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Folks, been looking for a pair of 6622s, and I was offered a couple of Philips tubes, but don't know if they're real or good. They have the same Mullard codes. According to him the test results are 13000/13000 and 13100/13000 on Mercury 2000 tester. I really need your help here.
Follow Ups:
...- returned the device they were intended for (Lab12 DAC).
Now gotta find some 12au7's for my preamp ...-
.
Have Fun and Enjoy the Music
"Still Working the Problem"
It's the Luxman cl-38uc. Got it lately. It has 3x12ax7 for the phono and 5x12au7 for other purposes. I don't remember any contemporary preamps with so many 12au7's. The stock tubes are from JJ, I never liked their miniature preamp tubes. Freaking NOS prices are unbelievably high.
The 12au7 is not linear enough to use without a ton of feedback. They do fine in a cathode follower stage (buffer stage) because of all the local current feedback but as a gain stage tube....no.The 6cg7 is very linear (just like the 6sn7) and is a great replacement for the 12au7. You have to rewire heater connections on the tube socket and the heater supply has to be able to do 600ma of 6.3 volts vs the 300ma that the 12au7 draws. Otherwise a 6cg7 will be perfectly happy in a circuit designed for a 12au7, there will just be a lot less harmonic distortion.
All 5 triodes per channel (2 1/2 tubes, 5 12au7s total) are involved with gain stages. I think the power supply will have trouble with the heater current draw doubling. 3 amps vs. 1.5 amps. So the power supply would have to be modified.
I will never understand why designers use this tube in gain stages.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
Edits: 12/22/23 12/22/23
I was told that two tubes on the left are for its tone controls, so only 3 tubes involved with gain stages. The encapsulated ones are for the phono. Got it mostly for the tone controls, and they're good. Basically it's a hybrid. No tube rectifier or voltage regulator.
I just couldn't resist
.
They look real, although the tops look a little dark(burnt) a possible indication of heavy use.
https://www.tubeampdoctor.com/en/e88cc-aka6922-bel-gold-pins/nos
BEL is the maker of your tube, they were part of the Philips/Mullard group.
I don't think so...
BEL's factory was in India - and they were very proud of the fact that Philips selected them as a disaster recovery center. In fact, all their tubes have made in India stamped on them. The tubes you refer to on Tube Amp Dr's site were sold to Andreas by me.
I think the pictured tubes are legit British tubes.
if that what i see is an etched "R" in the 2nd line that tube was made by mullard/mitcham.
Appreciate your feedback. I'm just curious about their Mullard codes. I have a couple of BELs, but non of them have any codes. I gues I'll pass.
Are you just being told they have matching Mullard codes but not what they are? Knowing the actual codes would help you confirm the type, factory and date. Then you're not guessing and can make a better decision. Otherwise pass on them as you say.
Jonesy
"I know just enough to get into trouble. But not enough to get out of it."
Hey Jonesy, it's a eBay stuff that's why I'm reluctant. But the tubes definitely have those Mullard codes. I don't have a tester, so I have to take his words for it.
If they test as specified the price is pretty good compared to similar on eBay.
I haven't purchased any signal tubes off eBay for sometime though, and not familiar with the seller of the item you are looking at. Prices sure have gone up for the premium tubes.
I really like the Mullard sound in some locations. Truly as described in the description the seller has lifted off of Brent Jesse's site. They will be different than the EI "Amperex" sound tubes you mentioned you have.
I have Amperex as my preferred tube in other locations. You never know until you try.
Good luck in your quest.
Jinesy
"I know just enough to get into trouble. But not enough to get out of it."
as the seams on top of the tube is hard to fake.
First they came for the dumb-asses
And I did not speak out
Because I was not a dumb-ass
!
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