GSSL HELP THREAD!!!

[osso1001]

well, did not check on imput/output of the regulator, because I was afraid of burn another 10R

Narrow it down.
Before powering on again, make sure there is no short between the 7915 pins (a magnifying glass might help) and the 7915 is a 7915 for real, so you didn't mistakenly fitted a 78xx (different sign voltage regulator and different pinout) here.
Next short this 10R out for now and cut the two -15V rail jumpers (next to the two 47K resistors and between the two DBX202C outlines) to exclude a short further downstream.
Power on and check this supposed to be -15V rail voltage.
If your reading is significantly higher, place a temporary 1K...2K resistor between the -15V rail and 0V to meet the regulators min.current load.
The 7915 shouldn't get hot.
All fine, power down, mend the 1st.cutted -15V jumper with a blob of solder, power on and check -15V rail again.
All fine, power down, mend the 2nd.cutted -15V jumper with a blob of solder, power on and check -15V rail again.
All fine, power down, remove the temporary fitted load resistor, exchange the jumpered 10R with a 10R resistor.
Done.
If the +15V rail or +12V rail should be latching/hanging on startup, fitting 4 (maybe 1N400x) diodes across the dual rail regulator outputs and 0V reference voltage, anode side to the lower voltage rail as shown on FI pg.302 (no need to fit them so close to the regulators, there are less tight spots for a more comfortable soldering) probably will fix this misbehaviour.

thanx for helping out Harpo,
so... I was following the steps, till I got something strange: when I put back the jumper on the -15v Raill next to the 47k resistors, I start to read mV, and not the15,4V, I had without the jumpers... so, then decided to take that jumper out and try the other one( next to the+15V jumper), and with that one on, got the -15,4v...
I guess is a bit ,nawored', but where/what should should I look for now!
Thanx again,
Mario

 

[Harpo]

Mario, just follow the -15VDC rail pcb trace from the jumper next to the 47Ks on its way to the 3 NE5534s and the 2 NE5532s and remove the short condition (might be an unwanted solder blob, a piece of stranded wire, an IC fitted in wrong position and/or wrong orientation, ..., double check as well there is no connection to 0V reference voltage along the pcb edge). Using a magnifying glass might help for easier spotting the culprit.

 

[osso1001]

cheers Harpo, Ill spend some time looking, cleaning up soldering points ... will come back hoppefully with good news
thanx, Mario

 

[Harpo]

Can you please describe to me HOW to hook up the the EXT Sidechain if I....

You are talking about the SuperSidechainFilter board, just to stop confusion. 

A. Am going to connect a quarter inch female jack

Be more specific. You are going to connect an isolated (socket with non conductive housing) TRS socket or alternatively two TS sockets for an external insert.
Tip connection of your socket connects to 'Ext' on SSCF board,
Ring connection of your TRS socket connects to 'Snd' on SSCF board (or alternatively to the tip connection of the 2nd.TS socket),
Shield connection of your TRS socket connects to '0V/Sleeve' on SSCF board (or alternatively as well to the shield connection of the 2nd. isolated TS socket).
If you don't want to use the external key, just don't switch the Lorlin to pos.8.

B. Not going to use it all (do I just run a jumper from point A to Point B?)

Then just set the Lorlin endstop to pos.7 instead of pos.8 in order to prevent this unwanted 'External' switch position and don't mount the external jack(s).

Looking at your pic sent by Gustav, what unlucky accident happend to your Lorlin switch with nearly all outer contacts shorting out to eachother ?

Assuming all parts fitted correctly (at least the TL trimmer looks suspicious) and the yellow wire from the Lorlin pole going below the board connects to 'SW Pole' (do yourself a favour and stop soldering external wires from traceside to pcb traces. These will break sooner or later, probably sooner. The drill holes are there for a reason.), the filterboard should work in its generic settings. For the pos.1 and 2 TM and TL switch settings, adjust the trimmers for same voltage out as voltage in from a 1kHz signal feed.

You still didn't update your profile with your location data. Not only mains voltages differ between various continents ...

 

[micah421]

Can you please describe to me HOW to hook up the the EXT Sidechain if I....

You are talking about the SuperSidechainFilter board, just to stop confusion. 

