Tube Amps / Music Electronics
For current discussions, please visit Music Electronics Forum. The sunn still shines online!

ampage archive

Vintage threads from the first ten years

Search for:  Mode:  

Help with SVT-300 Power Amp

6/2/2004 6:47 AM
Help with SVT-300 Power Amp
Hi all, I have an SVT-300 rack mount power amp, which is the power section of the SVT-II. It died at a gig, and then wouldn't come out of standby (LED wouldn't go from red to green).  
I replaced the (ancient) tubes that were in it with new matched tubes, and set the bias to .072 with my DMM, but the LED on the front panel still wont change from red to green. I _am_ getting audio, which sounds pretty good, but I don't fully understand the operation of the LED and what a 'red' condition signifies when the amp is out of standby.  
I haven't cranked it up although there seems to be plenty of power, because I am scared of frying the tubes or OTs when there is an obvious fault.  
I have the schematic from the factory, which is necessary as there is no silkscreen on the PCB!  
Any suggestions for diagnosing this problem?  
James, Leicester, UK

  Page 1 of 1