12BH7A Recommendation

W9TR

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I have a McIntosh MHA 200 tube headphone amp and am looking for recommendations on the output tubes - 12BH7A. They appear to be a bit of an odd duck.
 
I have a McIntosh MHA 200 tube headphone amp and am looking for recommendations on the output tubes - 12BH7A. They appear to be a bit of an odd duck.

I found the 12BH7A's that clicked for me were

Brimar CV5042's

I'd say around $40/50 tube possibly

Bruce
 
i have a power amp that uses the 12bh7a in the driver position. the stock tubes it came with are electro-harmonix which are perfectly fine new manufacture tubes. there is also JJ electronic new manufacture tubes which i would not recommend for either sonics or quality.

i swapped out the stock tubes for some 1960s NOS 12bh7a RCA tubes and have been very happy with them. if going the NOS route, i would recommend vintage tube services -- they have quite a few brands / vintages of 12bh7a tubes and are exceedingly knowledgeable.
 
Thanks Gents,
I'll buy both of your recommendations and check out vintage tube services.

The fun part about this amp is with only 2 12AT7's and 2 12BH7A's tube rolling doesn't break the bank.
 
Nos rca.

I keep typing the above in all caps and it keeps changing it to lower case letters except for the "N."
 
I've used them as the driver in tube amps, in place of 12AU7. 1950s Sylvania shiny black oval plates w/ D or horseshoe getters were the best (neutral and incredibly dynamic with a great midrange), but then the later dark gray and grey versions of these same plates are a lot less musical. RCA's of any era are pretty consistently good, and on the warm side. The oldest RCA "winged" plates (?) from late 40's early 50s are the sweetest sounding, but hard to find, especially with low noise. Tung-Sols (shiny black oval plates like those Sylvanias) are quite good, but a bit on the bright side. I remember GE and Japanese 12BH7 as being serviceable, if not spectacular. Haven't tried any pinched plate variants.

I can't overstate how much I prefer any good 12BH7 over 12AU7, when that sub is possible. I hate that 12AU7 is so ubiquitous in 2ch audio gear. My first experience was doing this sub for the driver slots of a Heathkit W5 pair, and the difference was massive.

Some of these tubes took a HEAVY load in the gear they were used in, so you're more likely to run into dog tired 12BH7 tubes than usual for 12A*7 variants. And they're also much more problematic for slots sensitive to microphonics - same gain as the 12AU7, but with much larger plates (similar issue with vintage 6SN7). Trust your seller or be willing to take a chance. Agree Andy at VTS is great for sourcing reliable 12BH7 tubes. I also like Brent Jesse but haven't bought 12BH7 from him.
 
Thanks! Looks like the RCA’s get high marks all around and I’ll definitely look for some of the Sylvanias with black oval plates and D/Horseshoe getters. Thanks a for the detailed recommendations. This is exactly what I’m looking for.

I have no illusions of finding true NOS tubes of this vintage so seller credibility will be critical.

One of the McIntosh OEM tubes is a bit noisy so that will be a key consideration for me in this headphone amp application.
 
There were a ton of 12bh7's made as they were used in TV's.
Should not have a problem finding NOS.
The older RCA's have white letters.
 
I wanted to give an update on my MHA 200 tube journey.

My first roll was to Gold Lion (re-issue) 12AT7’s and The Amp Doctor (TAD) red base 12BH7A’s. The TAD tubes are made by PSVane in China then selected by TAD in Germany.

This new tube roll extended the highs and provided better defined bass than the McIntosh OEM tube complement. Midrange is about the same. Background is quieter.

My second roll was to Sylvania 12AT7WA MIL/JAN tubes and RCA 12BH7A’s with red lettering. This combination brings more depth and dimension to the midrange with just slightly leaner bass and about the same treble as the GL/TAD new production tubes.

I still have to source some Brimar, Tung-Sol and Sylvania tubes to try out. Of those the Brimar tubes seem to be hardest to source.

I’m using Audeze LCD-4 and Focal/Drop Elex headphones to audition these different tube lineups. Fun project. 363F0FA3-7E56-4914-9950-E9960664ABD4.jpeg
 
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