GSSL HELP THREAD!!!

stereokillah said:

hello Harpo, i will use supersidecahin fron Barclaycon need i sue the 20k and the 10 k on the sidecahin in?
and Why about this resistor.

thanx

Click to expand...

Sidechainfilterboard (SCF) Rin resistors R12 and R13 are 20K resistors. Wiring the DPDT switch as shown will parallel these (2x 20K in parallel=10K) for the lower drawn SCF board (connecting to the GSSL sidechain VCA) in Turbo mode operation only. For the upper drawn SCF board you can either leave one resistor (R12 or R13) out and fit a 10K for the remaining spot or keep both at 20K but wire link the L+R input of this upper drawn SCF board. This set this SCF summing amp to unity gain with Rfb 10K (R15).
If your kinda music or program material is more center related, the Rin resistor values for a constant power calculation [1/sqrt(2)] might fit better, so use a 14K as Rin for the upper drawn SCF board and a 27K in series between SCF board L-in and the right switch pole (20K || 20K+27K) instead, so both SCF boards have voltage gain of 0.707 or -3dB each in Turbo mode.

Right i'm ok, i tought this resistors was outside of board after watch under the board i understand why with your good explain

It's 20k for, R 20k for L on gyraf mode and on turbo mode L and R together do 2x20k in parallel  for L ( 10k) and the second SSsichedechain give 10k for R.

thanx for all your explaination

Pins value are upside down actually, i just tought about that an hour ago, PIN 8 beeing PIN 1, and i believe that i've inserted the VCA maybe wrong way also when encountering that prob, so will have to check that, but if it is then sorry for bothering  :-[...

Hi tout le monde, (everybody)

I am trying to connect my toroid trasfo to the pc board
and I am blowing the fuse and the rectifier
so
1- is the toroid is  supposed to deliver  15 v dc to the board
2- I am connecting a dual Hammond(182G15) 2X 18v
3 there is a short somewhere in the psu
4- I jumb over the balcony!!

thak you

I am desperate.
Alain

Alain said:

Hi tout le monde, (everybody)

I am trying to connect my toroid trasfo to the pc board
and I am blowing the fuse and the rectifier
so
1- is the toroid is  supposed to deliver  15 v dc to the board
2- I am connecting a dual Hammond(182G15) 2X 18v
3 there is a short somewhere in the psu
4- I jumb over the balcony!!

Click to expand...

Welcome Alain,
maybe you can update your profile with your location.

1- Your transformer will not deliver DC voltages. You put AC in and get AC at a specific voltage ratio out.

2- Your Hammond 182G15 looks like a dual 15V and not a dual 18V, but all fine.
Get the transformer datasheet to identify its wires colour scheme.
Depending on your location (see your profile) your mains voltage might be 115VAC or 230VAC.
For 115VAC operation you want the transformer primaries in parallel by joining black+brown and white+orange. Both joined primary wires connect to fuse, switch and finally your IEC-connector/wall outlet.
For 230VAC operation you want the transformer primaries in series by joining white+brown. Isolate this further not needed junction. Remaining black and orange primary wires connect to fuse, switch and finally your IEC-connector/wall outlet.

3- Maybe/maybe not. This transformer has dual secondaries, but you need this toroid to operate like a center tapped transformer by joining the blue and gray transformer secondary wires. This junction is your center tap going to the middle of the 3 pcb holes for transformer hookup. The remaining red and yellow transformer secondary wires connect to the 2 outer pcb holes for transformer hookup.

4- Could be fun. Don't forget to use your parashute. ;D

Now that you had a happy landing, climbed up your stairs again and recognize you forgot to switch off your soldering iron before jumping over the balcony, you might replace the blown fuse and the blown rectifier. Get the rectifiers pin orientation right when resoldering.

Good luck

Hello everyone,

I almost finished my Gssl and everything seems to work except for my meter.

I want to use a VU-Meter, and have been told to put a resistor parallel.
But can't get it to work

Sorry for beeing a noob, but maybe someone  here can tell me how to figure this out ?

Thank you all very much.

Paul

Voodoosound said:

I want to use a VU-Meter, ...

Click to expand...

Nice idea, but ... the schematic calls for a 100uA (with shunt resistor in parallel) or 1mA linear scale meter to show the amount of control voltage for gain reduction.

