Carvin V3 Bias Video

This video is of a Carvin V3 Which shows how to bias the amp using a bias probe and also shows the Carvin method of measuring across the standby switch. Both these methods work exactly the same for the Carvin MTS, Legacy and Valvemaster. All of these amps including this particular V3 run right at 455 to 470 plate volts so the settings given in the video apply to them all for 6L6GC's, EL34's, E34L's, 6CA7's and the JJ KT77's. The Carvin Belair and Nomad amps are very similar and you can use the standby method and set them between 75 to 95 milliamps. We have had more questions on these so I though I would go into a little more detail. They will be close to exiting crossover distortion at 70mA and most players find they like them between 80 to 95 or if you like to brown them out a little you can run them as high as 100mA but you will shorten the tube life a bit. A note for you V3 players on bias: There have been issues with the V3 when running the bias at proper levels using EL34 type tubes. We first noticed this with one particular V3 back in April of 2008. Carvin recommends biasing all of their 100 watters at 100mA across the standby switch which is extremely cold and less than 25mA per tube, which is way into crossover distortion. To get the tubes where they should be, we recommend biasing between 150 to 180mA. What we have encountered with the V3 is that it will start to oscillate at about 120mA to 130mA which is still cold. this oscillation almost sounds like a heart beat or "motor boat" sound that you would hear from a bad cap. We have NOT encountered this phenomenon with all V3's, but we have run into several that have the problem. It does not seem to happen when running 6L6GC's but any type of EL34 tube including the JJ E34L's and KT77's. We do not yet know what is causing it. The only cure so far seems to be running the amp at lower bias settings which is too bad, because when biased properly these amps sound far superior. 03/07/12 Update: We believe that Carvin has addressed the motor-boating issue at proper bias levels! The complaints have dwindled down now and customers with newer V3's have reported no issues. Thanks Carvin!