Plexi 50w, sound goes through vol on zero

iFrancisG · Post by **iFrancisG** » Sun Jul 19, 2015 5:17 pm

Hi there

I just finished building a 50W Plexi and there is sound going through channel one and channel two but more quiet on two even if volume pot is off I also got hum. Is that normal ?
Any though appreciated

Thanks

neikeel · Post by **neikeel** » Mon Jul 20, 2015 7:59 am

If you can be more precise.....

Channel 1 is loudest and brightest. If you have a bright cap on C1 you get hiss at high volume settings

Channel 2 is quieter.

A normal plexi will have a little hum but if you have used the Larry ground system and correctly twisted and routed the heater wires it is rarely intrusive at all.

If you turn the volume pots right down you may get some sound through the unused channel due to bleed between the channels, again quite normal.

Without hearing or seeing your amp it is hard to tell if your amp is normal or not

iFrancisG · Post by **iFrancisG** » Mon Jul 20, 2015 9:40 am

Hi
Thanks for the reply
What i mean is when plugged to input I, both volume on zero my guitar sound still go through not very loud but loud enough, when plugged to input II same thing but less loud.
As for the Larry ground system, im not aware of it, I'll google it.
Of course I didn't expected my amp to be dead silent. How loud a hiss/hum have to get to be considered a problem that is the question.

I tried to post pics, doesn't work.

neikeel · Post by **neikeel** » Mon Jul 20, 2015 10:09 am

iFrancisG wrote:Hi
Thanks for the reply
What i mean is when plugged to input I, both volume on zero my guitar sound still go through not very loud but loud enough, when plugged to input II same thing but less loud.
As for the Larry ground system, im not aware of it, I'll google it.
Of course I didn't expected my amp to be dead silent. How loud a hiss/hum have to get to be considered a problem that is the question.
I tried to post pics, doesn't work.

Sounds normal (most pots let some signal through)
Larry ground is here with diagrams, IMO you should not build an amp without it!
Pics you have to use an online host (I use photobucket - it is free)

iFrancisG · Post by **iFrancisG** » Mon Jul 20, 2015 12:47 pm

Here is a pic

As for the "Larry ground scheme" its a bit too late to implement it, but I wish i could see it implemented in a 50w.
Since i just got a single 30W, 12" speaker its hard to tell if i got the normal kinda hiss/noise/hum or there is a problems,
but sound coming out event when volumes on zero ?? thats a first really.

Post by **VelvetGeorge** » Mon Jul 20, 2015 3:56 pm

Signal bleed is normal from V1 to V2. You can shield the wire from mix resistors to V2 pin 2 if you want. It will cut it down, but not eliminate completely. Only physical space and/or a metal shield can work fully.

George

iFrancisG · Post by **iFrancisG** » Mon Jul 20, 2015 4:51 pm

Thanks George

neikeel · Post by **neikeel** » Tue Jul 21, 2015 1:25 pm

iFrancisG wrote:Thanks George

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Plexi 50w, sound goes through vol on zero

Plexi 50w, sound goes through vol on zero

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Re: Plexi 50w, sound goes through vol on zero

Re: Plexi 50w, sound goes through vol on zero

Re: Plexi 50w, sound goes through vol on zero

Re: Plexi 50w, sound goes through vol on zero

Re: Plexi 50w, sound goes through vol on zero

Re: Plexi 50w, sound goes through vol on zero