A. Am going to connect a quarter inch female jack

Be more specific. You are going to connect an isolated (socket with non conductive housing) TRS socket or alternatively two TS sockets for an external insert.
Tip connection of your socket connects to 'Ext' on SSCF board,
Ring connection of your TRS socket connects to 'Snd' on SSCF board (or alternatively to the tip connection of the 2nd.TS socket),
Shield connection of your TRS socket connects to '0V/Sleeve' on SSCF board (or alternatively as well to the shield connection of the 2nd. isolated TS socket).
If you don't want to use the external key, just don't switch the Lorlin to pos.8.

B. Not going to use it all (do I just run a jumper from point A to Point B?)

Then just set the Lorlin endstop to pos.7 instead of pos.8 in order to prevent this unwanted 'External' switch position and don't mount the external jack(s).

Looking at your pic sent by Gustav, what unlucky accident happend to your Lorlin switch with nearly all outer contacts shorting out to eachother ?

Assuming all parts fitted correctly (at least the TL trimmer looks suspicious) and the yellow wire from the Lorlin pole going below the board connects to 'SW Pole' (do yourself a favour and stop soldering external wires from traceside to pcb traces. These will break sooner or later, probably sooner. The drill holes are there for a reason.), the filterboard should work in its generic settings. For the pos.1 and 2 TM and TL switch settings, adjust the trimmers for same voltage out as voltage in from a 1kHz signal feed.

You still didn't update your profile with your location data. Not only mains voltages differ between various continents ...

Thanks for taking the time to reply. Thanks for the suggestions I'll come from the top instead of the bottom.

I updated my profile, Im in Los Angeles.


Thanks for the explanation of the "EXT" although I can seem to find anywhere on the web where to connect the "snd" (send). I just noticed your post notes the "ring" should be connected to the "snd". Thank you, I could not find that anywhere on the forum.

Ive read somewhere several pages ago that I needed to run a jumper from the "ext" to the "snd" if Im not going to use an "EXT" source.

I just trimmed the Lorlin plastic peg to be shorter to fit my knob, I believe I did not damage it. (see picture)

So here is where Im at.

I have used a jumper from the "ext" to the "snd on the SSC and the THreshold, Ratio, Attck, Release controls do not function but the Make-UP gain, LED "IN" and bypass works (my bypass is just a on/off switch connected to the "To" and "RTN" (IN SW) on the SSC

Ive gone back to original build WITHOUT the SSC and it works perfectly.

So I'm just trying to figure out why my SSC is not working with the "control" functions (threshold, attk, release, ratio, and sidechain switch)

I noticed a user by the name Ericbazaar had a VERY simular issue around 16 pages back and no one was able to help him. I tried contacting him to see where he left it off.

Any other Ideas guys, thank so much!

 

[micah421]

So Gustav,

I've replaced the "7815" you shipped me with a new one and the problem with having to turn on/off the rocker switch several times, is now GONE and works as it should.

Also, I took your advice on doing what Jakob recommended....although I'm still having the same "no controls" working with my SSC board connected even when I used a jumper from the "ext" to the "snd on the SSC and the THreshold, Ratio, Attck, Release controls do not function but the Make-UP gain, LED "IN" and bypass works (my bypass is just a on/off switch connected to the "To" and "RTN" (IN SW) on the SSC. I have not connected the 0v to anything in that same section(would that do anything?)

 

[Harpo]

Ive read somewhere several pages ago that I needed to run a jumper from the "ext" to the "snd" if Im not going to use an "EXT" source.

only if you insist on exclusively using the filter select switch position 8 (why using a switch at all then) and having nothing plugged into your external key socket for whatever silly reason. Just read my previous reply again. (set the lorlin end stop washer to pos.7 instead of pos.8 )

I have used a jumper from the "ext" to the "snd on the SSC and the THreshold, Ratio, Attck, Release controls do not function but the Make-UP gain, LED "IN" and bypass works (my bypass is just a on/off switch connected to the "To" and "RTN" (IN SW) on the SSC

Signal gets interrupted by your SSCF board. At what switch position is your lorlin switch ? (you already displaced the lorlins end stop washer located below the fixing nut to pos.7 or pos.8 after turning the switch full CCW ?)

From your previous page blurry pic with no single readable part, what is the parts value of your GIANT blue caps next to the opamps on the SC filter board ? (should be 22pF, for usual the smallest parts in the complete build).

I noticed a user by the name Ericbazaar had a VERY simular issue around 16 pages back and no one was able to help him.

I gave him every answer needed to fix it and he never came back with a reply.

I have not connected the 0v to anything in that same section(would that do anything?)

