GSSL HELP THREAD!!!

[monsieur yumels]

Hi!

I have been tracking the signal (unbalanced) in both channels, shorting ground with pin 2 (i think). Audio path works perfectly without sidechain signal.

TL074 pin 7 one channel signal ok, two signals wobbling (see pictures). This is channel independent. so i am assuming the sidechain vca that 2181 cannot deal with the two summed signals simultaneusly and hence it is faulty. I Exchanged this chip with one of the audio chain and the wobbling reapeared now also in audio path, in both channels which i find weird.

I scoped pin 7 and 1 of tl072 with bypassed sidechain and i get -10mV Dc instead of 0mV. Is this normal operation?

Thanks!

 

[antiehdas]

THAT has better specs

but coolaudio, being sloppier, may have that "sheen" that some associate with the ssl4000

Most of the sound in this unit is sidechain function, not parts


..yes - the that 2150/2180 series are also marked like this:

https://www.thatcorp.com/datashts/THAT_2181-Series_Datasheet.pdf

/Jakob E.

edit: and no, usually only the vcas themselves gets damaged by this

Hello !

Got the new 2181's today and soldered them in. I also reverted to vanilla setup for now.

Now I have some other weird behavior. there is sound, but also only the makeup pot works in ON-position , like it should.

But here it comes, There is no compression at all. no Meter movement. But then I saw that the power led of the switch got lower , more dimm after a minute or little more. I turned the Unit off and on again , and to my surprise the Compression , the meter and everything , the whole function of the device fades in , like in a swell , and goes away again . like a big wave of normal behavior Wtf is that ??? is it some Power thing, capacitors , or ?? I don't get it . 15v on + and - stays constant all the time.

I could also upload a short video of the behavior if needed,

thanx again !

 

[gyraf]

Thermal shutdown of 12v-line, we've had this before. Search?

 

[antiehdas]

Thermal shutdown of 12v-line, we've had this before. Search?

I searched, and also heard before that the led can cause problems. should I try running it without the leds connected to check ?

UPDATE: Ok, disconnected leds. Even got back to the original stepped switch from ur ssl.pdf. just to get the pushbutton confusion out of the way for now

Meter shoes movement, makeup is working. but no compression, threshold Poti no effect at all.
that's so frustrating...

 

[Script]

Little jumper on front assembly board is installed? Not sure tho all board versions still need it.

 

[antiehdas]

Little jumper on front assembly board is installed? Not sure tho all board versions still need it.

U mean this one ? yes its installed