GSSL add-on help thread

[Script]

Which mode on multimeter? AC?
I attached the SSC Board in good resultion... There is one 47K for OFF and one going to return...

Audio signal is AC. And thanks for the pictture of the SSC filter board. Two 47Ks indeed. Follow traces.. One goes to a 22uf cap and from there to EXT (comp external SC input). And the other one ?

Osaki ni shitsurei shimasu.

 

[TimKR]

Audio signal is AC. And thanks for the pictture of the SSC filter board. Two 47Ks indeed. Follow traces.. One goes to a 22uf cap and from there to EXT (comp external SC input). And the other one ?

Osaki ni shitsurei shimasu.

... take your time

The other one... IC1 PIN 1, 22uf to 47k to Return

 

[TimKR]

... take your time

The other one... IC1 PIN 1, 22uf to 47k to Return

With multimeter in ac, black probe on ground and red behind 47K to return i don't get any different readings when switching through sc settings and tl tm adjusting is like dead... No changes in voltage or on db meter.. M

 

[Script]

OK, that's cos of your grounding scheme. Leave that for now. Instead, connect the black probe to the ground of the SSC board -- for instance by sticking the probe, if it fits, into the 0V of the crimp connector (on left side of board).

P.S.: If interested, for grounding the GSSL you could start read here for example: https://groupdiy.com/index.php?topic=31116.0. Question : Audio ground connected to starground, YES or NO ? -- And if connected, then only at ONE point to avoid ground loop hum).

 

[TimKR]

OK, that's cos of your grounding scheme. Leave that for now. Instead, connect the black probe to the ground of the SSC board -- for instance by sticking the probe, if it fits, into the 0V of the crimp connector (on left side of board).

P.S.: If interested, for grounding the GSSL you could start read here for example: https://groupdiy.com/index.php?topic=31116.0. Question : Audio ground connected to starground, YES or NO ? -- And if connected, then only at ONE point to avoid ground loop hum).

Yes my grounding is like you described - should be fine...

Gonna test with 0V at the ssc board later. Thanks so far

 

[TimKR]

Back by popular demand ???

Everything works properly now...

The problem was that i soldered the lorlin switch like in the pcb grinder documentation, but it didn't matched my front panel labeling. So i resoldered the switch to match the labeling and everything is fine now!

Thanks again for your help Script

 

[Script]

Happy compressing 

 

[Script]

CRC board cap orientation

 

[babaorum]

Hello,
I finish to assembly a GSLL with Turbo option (but without SSC).

I'm a bit lost with my switch which is an Don Audio classic British push Button here the datasheet :
https://www.don-audio.com/mediafiles//datasheets/british-push-button-DAPB400.pdf

So is my wiring seems to you alright ? :

turbo_switch_wiring.png ​

Shared with Dropbox

www.dropbox.com




Because I have a problem with the VU which is full right when compression and zero with no compression with this wiring.

Thanks for help !

Baba

 

[Potato Cakes]

Does it work with the Turbo board hardwired (no switch)? If it does, then you need to verify the switch pins with a multimeter. The problems you are describing sound like an issue with the boards and not the switch unless some of the pins are shorted together.

Thanks!

Paul

 

[babaorum]

So I have resolved a big part of the issue. Now in normal mode (GSSL) it works fine. In turbo mode only on the Right full pan it doesn't compress.
The wiring of my switch was actually wrong because there is a removable part on the button which was totally inversed !

 

[fritz]

Seems like you have a working unit How to calibrate the SSC filters with the trimmers is described above in this very thread twice. You might want to give it a try. It's really not that difficult.
---
5dB (actually 6dB on paper) build-up of sidechain signal in 'Aarhus' mode (not in 'Turbo' mode) is due to sidechain signals simply being mono'ed after leaving the filter boards. This makes the sidechain signal louder and therefore makes the unit compress more (by said 6dB). This is kind of 'normal' for Aarhus mode and observed by many builders, but it makes it impossible to directly A/B with Turbo modes, which is a real nuissance.

FIX: A possible 'fix' is at the audio input resistors to the SSC board. The how-to is actually described above, but worded differently: Those on-board input resistors want to be 10K on both boards for 'Turbo' mode, but on-board 20K on each board for 'Aarhus' mode to compensate for mono-build-up. With 20Ks at the inputs the signals are attenuated down before entering the filters, so that the mono-build-up at the '47K juntion' on the main board yields a signal loudness comparable to Turbo mode. Only then is it possible to A/B the modes at 'equal' compression amounts and really hear at the flip of a switch what the two modes really do.

HINT: (1) you have an unused relay on the second SSC filter board that could maybe be hacked to flip two signals. (2) The PCBgrinder boards come with TWO audio inputs per board for 'L' & 'R' channel signals, which are then mono'ed on-board before entering the filter section, but with two SSCfilter boards ONLY ONE input each is used. On your sketch, you use the L inputs with dark blue and light blue wires. (3) You have DC on your Turbo frontpanel switch.

I do not know the switches that you are using (you have to figure IN that out yourself), but trying to make them activate that extra relay might be worth the effort. Then that relay could be used to either (A) route the sidechain audio IN signal to either a 10K input or 20K input on the SSC board for the two modes, or (B) place a 20K resistor in parallel to an on-board 20K resistor (20K | 20K = 10K). Solution B is how I did it.
---

With turbo and 2xSSC filter boards you have opted to DIY a highly complex unit. You have made it this far and you are almost there...