No idea what you might be talking about. We have no idea of what you have done or have not done, if the unit is powered on with correct voltages arriving at the parts to supply or the amount and frequency of your applied audio signal. Try to be more specific. A close up pic from component side and trace side with context of connected wiring might help.

 

[micah421]

Thanks Harpo,

Ive decided to use a TRS Female jack mounted on the back of my case and connect it to the "Ext" poertion of the SSC. Thanks for your help with that.

My "Giant" blue ceramic capacitors are: (seem ok?)

81-DE21XKY220JB2BM01
22pf 250Volts %5
Murata Ceramic Disc Capacitors

While connected and signal passing I've made sure to turn the "Lorlin" switch to every position.

FYI: Someone else sent me a PM and told me I should try swapping out the two IC chips, I tried that, same results.

I've narrowed the issue down to the "Controls" section of the SSC board.Im just following the traces from the ON, OFF, COM, POTA, POTB. And my next step is to replace the "Relay" and "Diodes"

What does COM, POTA and POTB control?

Thanks again for all your time and help! I'm hoping I can figure this issue out.

 

[Harpo]

22pf 250Volts %5
Murata Ceramic Disc Capacitors

overrated but OK. (even 50V would be overrated).

While connected and signal passing I've made sure to turn the "Lorlin" switch to every position.

So measure while one side (L or R) connected and signal passing.
Measure AC voltage at connected side (L or R) of the balanced line receivers NE5534-pin6 on main board in respect to 0V reference voltage.
Half of this measured AC voltage should show up on SSCF board next to input connector NE5532-pin7 or ring connector of your external key socket. Case not, check for +15VDC arriving at this chip-pin8 and -15VDC arriving at this chip-pin4 in respect to 0V reference voltage at SSCF-board input connector. Check for L+R SSCF input is wired to left side holes (psu side) of the removed 47K resistors on main board.
Depending on frequency of your test signal and lorlin switch filter setting, same or slightly lower AC voltage as previous measurement should show up on your lorlin switch pole.
Same AC voltage as previous measurement should show up on this chip-pin1.
Check for  SSCF board output wired to one of the right side holes (VCA side) of the removed 47K resistors on main board.

What does COM, POTA and POTB control?

Connection points to the corresponding points on main pcb that the relais no connects instead of the bypass switch.

 

[Gustav]

Thanks again for all your time and help! I'm hoping I can figure this issue out.

Unfortunately, I do not have much experience with the Sidechain board, but the great thing now is, you have a working base-unit to work from.

And since you now have a working base-unit, it would be cool to shift focus a little before moving on.

so - try tracing the audio signal, and see if you are getting your voltages on the side chain board.

Also, I never tried it, but as far as I understand, with Jakob's new layout, you can implement a high pass filter simply by switching a capacitor in and out of the path at the HPF connections on the main PCB. More steps on the switch with different cap values = more high pass filter frequencies.

Or maybe I am mistaken...

Gustav

 

[micah421]

Thanks again for all your time and help! I'm hoping I can figure this issue out.

Unfortunately, I do not have much experience with the Sidechain board, but the great thing now is, you have a working base-unit to work from.

And since you now have a working base-unit, it would be cool to shift focus a little before moving on.

so - try tracing the audio signal, and see if you are getting your voltages on the side chain board.

Also, I never tried it, but as far as I understand, with Jakob's new layout, you can implement a high pass filter simply by switching a capacitor in and out of the path at the HPF connections on the main PCB. More steps on the switch with different cap values = more high pass filter frequencies.

Or maybe I am mistaken...

Gustav

Thanks Gustav,

Yeah, I am happy with my build, the compressor sounds great and is a lot of fun on the drum bus, My client is really happy with the mix I just finished for him. (I'm actually using it with out the correct meter(showing compression from left to right) but I have the smaller Hairball meter that fits my case, I found out the hard way that I need the VU PCB board in order for that meter to work correctly.

I took some more time with the SSC this weekend and replaced several parts including the ICs, relay, diodes) I traced all the solder points with my Multi-Meter "continuity" setting and everything seems good. I'm at a complete lost. Id really like to implement it to my build for two reasons, 1-it will obviously be a more flexible tool while mixing, especially so that kick doesn't trigger the threshold. 2-My case, was designed to implement it.

