Whats up with this c+ (weird)6-12ax7's

[Buster Leggs]

I just got this 60/100 c+ long chassis.Serial # 1237X. It passes the loop test but it has 6 12ax7"s. 4 across the front, 1 directly behind v1 (thats the odd one) and 1 between the transformer (105) and the power tubes (4).Can someone please explain what it is I have. I'm new to B.Board and have been doing alot of reading here so I don't ask questions that have been covered over and over, but I have yet to see anything on this.THANK YOU FOR ANY INFO !!!

 

[adonixx]

I just got this 60/100 c+ long chassis.Serial # 1237X. It passes the loop test but it has 6 12ax7"s. 4 across the front, 1 directly behind v1 (thats the odd one) and 1 between the transformer (105) and the power tubes (4).Can someone please explain what it is I have. I'm new to B.Board and have been doing alot of reading here so I don't ask questions that have been covered over and over, but I have yet to see anything on this.THANK YOU FOR ANY INFO !!!

Take out the chassis and snap some circuit pictures. Its hard to say without looking at the circuit.

 

[fretout]

Take some pics of the underside of the chassis (in case there's some tell-tale markings), some pics of the back of the chassis (in case a previous owner installed something unusual), and some gut shots (so we can look at where the preamp tubes "flow" to).

 

[Buster Leggs]

Thanks for the responces. I just talked to Mike B.at boogie (great guy) He remembers this amp. An employee of boogie that used to own some music stores, but then worked for M/B early 80's had Mike put in another 12ax7 behind v1. the purpose was somthing about cathode follower stages ( means nothing to me). to give it more head room . I gotta say this amps a mad man. Also Mike says it could be a factory c+ but cannot say for 100% sure. # 12379. A request was made to add the extra 12ax7 he said he can't imagine adding that to a non pulsed C. It left the factory as a new amp with the extra tube.
Also it was at boogie longer than the average production amp. Mikes initialed it 2/84 but month 6 was written on the side of the chassis
It's got HR 15" 6 on side eventhough it's a long chassis. It' got 2/84 with mb's initials in light marker. I couldn't get them to photograph.

 

[gts]

Interesting story about that extra/ added 6th pre-amp tube.

If I am remembering things correctly:
You have a 60/100 watt with reverb chassis that was originally in a Widebody (Big Brother) combo.
H=60/100 watt
R=Reverb
15" = EV15L / 15inch speaker (these 15" speakers only fit in the widebody combo shells)

 

[gts]

That's a very clean looking amp!

 

[Buster Leggs]

Thanks for the reply. It' reassuring that you feel that my HR is a clean looking amp. I appreciate the wisdom from you guys. THANKS AGAIN