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GB for DC coupled B1 buffer with shunt PSUs

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#2,975
Guys,

I've searched but only turned up endless posts discussing this problem!

I had to open my DCB1 (mesmerize) today to fix a broken wire that happened after a RCA socket came loose. Anyway, I had the box open and fired it back up and I was surprised to hear a buzzing from the board. I'm pretty sure its coming from the muting relay.

I seem to remember that there was a fix for this somewhere? Was it to change one of the BC550/BC517 or add another cap to their supply?

Fran
 
#2,977
Eh? I'm confused. On my board there's 2 transistors (c550 and c517) just above the dropping resistors for the relays.This is kinda in the centre of the board below the 4 x sk170s of the buffer?

Funny how I knew this layout when I made it a few years ago and the memory is just gone now!!

Fran

Edit: see the pic for what my board looks like:

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#2,979
Yes - the c550 and c517 are back to back (round to round).

I can't see any version number on it, except "mesmerize version by CRT"

I know its the mute relay because when I turn it on, its silent until it clicks and then the buzz is there. Now the thing still works - the relay is obviously latching ok....

I can't feel it though, but can hear it. Not very loud - and I think it would be hard to hear when the box is closed, probably why I never noticed it. I don't ever remember this happening though when I made it, and I had it open a lot then.


Fran


Fran
 
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