SB4000 Support Thread

[Ptownkid]

Good job Neily!

 

[Neily]

Thanks dude!!!


"Note* - If you don’t get any voltage at TP10 it means you are not in SSL mode."


I'm not getting voltage at tp10

any ideas anyone??

everything else seems to be working fine...

 

[Neily]

Figured it out! Works amazing!!

Woo!!

 

[dtrax]

Ribbon connectivity can be good, but if its backwards you'll get some issues.make sure the dots are on the same side of the cable.

Just to follow up, I got everything working! I had a delay in getting some new parts because I'd misplaced my credit card, and it took what seemed like forever to get a new one. Couple that with Mouser's shipping times, well, here I am.

In any event, my issue all along was a dodgy ribbon cable assembly. This time around, with new cable and headers, I simply used my drill press and clamped the f*ckers down nice and tight. I plugged in and fired her up, and was blessed with the squooshies.

I haven't even gone through the calibration (aside from the audio VCA trims) and things are sounding nice. I suspect final calibration won't change much of what I'm hearing, but I'll do that when I have the time.

As for the sound, it's definitely got that SSL vibe down pat. Talk about "sounding like a record"! To be honest, I can't imagine a mix engineer not getting by without one of these on the mixbus. I'm very impressed with how the unit manages to "let" transients through but maintaining a very consistent output level. Having mostly used plugin comps for the past 10 years, I forgot how a good analog compressor can be so punchy.

For Sh*ts and giggles, I quickly compared it against the URS 1980 w/ SC, and the sound is shocking similar. Kudos to URS, but the major difference is when you start to dig into compression. The plugin really starts to chew on those transients and sound flat. I don't want to get too off topic, but just an observation.

Thanks Mike for a great compressor. It has loads of features that I'll probably never use (not complaining at all though!!!). If I were to build another, I'd drop the Ext SC, meter, and Mono SC all together. But, that's my preference, so I'll shut up now

 

[sneakthief]

This build was very straightforward and the calibration went well. It's a pleasure to work with such well-thought out PCB's, panels & thorough documentation - thanks Ruckus 8) Not to mention, Ptownkid's kit had good quality components.

Here's a shot of it next to my newly-completed NTI EQ3D clone:

...I'm curious if I should upgrade the TL074's with OPA404's that I have lying around:

Had a cool experience with OPA404 I did not expect.

I replaced a TL074's of a GSSL (also with dual or turbo or oxford mode) sidechain rectification/ratio amp with OPA404. Gain reduction did not change as expected, but the sound of the compressor transformed dramatically! With OPA404 I could do much deeper gain reduction with less artifacts. It removed the "phat" SSL trademark sound, and it sounded more like some kind of transparent mastering unit. One friend commented that it "sounds like a plugin now". I guess TL074 has some serious issues with transients. Looks like speed counts immensely when we are buffering rectified (sharp discontinuities) audio. Looks like the slow TL074 "distortion" is a big part of the SSL sound.

 

[Ptownkid]

Good job Sneak! Really happy to see people completing these now!

 

[ripgtr]

I noticed in the build manual about cleaning the board with alcohol. I looked around but couldn't find much on this. So -
do I pour the alcohol in a pan and just set the board in it?
How long do you let it sit?

I see some people talking about using a tooth brush and then cleaning with a second alcohol bath.

Is this to get rosin off? Does it make a big difference to do it (some people talked about NOT doing it)? Do I want to scrub it or just let it sit for a while?

 

[Ptownkid]

It is to remove the flux, I just swab and brush.

 

[SimonB]

I finally got my SB4000 together and I'm having some trouble with it. When I try passing a 1Khz signal tone it changes the sound and only outputs on the right channel. In bypass mode everything passes fine. I tried passing some drum tracks through it and everything sounds really mashed and distorted.

Also U3 and U5 seem to be heating up A LOT.

Voltages are:

TP1 : -15.32 VDC
TP2 : -12.08 VDC
TP4 :  11.82 VDC
TP5 :  15.22 VDC

EDIT: I'm a *******. I had some 5532's and 5534's mixed up. All seems to be working now.

 

[SimonB]

OK now I tested things and started the calibration procedure. There are some problems:

1. The threshold knob doesn't seem to do anything.

2. Something is up with the "internal sidechain" switch. When I press it the turbo mode is off (TP10 reads 0.0 VAC) and when I disengage the button it turns SSL on (TP10 reads 0.6 VAC). I checked the wiring:

SWITCH "C1" goes to J10 "CM"
SWITCH "NO" goes to J10 "NO"

I can switch the wires and nothing changes. Should I wire it to the "NC" position on the switch?

3. When the unit is bypassed the stereo analyzer shows a mono image. When the unit is engaged the mono signal disappears even though I have both channel calibrated equally. It's like the channels are out of phase. I can still hear the signal but it sounds different.

UPDATE:

I removed the 47K resistor and jumpered R169 and this solved the threshold issue.
Also the mono image problem was due to the phase mode issue on the board. I had forgotten to crisscross resistors R32 and R36 but I crisscrossed the other resistors.

Now I'm trying to calibrate the ratios. When I send the test tone to the SB4000 at 2:1 ratio the DAW reports -10.0dbfs. I use an EQ plug-in with a gain section and just increase the gain by 10db. At the 2:1 ratio on the SB4000 the DAW reports -18.4dbfs. I try to turn VR16 but it only lowers the output instead of increasing it.

