loud hum on Krank Revolution 1

[Jack1962]

I have a Krank Revolution 1 on my bench , everything seems to be ok except , it has a fairly loud hum only when the volume on the guitar is turned up , as long as the volume is turned down or off is real quiet or if there is no cable plug in it's real quiet as well. Anyone have any idea's ? sorry I don't have a schematic for this amp.

[SILVERGUN]

Can you verify any of this? :

[sluckey]

Try another guitar and/or cable. If this problem is inside the amp it would be somewhere between the input jack and the grid of the first preamp tube.

[Jack1962]

Silvergun that diagram is close but the Valves are numbered wrong , I have never saw a amp that the input was on V3 , Krank marks eveything the input is on V1a , the diagram is incomplete , but basically what is there is right.

Yeah Sluckey , that's what I was thinking too , and I have checked it's shielded cable nice clean lead dress and it goes straight into the grid of V1a .


I have a little more info , when the amp is on the clean channel is as quiet as a church mouse , it only makes this noise when on the drive channels.

[sluckey]

I have a little more info , when the amp is on the clean channel is as quiet as a church mouse , it only makes this noise when on the drive channels.

Well that's a totally different story. Gonna need to see a schematic to make guesses now.

[Jack1962]

I know that's right , I would like to see one too lol

[SILVERGUN]

Thanks Jack,
I'm most interested in the switching for the dual Master Pots(thinking of "borrowing" that) ...(besides the "sweep" control slope res.)
I like the idea of the 2nd Master on the lead channel acting as a relay switchable lead boost...(Labeled RE2)

So I'm here for the wrong reasons...but, at least I was able to dig up that schematic snippet for you 

I have a little more info , when the amp is on the clean channel is as quiet as a church mouse , it only makes this noise when on the drive channels.

I would have to believe that your problem is somewhere to the West of those switches,,,so this should be the only schematic you need   

[Jack1962]

Yes it my very well be , but myself I'm leaning toward on of the caps on the power rail , I don't know why really just a feeling I guess .

[SILVERGUN]

Yeah,,,C19 stood out to me as a probable canidate

[The_Gaz]

Yeah,,,C19 stood out to me as a probable canidate

Why? I guess it can't hurt to try and jump the cap with a known good one. Surely the amp would still make noise if C19 was bad. But if there is hum only with the volume up on the guitar, Sluckey was correct that the problem is with the guitar, cable, or related input circuitry. Have you tried replacing V1?

Also, Silvergun, take a look at the way Splawn does their lead volume boost, using a switchable pot between the bottom leg and ground of the master pot. Easy-peasy, and you don't even have to use a relay. The way Krank does it is typical as well - take a look at the SLO.

[Jack1962]

If C19 is bad and I replaced it why would it still make the noise?
Yes I have replaced all the tubes in this amp with known good tubes . it only makes this noise on the high gain channel the clean or kleen as they call it works fine without noise.


 However , after talking to Mr. Tony Krank on facebook and being blown off and being told that he was going inform Krank Amps to not give me a support on this amp or any other , I will be returning this amp to the customer. Pardon my language people but Tony Krank is a DICKHEAD

[The_Gaz]

If C19 is bad and I replaced it why would it still make the noise?
Yes I have replaced all the tubes in this amp with known good tubes . it only makes this noise on the high gain channel the clean or kleen as they call it works fine without noise.


 However , after talking to Mr. Tony Krank on facebook and being blown off and being told that he was going inform Krank Amps to not give me a support on this amp or any other , I will be returning this amp to the customer. Pardon my language people but Tony Krank is a DICKHEAD

Right, it wouldn't. Guess it doesn't matter after your recent conversation with Mr. Kranky... But wow, I wouldn't mind hearing the little story behind that.

[SILVERGUN]

Also, Silvergun, take a look at the way Splawn does their lead volume boost, using a switchable pot between the bottom leg and ground of the master pot. Easy-peasy, and you don't even have to use a relay. The way Krank does it is typical as well - take a look at the SLO.

Thanks for that.....I hadn't really looked around enough, and that does look like a cool application for my build

Pardon my language people but Tony Krank is a DICKHEAD

Thanks for that.....now we know 
How dare you try to help his customer, Jack?.....who do you think you are? 

[Jack1962]

lol I don't know lol