What about a pair of Tele CCAs? They might be the best answer to quiet among NOS tubes, not to mention best sounding. That's also one I've been considering.
One of my former writers who occassionally frequents WBF, had replaced all ten 6922s in his ART with CCAs. Now that's a sxxtload of money! Othewise it would set you back about $550 for a pair of CCAs.
So is EAT actually manufacturing their own 6922 or are they just chasing NOS tubes and reselling them? Their website only shows the KT-88 and the 300B.
So is EAT actually manufacturing their own 6922 or are they just chasing NOS tubes and reselling them? Their website only shows the KT-88 and the 300B.
AFAIK these are new tubes, not like the old Gold Aero that were relabeled and tested current tubes sometimes amazing sounding and sometimes garbage. Their GA 5751 were something to drool over. Think they were the old RCA windmill getters. For a while the GA 12AX7s were relabeled and pretty good sounding Siemens. Then they switched to Chinese junk 12AX7s.
I thought I read that they were initially rebranded 6922 tubes but they were supposed to start manufacturing their own. They don't show them on their website.
I have to admit...with a NOS tube, break-in time must be a weird one to try to figure out. The thing is 40-60 years old and has an unknown history of use in truth. I have not found a dramatic break-in period in my GAT with either pair of Mullards. I also do not recall a massive change with the Amperexes. The only thing I do notice is that they sometimes start out super quiet, get a bit noisy in the first 30 hours and then quiet down again after about 100...but I am told this can be more about an old tube with teeny bits of sediment. as per Brent jessee...I take the tube out...tap gently on the rack and replace...and the occasional crackle is gone. And again after 50-100 hours I don't hear it again for about 12-18 months or so when sometimes the tube starts to just get noisy.
I have to admit...with a NOS tube, break-in time must be a weird one to try to figure out. The thing is 40-60 years old and has an unknown history of use in truth. I have not found a dramatic break-in period in my GAT with either pair of Mullards. I also do not recall a massive change with the Amperexes. The only thing I do notice is that they sometimes start out super quiet, get a bit noisy in the first 30 hours and then quiet down again after about 100...but I am told this can be more about an old tube with teeny bits of sediment. as per Brent jessee...I take the tube out...tap gently on the rack and replace...and the occasional crackle is gone. And again after 50-100 hours I don't hear it again for about 12-18 months or so when sometimes the tube starts to just get noisy.
Lee-Those two sentences don't jive unless you are trying to say there is no such thing as NOS. As far as "sediment," I think what you mean to say is a small amount of residual gas that gets absorbed by the getter(s) as the tube burns in.
Lee-Those two sentences don't jive unless you are trying to say there is no such thing as NOS. As far as "sediment," I think what you mean to say is a small amount of residual gas that gets absorbed by the getter(s) as the tube burns in.
I don't think they are in conflict at all. A New Old Stock tube is literally an oxymoron...a 'new' product that is 60 years old...which for the most part has been sourced from various locations where it is unlikely anyone can truly vouch it was NEVER used, not even for 10 hours. The guys who probably built these tubes and stored stored them originally could well have either retired and/or passed away in a number of cases.
The getter only absorbs residual gas at the moment it was evaporated. Usually tube burn-in in mostly due to cathode stabilization by electron emission - small micro whiskers and other micro defects that create an high electrical electrical field and emit spurious electrons resulting in noise sometimes disappear during burn-in. I have built a small tester - basically a simple one triode preamplifier for signal tubes coupled to a spectral analyzer - and the results of burn-in are sometimes very clear in the graphs.
Ralph Karsteen of Atmasphere advises us to "cook" the cathode of the tube without anode voltage in order to carry burn-in of power tubes.
The getter only absorbs residual gas at the moment it was evaporated. Usually tube burn-in in mostly due to cathode stabilization by electron emission - small micro whiskers and other micro defects that create an high electrical electrical field and emit spurious electrons resulting in noise sometimes disappear during burn-in. I have built a small tester - basically a simple one triode preamplifier for signal tubes coupled to a spectral analyzer - and the results of burn-in are sometimes very clear in the graphs.
Ralph Karsteen of Atmasphere advises us to "cook" the cathode of the tube without anode voltage in order to carry burn-in of power tubes.
Fransisco-To my knowledge, the getter(s) continue to absorb impurities from the metals as they out-gas over time until the getters are used up. When tubes are new, the getters are large and shiny and over time they deteriorate, change colors, and eventually shrink in size until there is nothing much left of them.
I also have CJ GAT and Lamm M2.2 both of which employ 6922. I never had a chance to try EAT but went through several NOS including Blackburn Mullard, Siemens CCa, Gold Aero 7308, Mazda, Amperex Pinched waist, both US and Holland etc. Personally my order of preference would be Holland Pinched waist 6922, US pinched waist then Siemens CCa. However, I wonder if anyone had a chance to compare EAT 6922 to either Amperex pinched waist or CCa at all?
I also have CJ GAT and Lamm M2.2 both of which employ 6922. I never had a chance to try EAT but went through several NOS including Blackburn Mullard, Siemens CCa, Gold Aero 7308, Mazda, Amperex Pinched waist, both US and Holland etc. Personally my order of preference would be Holland Pinched waist 6922, US pinched waist then Siemens CCa. However, I wonder if anyone had a chance to compare EAT 6922 to either Amperex pinched waist or CCa at all?
No but just ordered a pair of EATs. Music-Hall is temporarily out but should have them soon.
Did you ever try Teles? I have a pair of ECC 188cc/7308 sitting here too. Another would have been. Tele CCA. I think I would have also tried the Mullard E188cc/7308s too. Siemens always seemed a bit too lean for my tastes.
No but just ordered a pair of EATs. Music-Hall is temporarily out but should have them soon.
Did you ever try Teles? I have a pair of ECC 188cc/7308 sitting here too. Another would have been. Tele CCA. I think I would have also tried the Mullard E188cc/7308s too. Siemens always seemed a bit too lean for my tastes.
I did try some Tele 6922 but not CCa. As a whole, I also thought that Tele is also on the lean side, well extended at top and bottom end, every good clean detail but the midrange leaves me a bit cold. Kind of along Siemens sound but Siemens is a tad more full body in the midrange but yes, it is still on the lean side in comparison to Amperex. Don't remember the specific of tele that I tried though. I just got a whole bunch of 6922s from friends who collects lots and lots of tubes and he kept telling me short plate this, long plate that, ribbed something, halo getter, D-getter that etc etc. One of these days, I need to learn all of these stuffs!
PS just gave my friend a call, it was Tele 6DJ8 and Blackburn Mullard, gold pins O-getter that I have.
No but just ordered a pair of EATs. Music-Hall is temporarily out but should have them soon.
Did you ever try Teles? I have a pair of ECC 188cc/7308 sitting here too. Another would have been. Tele CCA. I think I would have also tried the Mullard E188cc/7308s too. Siemens always seemed a bit too lean for my tastes.
