GSSL HELP THREAD!!!

[intellijel]

I have a GSSL with THAT2181LA for all three VCA's.

I performed all the mods as described here: http://diy.fischerworks.com/gssl_vca.shtml

My issue is that I don't think this compressor is working properly. When I adjust the threshold and compress a tiny bit it seems ok, but as soon as I drop the threshold to the point where the compressor should be pumping, all I get is a much more distorted sound. When I crank the threshold all the way down then the volume drops dramatically.

I have meticulosuly checked every resistor value and solder joint a ridiculous amount of times now. I have no idea what is causing the problem... I am at the point where I may be willing to pay someone to look at this for me!!

Any clues?? Should I upload some photos and videos of me using it?

 

[NickLost]

Hey guys I'm putting together my parts list since I can't seem to find one up to date for the us and I have a quick question. Will the rohs complkiant versions of the op amps work? for example. NE5534APE4 instead of NE5534AP. I'm sorry if this is a stupid question but I am very new and am worried about buying the wrong thing. Thank you for your help in advance.

 

[andreimusic]

Hey that's great!!!

Will you be willing to share your part list when you finish it??

I'm planning to build my GSSL in very near future... as soon as I finish La2a....  8)

 

[loicmoreau]

hi everybody
i finished my gssl and i have a really wierd problem .
when i power up my gssl there's no sound untill i make a short between pin 6-7 on the that2181c of the left vca .
i noticed that while scratching between solder points on my board with a screwdriver.
it makes a little spark (probably not that good i guess) and after that everything work normally (comp sound nice on both channels, meter, knobs, bypass, power on led, everything work as expected)
it's a gssl without any mods
if anybody have any idea i would be very greatfull
thanks in advance

nevermind i tried the two 100nf/50v caps and a 1N4007 diode power trick and my problem is solved

 

[NickLost]

Yeah I will have no problem sharing once its done.

 

[tskguy]

Hey Yall,

I just finished wiring up my GSSL and in the process noticed I forgot to order a tl072 opamp. So I went to the trusty bin and found a tl052. I did a little research and noticed that it should be ok. What do you guys think? Im mostly a plug and play guy so Im not sure if I should change some things or just get a 072 and call it good.So far everything seems fine, maybe the makeup gain is a little low and  my meter seems unsensitive. But the sound I get through is plesent and quite. From reading this thread It looks like the meter issue can be resolved easily, but what should I do about th tl052 vs tl072

Thanks Eric

 

[tskguy]

Wow thanks for all the help guys!    :-\

Well I figured out that yes the 052 is fine! The datasheet says its a drop in replacment for a 072. Got that sorted.
And the meter and makeup gain was a problem becouse the +12v feed wire was pulled by accident so no positive voltage was going to the threshold and makeup gain pots.  Now everything seems to working fine!!! Sounds pretty darn nice.

I just need to put it in a case!

Eric

 

[ytsestef]

You should have given it some more time, every question gets answered here, no matter how obvious. 22 hours isn't enough though, as most people sign in every second day or so.

Anyway, IIRC from reading the texas instruments datasheet the TL05x series are direct upgrades to TL07x and TL08x BiFET opamps, introducing faster slew rate without increased consumption. The pinouts seem to match, too. But you already know that, now  ;D

Glad your box works, happy compressing!!  And DON'T OVERDO IT!!! 

 

[tskguy]

I Know....I should be more patient :

You know how it is. Thanks for the conformation regarding the tl052 a second opinion always helps.

This sight is very cool glad for all the help!

Eric

 

[regularjohn]

So I've been trying to figure out how the threshold is tied to the ratio, which is something I'm starting to find irritating.  I'm wondering if it has to do with the 1M2, 1M8, and 3M9 resistors on the daughterboard.  Those three resistors are connected respectively from each ratio to the threshold pot.  In order to "de-link" the threshold should they all be an identical value, so that when changing ratios it behaves like a normal compressor (ie - increased ratio increases GR)?

Or does it have to do with the 510K, 270K, and 68K resistors on that connect to "B"?

I'd really like to find a way to get rid of the link between the ratio and threshold.

Anyone messed with this?

 

[regularjohn]

Ok, so after comparing the GSSL schematic with the 82E26 and 82E27 card schematics the only differences I'm seeing between the ratio and threshold sections are a pair of 10uF caps going to ground between the ratio resistors and +/-12, and a pair of 3K9 resistors between +/-12 and the threshold control that aren't on the GSSL.  Are these couple of components enough to seperate the threshold from the ratio?

Also, I noticed that the Auto release setting on the GSSL schematic is wrong.  The resistor/tant cap pairs are reversed, however they are correct on the pcb.  According to the original SSL card schematics anyway.  (I think someone earlier in this thread was saying they were backwards on the pcb).

 

[Chrome Heart]

Hey guys I'm putting together my parts list since I can't seem to find one up to date for the us and I have a quick question. Will the rohs complkiant versions of the op amps work? for example. NE5534APE4 instead of NE5534AP. I'm sorry if this is a stupid question but I am very new and am worried about buying the wrong thing. Thank you for your help in advance.

It shouldnt make any difference. Just make sure you socket them.

 

[Chrome Heart]

Finally finished #3 with turbo.

 

[mokkinger]

I have a GSSL with THAT2181LA for all three VCA's.

I performed all the mods as described here: http://diy.fischerworks.com/gssl_vca.shtml

My issue is that I don't think this compressor is working properly. When I adjust the threshold and compress a tiny bit it seems ok, but as soon as I drop the threshold to the point where the compressor should be pumping, all I get is a much more distorted sound. When I crank the threshold all the way down then the volume drops dramatically.

