TheEvan Posted January 16, 2009 Share Posted January 16, 2009 Couldn't find mine. I must've let it get away some time ago. I want to put the 299 into my system. Somthing cheap and useful? Quote Link to comment Share on other sites More sharing options...
TheEvan Posted January 16, 2009 Author Share Posted January 16, 2009 Shoot, now I'm looking at the instructions and I'm finding them just a touch hazy to my utterly non-tech mind. This is a NOS Valves rebuild. It looks like the DC bias balance adjust pots are back by the transformers. Then the DC bias voltage pots are on the back to the right of the speaker lead blocks. If I'm right so far, then what are those 2 pots closer to the preamp tubes? Quote Link to comment Share on other sites More sharing options...
Guest " " Posted January 16, 2009 Share Posted January 16, 2009 " If I'm right so far, then what are those 2 pots closer to the preamp tubes?" Email NOSValves to be sure....but trim pots in the pre-amp circut, espeacially in the driver stage is a hum pot. A hum pot fine tunes the signal betwen both sides of a PP amplifer to adjust cancellation of hum. You normally would never ever want to mess with the hum pot. Quote Link to comment Share on other sites More sharing options...
russ69 Posted January 17, 2009 Share Posted January 17, 2009 Rat Shack pocket digital, cheap and good. Thanx, Russ Quote Link to comment Share on other sites More sharing options...
NOSValves Posted January 17, 2009 Share Posted January 17, 2009 " If I'm right so far, then what are those 2 pots closer to the preamp tubes?" Email NOSValves to be sure....but trim pots in the pre-amp circut, espeacially in the driver stage is a hum pot. A hum pot fine tunes the signal betwen both sides of a PP amplifer to adjust cancellation of hum. You normally would never ever want to mess with the hum pot. Well not really...... those pots are AC Balance pots to equalize the AC signal entering each output tube in the channel. There purpose is to limit distortion not hum. As far as a meter any basic modern digital multi meter should do the trick. It it can measure the voltage of a AA, AAA, C or D battery it can be used to bias the amp. Nothing fancy or expensive required. Craig Quote Link to comment Share on other sites More sharing options...
thebes Posted January 17, 2009 Share Posted January 17, 2009 Versitile, auto ranging and cheap: http://www.radioshack.com/search/index.jsp?kwCatId=&kw=22-813&origkw=22-813&sr=1 Quote Link to comment Share on other sites More sharing options...
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