GSSL HELP THREAD!!!

[G-Sun]

Install the missing 2K resistor to see action on the DC meter.

Thanks a lot! Found a 2k2 resistor. Will see how that goes.

 

[G-Sun]

My pwr transformer reads:

Primary: 0-230V blue-brown
Secondary:
0-15V:  org, yel
0-15V: blk, red

I have black and yellow wired together > board green 0V
Red > board red
Orange > board yellow

Seems right to me.

 

[G-Sun]

Rectifier seems good, reading:
+- 23-24,5V

 

[G-Sun]

btw: Where is the 79L12 regulator for the -12V
It's on the schematic but not on the component-placement/pcb.

 

[G-Sun]

Ok, I believe I've pinned it down to a bad ts7815 regulator
in is +24,2V
Out is +0,8V

 

[Potato Cakes]

Hello everybody!

After putting it on the shelf for 9 months, I just finished my GSSL with Cavendish, Parallel mix, and super side chain, and it all barely fits in a 1 space rack unit. Before I put everything back inside, I noticed that when running tests, I seemed to get more compression at lower ratios then higher ones. I wanted to double check this with some sort of compression curve graph, and the only thing I could find was one on the Alan Smart C1, which shows that higher ratios kick in at higher thresholds, similar to the 1176. Is this the same case for the GSSL or do I have one last thing to trouble shoot?

Thanks!

Paul

 

[Potato Cakes]

Here it is.  This was my first attempt at doing a rack mount piece as I said before was put on the shelf for quite sometime. I did all the rookie mistakes on this one: backwards opamps which fried the 10 ohm resistors (twice), some cables from ratio board to main board were swapped, one side of a capacitor not quite soldered in place, and a couple cold solder joints to name a few.

I modded one of Dan's GSSL case's to accommodate more knobs for the side chain selection and wet/dry mix. I cut a square hole where the power switch is supposed to go and put in a SSL style push button to turn compression on/off. I had to cut out the back panel to fit a switched IEC receptacle. The parallel mix board is near the power transformer and yes it does cause a hum, which I'm hoping to remedy with some transformer shielding material. If not, I'll have to rearrange the whole thing which will be annoying as there are a lot of cables crammed in that guy. Now to find the missing screws to put the chassis back together.

Also, there seems to be a stray orange piece of wire just laying in there. I think that helps with thermal inductance transfer suppression from other units in the same rack. I will consult the gearhead websites for actual terminology.

Thanks,

Paul

 

[Potato Cakes]

Another photo.

 

[Potato Cakes]

And the second one done. With turbo and CRC.

Compression works as it should from the get go. Now my only problem is that I've burnt out the yellow LEDs in the push buttons trying to get the lights to work with the meter LEDs. It seems these die much easier than the blue ones. I've manage to kill three of them now after finding out what I was doing wrong. I opened one of them up to see if I can just replace the LED, but after prying one of the open I'm sure I'll just break them in the process so probably better to just source some new ones. Does anybody know of a US source for the yellow push button switches?

I thought I had ordered the standard issue front panel, but I got the one with the Super Side Chain, which I have no plans to put in there since I am using the turbo and I have it on my previous build. The only thing that I can think of is to put a switch in there to be able to put transformers in line to the output that are either 1.5:1 or 2:1. The idea is if for some reason the there is a need/urge for unnecessary transformers, one would have to drive the output harder hitting the transformers harder, and, well, you guys know the rest. If I don't think of something I'll just order another front panel so I won't have an unused drilled out spot. Going to use it on a project this weekend and I hope it does what I think it will.

Thanks again to Jakob, Expat Audio guys, Don-Audio, and Gustav for their designs and making these products available!

Thanks!

Paul

 

[Potato Cakes]

The outside.

 

[HarthaX]

Hey  Potato Cakes,
Great looking build. I recently spent about 8 hours wiring up my unit. when I finally went to turn it....nothing happened. It did not power up. I think my confusion comes from trying to wire the iec/switch combo i have with the push button i have on the front. looking at your photos i can see that you have the same iec and same push button as I do and i was hoping maybe you could elaborate on the specifics of how you wired it. its not completely clear to me based on your pictures. anyway. great looking build. Thanks.

 

[Potato Cakes]

HarthaX,

I am not actually using any of the push buttons to switch the power on. Even though one of my builds has the buttoned labeled as power, I am actually using this to turn the compression on. I figure you would just use take the hot lead from the IEC switch to the push button switch to one of the primary inputs of the power transformer.


