once when they are working. Not sure all of them are going to be recoverable. Edit: typos

Wow, never seen three before. Good effort.

[quote name='Slipperydick' post='1271097' date='Jun 16 2011, 10:05 AM']Eddie Current... What a great name for a 50s Rock n Roll singer ![/quote] Eddie current and the vorticies.

Are you mixing your speaker nerds there?

[quote name='Big_Stu' post='1270009' date='Jun 15 2011, 01:10 PM']I take it this was a dry scourer? If not you're a braver man than I, not saying it's wrong - but I'd be scared of switching it on ever again. I also read that the rust on the tranny's assists them in some way, can't remember the details.[/quote] [quote]Step one, after selecting one that looked basically complete, was give it a wash. Damp scourer sponge and some washing up liquid for the tolex, and the top bit of the chassis. Nothing is gonna be passing current soon, so a bit of moist in there is going to do no harm.[/quote] Partridges are varnished anyway, it is a moist sponge rather than a dripping wet one. The 'theory' of the rust is the insulating oxide layer between the laminations breaks up eddy currents in the magnetic flux, but I have no idea if that is snake oil or not.

[quote name='Slipperydick' post='1269534' date='Jun 15 2011, 01:14 AM']Not an amp I'm familiar with, but tbh anything with ECC83s in,I'd swap the anode load resistors - all of em, theyre cheap enough and it often makes a huge difference.[/quote] Care to explain more?

[quote name='4-string-thing' post='1269424' date='Jun 14 2011, 11:23 PM']Welcome to the worlds best bass amp owners club! I have the same 220/402 rig and it does sound brilliant with almost any bass (but especially a Fender P) The 220 is rated at 125w into 4 ohms or 170 into 2 ohms, though the later ones were rated a bit higher I believe. They do sound brilliant, but are probably not as versatile as modern amps and are quite a bit bulkier and heavier! I bought my 220 new in 1980 and have only just retired it from gigging, it's never broken except for blowing a fuse once after it had been stored in a garage for a couple of months. If you do sell, there will no doubt be a few takers on here.... Out of interest Oli, did you get that 120 working yet?[/quote] Not done anything with it. Dunno much about SS stuff with PCBs, and the tech I had lined up for the work has gone AWOL.

Make sure there is an ECC81 in the phase inverter slot, loads seem to have 83s in there which make them really gainy and up the noise floor a lot. If it is unmolested, replacing the electrolytics will be the main thing to do. I've sent a list to a electronics parts supplier, hoping he gets back to me, and I can get a kit for you too.

All tips are appreciated. OK to copy them over to the other forums where these threads are, if I use them? Electronics stuff is most useful, I'm not super clued up.

I think venues and PA for hire people are the places to aim, rather than musicians/bassists. Less conservative.

Bit of an update because I had some thoughts whilst wandering around town today. Firstly, pipe cleaners for cleaning valve base sockets, dippe in meths, they came out grubby so I'm gonna assume it works: Still too big for pre valve sockets though. Second, I bought a can of this stuff for shining up car interiors. Seems to make things blacker and shinier, but means any dirt stuck in the basketweave shows up more. Should probably take a brush to it if I seriously gave a flying one: Actually, now I see it next to the original photos, it makes a fair bit of difference.

I'd be interested in the cabinet, and maybe the head, although I'm kind fo sorted for heads currently. I have a bit of an Acoustic fetish because my bass teacher used to talk about them a lot.