SA-3A (LA-3A Clone) Support Thread

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ComodoComplex

Well-known member
Joined
Feb 5, 2014
Messages
88
Location
Brooklyn, NY
Sliding some braided shielding cable over the power link wire did it for me without having to ground it or anything. I guess it creates enough of a faraday cage to stop radiated E-fields. It actually made no difference if I grounded it or not, and I secured heatshrink over the ends to make sure it couldn't short out on either side of the cable. I also had to cable-tie the assembly against a nearby cable to make sure the shield was squished down tight against the wiring to get rid of every last bit of hum, which is why I recommend using proper 3-4 conductor shielded cabling. Gotham 85225 cable would be luxurious, but you could also probably do with Mogami W2893 since the SA3A doesn't draw much current

This is what I used for shielding FYI:
https://www.mcmaster.com/shields/sleeving/interference-shielding-expandable-sleeving/

Hopefully can post some pix soon!
 

mypantsrblue

New Member
Joined
Mar 26, 2021
Messages
16
Hi,


While assembling a stereo unit for a friend I revisited and re-calibrated my two units (from a long time ago)


One of the channels has developed a little problem which I think I've narrowed down to a problem in the output gain.

(MOD, 50dB, Compress)
Feeding a -18dBFS signal into it I get one side to Gain +/-6 for a 0dB(VU) reading while I need the other side to be at 7. Around 6 the signal gets distorted (while reading about -2.7dB(VU)).
When I turn up the peak reduction the volume lowers (obviously) and the distortion goes away.
When I compensate for the lost volume the distortion returns at the same VU reading.


Looking at the schematic logic tells me to try and replace Q3, Q4, Q5 and/or Q6 to see if the problem goes away or am I wrong here?


Thanks in advance,
Herwig
did you ever fix this? i have a similar issue
 
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