I have meticulosuly checked every resistor value and solder joint a ridiculous amount of times now. I have no idea what is causing the problem... I am at the point where I may be willing to pay someone to look at this for me!!

Any clues?? Should I upload some photos and videos of me using it?

Hi
I don´t know exactly about your distortion problem, but I am having something quite similar here. I finished my GSSL a while ago, with turbo board and the 2 sidechain boards, and it works fine on f.e basic  808 drum beats and stuff, with Release set between 0.1 and 0.6 sek...but at 1.2 sek and more (Auto, think it´s 2.4 sec??) I get some quite heavy distortion as well, which really doesn´t sound nice. I already checked all the trimmers on the sidechain boards and set them according values to the calibration process posted here in the sidechain manual, so I don´t have a clue where to start the debuging.

Could anyone explain to me how I could check for the right calibration / setting of the sidechain trimmers? As I build the GSSL with the pretrimmed VCAs That 2180 B I guess I cant adjust the dist. trim anywhere... I do have an osciloscope, but I don´t know how I could measure if the output of the comp is right or not...

thanks & cheers
mark


 

 

[intellijel]

Could anyone explain to me how I could check for the right calibration / setting of the sidechain trimmers? As I build the GSSL with the pretrimmed VCAs That 2180 B I guess I cant adjust the dist. trim anywhere... I do have an osciloscope, but I don´t know how I could measure if the output of the comp is right or not...

thanks & cheers
mark

It turned out the distortion issue in Auto mode was due to the fact that my rotary switch was not modded to go 5 positions instead of 6. The result was that when I thought I was in Auto I was actually a step further past and it created bad distortion.

I still have the issue that my compressor does not sound to amazing... definitely not as good as an SSL or even the virtual SSL plugins I have tried.

 

[pietro_moog]

hi! i'm sorry to break balls, but i'm looking for a Gssl front panel layout,
with sifam ppm 14 meter, filter knob, turbo bypass and power toggle switches
thanks

 

[ytsestef]

I still have the issue that my compressor does not sound to amazing... definitely not as good as an SSL or even the virtual SSL plugins I have tried.

You had mentioned earlier in this thread that "when you try to get it pumping it just distorts". What attack/release times are you using to do this? In my personal experience the GSSL isn't capable of "pumping". Right after the book. Because I have similar experience with the original SSL's. I think it is a design thing, where short times with generous amounts of reduction obviously distorts, long times can't pump because it is constantly compressing and in moderate timing settings it is not fast enough to "pump" for today's standards. I am no expert but I think it has something to do with the feed forward/feed backward design combination.

Of course I'm not there, so, I can't hear if it sounds faulty or if it sounds normal and you don't like it.

In the case it sounds normal and you don't like it:
=====================================

Comparing the GSSL to the plugins is a real trap because the plugins don't go anywhere near the SSL 4k compressor in terms of sound. They do pretty good in the "looks" aspect though, especially the Waves one. I'll give them that  What you may think is "good" is actually the fact that the plugin is WAY more obvious than the real thing. So if you can't get that over-the-top tone and the artifacts the plugin can produce, that is a very good thing because neither an SSL can.

Now that we got the plugins out of the way let's see some possible reasons why it doesn't sound "awesome"
1) Have you implemented the turbo mod on your build? It's the way to go if you want faithful SSL compression. It behaves way differently without one.
2) Have you listened to an SSL 4000 desk bus compressor? It won't get near a 4000 because the 4000 has some.... errrr.... 4000 preamps on it 
Some minutes ago I finished my SSL 9K preamp and the first thing to try was feed a mix to my GSSL through my 9K preamp. BAM! Way more SSL-ish sound.

In the case it sounds faulty:
=====================

Please post some videos and soundclips.  ;D

 

[peat]

Hey Guys,

Im just piecing together a prospective parts list for a GSSL with turbo and 2x supersidechain

Ive tried to go with all Wimas and Nichicons

I know some of the Wimas are pretty big (wide mostly) but im pretty sure they will fit (with some help)
I tried to get MKP's where possible, but a few were out of stock or non existent, so for those ive used the FKP series

Was just wondering if someone with a bit more experience than me, or someone who has built with Wimas could have a quick look over this to see if there are any massive problems

Thanks in advance!

(see attached)

 

[mitsos]

Peat, no idea.. and a bit lazy atm.. only had half a cup of coffee.  Will give you a tip though.  MKP and FKP are generally huge. Check the size against the board layout.  Wima.com let's you search by lead spacing, type, voltage, whatever, so go there first. AND, unless you really want nichicons, I'd say skip them. Call Laura at TAW, get your wimas, tants, and Panasonic FC electrolytics from her. Tell her you're from here and you'll probably pay half or less what mouser would charge you. 

 

[regularjohn]

Hey Guys,
Im just piecing together a prospective parts list for a GSSL with turbo and 2x supersidechain
Ive tried to go with all Wimas and Nichicons
I know some of the Wimas are pretty big (wide mostly) but im pretty sure they will fit (with some help)
I tried to get MKP's where possible, but a few were out of stock or non existent, so for those ive used the FKP series
Was just wondering if someone with a bit more experience than me, or someone who has built with Wimas could have a quick look over this to see if there are any massive problems
Thanks in advance!

These will fit better: 505-MKS2.1/100/10
You want to find the ones with a 2.5mm x 7.2mm x 6.5mm case.  If you use anything with a bigger case it will be a serious pain in the ass to get them on the pcb.  Trust me, it's not worth it.  The difference between a 5% tolerance and a 10% tolerance is not worth the hassle of trying to solder in caps that don't fit.  All WIMA's are great.  You're being be too picky, no offense  ;D
Also, +1 on the panasonc FC electrolytic caps!