SB4000 Support Thread

[ruckus328]

With no compression and Gain at 0, input and output should be the same.  If not you have some other issue going on.

 

[Neil]

I hate capacitor code markings! Can someone explain how u1J250 is equal to .1 uF? Wouldn't that be 25 pF or .000025 uF?

Time to get a capacitor tester. I thought my Fluke 87 had it, but noooo....

 

[Neil]

Alright, I've figured the u1 is really .1 in uF, I suppose J is 5% tolerance and 250 volts?

 

[ruckus328]

The "u" is the decimal place (in microfarads).  So u1 would be .1uF, u01 would be .01uF, etc.

The J I'm not sure about, don't know if that's a standard or dictated by that particular manufacturer (probably)

250 I would assume means 250V, but doesn't really matter as anything over 50V is plenty fine.

 

[sr1200]

Yes the meter is the same if no compression is happening. The unit sounds perfect at this point.  Just a minor annoyance that the LEDs are just always hitting the top of the bargraph.  Now that i look at it more closely, i notice that the meter only goes to +2 which is probably about right now that i think of it.  according to my analog meter on another piece of gear  -14.1 on protools is equivalent to 0 on the analog meter. (and that coincides with what the 4000 is showing exactly) So i guess all is well

 

[etheory]

Hi everyone.  After all this forum has given me, I just wanted to share a little story and some images of my journey thus far building the SB4000: http://www.evolutionarytheory.com/2011/07/sb4000-bus-compressor-build-day-2/ ( it will be fleshed out with more detail and more pictures soon.... ).

Thanks so much to all involved for putting this kit together.  It's of an amazing quality and builds really well.  If you have help in the form of a second competent electronics buff, then set aside a build time of 3 x 8hr days.  If you are doing it by yourself, I'd probably double that estimate.  If you want to do it properly, you godda put in the hours.  But if you do, it's amazing.  Having said that, I haven't finished mine yet, so there's still room for tears ;-)

 

[envelope]

The "u" is the decimal place (in microfarads).  So u1 would be .1uF, u01 would be .01uF, etc.

The J I'm not sure about, don't know if that's a standard or dictated by that particular manufacturer (probably)

250 I would assume means 250V, but doesn't really matter as anything over 50V is plenty fine.

they are standard designations

J = 5% tolerance

K = 10% tolerance

250 =  voltage rating

 

[buildafriend]

Whats with the little stars on the 200Ohm R?
What is meant by CnB C'mon cut it? Why should I or should I not cut the trace?
What transformers and VCA combos have you had the best luck with?

 

[Neil]

Heatsinks on the regulators, do you recommend conductive paste, or just screw 'em on as is?

 

[minor_glitch]

Whats with the little stars on the 200Ohm R?
What is meant by CnB C'mon cut it? Why should I or should I not cut the trace?

You only cut those if you're adding the crush & blend circuit to your unit.  If not, just leave it alone.
I've been wondering about those stars myself actually, although I'm betting the answer is buried somewhere in the last 24 pages.

 

[sea_man]

Hi !
I bought the complete kit and i'm welding the electrolytic caps, but i have a question..

in the SB4000_REV4_Part_Numbers.pdf appears this:

8* CAP, 100uF, 35V, 20%, ALUMINUM ELECTROLYTIC, LOW ESR
18*  CAP, 22uF, 35V, 20%, ALUMINUM ELECTROLYTIC, LOW

But in the capacitor bag have only 17* CAP, 22uF, 50V, ALUMINUM ELECTROLYTIC and 8* CAP, 100uF, 50V, ALUMINUM ELECTROLYTIC

Is safe weld this  of 50v instead the 35v ? and is the 17* 22uf caps sufficient ?

Thanks !

 

[Neil]

Hi !
I bought the complete kit and i'm welding the electrolytic caps, but i have a question..

in the SB4000_REV4_Part_Numbers.pdf appears this:

8* CAP, 100uF, 35V, 20%, ALUMINUM ELECTROLYTIC, LOW ESR
18*  CAP, 22uF, 35V, 20%, ALUMINUM ELECTROLYTIC, LOW

But in the capacitor bag have only 17* CAP, 22uF, 50V, ALUMINUM ELECTROLYTIC and 8* CAP, 100uF, 50V, ALUMINUM ELECTROLYTIC

Is safe weld this  of 50v instead the 35v ? and is the 17* 22uf caps sufficient ?

Thanks !

Yes, it's safe. You can always go higher on voltage rating, as long as the capacitor physically fits.

 

[ruckus328]

Neil: it won't matter for the 15V rails, but the 12V rail runs hot, so if you have some I'd use it there.

sea_man: As Neil already said, higher voltage is fine as long as it fits.  If the BOM says qty is 18, then you'll need 18.

buildafriend: *resistors - they're dropping a little current on the relays.  Says on the schematic, if you use relays other than the ones I spec'd on the BOM, they may need to be resized.

CnB traces - do not cut.  They're only cut if you're using an external CnB board.

VCA and transformer specifications are on the BOM/schematic.

 

[ruckus328]

etheory - awesome job man, let me know when you're done so I can post a link at the beginning of the thread (if that's ok with you of course)

 

[buildafriend]

Okay, searching for the info.

 

[buildafriend]

Sorry for being a newb. I have the PTOWNKID kit. I looked at the values listed on the BOM but I have never read a datasheet for a relay before, its cofusing me. If I have his kit with the relays that read "TX2-12V ATX203" should I install the 200 Ohm Resistors with the little stars next to them?

 

[Ptownkid]

yes...they are 12V relays.

 

[Neil]

Hey Mike, what's that pad or insulator you've got under your transformer? The big square looking thing.

 

[tfletchii]

would anyone care to offer a manual or any tips on operating the sb4000? I'm new to the SSL bus compressor and want to make sure I'm making the most of this lovely unit

 

[minor_glitch]

Alright, last parts have arrived, it's all wired up, power supply powered up without exploding, rails measured roughly within +/- 0.5V to what they should be, I think I'm just about ready to attach the main board.

Question though,  are there any pretrim values for VR3/4 (dist) and VR6/9 (T2)?  Didn't see any on the schematic.

Oh, and for the main board, when you say 'turn the unit on and quickly measure...' are we talking <5sec? <1min? until it bursts into flames?