Anyone else have this strasnge SSL issue?

[dufo]

I have been looking for this fault on and off for a couple of years, only thing is, I just cant find one !! :0)

When moving the threshold from having it close to maxing out on the meter, gradually bringing it down, the meter will stop responding by slowly and consistantly dropping back down to zero. You can crazily twist the threshold while this is happening, but the needle will continue its drop back to zero.

Once its bottomed out, it will start responding again, showing compression for the given threshold. All the time its not responding to threshold, audio still passes Aok.

I have concentrated around the sidechain to try and find the problem, changed pots etc etc, all to no avail. Anyone else have a issue like this ?

 

[gyraf]

Is it in the clone stereo compressor or in the board? In case of the board - is it channel or mix compressor?

Jakob E.

 

[dufo]

bugger. Sorry, should have been more specific !!

It is the GSSL...

 

[gyraf]

It could maybe be latch-up in the TL072 because of inputs going full-rail? If it's a real problem (which I don't think it should be in real-life use), then try some other dual-opamp for the 072 - preferably one that allows full-rail inputs and is protected against latch-up..

Jakob E.

 

[CJ]

Probably a bad zener in the DBX 2001. :razz:

 

[dufo]

[quote author="CJ"]Probably a bad zener in the DBX 2001. :razz:[/quote]

Thanks Jacob! Will try that.

CJ- DBX2001 ? ?

 

[SSLtech]

CJ's drugs are wearing off.

The 2001 is an alternate to the 202C and 202X (or as in the case of most clone builders, the 202 substitute circuit using 2151's and 5534's)

The 2001 was the only class A VCA made to fit that application. All the others are Class B or AB from what I understand.

Keith

 

[dufo]

[quote author="gyraf"]It could maybe be latch-up in the TL072 because of inputs going full-rail? If it's a real problem (which I don't think it should be in real-life use), then try some other dual-opamp for the 072 - preferably one that allows full-rail inputs and is protected against latch-up..

Jakob E.[/quote]

I replaced the 072 with another 072, same one as I had in it before now. Now threshold works properly,EXCEPT on the auto release setting. At that setting its playing up like it was before. Very interesting ..... :shock:

 

[gyraf]

at auto you just see the very-very long (alc) part of the release. auto is a fast + a very slow release.