Mark II series: What preamp tubes were factory installed?

[Dana-L]

Hello!

I posted this in the tube section without response so I'm trying it again here. Thank you all in advance for your help!

In the mid-80's I caught the Boogie bug after a brief encounter with a blonde Boogie combo that I believe was a Mark II (I have no idea which variation).

In 1990 or so, I got my own Mark III. I love it but I'm interested in what brand preamp tunes were likely in my friend's Mark II so that I may try them in my Mk III.

Does anyone here know what preamp tubes the Boogie factory used throughout the Mark II series production? US, Russian, Chinese, Hungarian, British, German? The more detail the better!

Cheers,

-Dana

 

[JimmyB]

My IIa still has its original pre tubes: all US-mfrd GE 12ax7a/7025s. 8)

 

[Dana-L]

My IIa still has its original pre tubes: all US-mfrd GE 12ax7a/7025s. 8)

Thanks for the reply!

My Mark III is loaded with the factory Sovtek and/or Chinese glass but I've got some NOS RCA 12AX7A and used but strong 7025 tubes that I can sub-in.

I'm guessing that your IIa has a 7025 in V1 and 12AX7As in the remaining slots. Is that correct? Which ones are GE and which are RCA?

I appreciate your response!

-Dana

 

[Boogiebabies]

One of my IIC+'s came with four STR-415's and five Mesa labeled Ei's. This was from 11/1984.

 

[JimmyB]

My IIa still has its original pre tubes: all US-mfrd GE 12ax7a/7025s. 8)

Thanks for the reply!

My Mark III is loaded with the factory Sovtek and/or Chinese glass but I've got some NOS RCA 12AX7A and used but strong 7025 tubes that I can sub-in.

I'm guessing that your IIa has a 7025 in V1 and 12AX7As in the remaining slots. Is that correct? Which ones are GE and which are RCA?

I appreciate your response!

-Dana

Nope... they're all GE, all labeled "12ax7a/7025".

 

[Dana-L]

Thanks, guys!

I hope to do some tube rolling this weekend.

By the time my Mark III blue came off the line, they were still using US-made 6L6 and 6CA7 power tubes but had gone to Shuguang preamp tubes throughout.

If any other folks know what preamp tubes came in their Mark series amps, I'd love to learn about it!

Cheers,

-Dana

 

[dodger916]

I'll add only that I've found vintage preamp tubes (irrespective of brand) to be an improvement over new production preamp tubes.