A VU-Meter for showing the amount of audio compression might be built with a differential amp between output and input, followed by half- or fullwave rectifier, timing circuit, ..., and is not part of this GSSL schematic.

hi there,
i still have to fix some problems with my gssl, because I hear a great gain difference when I switch from 10:1 to 2:1, which compresses more....and even with no audio passing through the unit, when I set the ratio switch to 4:1 the meter shows 8 db of gain reduction and when it's to 2:1 it shows  almost 20 db ... only when it's to 10:1 I have 0 db on the meter...

there must be some problem here.. could somebody help me?

for my gssl i've followed this modded scheme that some italian guys have made for everyone uses the THAT2180...
the red marks show where some components have been omitted or just changed...I don't know if it can help you figure out what could be wrong whit my unit...

thank you guys for your help!

Hey everybody, First of all thanks to Kambo and his help,

Ok i have a working GSSL now, after a couple of issues, little contacts here and there, now i got it working, audio passes thru,no hum, no buzz, pretty much quiet, compresses, sounds good, meter works everything is ok for the signal passing, but i have some couple of issues while using it:

first of all ratio compresses more in 1:2 then the others, all resistors values are correct on the control board....

Second Make-up gain doesn't seem to work, i have checked if pin6 of TL072 and pin8 of TL074, but turning make up pot doesn't seem to affect the voltage in those pins, Threshold does, +12V is beeing fed to the pot no prob with that, 620K resistor is the right one, and the two 100K resistors around the TL072 are the right ones also, and TL071 seem to be healthy. I'm using a supersidechain board, i've wired the card as explained on a document, it's working soundwise, but when i hit bypass i don't have any sound coming out from the relay switch (it must make a click no?) It's correctly fed with a +15V rail, maybe this is why make up doesn't work, or i'm wrong about the relay making a click and his action is actually really happening, for me it seems ok soundwise, off was off, 200Hz roll of  compresses less so seem to be ok...
I've wired  COM / Off and ON of the SSC card to the bypass switch on front panel, from there it is wired to the control board is this correct?

Third, when using the comp, each time i dial a setting it takes a little time to go there, Vu meter goes down really slowly... Is this normal??? Of course when i hit bypass switch i have the setting right away, but it sounds like a cap takes a lot of time to discharge, or something like that...

And at last, i wanted to install a LED for the Bypass switch, but i don't know if it is a good idea to put it on the switch directly with a resistor, DC seem to be varying here with signal in, and i'm not sure how high...;

Thanks for your help!!

angelo2979 said:

hi there,
i still have to fix some problems with my gssl, because I hear a great gain difference when I switch from 10:1 to 2:1, which compresses more....and even with no audio passing through the unit, when I set the ratio switch to 4:1 the meter shows 8 db of gain reduction and when it's to 2:1 it shows  almost 20 db ... only when it's to 10:1 I have 0 db on the meter...

there must be some problem here.. could somebody help me?

for my gssl i've followed this modded scheme that some italian guys have made for everyone uses the THAT2180...
the red marks show where some components have been omitted or just changed...I don't know if it can help you figure out what could be wrong whit my unit...

thank you guys for your help!

Click to expand...

If wired as drawn wrong, exchanging the 'COM' and 'ON' wires to your relais will stop shorting the op-amp around the ratio circuit to gnd. This might also fix your ratio problems.
This relais is at least missing a flyback diode (kathode to gnd/pin-16, anode to relais pin-1), but your 78L12 might have survived a possible reverse current until now.
I don't like the idea of powering this relais (@ whatever current this draws) and bypass LED (@20mA) from the +12V rail, but YMMV.

Hi Harpo, i've just read your post for angelo, and you were i believe answering mine on the way, i am having the same ratio prob but with signal in, and i've just checked what you said to Angelo but COM and ON are wired correctly  from SSC board to SPDT switch, COM beeing the middle leg, no missing flyback diode, and still makeup gain doesnt work for me.
And for the bypass LED, i remember Gustav telling it's better to leave the +12V rail free of anything, so i will forget this one...
Just a last question do you encounter a latency form settings to settings on your unit? I mean a little time for the setting to settle?? Thanks Harpo

zayance said:

...first of all ratio compresses more in 1:2 then the others, all resistors values are correct on the control board....

Click to expand...

double-check diode orientation and resistor values around TL074 and ratio network.

