1978 Mesa Boogie

[thetone]

Anyone know much about re-tubing an original Mark 1 from 03/78?

It's got GT's in there (not the S's) and I thought it would benefit from some NOS tubes.

I received this from Angela Instruments -
A few weeks ago I sold Bruce Springsteen eight quads of Sylvania Phillips 7027As for his 20 year old Boogie Mark IIs. No current production tubes his crew had tried would work; the amps kept blowing fuses. We spent nine hours in the Verizon Center making sure the 7027A tubes would work. Jeff Bober had to do a bias resistor mod on each of the heads but that was about it. You should check with Boogie and make sure that your amp is 'plug compatible' for 7027As. The 6L6WGB has lower voltage ratings and would not be a good choice for a Boogie. I don't have a good stock of ANY 12AX7s but I expect some GEs and Sylvanias in next week.


Does anyone know what this all means? or where I can get "the right" tubes for this. I think what I want are Sylvania 6L6 GC's and I'm not sure what all the plug compatibility on 7027's exactly is.

Also - any know a good amp tech in Cleveland OH for THIS amp? Thanks.

[Don A]

I'd post this on The Boogie Board.

[Mark Kane]

I'm running wafer base Sovtek 5881's in mine and they sound great. I use the yellow label Sylvania 12aX7 preamp tubes. I don't think this amp could sound any better.

[Denyle_Guitars]

GE 6L6 in mine. I didn't care for the 5881.

Re the 7027A, it uses pin 1 while the 6L6 does not. Often, the open pin 1 lug will get used as a junction point or get tied to the ground, making the use of a 7027 a bad idea. It has a max plate V of 500, while the 6L6 is 400V.

[phsyconoodler]

I really like the boogie tubes. I have used mesa tubes in a few builds and really like the tone over other current production tubes.
That being said,NOS is a great way to go as long as the bias is right.