Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Shovelhead on July 22, 2024, 07:26:15 pm
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Greetings,
I just purchased a brand new Mercury Magnetics Output Trans and Power Trans for a Blackface Vibrolux Reverb fresh build project. To make a long story short, I've scrapped that idea. Since I have a spare 65 SRRI, I decided to investigate the possibility of 'stepping' down the power a little with these 2 new trannies.
MM confirms the swap will work however; I think I'll go one step at a time first by replacing only the Output Tranny first. The 2 amps are very close schematically and all wires are the same on the stock SR as they are on the new Vibrolux Reverb OT.
What say you? :icon_biggrin:
Thx.
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Super reverb is an upgrade from vibrolux, so I would think that you won't hurt the transformer(s).
You may have an issue with voltages...
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Doesn't the SRRI have a 2 ohm output whereas the VR has a 4 ohm output? Why would you want to create an impedance mismatch even if it was doable? Or are you thinking this will lower power output. I guess you could disconnect two speakers on the SRRI then it would be 4 ohm load to match the OT and there would be a perceived drop in output.
Why do you want to install those beautuful transformers into a PCB amp in the first place? Personally I wouldn't do that. Why not just install some 5881 power tubes and adjust the bias.
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... Mercury Magnetics Output Trans and Power Trans for a Blackface Vibrolux Reverb ... I have a spare 65 SRRI ... replacing only the Output Tranny first. ...
Disconnect 2 speakers, and you're all set! Though I suspect you already knew to do that...
... Blackface Vibrolux Reverb ... 65 SRRI, I decided to investigate the possibility of 'stepping' down the power a little with these 2 new trannies. ...
You're not really "stepping down the power." You should consider Super Reverb = Vibrolux Reverb, at least in clean output power.
The original Vibrolux Reverb had a slightly less-stout power & output transformer, so it wouldn't be quite as-bold as a Super Reverb. It also has a smaller cab & 2x speaker rather than 4x. But otherwise, they're pretty similar amps.
I expect the Vibrolux-switch will soften your Super Reverb's sound a bit. I know my old 1966 Pro Reverb was similar, though a little sweeter, than my 1967 Super Reverb. I'd expect a Vibrolux to be similar.
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Thanks for your comments!
I've been performing with Supers and Twins since the late sixties. It wasn't until the late 80's when clubs started to freak out over volume levels. Hence; the elimination of 2 of the four SR speakers. The Twin stays in my home. The SR did and still does sound terrific on a 4ohm load.
At my age, I'm not going to be buying any more amps of any kind. So, since these heavy weights are too hard to sell nowadays, let us fool around a bit to see what we can come up with.
BTW ... my MM output tranny (FBFVLR-om), is a 2 and 4ohm ToneClone unit.
Sometimes I think I'm losin' it. Both my SRs sound equally amazing with my Strats, Teles and mostly my Firebird V. Why am I doing this :dontknow: .... because - I can :l2:
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Perfectly understand now ..