Hi Script, thanks again for your tips and answers. Before I start the calibration, there is actually another problem that needs to be clarified. After a few weeks of using the compressor, I noticed the following errors:

- when I integrate the unit into my DAW, I use the inputs and outputs number 3/4 on my audio interface. So far so good. In addition, however, the LEDs on the interface for outputs 5/6 also light up, although these are not used. This is weird and shouldn't be.
- I have also observed that the compressor only works reasonably well when I only work with audio files. MIDI files are only played halfway, sometimes not at all.
- I mainly use the compressor on my mixbus, which is then routed to the master bus. If I add another plug-in after the compressor, it can happen that the gr meter display on the compressor goes out and there is no more compression. The same problem also arises when I integrate a signal generator, for example, and then the meter simply goes out and there is no more compression, so I have to turn the unit off and on again.

unfortunately, these properties do not make the compressor a fully functional unit. On the other hand, I have to say that if it works, I think it does what it should. and very well. For fun, I compared the compressor with various replica plugins (also UAD plugins, G Compressor or API 2500). The uad versions come close, but in my opinion the external unit sounds rounder and deeper, especially in turbo mode. wonderful, I'm really very satisfied with the device, except for the problems described above. Maybe you still have an idea why that could be. I'm overwhelmed by this because I now think that it's less a problem of the cabling than of the components themselves. Best regards Fritz

 

[Script]

As for the compressor, maybe, but only maybe, you have a loose cable somewhere inside the unit that connects and disconnects with vibration or whatever. I'd open the unit, run audio through it while its powered up, and poke cables with a pen to see whether audio drops out.

As for the first half of your post about your DAW, I have no idea what you are talking about.

 

[fritz]

As for the compressor, maybe, but only maybe, you have a loose cable somewhere inside the unit that connects and disconnects with vibration or whatever. I'd open the unit, run audio through it while its powered up, and poke cables with a pen to see whether audio drops out.

As for the first half of your post about your DAW, I have no idea what you are talking about.

hi, have now selected everything again after loose contacts, but could not find anything. When checking out, however, I noticed that an xlr input socket is missing a contact. I mean this fourth contact, to which no cable is soldered, but which is connected to the ground pin. I noticed this because there is contact between the other 3 sockets, except for the socket on the far right. Perhaps the socket is broken or defective, so that the signal causes errors in the interface.

 

[Script]

Not an add-on

Speculating, but maybe your soundcard doesn't like your pin 1 connections (loop from soundcard through comp XLRs pins 1 back to soundcard) ? Could try connecting pin1 only on input XLRs to chassis, but not connect pin 1 on output XLRs. Make sure to search for "pin 1" in GSSL help thread and also "Pin 1 problem" on entire forum..

Also, I'd twist the input and output + and - cables from board to XLRs, if cables long enough, and definitely put shrinktube over the + and - solder joints.

That nut on the right is your safety ground ? Looks a bit flimsy. Case is properly grounded all round ? Better check. You 220V country ?

 

[babaorum]

Hello I'm on the end of my GSSL, to add the turbo mode. All is ok in standard mode. When I test the turbo mode, if I pan to the right the signal source, the VU indicates no change, if I pan to the left the VU go to lower level at -4dB (like in standard mode), it's the last issue I have on my project.
I have a little doubt about the THAT2181C I put on turbo pcb which have no indicator for the pin 1 so maybe it's inversed ... I don't know do you think that could explain the issue ...?
Thanks for your help.
I can do a video if you prefer.

 

[fritz]

Not an add-on

Speculating, but maybe your soundcard doesn't like your pin 1 connections (loop from soundcard through comp XLRs pins 1 back to soundcard) ? Could try connecting pin1 only on input XLRs to chassis, but not connect pin 1 on output XLRs. Make sure to search for "pin 1" in GSSL help thread and also "Pin 1 problem" on entire forum..

Also, I'd twist the input and output + and - cables from board to XLRs, if cables long enough, and definitely put shrinktube over the + and - solder joints.

That nut on the right is your safety ground ? Looks a bit flimsy. Case is properly grounded all round ? Better check. You 220V country ?

hi, so if i understood you correctly it should look something like this right?


The + and - contacts are turned on the inputs and outputs and only pin 1 of the inputs are grounded with the chassis

 

[Script]

Output pins 1 not connected at all. You'd bette read up on pin 1 as well as grounding in general.

 

[fritz]

Output pins 1 not connected at all. You'd bette read up on pin 1 as well as grounding in general.

ok, now i got it . It took me a while to find a reasonably understandable article in German. after I soldered this correctly, I noticed the following things:

- no more problems with midi files, virtual instruments and the interface in general, so the re-soldering of the xlr ground was apparently successful

However, I noticed the following errors, which had to be there before, but I didn't notice them because I mostly used the compressor in auto-release and long attack times (10 or 30 ms).
- Anyway, whenever I switch between the ratio up or down, the gr needle slams strongly to the right for about half a second (no sound in this half second).
- If the ratio is set to 4 or 10, the same thing happens with the needle every few seconds without doing anything on the compressor.
- The shorter I set the attack and release times, the more often this happens. It can happen that the gr meter goes out, the compression fails and I have to switch the unit off and on again, so the old problem, but much less than before.
However, if the compressor runs with a ratio of 2 and a long attack (10 or 30 ms) and release times (1.2 or auto), these dropouts do not occur and it does what it should. everything strange here, I am already thinking about buying a new board and re-soldering it, although I can feel that this can no longer be a major mistake

 

[Script]

However, I noticed the following

Search GSSL help thread(!) for "needle" "drop", maybe also "47u" "u47" and "6u8" capacitor orientation, as well as "latch" or "latching".

I have a feeling you might want to use Google website translator to read the threads in German.