Randall RG75 G3 Combo, hum then pop, then everything OK

[Emetal]

Hi everybody, got Randall RG75 G3 combo for repair, when turned ON it hums for about 5 seconds, then pops and from there on everything goes normal. Only happens...

[g1]

Does this one match?...

[Emetal]

I have just actually opened the amp, look like those schematics I uploaded are not correct, I do not se any tube or a relay as shown on these schematics,...

[g1]

The board says RG75-B on it, I wonder is this schematic is close....

[Shawng]

I知 looking for a diagram for a Randall RX75rg2 , I can稚 find one anywhere, is it the same as the RG75?
What痴 the difference between the RX75 and...

[vintagekiki]

Randall RG75-A(G3) preamp (Attached File)


Reason for Editing

https://music-electronics-forum.com/forum/schematic-request...

[jperrizo]

I have posted a picture of the guts, and I have read a multitude of posts that says this has a tube (even specifying it as 12AT7), and others the opposite....

[xtian]

I see no reason to believe there's a tube inside:

Randall RG75-G3: https://www.musiciansfriend.com/ampl...rg75g3-g3-seri...

[bsco]

Good day to everybody...I have this one here and after going through the circuit, I have audio up to the relay.....the relay is not being activated so the...

[Mick Bailey]

Has anyone got the schematic for this amp? - this is the one with the 12AT7 in the power amp. The schematic is one of those that got lost a few years bac...

[Mick Bailey]

Rather than continue under Schematic Requests, I thought I'd post this separately.

I did a repair on this amp in September last year. The owner...

[g1]

This one?
http://music-electronics-forum.com/a...ll-rg75-g3.zip

[andywragg]

Hi There,

Looking for some advice on the speaker voltages I should be seeing on this amp when at full chat. I have the amp connected to my...

[Valvehead]

Have a rh100 that has a big short to ground somewhere.

i think the RG75 scem is the same amp

Initially I found D3 and R19...

[diydidi]

Gi Guys.
I need a schematic for this amp asap. Any help will be much appreciated.

[andywragg]

Hi Need to bump this thread. I'm new here and I have a Randall RG75 3 on the bench. Where did you find the schematic? I've searched the site and can't seem...

[cmanningjr]

Hi all, new guy here.

I just got a Randall RG75 G3 amp. As soon as you turn it on it had a constant hum. Knobs have no affect and it does it...

[Jazz P Bass]

Randall RG75 Schematics

This is everything that I have for the RG75....

[screamersusa]

Ive owned much better and working with what ive got.



Ive owned two professionally hot rodded marshalls, a dual rec, upgraded...

[DrGonz78]

Look into getting a guitar amp that was made in the 80's if that is the sound your looking at...? I like the Randall RG80 combo amp, but not all them have...

[dmcastillor]

RX120RH Power Amp Schematic

Hey, I have a Randall RX120RH with a RG75-B power amp, I need that schematic, this board has more than 28 resistors,...