GSSL HELP THREAD!!!

Hell yeah, it's working first try, everything seems fine. Just the Meter sometimes stays in the middle, but I think its the test-wiring. Need to order the Front and Start wiring the sidechain. Thanks guys

cray said:

weiss said:

what voltages do you read coming out of the transformer?

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i dont know if the question is for me.

i dont want to connect it before asure its ok and working. i know the best proof is to connect and measure.

but reading about it.. measuring  the resistance..you can know if its ok.


Im . right?

thanks

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measuring the secondaries,
connected in serie:  tapered with blue  gives 18v.
tapered with green , nothing. so  one secondarie is dead .

if i measure from blue to green..18v. Here i must get 30v more or less..right?

i need a new one right?

thanks!

Random question:

I've got some OPA1642 chips that I've mounted on DIPP adapters, just sitting in my desk.  I was wondering if anyone had tried them in 5532 positions, who has a scope.  I think the unit sounds great, with the 5532s, but I figure, why not try the others?  The only thing that's stopping me, from trying a swap, is that I don't have a scope, and I often see that you should check swapped opamps for oscillation, if the difference in slew rate is too high.  The 1642s are twice as fast, so I thought that might be an issue.

glenn

Most of "sound" comes from VCA's (this is by far the weakest link), so there's not really anything to be gained from upgrading opamps..

Jakob E.

Hey, since there is no schematic, I was wondering if the link in the SSC board has to be connected. I think it is an Option, but not sure and couldnt find anything. Thank you.

Hi Folks
I have a problem with my GSSL witch is kinda hard to describe.
But to put it simply, as soon as I engage the compressor or un-bypass it the compressed signal sounds very tinny or plate-reveb sounding.
Not squashed or overly compressed  like if you compress a pair of room mics to get more ambiance for eg.

Other then that it seems like the attack and release works properly. But i have to have the makeup-gain turned all the way to make the signal same as input level. So there is some loss along the way i think.

I don't quite know where to start fault tracing. Anyone got a clue? Should add also that this is the normal gyraf pcb with no mods. THAT VCA's.

Hey GSSL gang! I case some of you are interested, I am selling some front plate printing here : http://groupdiy.com/index.php?topic=58817.0

Hit me up if you have any more questions!

Thomas

Byzance said:

I don't quite know where to start fault tracing. Anyone got a clue?

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Yes - read this thread, looking for something similar. This help section is not meant as a online help-chat, but a place to look up fixes to various problems

I fully understand it's a long read, but there is so much great information and error-tracing information collected here. No matter how the outcome, you'll learn important things from this.

Jakob E.

Hello, after finishing the wiring for the SSC, my Meter still sometimes hangs in the middle position. It continues to show the gain reduction if I slightly tip on it. It seems, that it also continous if the threshold is further lowered, that the reduction is higher than half the range. Anybody some suggestions? Could it be a mechanical issue? Thanks.

Yes, can't really be anything but a mechanical issue.

Look closely, and you may be able to identify and fix the problem.

Just don't get any magnetic dirt (like metal shavings or cut-off component pins) in there while it's open - this most often makes it unfixable.

jakob E.

Hey guys.

I just wanted to say that i finally got my unit up and running. I was reporting awhile back that my gssl was "gating" the signal over thresh..
It turned out the two 120R resistors right next to the VCAs were 10k ones (code read backwards >.<). With those replaced with the proper resistance ones my Comp is compressing and working just fine.

The only grape I have with it right now is the ammount of noise it generates. I have read that this kind of noise can be due to "transformer sag" - but I don't have any accessories whatsoever powered by it. May this be a ground issue? I tried to ground the xlr jacks and the pots by hand (directly running a cable from transformer ground). This din't lower the noise, though.
I'm running a 2x15V 30VAC transformer with the onboard PSU.

Thanks for any advice!

Edit: I mean the noise isn't bad. When I run pretty hot signals through it, you won't notice. But I like to keep quiet some headroom on my master with my mixes. It would be nice if the SN ratio would be a little higer for that.

TheBassgasm said:

It turned out the two 120R resistors right next to the VCAs were 10k ones (code read backwards >.<). With those replaced with the proper resistance ones my Comp is compressing and working just fine.

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You'll need a little luck for a 'working just fine' condition and it obviously isn't that fine ...