Paul

 

[G-Sun]

Finished! All working

Thanks a lot to: The original designers, Jakob, Gustav, Michael and Frank!

Unfortunately I've changed my idea of workflow,
and the Gssl seems not so usable for tracking.
So, this one goes for trade/sale.

 

[stanmart]

Just built a mic and mod GSSL. Im having faint output out of right side and nothing out of left bypass or not. I have signal coming in. The gain reduction needle is active when running sine wav.

I check voltages in a bunch of spots. Transformer is getting 18V AC to the PCB. Around 23.6 to 24 volts on transformer side of rectifiers.

Voltage Regulators

78L12 11.95V DC on pin toward side chain and other side 14.68V DC

79L12 -12.25 DC on pin toward side chain and other side nothing. Maybe this is the problem? I did a continuity check and the leads beep that are connected to that lead.  But no Voltage.



IC Socket Pins 7/8 <  i think these are pins 7 and 8. Only ones giving voltage readings

2 5532P on output section are both reading 14.79 PIN 8

2 5534P on input section are both reading 14.79 PIN 7

2180 VCA sockets both read 14.79V DC

2 5534p in VCA section both read 14.79 DC

TL072 is 11.95 V DC

TL074 is -12.25V DC Sidechain side and 11.96v DC input output side.

Any insight you guys could give would be awesome. I have heard there are manufacturing flaws with these boards.

 

[G-Sun]

Any insight you guys could give would be awesome.

The obvious: Check solder-points and wiring

 

[stanmart]

What is the watts of the two 10 ohm resistors on supply side? I got 1/4 watt replacements and i think they are too low.

Bah.

 

[stanmart]

Can someone post a pic of what all the voltages should be around the main PCB and control board? I cannot find anything to save my life. Need to know what to measure and what all the voltages should be in all points so i can narrow down what is ailing this thing. I think i know i gotta be missing some. 

I checked all IC socket pins and im getting really close to + and - 15V and + and - 12 volt up top. Seems right according to what im reading. My main rails are reading close to -15 and +15. My supply side voltage is 18 v AC on the dot. Im getting almost 24 volts DC on the supply side. near 15 and 12 after regulators. Im getting 15 and 12 at the transistor looking rectifiers as well.

I got sound coming thru clear as a bell but im not getting any compression. None of the front panel knobs are doing anything. I changed out all IC chips too. they are in correctly. 

Im scratching my head. Thanks guys. This is a pesky build. Hardest one yet for me.

 

[Gustav]

Can someone post a pic of what all the voltages should be around the main PCB and control board? I cannot find anything to save my life. Need to know what to measure and what all the voltages should be in all points so i can narrow down what is ailing this thing. I think i know i gotta be missing some. 

I checked all IC socket pins and im getting really close to + and - 15V and + and - 12 volt up top. Seems right according to what im reading. My main rails are reading close to -15 and +15. My supply side voltage is 18 v AC on the dot. Im getting almost 24 volts DC on the supply side. near 15 and 12 after regulators. Im getting 15 and 12 at the transistor looking rectifiers as well.

I got sound coming thru clear as a bell but im not getting any compression. None of the front panel knobs are doing anything. I changed out all IC chips too. they are in correctly. 

Im scratching my head. Thanks guys. This is a pesky build. Hardest one yet for me.

Since all your voltages to active components are good, I would not worry about voltages on the rest. You can check if you are getting 12V +/- through the lines on the 10 way connector (check schem for which lines), but other than that, I would look at how the bypass is set up.  For further signal tracing, a scope would be nice, but you could also use a simple speaker-to-wire probe.

Is this an illuminated push-button build, or are you using a toggle or rotary for the bypass? If its the first, your problem is common, and it has been solved quite a few times in this thread.

Gustav

 

[stanmart]

I am getting 12 at the pad next to F. I am also getting 12 at the power led. Just for testing sake. I tested the 6 resistors to the left of attack. Nothing there. I believe they are connected to D. But power could depend on which switch the attack is on im guessing? How much power should be at D connection?

Im using illuminated push button. What are some of the common problems? I swear i have this thing wired right. But i might be wrong. Any good links on the push buttons? Maybe that's my issue.

Thanks again.

 

[stanmart]

Oh and should all lettered connections on control board be giving me a reading?

Not familiar with speaker wire probe. Is there a cheap oscilloscope out there you know of. I'm sure it would make life easier.