Comprehensive Mesa Boogie Cathode Follower list?

[tbonesullivan]

I have been reading up a lot more about preamp tubes, and came upon issues regarding modern-design tubes out of the Reflektor plant having issues with the filaments when used in a cathode follower position. Something about the voltage differential between the heater filament and cathode in those positions causes issues.

I did find one list, but it's from 2012 and doesn't have a list of amps that do not have any of these positions.

Lone Star & LS Special: V3
M-Pulse: V2
Stiletto: V3 & V4
Venture: V2
Road King I: V3 & V4
Big Block 750: V4
Road King II: V3 & V5
Titan: V4
Roadster: V3 & V5
M2000: V2
Dual & Triple (2ch or 3ch): V3 & V4
Bass 400+: V2
Tremoverb: V3 & V4

Does anyone know if the Maverick and DC series amps have any cathode follower circuits?

 

[Buster Leggs]

I bought a C+ off eBay and when it arrived I realized it had 6 preamp tubes, the typical 5 and then had one extra one behind V1 by the output Transformer. I was getting some work done on a C+ at the time and when Mike B. called me I mentioned to him this C+ with strange 6th tube. 2/84 was on the chassis HR 6 and a 15 was marked with sharpie on the end. It had the 105 Transformer but one of the lowest serial numbers for a factory Id ever seen. Mike B informed me there was a gentleman, owned a chain of music stores in California and he sold those and couldn't handle retirement so he got a part-time job at Boogie. When the C+ circuitry was developed and perfected to their liking this gentleman wanted one but he wanted it to have more Headroom. Mike B. Remembers this amp and the story behind it. He put a cathode follower in it and it left Mesa a factory Mark II C plus with a cathode follower tube. Got a little excited when he was describing it to me because I believe that's the only one he ever did that too. It's without a doubt one of my best C+'s, definitely has the best clean of all of them and rates right up at the top with the gain channel. I didn't know anything about Russian tubes in a cathode follower circuit but found out immediately.I put a Russian in there and it lasted all of about 4 minutes. I've since put an old Chinese tube in that spot and haven't had a problem since. I know very little about cathode followers but this is definitely a special amp.

 

[tbonesullivan]

awesome! I had read that pretty much none of the Mark series amps have cathode followers, so that makes it a rare beast indeed!

 

[Buster Leggs]

Mike customized it for a friend/employee. After the conversation with him, I wished I would have asked him if he had ever done that before for anyone. I'm sending a different one to California to get it recapped and looked over, I'll remember to ask Mike had that ever been done before or since when he calls me to discuss this other amp. I posted gut shots a couple years back before I talked to Mike to get some feedback. No one has heard of that before but I did get some comments on how clean it looked. I'll definitely never get rid of it. The only reason I mentioned it was to add an oddball to the ops list of cathode follower amps.

 

[tbonesullivan]

Just found two more while searching about, and one of them is in fact very pertinent to me: a Maverick.

V1 in the Mesa Maverick and Blue Angel.

The Bright/Fat switch in the Maverick and Blue Angel apparently involves switching from plate fed EQ to a Cathode Follower fed EQ. There are other changes, but that is one of the big ones. So V1 in those cannot be Russian Spiral filament.

 

[3124+]

For the record, I've been using Reflektor-made 12AX7 tubes in the cathode follower stages of my Dual and Triple Rectifier Solo heads for years with no problems at all. I use Electro-Harmonix and Sovtek LPS types.

 

[Pyramid Head]

Anyone knows about the Subway Blues?
Any cathode follower tubes?

 

[woodbutcher65]

The Subway Blues does not have a tube cathode follower stage. I'm now extremely certain of that.

 

[Nerd]

Hi

Anyone knows Fillmore 50?

Thank you

 

[woodbutcher65]

FYI, the Sovtek 12AX7WB is specifically made to handle the demands made on it in a cathode follower application.

It's the exception to the "Don't use Russian 12AX7 tubes in a cathode follower circuit" rule.

 

[Nerd]

How about 12AT7 in cathode follower? It has current handling capability. Any experiences to share?