These 120Rs are part of a voltage divider in the 'DBX202 emulation circuit'. Ignoring there might be any audio signal present, the amount of makeup gain is set by a pot connected between +12VDC and 0V reference voltage. This 0...+12VDC voltage range at the pots wiper connection is setting the amount of gain in the following inverting summing stage with factor -100K/620K, so the DC control voltage will be in range 0V...-1.935VDC at the output of the TL072. Before the L/R split to the parallel (shorted out) 1Ks and the emulation circuits is a common to both 100R, so depending on connected load with given parts values, the 'CV to VCAs' point will have a voltage 0V...-1.769V or 0V...-1.642V. This voltage will reach prementioned voltage divider in front of the non-inverting NE5534 buffer (the 'DBX202 emulation circuit), so the VCAs control voltage is padded down to -1.642VDC*120R/(1K+120R)=-0.176VDC (or -1.769VDC*120R/(1K+1K+120R)=0.10VDC if the 2.nd 1K resistor would have been mistakenly fitted) just by turning your makeup pot full CW without any audio signal. Substitute this 120R resistor with your mistakenly fitted 10K one will give you -1.900VDC*10K/(1K+10K)=-1.728VDC (or -1.904VDC*10K/(1K+1K+10K)=-1.586VDC if the 2.nd 1K resistor would have been mistakenly fitted). This is far exceeding the assumed fitted THAT218x VCAs Ec ports absolute maximum rating of +/-1V between VCAs pins 2/3, just in case you ever turned the makeup pot full CW with the unit powered on, so these audio-VCAs might be damaged.

just my 2ct.

edit: calc was missing the single 100R between makeup summing amp and both parallel DBX202C_to_THAT218x 50mV/dB to 6.1mV/dB scaling attenuators. 
(For similar behaviour as the 50mV/dB control law DBX202Cs, both 120Rs in the emulation circuits would better be 167R with one 1 K resistor fitted or 307R with two 1K resistors fitted in order to scale down for factor 6.1mV/50mV.)

Wow, Harpo.
Thanks an awful lot for this very elaborate answer!

I do have two 1k resistors fitted within the DBX emulation circuit. But they are just the ones printed onto the pcb - did you mean those?
The makeup pot, in absence of knowledge, most certainly has been fully CW at some point. 

Thank you very much again for helping me out. I'll think about whether two new 2180s are worth the try for me.

Cheers!

Gustavs kit:
I forgot to cut the wires from panel pcb to main pcb,
so they are 25-30cm.
Is that a problem?

I've been searching this board all night and can't find my answer  :-\
I have the suggested EAO push button switch for using a push button bypass.. I am not using a side chain board. I can't find anything on how to construct the relay board I've been reading about to get it to work since it doesn't have 3 poles. Any help? I don't want to come off a lazy because I really have tried to find this information. This is. PCB Grinder Kit

Jeffhucik said:

I have the suggested EAO push button switch for using a push button bypass..

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Be a lot less vague (this will have a part#). The EAO configurator (EAO for sure?) lists 3466 different illuminated pushbutton switch products (or 691 different pushbutton switches without illumination). They differ in lots of parameters.

..the relay board I've been reading about..

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Might be useful to provide a link to the thread/this specific relay board in order to be talking about the same subject. This might be switch dependant as well...

Does this pcb look to be stuffed correctly?

Here is another section of the pcb, is there anything amiss here?

And the last pic, covering the rest of the pcb.  If anyone sees anything please respond.  I build aerospace structures, but am not quite adept at troubleshooting, I bought these pre-stuffed from a member.  After probably $1000 worth of parts and payments I long for this unit to be functioning.  I will not sell it! All help is greatly appreciated.

Hey, first I want to thank the people that help all the beginners and first timers here!
As I'm also one of them I hope you can help me too
Okay, I populated the board and now I'm placing my (hopefully) last order. After I ordered the false power toggle switch (https://www.reichelt.de/Kippschalter/KS-C3900/3/index.html?&ACTION=3&LA=5000&GROUP=C21&GROUPID=3275&ARTICLE=105429&START=0&SORT=artnr&OFFSET=500)
I now want to be sure the one I'm about to order is going to work.
http://www.digikey.de/product-detail/de/M2022ES1W01/360-1832-ND/1006911
This is the Power Transformator I have
https://www.reichelt.de/Ringkerntrafos/RKT-3015/3/index.html?&ACTION=3&LA=5000&GROUP=C55&GROUPID=4539&ARTICLE=15275&START=0&SORT=artnr&OFFSET=500

I would also like to use the Power LED thats included in the PCB Grinder Kit and the Meter LEDs. Can I power them both with the auxiliary 12V output?
I'm building the basic Rev. 11 GSSL without any mods.