 

[ruckus328]

OK now I tested things and started the calibration procedure. There are some problems:

1. The threshold knob doesn't seem to do anything.

2. Something is up with the "internal sidechain" switch. When I press it the turbo mode is off (TP10 reads 0.0 VAC) and when I disengage the button it turns SSL on (TP10 reads 0.6 VAC). I checked the wiring:

SWITCH "C1" goes to J10 "CM"
SWITCH "NO" goes to J10 "NO"

I can switch the wires and nothing changes. Should I wire it to the "NC" position on the switch?

3. When the unit is bypassed the stereo analyzer shows a mono image. When the unit is engaged the mono signal disappears even though I have both channel calibrated equally. It's like the channels are out of phase. I can still hear the signal but it sounds different.

UPDATE:

I removed the 47K resistor and jumpered R169 and this solved the threshold issue.
Also the mono image problem was due to the phase mode issue on the board. I had forgotten to crisscross resistors R32 and R36 but I crisscrossed the other resistors.

Now I'm trying to calibrate the ratios. When I send the test tone to the SB4000 at 2:1 ratio the DAW reports -10.0dbfs. I use an EQ plug-in with a gain section and just increase the gain by 10db. At the 2:1 ratio on the SB4000 the DAW reports -18.4dbfs. I try to turn VR16 but it only lowers the output instead of increasing it.

Which VCA's are you using?  Have you configured your jumpers correctly on the audio VCA's?  Be sure to do all other calibrations first before calibrating the ratios.  Also, make sure you're already compressing at least 10db before you perform the ratio calibration to ensure you're well past the comp knee. 2:1 is probably the worst setting to use to calibrate because of the softness of the knee, 4:1 or 10:1 would be the better way to go.  Also note, you'll never get all 3 dead on, it'll always be a compromise between the 3, same as with original ssl.

 

[ripgtr]

It is to remove the flux, I just swab and brush.

I guess I have some soldering questions. After reading this I went out and did some research. I have soldered before - a homebrew THAT 1510 mic pre, headphone distro amp, guitar amp. Nothing this sophisticated. I looked on Kester's website and they say cleaning isn't needed on rosin core solder. -
http://www.kester.com/SideMenu/TechnicalSupport/KnowledgeBase/tabid/176/Default.aspx
"Rosin flux residues are non-conductive and non-corrosive. Under normal circumstances they do not have to be removed from a printed circuit assembly."
Is it still a good idea?

Or are we talking about using extra flux, like they have in the flux pens? I have never used that. Is that something I should be doing?

I did go out and buy a Hakko soldering station a couple years ago, it was amazing what a good iron will do, but I am still learning. Like I said, I am starting to move into things beyond "this is  a handy tool" to more serious products like the SB4000 and want to do it the best I can.

Thanks.

 

[Ptownkid]

I've never read that before...I just do it because I've seen corrosion around joints on home etched pcbs in the exact shape of the flux stains...

 

[ripgtr]

I've never read that before...I just do it because I've seen corrosion around joints on home etched pcbs in the exact shape of the flux stains...

Thanks. Yea, I googled it and some said they did and some said they didn't. Sounds like cleaning it is not a lot of work to prevent a possible problem, so I will go ahead and do it.

 

[SimonB]

Which VCA's are you using?  Have you configured your jumpers correctly on the audio VCA's?  Be sure to do all other calibrations first before calibrating the ratios.  Also, make sure you're already compressing at least 10db before you perform the ratio calibration to ensure you're well past the comp knee. 2:1 is probably the worst setting to use to calibrate because of the softness of the knee, 4:1 or 10:1 would be the better way to go.  Also note, you'll never get all 3 dead on, it'll always be a compromise between the 3, same as with original ssl.

I double checked and all of the resistors and jumpers are properly installed for the THAT 2181A's I have installed. My DAW only shows a 0.1dbfs difference when switching between 2:1, 4:1, and 10:1 ratios.

Also how is the level meter supposed to work? Is the I/O an on/off switch? Because when I have it in the ON position, it just seems like the level on the meter is higher, on the OFF position it is just lower (doesn't get into the red).

 

[electrisizer]

Have you configured your jumpers correctly on the audio VCA's? 

high im in building progress... do i need to jump all in the VCA section?
(have the ptownkid-kit  VCAs)

 

[sneakthief]

high im in building progress... do i need to jump all in the VCA section?
(have the ptownkid-kit  VCAs)

Read the table in the schematic - it will tell you which ones to jumper:

http://dl.dropbox.com/u/4740474/SB4000_Production/SB4000_REV4_FORUM.pdf

 

[sneakthief]

Magic crush setting:

If you want to get something that sounds like 20:1 compression, try setting the ratio switch in between 2 and 4 (or 4 and 10). It's tricky to get the knob centered there but you can definitely hear it smash the heck out of the signal.

 

[electrisizer]

FINISHED  ;D

works from first startup nothing explodes nothing distorts. it was a true pleasure to build with pts kit and the very logical layout of ruckus high quality board. thanks men!

it sounds exactly like i wish    a true pumping machine for my electronic kind of music.

 

[SimonB]

I have everything working properly but still cannot figure out why the internal sidechain switch is not working properly. When I press the button it actually turns off the SSL-mode. The light on the button turns on when depressed and it's wired properly.