Second Make-up gain doesn't seem to work, i have checked if pin6 of TL072 and pin8 of TL074, but turning make up pot doesn't seem to affect the voltage in those pins, Threshold does, +12V is beeing fed to the pot no prob with that, 620K resistor is the right one, and the two 100K resistors around the TL072 are the right ones also, and TL071 seem to be healthy.

Click to expand...

Thats not two 100K resistors, its one 100K and a 100R=100ohms. If you mixed up the 'R' with 'K', there might be other resistors with the same factor 1000 difference.

I'm using a supersidechain board, i've wired the card as explained on a document, it's working soundwise, but when i hit bypass i don't have any sound coming out from the relay switch (it must make a click no?) It's correctly fed with a +15V rail, maybe this is why make up doesn't work, or i'm wrong about the relay making a click and his action is actually really happening, for me it seems ok soundwise, off was off, 200Hz roll of  compresses less so seem to be ok...
I've wired  COM / Off and ON of the SSC card to the bypass switch on front panel, from there it is wired to the control board is this correct?

Click to expand...

There are some different supersidechain boards, yours probably the barclaycon one. http://picasaweb.google.com/barclaycon/GSSLSuperSidechainPCB#5186631869292869794
Obviously something wrong wth your relais or its wiring when 'E' or 'Pot B' doesn't receive the varying 0 to +12V control voltage from the makeup pot. Check if kathode side of the flyback diode (next to the relais) changes voltage from 0 to 15V when activating the gssl-bypass switch, connected to 'To/In SW/Ret'. [Edit: 'Com/On/Off/Pot A/Pot B' don't connect to the switch but only to control pcb] If it does so, replace the maybe broken relais, else replace the maybe broken switch.

Third, when using the comp, each time i dial a setting it takes a little time to go there, Vu meter goes down really slowly... Is this normal??? Of course when i hit bypass switch i have the setting right away, but it sounds like a cap takes a lot of time to discharge, or something like that...

Click to expand...

You surely have fitted 0.47uF caps after the release switch and not 47uFs ?

And at last, i wanted to install a LED for the Bypass switch, but i don't know if it is a good idea to put it on the switch directly with a resistor, DC seem to be varying here with signal in, and i'm not sure how high...;

Click to expand...

Use the connection '+/In LED/-' on your supersidechain board for just this purpose. Have a look at http://picasaweb.google.com/barclaycon/GSSLSuperSidechainPCB#5193005367618854546 to get the idea.

Good luck

I was actually redoing my wiring when you posted back, Yep wrong wiring from me :-[, relay switches, make up pot works, but i still have ratio reversed, i'll have to check the resistors back around TL074, thanks for your help, i will post results....

Well everything is fine around TL074, resistors ok, diodes ok 100K and 100R ok, wiring is ok now also, make up works etc... but ratio still not good, what can make it backward? Doesn't seem to be a very popular problem in the Help thread, thanks for your help...

angelo2979 said:

hi there,
i still have to fix some problems with my gssl, because I hear a great gain difference when I switch from 10:1 to 2:1, which compresses more....and even with no audio passing through the unit, when I set the ratio switch to 4:1 the meter shows 8 db of gain reduction and when it's to 2:1 it shows  almost 20 db ... only when it's to 10:1 I have 0 db on the meter...
there must be some problem here.. could somebody help me?
for my gssl i've followed this modded scheme that some italian guys have made for everyone uses the THAT2180...
the red marks show where some components have been omitted or just changed...I don't know if it can help you figure out what could be wrong whit my unit...
thank you guys for your help!

Click to expand...

This page will tell you all you need to know about calibrating the GSSL for 2180/2181's.
That diagram you have is missing some wire links that need to be added in place of resistors, and also has some wrong resistance values.
http://homepage.mac.com/marten.thielges/gssl/calibration.html

Hello again. Today I finally collected everything I needed. I'm going to start soldering tomorrow!

I have a consideration though:
While the 1000uF, 0.47uF, 22pF and 0.1uF caps snap perfectly into place, there seems to be a slight lead spacing mismatch between the caps that were sent to me (I made sure I followed faithfully jakob's BOM) and the holes in the PCB. The values and voltages are correct though. My question is: Is it too important to ignore or should I start soldering anyway? The radial caps need to be ever-so-slightly stretched outwards to be able to solder them 2mm above the pcb surface, while the other ones need to be stretched inwards, again, for a 2mm distance-from-pcb goal.

