Another 12AU7 / ECC82 Tube recomendation needed

Yes, that's why he charges a premium price.
After measuring them, the dealer noise-tests by inserting the valve into a headphone amp with high gain and listening. He'll tap on the valve to check for microphonics, any ringing and the tube is no good. Not every dealer is set up to do this.

 

An ordinary 12AU7 RCA is very inexpensive over here, mil-spec cost a bit more.

 

That must be a pain in the ass to test every tube like that, i have watched some of kevins videos and thought he knows his stuff

 

Yeah, he really knows valves. Always sells the highest quality because he knows where to find them and then does his noise testing procedure.
I usually buy from Brent Jessee who has a larger inventory and best of all, he gives a trial period and accepts returns. I once went through 3 or 4 sets of tubes until I found what I liked.

 

If Brent tests the returned valve and it no longer tests as new, then you only get a partial refund. But it works for me since I'm a tube roller. It's become an addiction.

 

what did you find the best tubes, it can be costly this tube rolling

 

Are you asking what are the best tubes I found?
It depends on which circuit you're using them in; amp gain stage, amp driver, preamp.
I guess the best for my taste could be the Tung Sol 12AU7 blackplate black glass. Very rare from 1950's, 60's. Transparent, good detail, dynamic with airy highs, a wide and deep soundstage. Midrange is accurate and realistic.

I love the Brimars, I have the CV4003 boxplates and the ECC82 longplates. Also CV492 which are supposed to be the same as 4003.

 

sorry, I meant pre amp tubes, I like a clear balanced sound from top to bottom, don’t like bright, hard, Boomy sounding tubes
If these Brimars sound great after 3 weeks I will be buying another matched pair or two
I do like the solid imaging these tubes provide though, the bass is slightly boomy and deep, I put that down to lack of burn in

 

A good friend of mine came across a 12au7 red tip silver plates nos. I think it could be a Siemens medical nos tube. I tested it and it reads nearly nos new. I installed it in my Eastern Electric MiniMax dac. I had a rca clear top 12au7 in there. WOW factor big time. I'm extremely lucky to have this amazing tube.

 

Does anyone know if all RCA 12AU7 "clear tops" actually have clear tops? Thanks!

 

????
Well, if the getter flash is at the bottom on a side, it´s a clear top... If it is at the top, it isn´t... There are some RCA clear tops that were not made in USA, but they are still clear tops... So... Not sure what you´re asking...

 

I got some tubes that I was told were RCA clear tops, but the tops are like all other tubes Ive seen (not clear). Then I saw a picture of an RCA clear top and it did indeed have a clear top (and the first time Ive ever seen this). So Im wondering of my RCA clear tops are really RCA clear tops.

 

The tca 12au7 clear top has a side getter. The top is so clear you can see through the top of it.

 

What Weber said, the silverish thing you usually see at the top of most tubes, is called getter flash, in a clear top, it is not at the top, that is why is clear top, the getter flash is at the side and you get to see through the top glass. Sometimes the getter flash is almost at the bottom, and it can be perceived from far as a stain. Check up this picture, chances are you got RCA´s but not clear tops.

12AU7 RCA Clear Top, Used

 

The Brimar 13D5 long plate is about as 'do it all' you can use.

 

Anyone know much about the red tip silver plates 12au7 ? Not much on the net about them. Just that they are rare.

 

I just came across another 12au7 silver plate nos tube. This one doesn't have a red tip. It has Dumont screened on it. This could be a GE made nos tube. I'm not sure about that either. Any one know anything about this tubes. This tube has the same sound quality as the red tip one a have. Both test the same on my tube tester.

 

Thanks for the link. I dont know what I was thinking before as today is the first time I noticed that I do indeed have a couple tubes with clear tops. No where on them do they say RCA, but they do look like the tube in the linked picture, except mine have "U.S.A." printed (difficult to see in pic)above the "12AU7A" logo. Thanks everyone for your help!

Next 12AU7 tube Im gonna try (thanks to MKane ) is the green Conn. I have definitely noticed differences in how tubes sound and am confident I could pick out some fairly different sounding tubes blind ABX, but others would be tough.

 

So far Ive tested 4, 12AU7 and here are my preferences which basically go from "warmest/most "tubey" sounding/least neutral" to "most neutral" sounding. Ive read people describing the RCA clear tops as warm sounding, but they sounded pretty neutral (or at least more neutral sounding than the Ei and Gold Lion) to me.
1. Gold Lion
2. Ei Yugoslavia
3. RCA Clear top (I think I just didnt notice the clear top until today)
4. Baldwin (red label)

 

Many Baldwin and Conn were made by RCA. Also other US brands.

 

Do you mean that other "U.S. organ brand" tubes were made by RCA? Or that Baldwin and Conn tubes were also made by other U.S. tube manufacturers other than RCA(I think this is what you mean, just want to make sure)? Thanks! Ive gone through Brent Jessee's list of 12AU7 and it seems rather confusing trying to figure out what is what, especially when it comes to organ tubes.

 

Yes, you've got it right. I've owned Balwin and Conn which were RCA. But other US plants also made tubes for organs. They're high quality.

 

Any thoughts on using 2 pairs of 2 different 12AU7 in a preamp that requires 4 total 12AU7(Belles VT-01)? I know the 2 pairs do different things, but I also know David Belles specd this (i.e. it comes with) with 4 of the same tube. Im a tube noob and just not sure if "mixing pairs" of tubes in a preamp that requires 4 of the same tube is ever done or is this frowned upon in tubeland? I realize in theory one wants all 4 tubes matched as closely as possible, but what about 2 pairs of different tubes where each pair is matched? Thanks!

// I just started a separate thread on this topic.

Mixing pairs of tubes in a tube preamp that requires 4 of the same

 

Interesting - so the Gold Lion is the warmest sounding, and the Baldwin the most neutral?