Sony SQD-2020 - wtf?

[elguapo511]

Just trying to understand this thing.

I need two amps?

What if I have an integrated amp with multiple tape loops? Like a pioneer qx-949.

is this a common setup?

Is there a benefit to a rear amp or was that just how they introduced it to the market.

Ive read the threads here about it, but which is the output that decodes?
Does the two channel output go to the front right left of the front amp
and does the "to back amp" out put go to the rear right and left.
Seems obvious but since there is not 4 channel output it is confusing.

i just grabbed one and its crazy scratchy, but i think with a little help from my friends, i will be in business...

and another thing. is this similar to a lafayette sqw? or more of a sansui sq type

thanks all

 

[Soundfield]

If you haven't got the user manual you can download it from HiFi Engine | Owners and Service Manuals (requires free registration).
It's got lots of useful info like this connection diagram:

 

[elguapo511]

Thanks Soundfield.

I got it all hooked up.

I am experiencing a poor signal from all channels.

Sounds like a very scratchy record with heavy bass, like a connection is breaking up.

The sound gets worse or better when I switch to 2>4, or SQ, or R-MTX. Its the worst for the sq.

I deoxet everything and things perked up, but the scratchiness seems like a failing component, not dirty pots.

Anythoughts on a fix, or is it even worth it. This is a beautiful unit.

The poor sound continues even when there is no signal...

 

[Soundfield]

Thanks Soundfield.

I got it all hooked up.

I am experiencing a poor signal from all channels.

Sounds like a very scratchy record with heavy bass, like a connection is breaking up.

The sound gets worse or better when I switch to 2>4, or SQ, or R-MTX. Its the worst for the sq.

I deoxet everything and things perked up, but the scratchiness seems like a failing component, not dirty pots.

Anythoughts on a fix, or is it even worth it. This is a beautiful unit.

The poor sound continues even when there is no signal...

If it’s making all those noises on all outputs with no input connected there could well be a serious power supply problem. Whether it’s fixable is difficult to say, but might be tricky if you’ve not got the service manual and some test gear.

 

[Doug G.]

You may have to resolder connections on the circuit boards, particularly if there are feed throughs from one side of the board to the other. Sony's of that era are notorious for those going bad. I had to redo both of my SQD-2050s.

Doug

 

[elguapo511]

Well, i no longer am interested in this unit. I am in Chicago and if anyone wants it, please let me know. $ would be great, a trade would also be cool. Either way, looking for a good home.

everything works, lights, meters, switches, but should be recapped.

 

[Soundfield]

everything works, lights, meters, switches, but should be recapped.

So you solved the problems you were having with this unit then?....

I am experiencing a poor signal from all channels.
Sounds like a very scratchy record with heavy bass, like a connection is breaking up.
The sound gets worse or better when I switch to 2>4, or SQ, or R-MTX. Its the worst for the sq.
I deoxet everything and things perked up, but the scratchiness seems like a failing component, not dirty pots.
The poor sound continues even when there is no signal...

What did you do to fix it?

 

[elguapo511]

I opened it, blew it out with air and a light brush, de oxt. But nothing further.

 

[GBAF70]

What causes the sound from the rear channels to be intermittent?

 

[elguapo511]

Probably old capacitors?

 

[MidiMagic]

Look at switch contacts first.

 

[senorverde]

The 2020 can be a PITA to work on. Double sided circuit boards and 100% discrete with almost 100 transistors and diodes. To answer your first question, this pales in comparison to an SQ-W. However, it's better than the Vario-Matrix assisted SQ decoding found in the QRX line of receivers (those could only do center front/back logic while this does that AND corner logic). The point of the rear bass/treble controls is so it could be used as a rear channel preamp so totally ignore those in your case. If you're getting distortion in RM mode too then it's a problem on the electronics side of things. RM is essentially the same as the 2020's SQ decoding mode but the logic is disabled and the .7 blend is taken out (so in essence it becomes as basic as of a decoder as it can get).

I second Doug's idea. Flow some new solder in the vias. Also a recap wouldn't hurt considering these use all crappy gray Nichicons.

I got mine off a guy from Facebook Marketplace where it had lived a hard and damp life in a garage. A total recap got it working about 90% of the way.