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Old 21st June 2012, 03:21 PM   #901
Salas is offline Salas  Greece
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Quote:
Originally Posted by cjkpkg View Post

So, I am thinking I need to have all my signal wiring as per "normal" signal to signal and ground to ground and switch my speaker outputs on the power amp?
Don't ground your signal. Polarity reversal in SE is done on the speakers inputs which are floating devices.
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Old 21st June 2012, 03:27 PM   #902
cjkpkg is offline cjkpkg  United States
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gotcha...I recieved my regulated PSU yesterday too so I will try and stuff that tonight as well and get everything sorted out tonight maybe.
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Old 22nd June 2012, 02:15 AM   #903
cjkpkg is offline cjkpkg  United States
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well...no dice yet...

hooked it back up with signal to signal and rca ground to rca ground and nothing but terrible loud hummmm...switching speaker outputs made no difference.

I am thinking now that maybe my pot is not hooked up correctly...

What are your successful wiring schemes for your input to pot to board to output wiring schemes?

I have an alps blue dual pot.

I went RCA ground to pot ground. then ran another wire from pot ground to board ground input. Could this be causing my ground loop?
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Old 22nd June 2012, 02:22 AM   #904
Salas is offline Salas  Greece
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Wiring a Pot
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Old 22nd June 2012, 02:25 AM   #905
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Pictures are worth a thousand words Step away, play a game of chess or listento music, then recheck wiring. After pi cof course. If these guys got me up and running, i am sure they can help.
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Old 22nd June 2012, 07:32 AM   #906
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Just a suggestion - do you have three or four pin Alps pot?
The four pin:

On the back it says:
Alps Japan RH2701 50KAX2
with terimals are
#1 Ground
#2 Out to amp board
#3 In from sel
#4 NC or Loudness

So if you have it on 4 you will get hum (open connection)
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Old 22nd June 2012, 12:50 PM   #907
cjkpkg is offline cjkpkg  United States
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OK, well that is how I have it...

RCA input Earth to pot, then from the pot earth connection to the board input ground.

Question though...where should the RCA output ground originate? The way mine is set up it ends up being the same point as where the input ground originates. I started thinking that this may be causing the loop.

It is a 3 pin pot and I have three others to reference so I am sure I am OK there.

I still suspect that it has to do with the output RCA's and the grounding scheme.

Last edited by cjkpkg; 22nd June 2012 at 12:53 PM.
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Old 22nd June 2012, 01:00 PM   #908
Salas is offline Salas  Greece
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Star earth signal gnd everything to the cathode resistor's ground point to have a visually clean earth reference node, could be one idea.
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Old 23rd June 2012, 12:19 PM   #909
cjkpkg is offline cjkpkg  United States
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OK, one more update.

I am using Broskies PS-1 for the PSU which has regulated B+ and heater supply. I originally had the heaters set up for series but last night I changed them to parallel.

I ran the RCA ouput ground to the ground on my PCB and the RCA output signal to the signal output and nothing but terrible hummm.

THEN I swapped ouput wires, PCB ground to RCA signal output and PCB signal output to RCA ground and IT MADE LOVELY MUSIC...for about 40 seconds...then the terrible hummm returned. UGHHH!!!!

This one is really stumping me...
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Old 23rd June 2012, 12:34 PM   #910
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post pics of your amp. It may be a routing/wiring issue. Show the whole amp with pics of each compartment/section. May be good idea to look at your amp and draw diagram/ schematic. Sometimes in drawing it yourself, you can see where you made an error.
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