I am really at a lost and unfortunately do not have the proper knowledge to go any further trying to discover what the issue is.  I have it all stuffed and wired and I am willing to mail it to someone who is willing to test it all out for me and possibly correct any issues. Obviously I'll pay for their time.

My next step is to get the proper meter or install the VU PCB. Do you know a good resource for purchasing "THAT VCAs"? I've looked online and found a few on eBay but in China.

Really appreciate all your time and please let me know if you can recommend anyone who might be interested in testing/fixing my SSC. 

Have a great day

Micah

 

[ding]

I think your board is fine. It could very well be the way you are connecting it to the main board. Can you draw a diagram of how you are connecting it to the main board and the switch board?

 

[matta]

Hey Guys,

I've been given a GSSL to work on that was built from one of Gustav's kits on Jakob's new boards.

It arrived not compressing, a couple build issues that I've fixed like cold joints, poor wiring, replaced the latching 7815 regulator and an intermittent short in the torrid.

It's now working, it's passing audio in bypass and compressing in compression mode, the front panel controls are working, but the threshold seems to make no difference to the audio even when 'off' it seems to be compressing pretty hard, though it is 'working' in that it is working as a voltage divider, at point F I measure -11.99VDC with the threshold fully CW and 0.652VDC when fully CCW.

The 47K series resistor is fitted, which I seem to recall is the 'cure' to for the threshold sensitivity.

The meter is useless as it's a VU and the scale is as such rather than a 1DC mA, so can't use that to compare so doing it in listening tests.

Any thoughts on where to go from here?

Cheers

Matt

 

[SEED78]

hi all,

is there any real difference in sound between the 2150B VCA and the 2150A VCA?

I've just bought a GSSL with B VCA, and was wondering if I should upgrade to A?

I've got some gold can VCA that eventually I will install, but it might not be for 6 months and I was wondering if the A would give me a leap up in quality in the meantime....

I'll prob get the turbo board added at some point too, currently just got the standard.

 

[Harpo]

... but the threshold seems to make no difference to the audio even when 'off' it seems to be compressing pretty hard, though it is 'working' in that it is working as a voltage divider, at point F I measure -11.99VDC with the threshold fully CW and 0.652VDC when fully CCW.

Double check the supposed to be 220K resistor value going thru a hopefully fitted jumper to TL072-pin2 (resistor closest to pin8 of the sidechain VCA) ?

 

[micah421]

I think your board is fine. It could very well be the way you are connecting it to the main board. Can you draw a diagram of how you are connecting it to the main board and the switch board?

Thanks so much for your reply and your effort to help me!

I've connected my SSC board to the "Control" PCB and the Main PCB, exactly how it said in :

https://pcbgrinder.com/download/SSCdocuments.pdf

I've actually have removed the SSC and installed it several times, trying to figure out why the threshold, attack, ratio, release works without it connected.

I feel like I've narrowed down the issue. If while the SSC is connected, the unit passes audio, the bypass and makeup gain works and the power for the led works, Then it must have something to do with COM, ON, OFF, POTA, POTB section.

Thanks again.

1. If anyone is interested in testing my SSC out if I mail it to them, just let me know...thanks

2. What is a good place to order "THAT" VCAs? (update, after calling Tom from THAT he gave me the Mouser Part #)
http://www.mouser.com/Search/ProductDetail.aspx?R=2180BL08-Uvirtualkey61220000virtualkey887-2180BL08-U

 

[ding]

Just to make sure you don't have a link on pot a/pot b.

 

[micah421]

Just to make sure you don't have a link on pot a/pot b.

That is correct, NO LINK,.....


just like there is is NO LINK without the SSC

 

[Harpo]

I feel like I've narrowed down the issue. If while the SSC is connected, the unit passes audio, the bypass and makeup gain works and the power for the led works, Then it must have something to do with COM, ON, OFF, POTA, POTB section.

... then you proved that it has nothing "to do with COM, ON, OFF, POTA, POTB section" as this part of circuit is obviously working fine.
I already suggested how to proceed. Maybe you give it a try to see where and why your filter board is interrupting your signal. Owning a multimeter only makes sense when you use it. YMMV.

 

[Harpo]

is there any real difference in sound between the 2150B VCA and the 2150A VCA?

AFAIK a DBX 2150B has never existed.
Could it be you're taking about THAT 2180A/B differences. Just look up this parts datasheet and have an eye on noise and THD numbers. Maybe this matters to you and if so, you probably won't go in the opposite direction with a DBX202C at a later step.