GSSL HELP THREAD!!!

[ptron]

nice pictures! thats very helpful i hope i dont encounter that problem!
i want to know just one thing..
i am building gssl +1xturbo+1xsupersidechain+1crcboard(not sure if necesary) + relay bypass x2(igor`s)
i got traffo output 2x15VAC @25VA is this enough?

all the best! thanks for the help

 

[Harpo]

i am building gssl +1xturbo+1xsupersidechain+1crcboard(not sure if necesary) + relay bypass x2(igor`s)
i got traffo output 2x15VAC @25VA is this enough?

Maybe (impossible to answer without additional/detailed information). For usual the type of relays (coil resistance and operating voltage) and/or type of illumination (LEDs or incandescent lamps) used set the limit. A single miniature light bulb (for meter illumination or inside a switch) can draw more current than some (>2) complete GSSLs without.
For the latest GSSL pcb revision and 2x15VAC secondaries transformer you probably don't want an additional CRC board in front (giving a rectifyer-CRCRC-rectifyer-CRC) in order to keep the input of the voltage regulators above dropout voltage.

 

[Gustav]

i tried to power the compressor one time with and one time without meter connected. Both times, the two resistors started to burn. And i did not solder the secondaries, but added all cables to a screw terminal for easy connecting. So here are some pictures..

I may have misunderstood, but I thought that there was no problem before you connected the meter in the first place. If so, I would focus on what changed. I already suggested you might have shorted something soldering the secondaries off and back on, but if they were set up as they currently are, before you added the meter, thats a bad bet of course. If the problem was always there, I would do another scan for shorts in the circuit - and if the modification/the switch is drawing any current for a light or lamp, I would also check how the circuit behaves without that.

You never revealed which transformer you are using, and that might help.

As always, it would have been best to make sure the unit was working perfectly before adding mods (alternative switches, added circuitry and meter lights). It helps keep the relevant variables at a minimum when trouble shooting.

Gustav

 

[weiss]

No Gustav, it appeared afterwards but not immediately. I checked some voltages the day before and then after turning on the device again it began smoking. I obviously replaced the resistors, removed the meter cables and voila they started smoking again.. Could be that i made a short the other day and didn't notice, but which part could cause the resistors overheating? I am using the power transformer which you sell on you website (15V secondaries and parallel wiring).

weiss

 

[Gustav]

but which part could cause the resistors overheating?

As I read it, if the circuit is drawing too much current, the power running through those resistors will rise, making the resistors power rating insufficient (They are 1/2watt). Its a symptom of a problem, so you should not try to fix it by adjusting their power rating.

It also happens if the PSU is not able to supply sufficient current for normal operation (The one I have is 30VA, so that should not be a problem). There are probably other possibilities, but I would start with these.

"Where" is pretty wide. It could basically be anywhere your supply could short to ground or connections providing a lower impedance connection to ground, draining the current. It can be either on the 15V or dropped 12V rails. If your meter light had introduced the problem, we would probably have concluded the trafo was not able to supply both the basic circuit and the light, but your investigations ruled that out.

I have no idea wether this could be caused by a faulty component or somewhere else, but I am sure someone smarter than me will chime in, and in short - I would check for shorts.

Or maybe a faulty opamp, but I got the impression the unit was working "pre-meter light"

Gustav

 

[weiss]

Thanks for you help! Indeed it worked.. well hopefully someone can sort it out i go through all the connections again now

weiss

 

[ptron]

i am building gssl +1xturbo+1xsupersidechain+1crcboard(not sure if necesary) + relay bypass x2(igor`s)
i got traffo output 2x15VAC @25VA is this enough?

Maybe (impossible to answer without additional/detailed information). For usual the type of relays (coil resistance and operating voltage) and/or type of illumination (LEDs or incandescent lamps) used set the limit. A single miniature light bulb (for meter illumination or inside a switch) can draw more current than some (>2) complete GSSLs without.
For the latest GSSL pcb revision and 2x15VAC secondaries transformer you probably don't want an additional CRC board in front (giving a rectifyer-CRCRC-rectifyer-CRC) in order to keep the input of the voltage regulators above dropout voltage.

thanks a lot harpo  i hope i can supply the right information here
relays are omron G5V-2H1 (12VDC)not sure coil resistance tho!
im using 5mmx1 LED for bypass, x1 for meter light (optional) and 3mm LED x1 for "compression bypass" illuminated switch.
i will keep the CRC`s for another build then

again, thanks a lot!

