Monckyman Posted November 27, 2011 Share Posted November 27, 2011 Helo all. I just stumbled over an Ampeg SVP pro at a greta price so snagged it unseen or heard via a freind. I just got it home today and gave it a test. Initially it was appalling, scratchy pots etc, not bothered about that, I can clean them up. What got me was a very poor tone,almost no gain and the red peak light coming on in my opinion, too early. There was also a quite obvious earth buzz that remained regardless of master out volume. So having read a good few posts on here and TB I`m thinking Valves. I whipped out the sonic screwdriver and removed the lid and had a look at the valves. I took them all out, after noting their positions, and makes and then stuck them back in and took a pic. They are V1 Electro-Harmonix ax7, V2 Sovtek ax7,V3 Sovtek ax7,V4 no name au7,V5 Electro Harmonix ax7. Anyway, valves 2 and 4 are to my eyes visibly dim and nowhere near as bright as the Sovteks. I swapped a bright sovtek into V2 position and the EH into V1 and the EH valve remained dim and the Sov stayed bright. Here`s a pic. Am I correct in thinking these two badly illuminated valves are in need of replacement? Regarding sound, it actually sounded pretty good once I got a bright valve into V1 and I left the valves as you see in the pic as Sov>EH(dim)>Sov>Aux(dim)>EH The drive pot doesn`t seem to do anything which makes sense if that dim valve is where the pot gets routed. Ta in advance. MM Quote Link to comment Share on other sites More sharing options...
Mr. Foxen Posted November 28, 2011 Share Posted November 28, 2011 The glow won't tell you much. Just means more or less of the heater filament is covered by other components. Easy way is get some more valves and swap about. Quote Link to comment Share on other sites More sharing options...
Monckyman Posted November 28, 2011 Author Share Posted November 28, 2011 Ta for the reply Mr F, I`ve ordered a couple so I can swap them out. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.