Bit of a long shot I think, what could cause an inbalance in pre amp o/p ?

D

Deaf Cat

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Hiya,

I bought a second hand pre amp processor and the lh main channel is 4.5dB quiter than the rhs main.

On analogue pass through the lhs is pretty much silent compared to the the rhs.

I understand capacitors may be the week point of this particular thing.

Just thought I'd ask, I know little about electronics and as far as I know it could be a relay, a chip, a resistor, or anyting else in the box for that matter. It looks such a simple lay out I got tempted to find out more.

Once I've worked out how to shrink the jpg of the board to 100kb I'll pop in here.

Cheers for any thoughts or comments,

DC
 
Err sorry first one went a bit small....which is the second one here??
First pic is the right hand side of the board second pic is the left part.

Must apologise for the pics, dreadful, I think I need more pratice :( or help

DC
 

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lets give it a go......

http://img98.imageshack.us/img98/4257/p1140095vm4.jpg


(Its a Thule PR250-B pre amp processor)

EDIT:
Cheers Tenson it works :)


It looks very simple to what I was expecting to see, thing is, I can't see anything that looks a tad burnt out... so I guess its an invisible fault, this is where even though it looks a nice easy layout, I have not got a clue, as to what the things do, apart form the two big gray boxes :)

May help, may not:
- top left XLR inputs and outputs on little board connected to main board with ribbon cable & surround outputs (below little board) on main board,
middle top digital inputs,
right hand side little boards s-video and composite inputs,
right hand side (below little board) on main board analogue inputs, tv, sat, tape, etc.
 
Last edited by a moderator:
Just tested balanced outputs (converted to rca) with digital input, and gives the same result as the rca outputs, lhs need 4.5dB boost to bring in line with rhs.

:eek:
 
Now eventually fixed :)

Just incase any one was interested:

I'm informed by Kevin at theaudiocellar - that the problem was with two resistors in the feedback part of the op amp circuit, that were knackered....or along those lines anyway. Kevin kindly changed the two on the right channel as well, just to ensure left and right channel circuits are now exactly the same.

One happy Bunny!
:)
 

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