Same circuit and components?

[andresbriceno]

I know the fender pro reverb (maybe other fenders) got the master volume around 74, not sure.

Do the Master and Non Master have the same components and circuit?

If I mod and by-pass the master do the come out sounding the same?

Please I need help fast...

Andrew

[Mesotech]

They can't be the SAME circuit, obviously because one has a master volume and one doesn't. There's at least one difference in circuit right there. They could however be very similar.

Likewise, any changes to the existing circuit (aside from direct component replacement) is going to to affect the way it sounds somewhat. To what extent the sound will change will be determined by what you change.

If you need help fast, then it's probably not a good idea to make any changes until you do have time to sort out any problems resulting from a change, or at least time to put things back to stock again.

I know that my answer is a complete non-answer, meaning that I didn't help in any way, but hopefully you'll understand that I'm not trying to be harsh, but instead to try and get you to think about what you want to change, why you want to change it, what you expect the results to be, and to have ample time to perform the change test the result and correct any difficulties without being held to a time crunch.

[andresbriceno]

Thanks for the advice,

I have learned that there are 3 SF Pro Reverb, one with out the master volume, one with master volume, and one with master volume and pull boost...

[ampdan]

I did a customers 76 Twin Reverb that had the master/ pull boost. I removed both and blackfaced it. The amp sounded fantastic afterwards.

[andresbriceno]

Its a 45 watt, master vol but no pull boost

[Wilko]

There are several Pro Reverbs. The good ones have a tube rectifier and max out at about 40 watts.

The later ones are ultra-linear and have solid state front ends. They tend to sound more like Twin reverbs and have almost zero the benefits of the early Pro Reverbs.

[Gary M]

I have a '78 Pro Reverb that has the master volume like yours. Leaving the MV pushed in and dimed "essentially" takes it out of the circuit. (You don't really have to remove it from the amp.)

There are several differences between your amp and the non MV Pro Reverb.

The MV PR has:

1. 70 watts output
2. Middle tone controls
3. Is really, really loud and more llike a twin reverb.
4. Has an output tube balance instead of a bias adjustment.
5. With the MV at ~7, it will sound brighter because there is a treble bleed capacitor on the pot.

From the factory, the amp is biased cold. Mine still had the original tubes in 2005. Proper biasing was the biggest sonic improvement that I made to the amp. You can partially Blackface the amp which IMHO improves the tone somewhat.

Cheers!

Gary

[andresbriceno]

what do you mean by dimed, turned down?

My in 45 watt a 4 ohms, not 70 watt

75, MV pull boost

[Gravity Jim]

"Dimed" means "turned all the way up." The expression gets used because the highest number on an amp dial is usually 10 and a dime is 10 cents. So, turned up to 10 = dimed.

[rudutch]

"Dimed" means "turned all the way up." The expression gets used because the highest number on an amp dial is usually 10 and a dime is 10 cents. So, turned up to 10 = dimed.

I could not imagine how difficult it must be to figure out "American English" with all the slang and inuendos..

Nice interpretation, Jim