Coldsnow

GSSL not working, where to start?
« on: March 20, 2005, 09:42:15 AM »
I tried to search and sorry if I missed it or am asking a redundent question.

I finished my SSL.  The sound comes through but VERY distorted and at low volume.  Does not appear as though the controls are doing anything.  Where do I start?


radiance

SSL not working, where to start?
« Reply #1 on: March 20, 2005, 02:29:41 PM »
Maybe you should use the SSL Help Thread for this... but anyway.

Are your voltages OK? > Always check this first before putting in any IC.
If they're OK check weither your IC's  are getting the right power @ the right pin....THEN put them in and proceed.
"Knowing that you are dreaming, however, does not automatically guarantee full rationality.
Then again, being awake doesn't ensure good thinking, either." -  Lynne Levitan

Michael Krusch

SSL not working, where to start?
« Reply #2 on: March 20, 2005, 05:07:48 PM »
Do you have distortion on both chanels?

Coldsnow

SSL not working, where to start?
« Reply #3 on: March 20, 2005, 06:02:32 PM »
Yea distortion on both channels.  Oddly enough I can run the input into one channel and the output into another channel and it sounds the same.  I think I really messed up somewhere. I've never used a multi meter.  I do have one and I'm going to give it a try.

Michael Krusch

SSL not working, where to start?
« Reply #4 on: March 20, 2005, 06:13:33 PM »
If you lower the input will the distortion be smaller?

jensenmann

SSL not working, where to start?
« Reply #5 on: March 20, 2005, 06:15:47 PM »
If all the voltages are ok check the polarity of every ´lytic/tantalum cap if it´s mounted right. Having done this check every wire if it comes from/goes to the right place.
have a  :sam:
 :wink:
Jens
Jens
Quote from: PRR
The tubes of course don't care what frequency they distort

Coldsnow

SSL not working, where to start?
« Reply #6 on: March 20, 2005, 06:40:22 PM »
What dial point do I set my multimeter at to do the checks?

jensenmann

SSL not working, where to start?
« Reply #7 on: March 20, 2005, 07:12:50 PM »
Higher than the voltage you are expecting to measure. AC for measuring around the tranny, DC for every voltage behind the bridge rectifier. Connect the black cable of your DMM to ground and measure the voltages with the red cable.
 :!: aleays measure with one hand in your pocket (this is no sh*t)
Jens
Jens
Quote from: PRR
The tubes of course don't care what frequency they distort

Coldsnow

SSL not working, where to start?
« Reply #8 on: March 20, 2005, 09:31:09 PM »
This is what I could get.  I really don't know what I'm doing.  The back cable in the COM port and the red in the V ma port, and the meter set to 200

On the channel strip section, on the vca, the 6th hole measured  .5
the 5534 the second pin on the right, to the top (when power supply is on top) I got 85.9

on the side chain,
The 3rd pin of the VCA measured 34.5
on the TL074
(looking at the board with power supply on top)
on the left side of the TL074  the 3rd pin from the top on left was .5
the 5th on left from top is .6
on the right side, 3rd from top was also .5

The TL072  (top being the power supply side)
3rd pin from top on left was  .5
The bottom right pin was .5

jeroddumas

SSL not working, where to start?
« Reply #9 on: March 20, 2005, 11:25:50 PM »
You need to set the meter to read Volts DC or Volts AC.  You need to measure the voltage, not the amperage, which is what it looks like you are measuring.  If you are measuring voltage you are very off somewhere.
genius is the highest level of insanity


alk509

SSL not working, where to start?
« Reply #10 on: March 20, 2005, 11:56:32 PM »
Quote from: "Coldsnow"
I got 85.9


Quote from: "jeroddumas"
ou need to measure the voltage, not the amperage, which is what it looks like you are measuring.


I very seriously doubt that any part of that circuit can spit out 85.9A!!! That's not to say you're measuring things right, since there also shouldn't be 85.9V anywhere in that box... Do a Google search on how to use a multimeter. Good luck!

Peace,
Al.

Lest laziness get the best of you!

Coldsnow

SSL not working, where to start?
« Reply #11 on: March 22, 2005, 06:09:11 PM »
I bought a new meter.  Very good investment.

Anyways here are the numbers

The +15 jumper in the middle of the board registered at 14.64
The -15 jumper didn't register (is this the problem)

The side chain
vca 3rd pin -40.3
vca 7th pin 12.1
TLo74 right side 4th pin -12.2,   6th and 7th 9.3
TLO74 left side 1st pin 3.7,    4th pin 12.11
TL072 left side 4th pin -12.1

channel VCA 7th pin 14.64

VCA 5534  3rd pin on left 14.64

on output
5534 3rd pin on right 14.64

The two jumpers at the bottom of the card (opposite side of the power supply) both register at 20.1

Mark Burnley

SSL not working, where to start?
« Reply #12 on: March 22, 2005, 07:03:56 PM »
Hmm,

No -15V supply would be a big problem. With your DMM 0V (black) probe connected to 0V, check your voltages at the voltage regulator Input and Output pins. If there is no -15V rail, suspect the 7915 IC. But be careful- it may not be just a case of replacing it- faults further on in the circuit may be causing a short circuit making the 7915 shut down.

Things must be okay with the -Ve side rectifier, because you're getting -12V on the sidechain TL072.

Good luck!

Mark
O_O tape is life O_O

Coldsnow

SSL not working, where to start?
« Reply #13 on: March 22, 2005, 08:47:30 PM »
I noticed the jumper after the regulator goes to nothing (for the onboard transformer that I'm not using).  Should this be disconnected or doesn't it matter?

Coldsnow

SSL not working, where to start?
« Reply #14 on: March 22, 2005, 09:10:48 PM »
Which component is the voltage regulator?

I checked the pin on the 7915 that leads to the +22U then to the -15 jumper and it registered a 0.  On the (I think it is a diode) coming of the power transformer the plus side registers 25.7 and the side leading tot he big caps registers -25.8.

Coldsnow

SSL not working, where to start?
« Reply #15 on: March 22, 2005, 09:18:55 PM »
Also the plus side of the 1000 cap registers 25.7 and the negative side of the second 1000 cap registers -25.8

The second w048 228 diode thing that is closest to the space for the onboard transformer is not used if using an external correct?

Coldsnow

SSL not working, where to start?
« Reply #16 on: March 23, 2005, 12:44:52 AM »
THAT WAS IT.

Thank you so much guys.  I swapped the 7915 and got the -15 working fine.  Both on the jumper and the chips holders.  So am I ready to put the chips back in and pass audio again?

Thanks again you guys are awsome.

Coldsnow

SSL not working, where to start?
« Reply #17 on: March 23, 2005, 07:41:26 PM »
Well I put in the chips and gave it a try.  No audio at all.  Any suggestions as to where to go next?

Mark Burnley

SSL not working, where to start?
« Reply #18 on: March 24, 2005, 09:30:28 AM »
Hi,

I'm busy at the mo so can't talk you through, but check my signal-tracing article here:

Signal Tracing

It may help pointing you in the general direction! Check and recheck all your component values, and wiring to In/Out connectors etc. Apply an input signal and see how far you can trace the signal into the circuit.

 :thumb:

Mark
O_O tape is life O_O

radiance

SSL not working, where to start?
« Reply #19 on: March 24, 2005, 09:44:31 AM »
Nice article Mark!
I'm going to build myself one of those....
"Knowing that you are dreaming, however, does not automatically guarantee full rationality.
Then again, being awake doesn't ensure good thinking, either." -  Lynne Levitan


 

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