GSSL HELP THREAD!!!

[vertiges]

[quote author="ixi"]it's maybe preble in conection btw main and control board. I have now for conection cabel from computer witch conect Harddisc & mainboard!
It's this cabel OK or NO
[/quote]

No problem at all with a computer cable !

eD

 

[ixi]

[quote author="vertiges"][quote author="ixi"]it's maybe preble in conection btw main and control board. I have now for conection cabel from computer witch conect Harddisc & mainboard!
It's this cabel OK or NO
[/quote]

No problem at all with a computer cable !

eD[/quote]
OK :wink:

 

[ixi]

[quote author="vertiges"]I'm glad, you finally found what caused the 5.1 dB "offset" between L and R. You see, most of the time the problems come from shorts, bad solders or errors in the component values. Sometimes it's good to take a break and come back later.
For the problem of no compression : there are a lot of cases described and solved in this thread... I know it's long one, but il also the more documented one ! I'm pretty sure all the possibilities of errors/mistakes have been covered...[/quote]
This is't now OK


[quote author="vertiges"]1) is the orientation of the THAT chip in the sidechain correct ? You can also try to swap it with one of the channel for being sure it works correctely. Pay attention if you put the 2180 in the wrong orientation in the sidechain socket, you'll destroy it. (I know what I'm talking about... :green: )[/quote]

Orientation of the THAT chip in the sidechain it's OK, i'm shure, i swap it with one from the channel.

[quote author="vertiges"]2) is your bypass is wired correctely ?[/quote]

Bypass it's wired correctly!

[quote author="vertiges"]3) have you checked all the connections between the main board and the control board ?[/quote]

Connectio btw main and control PCB it's OK.

I Check with multimeter :

[quote author="vertiges"]TL072 pin1 should change with threshold variations (and with the signal level) [/quote] OK
[quote author="vertiges"]TL072 pin7 should change with makeup variations (and with the signal level) [/quote] OK
[quote author="vertiges"]TL074 pin14 should change with the ratio settings (and with the signal level) [/quote] OK


[quote author="vertiges"]5) Check if you have signal coming at the input of your sidechain: pin 7 of the TL074.
You must have DC varying with signal at the output of the sidechain: pin 8 of the TL074.[/quote]
How i this check ??

Just for info: when i remove thid TL074, sound goes through, and threshold acts as ratio! It's that OK ??

Thx

 

[ixi]

Hi, vertiges!

You said me let remove this 2 resistor - it's this OK ?
I read posts on forum, and i see mush picture when it's resistor 10K inside ???

 

[MartyMart]

I have a second GSSL about 1/2 done, do the 22uf's have to be 25v and
good quality ?
I have 16v ( pushing it a bit ) and plenty of 47uf's @ 25v.
If so, any suggestions for a "type" ?
Ta,
Marty.

 

[ixi]

Thx vertiges & Harpo!

Now working :razz:

Problem: One of chips was broken (TL072 or TL074)


Thx one more time, and see yaa on nex project )) i worship beer :sam: :guinness:

 

[vertiges]

[quote author="MartyMart"]I have a second GSSL about 1/2 done, do the 22uf's have to be 25v and
good quality ?
I have 16v ( pushing it a bit ) and plenty of 47uf's @ 25v.
If so, any suggestions for a "type" ?
Ta,
Marty.[/quote]

Hi Marty,

Actually they are in the audio path... It's important.
I used Black Gates in my second GSSL. I haven't had the time yet to AB-test with my first one (Panasonic FC). Both sound great to me... :thumb:

From Greg : "Panasonic FC electrolytics, for a very hi-fi type sound (extended top and bottom with mid scoop). Nichicon PW for smoother sound with lush mids (my personal favorite). "

eD

 

[vertiges]

[quote author="ixi"]Thx vertiges & Harpo!

Now working :razz:

Problem: One of chips was broken (TL072 or TL074)


Thx one more time, and see yaa on nex project )) i worship beer :sam: :guinness:[/quote]

Ixi, that's a great news... What about some pics of the finished unit ? :wink:

eD))

 

[ixi]

SSL01:








SSL02:








This is my product :razz:
Now i work on Steffen's GSSL High Pass Filter & APi Trust

 

[MartyMart]

[quote author="vertiges"]
Hi Marty,

Actually they are in the audio path... It's important.
I used Black Gates in my second GSSL. I haven't had the time yet to AB-test with my first one (Panasonic FC). Both sound great to me... :thumb:

From Greg : "Panasonic FC electrolytics, for a very hi-fi type sound (extended top and bottom with mid scoop). Nichicon PW for smoother sound with lush mids (my personal favorite). "

eD[/quote]
OK, have ordered some "audio grade" Panasonics, could be SK series ?
Not too expensive, about 29p each, hope they are OK !!

MM.

 

[MartyMart]

One last thing, I'm short of three 0.47uf tantalums for the control board.
Do they HAVE to be tantalum as I have a ton of poly's in that value, non
polar of course, may have some electro's too though ???

Ta,

MM.

