Your favorite 12AX7 and 12AU7 Pre Amp tubes and why?

My 12AU7s are 12BH7s and my 12AX7s are RCA triple mica black plate 5751s :D

That being said, there are lots of 12AU7s one can try for little money. Used vintage ones can be bought online for under $10 plus shipping all day. RCA black plates, RCA cleartops, Sylvania gray plates.

Ditto 12AX7s, but expect to start for $25/pair for them.
 
Who made Motorola 12AX7s (Made in U.S.A) label?

They were the ones that worked best and sounded best as drivers/phase inverters in my previous tube amp. Tried Mullards, Teles, and some others. The Motorolas always went back in.

In the Grounded Grid pre (12AU7s) I think I settled on a Clear Top in V3 and a pair of Raytheon black plates in V1 and V2.
 
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I finally decided to go with a matched set each 12AX&-12AU7 of the Genalex Gold Lion Gold Pins after speaking to a few guys familiar with my Pre.

I just ordered them and have to wait til next week sometime to get them in and warm.

I didn't want o buy and be unhappy, yet wanted the best bang for the buck so I am hoping these are it for a while.

I did find at least 1 of the AU7s singing that stops after a finger flick and loud pop, but comes back.
 
I've never bought new tubes....

Having picked up lots of consoles over the years...had vintage tubes to play with.

Don't know a lot about tubes.....but, for the 12ax7....have Telefunken, RCA black smooth long plates...magnavox....BugleBoys....

But the sweetest sounding to me are a pair of Webcor branded Mullard short plates....they sound great. Probably from around 1962. :music:
 
West German Amperex 12ax7 give lots of detail and a wide, deep soundstage. Sylvania 12au7's overall clean and smooth.
 
12ax7- Raytheon jrp-12ax7 long blackplate... tungsol long greyplate d getter... cbs 7025 long greyplate d getter, cbs 7729, RCA 7025 longplate d getter.

12au7- Raytheon or cbs 5814 two mica blackplate, Raytheon or cbs 7730, cbs 7318, amperex Holland longplate d getter 7316, valvo hamburg longplate d getter foil strip, siemens silverplate 12au7 or three mica 5814a.

take your pick and be amazed...
 
Just picked up "new" integrated mono amp that uses 12AX7 ... first one in the collection. Had a hodge podge of old tubes that didn't sound bad, but decided to try some new production. The amp is a "Williamson" circuit and very sensitive to noise, and spiral wound tubes are highly suggested. I went with a Sovtek 12AX7LPS for the phono section and a pair of TAD 7025WA's as drivers. Nice, tight, and mellow, and they ain't even broke in yet! Very nice for the price! :thmbsp:
 
Did a lot of rolling before I settled on vintage Mullard Blackburn 12AU7 and 12AX7 with date codes back the early 60's on my CJ equipment. All microphonics dissappeared with a comforting silent black background.
 
It really depends on the equipment: how the attributes of a particular tube compliment the circuit design.
 
Actually I'll go one even further and say that over the course of the last 16 years of researching tube factories - as more often then not, most tube companies had on an average 2 - 5 different ones producing tubes and some were much much better then others as far as resolution and fidelity goes.

I'm more inclined to say one should learn how to combine said factories as a collective means of voicing ones tube components - as I'm very very very fond of the following combination of signal tubes on my main tube integrated, I can only state what works for me, so here goes.

[1]

NEC ( Japanese Grey Long Plates NOS 1950|59 ) 12AX7|ECC83 or Tungsram ( Hungarian NOS 1953 Silver Plate ) or CSF - Thompson 12AX7|ECC83 ( Grey Plate NOS 1960|67 France ) x 2 as Phase-Splitters.

[2]
Along side a single NEC 12AX7|ECC83 or TEN Kobe 5715 ( Japanese tubes ) as Preamp Tube.

[3]
And these combined with either Mazda 12AU7|ECC82 ( Grey Plates - Solid Box Plate NOS 1956|62 France ) or Siemens 12AU7|ECC82 ( Silver|Chrome Plate Germany ) x2 as Input Tubes.

All of these are of course voiced to be used along side a Quad of Telam|Polam EL84s ( Warsaw | Poland NOS 1960|68 ) in which again, I must stress is about how said combination of tubes are used together to create an end result that suits ones ears|system|senses correctly.

And said combinations bring out the very best in multiple genres of music and are extremely well matched for highlighting the best in vocal based music, as well as allowing me to dig even deeper into instrumental type recording and allowing every strand of the notes to be rendered in a manner to which I find very addictive, so much so that I tend to hoard only these tubes that to my ears|senses have taken me to that magical point in life where I no longer think about pursuing different components just for the sake of change, and am quite content where I'm at system wise.

Odd changes are, but I'm going to throw one at some of you whom mightn't have thought of this before - but combine say a Telefunken 12AX7 ( Flat Plate - not Smooth Plate ) with a pair of Sylvania 12AU7 ( Long Black Plate - Square Bent Getter NOS 1952|57 ) and tell me what you think of said tandem?. I think you're in for quite a surprise, but as with most items in our shared hobby, it's all subjective.

But give it a shot none the less.

Happy Rolling.
o_O scar
 
My favorites are RCA black plate for 12ax7 and RCA clear top long grey plates for 12au7. Mainly because they're rock solid and still very affordable.
 
I have the VAC Standard LE with the tube compliment - 2 12AU7s, 2 12AX7s. The best tubes I've found are NOS Mullard CV4003 and CV4004 tubes from Upscale Audio.


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My all time favs are Amperex BB made in Holland...hands down. Alos like the Raytheon 12AX7 with the long shiny black plates. Lots of them labeled for Baldwin for use in organs. Great for guitar amps but a bit grainy for audio. For 12AU7s I have to say RCA clear tops...all my personal preference and nothing more.[emoji12]

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I have an ST-70 with a DIYtube board and my winning combo is tungsram E80CC tubes and a Siemens 12ax7 or Amperex BB 12ax7 mC4. Both of the front end tubes brought more bass out of this system, Probably the Amperex tubes more so. The best 12AU7 isnt a 12AU7.
 
Reading thru this thread a couple times, Im a little amazed at some of the crusty old brand names and types (and rarely used) that have been mentioned. Betcha less than 8% have been tested on a good calibrated tube tester, and "matched" even though they are pre-amp.

The notion of leaking NOS is almost a moot point anymore.

At a minimum, Genelex Gold Lion.

Just because they are (or were) made in Russia does not say anything about the condition/quality of the specific in-hand tubes mentioned.
 
Reading thru this thread a couple times, Im a little amazed at some of the crusty old brand names and types (and rarely used) that have been mentioned. Betcha less than 8% have been tested on a good calibrated tube tester, and "matched" even though they are pre-amp.

The notion of leaking NOS is almost a moot point anymore.

At a minimum, Genelex Gold Lion.

Just because they are (or were) made in Russia does not say anything about the condition/quality of the specific in-hand tubes mentioned.

If 2 tubes measure the same on an un-calibrated tester, don't they match?
 
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