GSSL HELP THREAD!!!

[gyraf]

No IC is plugged.

PLEASE try reading up on this help thread before asking - it is originally meant as a reference thread to be read by people that run into problems, it's not meant as a help-chat thread.

What I mean is - your question has been answered numerous times before in this thread: Measure voltages with IC's mounted.

Jakob E.

 

[dirtyhanfri]

Working both channels in my unit, as many times here it was... a wrong resistor value, I put a 470K instead of the 120r in the left channel VCA.

Sorry for be asking to much, it ha been a strange build for me, anyway, it works great, the hum appeared yesterday while I was checking, but when unscrewing the only point of the pcb connecting to chassis it was gone (just turned the screw a bit), so I decided leit it there. Today I'm gonna close the case and rack it.

It's great when you finish something after being troubleshooting it for a while (like 3 months for my unit).

Thanks for all your advices and tips, I got stuck many times and I couldn't go forward without this thread, thanks!.

 

[Spaturno]

No IC is plugged.

PLEASE try reading up on this help thread before asking - it is originally meant as a reference thread to be read by people that run into problems, it's not meant as a help-chat thread.

What I mean is - your question has been answered numerous times before in this thread: Measure voltages with IC's mounted.

Jakob E.

I just plug the IC's and is all working perfect, not really simmetric V+ and V- but audio test was perfect so i#m happy for the moment,
maybe later some fine tuning.
thanks anyway 

 

[Holger]

Something I'd like to share here:
I troubleshooted one of my GSSLs today and found a strange bug in the control PCB: a hole in the circuit path from the pole of the ratio switch to point A. I certainly did not drill the hole in there... Took a while to find it, looks like it was intended, something like a Via. The hole disconnected the pole from point A. Anyone discovered something similar?

 

[gyraf]

Ouch. Looks like a switch center marker teleported from silkscreen to drill layer.

Is it one of Gustav's pcb's?

Approximately from when?

Jakob E.

 

[Majestic12]

I have a small dent there too, but its not a big hole that damages the trace.

 

[Holger]

Ouch. Looks like a switch center marker teleported from silkscreen to drill layer.

Is it one of Gustav's pcb's?

Approximately from when?

Jakob E.

Jakob, I've bought this compressor from a forum member five years ago, so this PCB is very old. I never really used this compressor, just wanted to clean it up. Since the hole is exactly in the center of the switch I assumed that it has something to do with the production process.

 

[dirtyhanfri]

Hi

My clone is working, but I hear (and the meter reads) more compression in ratio 1:2 than in 10:1, I've checked resistor values around the ratio switch and the switch itself (in pos.1 pin A goes to the right point) and everything looks fine. Is it normal?

My understanding says I would get more compression with 10:1 ratio, or I'm misunderstanding something?

 

[ptron]

seems to be compressing more because of the slope. (i believe)...

 

[MeToo2]

Hi

My clone is working, but I hear (and the meter reads) more compression in ratio 1:2 than in 10:1, I've checked resistor values around the ratio switch and the switch itself (in pos.1 pin A goes to the right point) and everything looks fine. Is it normal?

My understanding says I would get more compression with 10:1 ratio, or I'm misunderstanding something?

FAQ. Do a forum search. 2:1 and 10:1 is the slope of the compression. Not the absolute value. Nor is it valid for performance near the compression knee. So set up a test tone at a nominal level and adjust the threshold to give say 6dB compression with the ratio switch on 2:1. Increase your input level to give say 8dB compression without changing the threshold or ratio. How much did your input have to change for 2dB additional compression? For 2:1 that should be 4dB more input signal than your nominal level. Set the ratio to 10:1. Reset your test tone to your nominal starting value, and now re-adjust your threshold to once again give 6dB compression [this will almost certainly NOT be the same point as for the 2:1 ratio setting!]. Now increase the input tone to generate 2dB more compression without changing the ratio switch or threshold = 8dB total compression. For 10:1 ratio that should now require 20dB more input signal above your nominal level (10*2dB).

 

[dirtyhanfri]

Sorry for the FAQ, It's hard to find info on this thread sometimes, and I didn't remember any comments about it on the forum, but usually I don't like to ask every step I do. Anyway, thanks a lot for the explanation, it makes sense now.

I've been messing with test tones, measuring attack/release times, just when looking if the ratio setting makes any effect on the time response I noticed it.


BTW a pic of the "almost-finished" unit, I've replaced the meter graphic for a black one with white lettering, marking 3, 6 & 9 db's of GR. For the front pannel I used a vinyl sticker, cheap and nice, but not so sure about durability...

Thanks for the replies and tips, you guys are great

 

[ptron]

hehe cool picture diy totally

sorry bout last post (very brief) i meant the knee on the slopes are different on each ratio...

good to see some vynil sticker at last!! ive done laser router .. it just burnt the anodized .. looks nice but ill try silkscreening next time..

cheers!

 

[dirtyhanfri]

good to see some vynil sticker at last!! ive done laser router .. it just burnt the anodized .. looks nice but ill try silkscreening next time..

For the next project I'll try to paint the pannel, get only the lettering in vinyl, and then varnish the whole thing.

Back to the topic, I've been messing with it and I understand it better now, and really like it, just played some mixes and I like it, maybe I find it a bit difficult to set up propperly, but when you finally fit it into the song is just great. Actually I've routed it in my patch pannel just at the mixer output, after a poor mans pultec and I'm just pleased!

 

[MeToo2]

Sorry for the FAQ,

I didn't mean to be short with you: I'm just busy at the moment. Glad to read you're happy with the result!

 

[dirtyhanfri]

I didn't mean to be short with you: I'm just busy at the moment. Glad to read you're happy with the result!

No prob

 

[beatnik]

Please can anybody confirm this is a suitable switch for GSSL bypass?

http://www.digikey.com/product-search/en?x=0&y=0&lang=en&site=us&KeyWords=KB26SKW01-5C-JC+

I'm confused by the lamps. This one has red LED with no resistor. The GSSL bypass works on 12V so should I add a resistor by myself or choose another switch?

Here is the datasheet for the KB series by NKK

http://www.nkkswitches.com/pdf/KB.pdf

 

[gyraf]

As it's a DPDT, it should be useable for bypass

BUT you can't get light indication for bypass as well - that would take one more switching unit, as we use both switch parts already (one for disabling GR and one for disabling makeup gain in bypass)

For bypass light indication, an additional relay would probably be needed (I'm sure it has already been discussed around here).

Jakob E.

 

[Harpo]

...This one has red LED with no resistor. The GSSL bypass works on 12V so should I add a resistor by myself ...

When your 'GSSL bypass' is operating from 12V, you might be refering to the gssl-supersidechain board. The switch will work with this circuit to activate the relais and a current limiting resistor (2K2) for the LED is on pcb.

 

[beatnik]

Thanks for the quick responses.

So an additional relay is a must... But in this case, I could even go with a SPDT switch, because is possible to  switch both the illumination and relay with the same pole. Am I right?

About the relay... I'm not really an expert. What parameters should I consider apart from the 12V operation and DPDT configuration?

 

[Harpo]

... I could even go with a SPDT switch, because is possible to  switch both the illumination and relay with the same pole. Am I right?

Yepp

What parameters should I consider apart from the 12V operation and DPDT configuration?

IMHO high coil resistance, non-latching type (something like maybe OMRON G6H-2), and don't connect it to the +/-12V rails. Use a voltage dropping resistor in series between +15V and 0V or 0V and -15V or use a 24V relais type and connect between +/-15V with the voltage dropping resistor in between.