GSSL HELP THREAD!!!

[jicama]

Hello guy´s first of all thanks for exist!! I´ve been reading you and its awsome! and excuse my english.

Now the question:
I´m almost done with my gssl proyect, I´ve been looking for a decent good looking cheap meter, I really like this one for my gssl http://www.selectronic.fr/vu-metre-style-retro.html
it says is sensible to 500µA, I know I have to search for 1ma dc meter, but i dont loke the look of them, Is there a way I can use the retro VU meter to see the gain reduction??

Thank you for your help

 

[fingercarlos]

hi guys do you wha can i do y my main rails show me + 5v  - 15 volts

 

[John Isaac]

Hey all! I desperately need help with my transformer. I'm on my fourth read through the full 305-page thread and I still am puzzled  I've built 1234590 pedals, but have never worked with a transformer before.

I'm using this transformer: http://www.digikey.com/product-detail/en/62063-P2S02/TE62063-ND/299867 and running the primaries in parallel (for 115v) and running the secondaries in series (as directed by the transformer manual). I've got the earth, hot, and cold wires connected correctly and there's a 1/2 amp fuse in the IEC built-in fuse-slot. I have the a lead from the IEC Earth connector grounded to the chassis of a gutted computer case.

When I plug in the power cord and measure the voltages of the secondaries, I get anywhere from -100mv to +100mv on all secondaries that fluctuates greatly. Shouldn't I be getting 15v? Does this transformer not put out any voltage until a circuit demands it? I figure one of three things must be wrong:

1. I have a faulty transformer.
2. I just fried my multimeter (although I measured some components and it works fine!)
3. Something very basic I have forgetton.

Help, something? What am I doing wrong? Thanks!

 

[gyraf]

measure ac? is fuse mounted?

 

[fingercarlos]

im having problems with my gssl,  the + out of the bridge rectifier shows me 5v  and the negative 19v   

the problems its that on the main rails i meaeaured + 5v    -15 v

the transformer its ok im i checked twice and its output is 20vac

 

[John Isaac]

I didn't have my multimeter's "line input" switch engaged. I now have 40, 52, 62v on my secondaries.

 

[Harpo]

the transformer its ok im i checked twice and its output is 20vac

20VAC is wrong, so the transformer is not OK.
You need a 30VAC center tapped transformer or a dual secondaries 2x15VAC transformer.

 

[fingercarlos]

the transformer its ok im i checked twice and its output is 20vac

20VAC is wrong, so the transformer is not OK.
You need a 30VAC center tapped transformer or a dual secondaries 2x15VAC transformer.

this is my transformer
http://www.mouser.com/ProductDetail/Triad-Magnetics/VPT36-690/?qs=wkKrz7WmEgMur335Y%252benyA==

the output its connected in parallel.  oops im doing something wrong? 

 

[Harpo]

this is my transformer
http://www.mouser.com/ProductDetail/Triad-Magnetics/VPT36-690/?qs=wkKrz7WmEgMur335Y%252benyA==

the output its connected in parallel.  oops im doing something wrong?

Wrong. Transformer secondaries (output) connected in series (IE join red with orange for your center tap connection that connects to the middle hole at the AC input on pcb), black wire to first AC input, yellow wire to the other AC input on pcb.

 

[Harpo]

I didn't have my multimeter's "line input" switch engaged. I now have 40, 52, 62v on my secondaries.

Whatever multimeter might have a 'line input' switch,
set your multimeter for measuring AC voltage in an expected range, maybe 200VAC, black probe wire connected to the meters [COM] terminal, red probe wire connected to the meters [V, Ohm, ...] terminal. Measuring with your probe wires between your blue and green transformer secondary wires with transformer connected to AC mains will give a readout of about 35VAC with your red+brown wire joined for the center tap connection. Measuring between this center tap connection and the blue wire will give a readout of about 18VAC, same as between center tap and green wire. Voltages might vary +/-10%, depending on local AC mains voltage (that isn't a constant). Your safety ground connection is not involved in this measurement.

 

[fingercarlos]

this is my transformer
http://www.mouser.com/ProductDetail/Triad-Magnetics/VPT36-690/?qs=wkKrz7WmEgMur335Y%252benyA==

the output its connected in parallel.  oops im doing something wrong?