 

[Harpo]

relays are omron G5V-2H1 (12VDC)not sure coil resistance tho!

Maybe RTF datasheet. For your DPDT high sensivity type relay each will draw 12VDC/960R=12.5mA (for comparison the same 12VDC standard type relay would draw 42mA each).

im using 5mmx1 LED for bypass, x1 for meter light (optional) and 3mm LED x1 for "compression bypass" illuminated switch.

LED diameter has mainly a mechanical or estetical meaning and doesn't say anything about your LEDs typical forward voltage Vf, max.allowed forward current If or viewing angle degree, just to name a few. LEDs Vf is colour dependant and LEDs are current operated devices. You maybe allow for 10mA per standard LED (or a fraction of this for high efficiency types) in order to not building a headlight. Current limiting resistor needed is (supply voltage - LEDs Vf) / amount of current you allow for in A. For a red LED this might be (12V-1.8V)/0.01A=1020R. A 1K probably will fit for this colour. Increase resistance for lesser brightness or vice versa but have an eye on parts limits. Maybe use the regulated 12VDC output from the GSSL aux supply for your additional relays and LEDs (a LED is NOT an incandescent lamp that would be happy with an AC voltage feed). No problem expected from your 25VA transformer.

 

[darkus]

Thanks for you help! Indeed it worked.. well hopefully someone can sort it out i go through all the connections again now

weiss

Btw what size of fuse you are using? You need a 315mA slow blow.
Its not normal for something to burn inside your unit

 

[Harpo]

Btw what size of fuse you are using? You need a 315mA slow blow.

??? Without knowing the OPs local mains voltage and the type and VA rating of the transformer used, you'd have to have clairvoyant abilities to give such recommendation.

 

[weiss]

??? Without knowing the OPs local mains voltage and the type and VA rating of the transformer used, you'd have to have clairvoyant abilities to give such recommendation.

I am using 15V toroid secondaries, wired parallel (230V)

Harpo, i saw you replying few months earlier to the exact same problem. You wrote about a short between two transistors and a capacitor. I had them checked and there were no shorts. So the problem has to be elsewhere..

 

[Harpo]

wired parallel (230V)

Boom.
Transformer primary windings will be connected in series for 230VAC mains. (If this wasn't a typo, expect some parts to be blown from double voltage).
Without knowing the type of mains transformer you are using (there will be a label attached to the transformer), I have no idea how to hook it up correctly. Colour coding of transformer wires is not standarized and same colour of wires might have (I know at least two which surely have) a different meaning between different manufacturers.
Please update your profile with your location data. Not only mains voltages differ when asking at an intercontinental forum.

 

[salomonander]

can anyone point me towards a document that explains what exact resistors are needed for 202c and 2150 vcas? cheers

 

[weiss]

It found the error, dead IC "NE5534P"! But now i experienced another problem, the left channel signal is badly distorted and less noisy. How can i calibrate the meter? Do i even have to calibrate?

thanks for the help!

 

[salomonander]

can anyone point me towards a document that explains what exact resistors are needed for 202c and 2150 vcas? cheers

anyone? i can not find clear instructions on the official site. or maybe im too stupid to find them. id really appreciate some help. im just unclear about all resistors/trimpots marked with %. everything else is clear to me.

EDIT: i just found this overlay of the old pcb
can anyone confirm that these values are correct for 202c and 2150? i assume so. if im correct, would i still want to replace the 15k resistors with the new 27ks?

 

[Che_Guitarra]

I'm getting ready to install the SSC and Turbo boards on my kit.  One thing - i'm having trouble finding 1N4001 diodes... can I substitute with 4004's instead?

 

[ptron]

http://mx.mouser.com/Search/ProductDetail.aspx?R=1N4001virtualkey51210000virtualkey512-1N4001

 

[Che_Guitarra]

I don't really want to pay $40 postage just for three diodes (I live in Australia).  And I already have some 4004 diodes in my kitty.

 

[Harpo]

i'm having trouble finding 1N4001 diodes... can I substitute with 4004's instead?

No problem with this (not needed) upgrade for withstanding a by 350V higher peak repetitive reverse voltage.

 

[Dannytech]

Hello!
I've just finished the GSSL compressor, and I have some issues :-\ : When I play stereo music through it, I only hear the right side coming back. The bypass switch is working, and when it's ON position, I can control the output gain pot, but nothing else. The LED is working, but the meter is not. And two of the three big regulators are heating (7812, 7815), when the mains plugged in.
Please help me!