You'd be trading a slightly faster tube burn-out, for slightly greater dynamics.
A question of bias for new tube set
Something seemed a bit off with my system so i checked the temperatures of the EL34 power tubes on my Cary Audio Six pacs with a pyrometer and found all the tubes reading a temperature around 360 deg F +/- but one. The errant tube was reading around 175 deg F. Checked the bias on each mono block and found that the set with the errant tube was way off the recommended bias I usually set which is 220 ma. It read 180 ma. The other mono block was operating in spec. I also noticed that with a music source, the bias readings on both mono blocks seemed to swing 10 or so ma with the music. Didn't know if this was normal or not but figured since i had a bad tube and had no idea of the age of the tube set (bought the Six Pacs used), I figured it was time for a full set replacement.
The existing tubes were Svetlana Winged C EL 34s but after some research, I decided to buy a matched set of Electro-Harmonix EL34s from Kevin Deal of Upscale Audio. According to Kevin the EH tubes were less extended in the bottom end but added some sparkle to the upper range. Since they were about half the price of other competitive tubes (I needed 12), came matched and burned in for 72 hours, I figured I'd give them a try.
Swapped them out and set the bias to the Cary recommended 210-230 ma (I chose 220 ma). Noticed a few things. First, the bias with music was now rock steady at the 220 ma setting on each monoblock. And Kevin was spot on in his description of tube sound. However, each of the tubes came marked with specs including bias which were all within a tenth of 41.6 ma. That would equate to a bias setting of 246+ ma on each Six Pac. So my question is, should I stick with the Cary recommended bias of 210-230 ma or crank it to 245 ma?
Comments appreciated,
J.Chip
The existing tubes were Svetlana Winged C EL 34s but after some research, I decided to buy a matched set of Electro-Harmonix EL34s from Kevin Deal of Upscale Audio. According to Kevin the EH tubes were less extended in the bottom end but added some sparkle to the upper range. Since they were about half the price of other competitive tubes (I needed 12), came matched and burned in for 72 hours, I figured I'd give them a try.
Swapped them out and set the bias to the Cary recommended 210-230 ma (I chose 220 ma). Noticed a few things. First, the bias with music was now rock steady at the 220 ma setting on each monoblock. And Kevin was spot on in his description of tube sound. However, each of the tubes came marked with specs including bias which were all within a tenth of 41.6 ma. That would equate to a bias setting of 246+ ma on each Six Pac. So my question is, should I stick with the Cary recommended bias of 210-230 ma or crank it to 245 ma?
Comments appreciated,
J.Chip
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- 12 posts total
I own the last run of AES Six Pacs. The choke is moved from the center to the side, and a pair of small smoothing caps are added to the power supply. After that the Hexfreds, Jupiter Copper foil caps,and silver wire (take your pick). I run them at 210-220, if I'm pushing the amps. I go to 240-50 for late night listening, and low volume, kind of a winter time setting. But when I blast (hard with Six Pacs) 210-20 mA EH valves are close to Ruby in SQ, and a LOT more dynamic, than a Golden Lyon, by far. Because I don't use valve amps for bass duty, I prefer a better Mid Bass, Dynamic (almost bloated) mids and silky smooth highs. EH GREENs are a great valve. Still not quite as freakishly GREAT as Ruby Valves and Cary products. I don't know why.. But for some reason they outperform all of the EL34 stuff. In their, V12s V12i and V12R, ALL just sound better with, Ruby, or EH, valves. Really not the most expensive valves out there. PSVANE That's next on the list of try outs and power valves, $$$$ though. Sure make a good signal valve, 12AX7, 12AU7. Regards |
These sound way better than any EL34 IMO Genalex Gold Lion KT77 Power Tubes They are worth the money and are a sub for EL34 but BETTER !! Explanation at the link below https://www.tubesforamps.com/el34-6ca7-kt77-differences Where to buy Quad Matched https://www.sweetwater.com/store/detail/GENKT77QM--genalex-gold-lion-kt77-power-tubes-matched-quarte... |
- 12 posts total