# Help separating hard-wired amp head from cab



## Johnny (Nov 30, 2010)

Hello. I have a Canadian made Silvertone 100 solid state amp that has the head hard-wired to the 2x12" cab. I was hoping to separate the head from the cab so that the head could be used with other cabs and the cab could be used with other heads. The speaker wire from the amp head is soldered directly onto 1 of the speakers in the cab. I thought it would be easy enough to add a female speaker jack to the back panel of the cab and attach speaker lead wires to the speakers as the head was wired and then attach a 1/4" male jack to the wires from the cab. I tried this but did not get any sound. I also tried to use a different head with the cab and no sound there either. Am I doing something wrong? Any help at all would be appreciated. Here are some pictures.











































Also, Channel 1 has a very noisy and intermittent volume pot that has been deoxed but still is posing a problem. Volume will come out sometimes and then be gone and if I tap the knob (attached to that pot) the sound comes through in very loud bursts and dies again. Channel 2 works great as does the reverb and tremolo on Channel 2. I'd really like to get channel 1 up to speed though. Is a volume pot replacement needed? What size/style volume pot will I need? Are there any precautions needed when working on solid state amps (voltage issues like with tube amps) that I need to be careful of? Here' a picture of the volume pot. Sorry, kind of blurry... 









Here's a clearer picture of another pot from the same amp...


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## greco (Jul 15, 2007)

I am not an amp tech...just interested in this type of thing.

I know this is basic, but did you test for continuity and for shorts on all the changes you did?

When working on the amp you need to either drain or stay away from those big caps in the blue cans.
They might have been installed with some way that they are drained through the design of the amp...but I wouldn't trust that. 

Others can advise you on further precautions.

Cheers

Dave


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## WCGill (Mar 27, 2009)

Is that a 3 terminal switching jack? Hard to tell but make sure that you're not wired onto the switch terminal instead of ground or hot. Sounds like your volume pot needs to be replaced also. Disconnecting it and measuring resistance between the two outside terminals will give you the approximate value you're looking for, or find the schematic and read the value.


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## Johnny (Nov 30, 2010)

WCGill said:


> Is that a 3 terminal switching jack? Hard to tell but make sure that you're not wired onto the switch terminal instead of ground or hot. Sounds like your volume pot needs to be replaced also. Disconnecting it and measuring resistance between the two outside terminals will give you the approximate value you're looking for, or find the schematic and read the value.


Yes, it does appear to be a 3 terminal jack...perhaps that is the problem. Can I just switch to one of the other terminals?
Also, concerning disconnecting the volume pot, is it safe to unsolder this pot (I will have amp unplugged of course)...and then you take a voltage meter and read across the outside terminals?

Thanks,
Johnny


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## Johnny (Nov 30, 2010)

Thanks Dave. It interests me too and some stuff I feel I can do on my own but I will ask if I don't know how to do something.


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## greco (Jul 15, 2007)

Johnny said:


> Yes, it does appear to be a 3 terminal jack...perhaps that is the problem. Can I just switch to one of the other terminals?
> Also, concerning disconnecting the volume pot, is it safe to unsolder this pot (I will have amp unplugged of course)...and then you take a voltage meter and read across the outside terminals?
> 
> Thanks,
> Johnny


You need to make sure the terminals that you solder to on the jack are for the tip and sleeve.
This is easy to determine with continuity, if you aren't sure visually.

Yes, you will need to unsolder the pot and measure across the terminals.

Cheers

Dave


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## Johnny (Nov 30, 2010)

I did it. I think that 3 terminal jack had me confused. I just replaced it with a 2 terminal one I had in spare parts. 
Here are pics of the cab wired and the head wired with 1/4" terminal. Thanks everyone. 



















I will get to the volume pot next.


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## greco (Jul 15, 2007)

Well done!

Please let us know how everything goes re: the volume post change. 
Many of us learn from threads like yours and the pics are especially appreciated....Thanks.

Have you found a schematic for your amp?

Cheers

Dave


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