50/50 Power Amp Tube Layout

[mflemmer0429]

In the 50/50 (blue led version w/deep mod), I mainly need to know about the three 12AX7'S and their physical positions when looking from above. I know one is a driver and the other two phase inverters. Which is V1, 2 and 3, and is V1 the driver? I suspect V1 may be closest to the inputs, which would be far left from the rear (power tubes facing me), then V2 and 3 as you move to the right. Someone out there who knows for sure, is that correct? I already asked Mesa directly, and they sent me a schematic but weren't sure from a physical standpoint. Help, please?

 

[Henz]

To me , that would be correct. I have a 2:90 and I would assume its the same. If viewing like you are, from rear, tube on far left would be input tube for both channels. V1. Next to right is V2 PI tube and so on.

 

[mflemmer0429]

Thanks for that info. Anyone else out there who would concur with that?

 

[Henz]

Yw brother. Just curious, what's going on inside that you want to verify this? If you're anything like me, I'm a need to know guy lol. I trace out my amps to make sure that they are consistent with the schematics. I found a couple of errors. No biggy.

 

[mflemmer0429]

Yes, I'm also a need-to-know guy, a tech geek and an info junkie. No problems with the 50/50 currently, but I just recently acquired it to use with my Studio Preamp. I had been running that through the power amp and speakers of a Peavey VTX Heritage combo. Sold the Peavey, got an Orange Rockerverb combo, now using the MB setup through those speakers (unless using the RV's circuitry, of course). Not to slam on Peavey stuff, but it's obvious now how much it was darkening my tone. The 50/50 is so much more crisp & articulate (still using the same speakers).

I don't mean to second-guess what you told me, I just tend to like a consensus opinion from at least 2 or 3 knowledgeable people (such as yourself ).

 

[Henz]

Hey brother, no worries. You have OCD to eh? I'm the same way. If I had to do it over, I wudda got a 50/50 instead of the 2:90. 50/50 is a lot less maintenance. I did a total recap on it plus repaired some circuits. What a pain and time consuming job that was lifting the PCB. Ugh! I'm kinda speaker shopping. Any thoughts on the celestion red backs? I love mids. Not a scooped tone guy.

 

[mflemmer0429]

I haven't tried Celestion Red Backs. Online demos sound good. Based on what I've read they might be a little dark for me. I like mids, but they need to be balanced while allowing the highs to be open and bright--not harsh like with V30's, especially when clean and with lower gain. I had Eminence CV-75's (from their Redcoat Series, if you're familiar) in my Peavey (replacing the original Scorpions) for several years. When I got the Rockerverb I compared using both the stock V30's and the CV-75's, and preferred the latter. Put them in the Orange, sold the V30's with the Peavey. CV-75's are in the same vein, but more even and relaxed in the mids (while not being scooped), a bit more controlled in the lows, and the highs seem more open and airy, probably because the upper mids are more relaxed and don't dominate the higher frequencies.

 

[Henz]

Ty for you input. Ola on YT tried these speakers. They blue label something, dang, can't recall , that's awful. They may be eminence. I have to go back and check. I kinda liked them.