Wrong. Transformer secondaries (output) connected in series (IE join red with orange for your center tap connection that connects to the middle hole at the AC input on pcb), black wire to first AC input, yellow wire to the other AC input on pcb.

thank you harpo now its working

 

[John Isaac]

black probe wire connected to the meters [COM] terminal, red probe wire connected to the meters [V, Ohm, ...] terminal. Measuring with your probe wires between your blue and green transformer secondary wires with transformer connected to AC mains will give a readout of about 35VAC with your red+brown wire joined for the center tap connection. Measuring between this center tap connection and the blue wire will give a readout of about 18VAC, same as between center tap and green wire. Voltages might vary +/-10%, depending on local AC mains voltage (that isn't a constant). Your safety ground connection is not involved in this measurement.

Thank you! I clearly didn't know how to measure the secondaries properly. I did as you said and got 18.75VAC on both leads. Gustav's GSSL pcb says 2x15 or 2x18v's on the psu input holes, so I believe I am in the clear so far. Thanks again!

 

[fingercarlos]

now i have another problem.  all the voltages are ok,  the sound pass thru the compressor but i cant modify anything with switches and pots.   

 

[gyraf]

now i have another problem.  all the voltages are ok,  the sound pass thru the compressor but i cant modify anything with switches and pots. 

Look up the possible problems+solutions already mentioned in this thread?

Jakob E.

 

[fingercarlos]

now i have another problem.  all the voltages are ok,  the sound pass thru the compressor but i cant modify anything with switches and pots. 

Look up the possible problems+solutions already mentioned in this thread?

Jakob E.

yeah i know i have been reading this post all day,  but i still cant right now im testing each track of the controls to see whats its going on

 

[gyraf]

Very good! Compare to schematic to estimate expected behavior.

BTW- have you mounted the needed sc-hpf jumper (new on latest revision pcb)

Jakob E.

 

[fingercarlos]

Very good! Compare to schematic to estimate expected behavior.

BTW- have you mounted the needed sc-hpf jumper (new on latest revision pcb)

Jakob E.

sure I did the hpf connection .

i already check everything and  i found a  shorted track and now the led turn on, the makeup, and the on/off switch work.  but nothing happens with ratio threshold and release

i think the problem could be that attack and release rotary switches doesn't have the letters and numbers in the back so maybe its oriented wrong but, does this affect?  if yes how could i know how to place the rotary switch? 

 

[Harpo]

..all the voltages are ok, ...

probably not all 5 supply voltages (+15VDC, -15VDC, +12VDC, -12VDC, Aux +12VDC) in respect to your 0V reference voltage
when you say in your following post

i found a  shorted track and now the led turn on

and this LED only shows the +12VDC operating. Measure the remaining supply voltages to confirm proper operation.

i think the problem could be that attack and release rotary switches doesn't have the letters and numbers in the back so maybe its oriented wrong but, does this affect?

These switches are built symetrical, IE doesn't matter, as long as you have fitted the 2x6 Lorlin type rotary at the attack and release pcb positions and the 4x3 Lorlin type rotary at the ratio pcb position. Remove the rotary switches fixing nuts, remove the lockwashers below these nuts, turn the rotary switches full CCW, place the lockwashers back in to pos.3 for ratio, to pos.6 for attack and to pos.5 for release. Put the fixing nuts back on.
Next double check your bypass wire connections ...

...and nobody can see thru the internets what you see or what parts you have fitted, so try to describe a problem as if you would do to a blind person.

 

[ding]

I have to send it very, very and I mean very low levels ...

that would be a measurable AC voltage, so we get your idea of very low ...

or else it will distort like crazy.

No surprise with at least the two wanted 5K1 resistors connecting to audio-VCAs pin 5 being 51K and the wanted 3K9 resistor connecting to sidechain-VCA pin 5 being 51K.

Just an FYI this was indeed what was wrong. It sounds fantastic now.

 

[dipfrik]

Hey,

i finished my build a few minutes before an checking voltages now, but i have a problem with a -15V which show 1.99V right now.
I have attached a picture. Any idea? All other voltages are fine so far.

update: no signal in bypass at all on the output. Only the right channel making a very quite distorted noise. ;(

Thanks in advance, Sven

…missed a jumper and now i have different voltages ( see my new post)