Who has tube-rolled Audio Note amps?

Does anyone know what series/years I should be looking for of the Amperex Holland 12AX7 / ECC83 NOS tubes that Steve recommended?
There seems to be a fair variation out there.

For example:

1958 Amperex Bugle Boy treble clef logo 12ax7 tubes with long gray plates and the foil strip D getter
Amperex/Philips 12AX7 ECC83 NOS pair from 1964 aka Bugle Boy
Amperex Bugleboy 12AX7 or ECC83 vacuum tubes. Heerlen, Holland delta factory codes and both dated mid 1960s. Beautiful Bugle Boy cartoon tube logos.
Etc., etc.,

I have no clue which ones are the "sought after" models, dates, years.

Any help appreciated. Thanks in advance!

 

Have you looked at Brent Jessie’s site? He has good descriptions, and the prices reflect the age and scarcity, but he also discusses the sonics. You should call him and let him give you some guidance based on where you are plugging them in. I think ’50s is going to be the sweet spot, but price is going to pivot on if you need matched pairs. With the auto-bias feature, this may or may not be a big issue.

http://www.audiotubes.com/12ax7.htm

 

Awesome. Thanks!

 

You don't bias signal tubes.

 

Right, but even his power tubes are self-biasing, and I have no idea if AudioNote likes matched pairs in various positions. If I recall, that amp may take three of a kind. I have a 12AX7 for my balanced input. It does not need to be matched to the other two. Thought I would send him to someone who knows.

 

The newest Oto Line SE takes two 12AX7s in the pre, and four EL84s in the power stage. I'm guessing a matched pair of 12AX7s and a matched quad of '84s?

 

That is what I would do. Brent does great matching, and has several levels depending on where they are used. I always feel like I like everything to be running close to the same even if the circuits can compensate for a mismatch. I think you'll be very surprised at the difference, but it may take a while to figure what you like best. I generally find myself wanting everything.

 

Regarding the 12AX7's, you'll probably notice a bigger difference between brands, than having really tightly matched sections. Having tightly matched EL84 pairs for each channel is important for a parallel SE amp thou.

jeff

 

I see an Oto up on ebay at the moment.

 

They don't come up often. An Oto SE Signature was on the 'gon for about two hours before it was sold.

 

1,500 bucks. What I need at the moment is my phono preamp back from Micheal Yee. He is working on a redisign with Wima Caps, and my unit is the Frankenstien. I've been two weeks without a turntable, but I am also working night and day on a lovely Helen Frankenthaler book, so no complaints. I would happily audition the Oto, but I believe those who say that to best the M88, you would need to spend more than $5,000 £. So very happy with my current arrangement. Ready to give this Beatles Mono Box a spin, as it is mocking me from the corner.

 

Can anybody comment on tube rolling a phono stage?

The Audio Note UK M1 RIAA I have on order has two tubes; an ECC88 dual-triode and a ECC83 dual-triode.

I'm looking at Amperex tubes for this unit once it's broken in, but I'm unsure how the unit utilizes each tube and what particular qualities I should be looking for in tubes for a phono stage that would differ from my amp's linestage?

 

Well, there is a level of complexity beyond which the number of variables becomes magic. Tubes in circuits can tend to roll off frequency response, or even emphasize certain ranges, or dry out certain ranges. Think of it in terms of upstream. Maybe you want a more balanced signal going into your amplification, which may then color that signal. It might pay to leave the manufacturers tube in place in the phono stage and find a final solution for your integrated before fooling around with upstream tubes. IDK that there is a right way, but if you are changing the source and amplification at the same time, your ability to make judgements becomes doubly subjective.

 

This is a great point, and it makes me wonder if I should wait to tube roll the amplifier until I've sorted the phono stage first?
ie; tube roll closest to source first?

 

Maybe. A methodical approach is probably going to give you the most confidence. If you modify the source first, you sort of don’t know clearly what those modifications are doing, particularly if a tube downstream is coloring the sound. You only know what the source tube sounds like in a particular context.

If I were you, I would invest in a few preamp tubes while you have the Sutherland in position, and assume that it is a pretty neutral source. Find the preamp tubes that give the most of what you want, then start changing in tubes in your new phono pre. In my experience, this approach works pretty well, but I always backtrack and reconfirm past failed combinations.

I have sort of a similar scenario because I can use many different power tubes. I really have to get the power tubes I like best in place before I can say which preamp tubes are the best match. I simply can't sort it out the other way.

There is an area where it gets complex enough that pretty much no one can tell you, you have to cut your own trail. It would honestly take me years to sort through three layers of tubes and come to any conclusion, not to mention what I would spend on tubes. I bet three good combinations in your preamp section is a good place to start. That seems like enough to get a glimpse of what the phono stage is doing—like bracketing exposures with a shot, you can check the highs and lows and capture the most in the way you like. Maybe that makes some sense.

 

Good advice.
"Bracketing" is a very apt term for helping to sort through/problem solve this type of issue.
Many thanks JB.

 

I found the best sounding tube to me ever. The Amperex 12ax7 BugleBoy foil D getter Long Plate from 1956. The remarkable width and breath of the sound when in the recording and the timbre and harmonics of instruments with a bass thats tight and bla, bla, bla. ^YMMV ofcourse...
Similiar to the Mullard 1956-58 Long plate square getter tubes, in fact at one time these two tubes were made by the same factory.
Telefunken and Mullards best had a child and its an Amperex foil BB. Take care John M.

 

Cracked the cover off the Oto SE today to check which tubes it shipped with, appears to have Sovetk EL84s and unbranded 12AX7 pre-amp tubes. I'll need to do something about that I think. Perhaps the Amperex 12ax7 Bugle Boy foil D getter Long Plate from 1956 to start?

 

They're probably just bulk unmarked Sovteks, but that's just a WAG on my part. Pretty hard to tell without a closeup pic.

jeff

 

Take a pic of the getters and someone will know. Some NOS are unbranded, so who knows.

 

That's as close as I could the camera without popping the tube. There's no markings on them whatsoever.
They are beautifully built amplifiers. Just a work of art IMHO.

 

I'm swapping them out soon anyway. Just contacted a guy regarding some NOS Mullards.

 

Very nice looking traffos. The Psvane 12AX7s are very nice at under $100 a pair.