Ampeg SVT not working at all.

bexkex · #1 07-04-2011, 06:36 PM

hey everyone,

my Ampeg SVT-CL head has been on a hiatus for the past 1-2 years now and I bought a cheap Ashdown head to cover it while saving money for repairs/tubes etc.

Does anyone recognize a problem where the amp just does not work? I turn it on, there is no sound and then in a couple of seconds the power-lights start flickering in red and green. I havent got any help with this at the shops and I was wondering if anyone has faced the new problem?

I always wondered if the fan on the inside broke down or is this just another case of tube-repair? It has gone through some really ****** mixes at the shops that rarely have the rightly paired sets of power tubes etc. etc. etc.

help me out here
- bergur

**B-string** · #2 07-04-2011, 07:58 PM

Output tubes or bias fault detect circuit. First two possibilities that come to mind.
Is Jerrold Tiers still around these parts?

Jerrold Tiers · #3 07-04-2011, 09:40 PM

if it was working when it was put away, probably just bad contacts , maybe a broken solder.

Try pulling each tube and re-seating it. Use contact cleaner if you have it.

A tech might do the same to the various internal connectors.

**B-string** · #4 07-04-2011, 10:23 PM

I think it was sent to pasture due to being dead?

okcrum · #5 07-05-2011, 01:49 AM

Well, according to the manual that's the indication for a bad power tube. OP, you can download the manual in .pdf form from Ampeg.

micahturner · #6 07-05-2011, 01:38 PM

I had a plate resistor go out on mine, which caused problems similar to those that you are experiencing.

bexkex · #7 07-12-2011, 04:26 PM

Alright, thanks for the help.

Ive ordered a pack of tubes which will be here in about a week or so.

I think thats the problem, I took to a repair guy a couple of times about a year ago - and since the shops never had a decent matched set of tubes he kept mixing used ones forcing them and tuning them to "work", but never for a very long time. This is probably the problem with the amp as it is...

Is it worth the try to put a new set into it with the "bias" set "off" (no lights) and then slowly working it back up? is that a decent way of retubing after a long hiatus like this?