 

[vertiges]

Hi Marty,

The tantalums are the timing caps (attack, release).
Tantalums are good for that kind of things as they have a very stable capacitance.

eD))

 

[ixi]

hi, im back

i much work in studio.
now i made SC HPF by Steffen, when connected him on PCB compression doesn't work :shock: , whem remove SC modul compression work.

It's here another special trick ???

Thx

 

[Harpo]

[quote author="ixi"]hi, im back

i much work in studio.
now i made SC HPF by Steffen, when connected him on PCB compression doesn't work :shock: , whem remove SC modul compression work.

It's here another special trick ???

Thx[/quote]
Hi ixi,

doublechecked your supply voltages at opamp pins 4 (-15V) and 8 (+15V)?
Maybe something wrong with your wiering.
Should be wired something like this

 

[ixi]

[quote author="Harpo"]Hi ixi,

doublechecked your supply voltages at opamp pins 4 (-15V) and 8 (+15V)?
Maybe something wrong with your wiering.
Should be wired something like this [/quote]


I have PCB by Greg.
I check wiering, everything looks OK.
When i conect this in chain => no compressio and
in this case is also makeup gain dead.
supply voltages at opamp pins 4 (-15V) and 8 (+15V) its corect.

I don't no whats i make wrong :? :grin:

 

[Harpo]

could be a faulty switch or opamp.

Feeding the input of your gssl with a signal, you should be able to measure (or listen to) the same inverted signal at the 'SND' point after the first opamp stage.
Case not,
- there probably is a short between opamp pin-1 and pin-2
- or the opamp is broken.

If the first stage passes your signal, measure (or listen to) this signal at the 'SW' point (center-terminal 'A' of your lorlin switch). Depending on switch position (pos. 1,2,3,4,5) and your signal frequency you should be able to measure (or listen to) the same or a little lowered signal.
Case not,
- the switch is broken, replace it,
- you don't have a 1x12 but a 2x6 lorlin and connected to center terminal 'B' instead of terminal 'A',
- the end-stop washer was placed to pos.6 when the switch was in a higher step position, now switching between pos. 7 to 12. Pull out the end-stop washer, turn the switch full ccw and place the washer back to end-stop pos.6.

Measure (or listen to) this signal at pin-7 of your opamp or between C10/R8 ('OUT', the right side of R8, is current, not voltage, so not audible when connected to your gssl). With potentiometer centered (R7+RV1=6k) you should read ~0,5x (-6dB) of the previous level. (replacing R7 from 1k to 5k6 and keeping RV1 near center (R7+RV1=12k) will set this stage to unity (+/-0dB) with the option to adjust back to -6dB).
Case not,
- there probably is a short between opamp pin-6 and pin-7
- or the opamp is broken.

edit: "When i conect this in chain => no compressio and
in this case is also makeup gain dead." Doublecheck if +/-12V on GSSL pcb is still alife at TL072 pin 4+8 or TL074 pin 4+11.

 

[ixi]

Hi Harpo!
First thx for answare.

I found mistake, again bed stuff - lorin switch i replaced him and now is OK.
Say me please, witch function have this trim pot 10k on picture in this SC HPF ???

Another question it's: Can i here conect of extra LED, and it won't harm activity of compressor ?

 

[Harpo]

[quote author="ixi"]Hi Harpo!
First thx for answare.

I found mistake, again bed stuff - lorin switch i replaced him and now is OK. [/quote] :thumb:

[quote author="ixi"]Say me please, witch function have this trim pot 10k on picture in this SC HPF ???[/quote]
Function of this 10k trimmer RV1 in the feedback loop is to adjust the gain of this inverting gain stage. With Rin (R6) 12k the voltage gain (1k+RV1)/12k can be trimmed from 0,08 (RV1 full ccw) to 0,917 (RV1 full cw). Convert this to a dB reading by log10(voltagegain)*20 = -21,58dB to -0,76dB. Some like it adjusted to a -6dB level, this is voltage gain of 0,5. This is set with trimmer RV1 centered (5k). If you don't like to fiddle with adjustment, replace the (1k + 10k trimmer in series) with a 12k resistor for +/-0dB or 2x 12k resistors in parallel (giving 6k) to get this -6dB level.
Only R6 (12k) is part of the hpf circuit. The -3dB hpf cutoff frequency is set by 1/(2*PI() * R6 * (C4,C5,C6 or C7, depending on switch position)), giving 195, 133, 88 or 60Hz.

[quote author="ixi"]Another question it's: Can i here conect of extra LED, and it won't harm activity of compressor ?[/quote]
For usual no problem expected. Make shure to have a sufficient rated resistor in series with the LED. You'll have to drop ~28V between +15V and -15V. For usual more than 10mA LED current is too bright. (30V - ~2V LED)/10mA=~2k8. I'd try a 3k/0,5W in series with the LED.

 

[ixi]

Harpo Thx for answare. :razz:

My next project is API-Thrust MOD, so that probably i needed another direvtive. :grin:

Thx one more time and have nice day.

 

[guavatone]

I could be wrong. But are the Outputs + and - reversed on the schemo in relation to the PCB?

I am trying to scope my noise but for last half hour I can't seem to find the paths.