Is it supposed to be like this? Or do they have to touch the PCB?

PS: The 22uF fits perfectly in the turbo board while stretches out a bit on the main gssl board.  ???

ytsestef said:

Hello again. Today I finally collected everything I needed. I'm going to start soldering tomorrow!
I have a consideration though:
While the 1000uF, 0.47uF, 22pF and 0.1uF caps snap perfectly into place, there seems to be a slight lead spacing mismatch between the caps that were sent to me (I made sure I followed faithfully jakob's BOM) and the holes in the PCB. The values and voltages are correct though. My question is: Is it too important to ignore or should I start soldering anyway? The radial caps need to be ever-so-slightly stretched outwards to be able to solder them 2mm above the pcb surface, while the other ones need to be stretched inwards, again, for a 2mm distance-from-pcb goal.
Is it supposed to be like this? Or do they have to touch the PCB?
PS: The 22uF fits perfectly in the turbo board while stretches out a bit on the main gssl board.  ???

Click to expand...

It's fine.  That's what component leg benders are for.

Though I actually typically use higher uF values.  1800-2200uF for the power caps and double of the others...but that's ONLY for electrolytics.  The ceramics and film caps need to remain what they are.  Upping electrolytic values gives the active components in the circuit a larger reservoir of current to draw from.  Although if you go too large, you can introduce problems into the circuit.

Hi ,

I am no shure that this is the place to ask a question
but if I am wrong,

1- I build a gssl
2- fired it up
3 found some short because I put the 7815 and 7915 on the chassis to avoid heating the pcb
  got a short from this
4 put back a new pair of 7815 7915 .

I tried to plug the gssl in gear

got the most horrible bzzz or whaterever sound
...........question?

should repopulate the whole thing
should I replace all the chips (that 2181, the tl 074 and ne 5534 and so on)

when I got the short the jumpers nexs  the bridge rectifier  and beheind the 7915 were not in place!

thenk you

In fact I need to test if the chips are still good!
thank you

Harpo said:

Alain said:

Hi tout le monde, (everybody)

I am trying to connect my toroid trasfo to the pc board
and I am blowing the fuse and the rectifier
so
1- is the toroid is  supposed to deliver  15 v dc to the board
2- I am connecting a dual Hammond(182G15) 2X 18v
3 there is a short somewhere in the psu
4- I jumb over the balcony!!

Click to expand...

Welcome Alain,
maybe you can update your profile with your location.

1- Your transformer will not deliver DC voltages. You put AC in and get AC at a specific voltage ratio out.

2- Your Hammond 182G15 looks like a dual 15V and not a dual 18V, but all fine.
Get the transformer datasheet to identify its wires colour scheme.
Depending on your location (see your profile) your mains voltage might be 115VAC or 230VAC.
For 115VAC operation you want the transformer primaries in parallel by joining black+brown and white+orange. Both joined primary wires connect to fuse, switch and finally your IEC-connector/wall outlet.
For 230VAC operation you want the transformer primaries in series by joining white+brown. Isolate this further not needed junction. Remaining black and orange primary wires connect to fuse, switch and finally your IEC-connector/wall outlet.

3- Maybe/maybe not. This transformer has dual secondaries, but you need this toroid to operate like a center tapped transformer by joining the blue and gray transformer secondary wires. This junction is your center tap going to the middle of the 3 pcb holes for transformer hookup. The remaining red and yellow transformer secondary wires connect to the 2 outer pcb holes for transformer hookup.

4- Could be fun. Don't forget to use your parashute. ;D

Now that you had a happy landing, climbed up your stairs again and recognize you forgot to switch off your soldering iron before jumping over the balcony, you might replace the blown fuse and the blown rectifier. Get the rectifiers pin orientation right when resoldering.

Good luck

Click to expand...

Thank you Harpo

I got it right now
I also got the 15 v (13.9)
and the 12 v (11.3)

I finish the assembly and I plug it

What a noise,

Maybee it is ground issues I am not shure ,
I insert the + in pin 2 (XLR) , - pin 3 (Xlr)
and o to pin 1 and Chassis

but no sound at all just loud buzzzzzz

Thank you