SB4000 Support Thread

[minor_glitch]

Thanks Ptownkid.  Go figure, I work about 10 minutes down the road from Sayal and I've never bothered to check them out.

 

[buildafriend]

This thread looks like it is going to be a huge help. The step by step instruction PDF seem like it will clarify everything once I get the board populated.

 

[buildafriend]

Hey I don't see anything on the BOM for the DBX unit/units. How many are in the project? I might just be missing it because I am uncertain what to look for.

http://dl.dropbox.com/u/4740474/SB4000_Production/SB4000_REV4_Part_Numbers.pdf

 

[0dbfs]

Got two units just about complete. I worked on these between sessions and various gigs. Could have banged them out sooner but had to put em down for a little while (and read through the prints). Can't wait to use these in a mix. Should be plenty fun!

Thanks a ton to all the guys that helped get us to where we are today.

Best,
Jb

 

[ripgtr]

Hookup wire.

Any minimum I should be looking at for the gauge of the hook up wire between the boards and say the power board or the switches? I have a bunch of #26 in different colors. Should I be using something bigger? Yes, I know about the 14 gauge for the star ground but I am looking at all the other wires.

So, I see the power supply as - Transformers 36.0V CT @ 0.69A 18V  - and looking on the web, see #26 up to 2.2 amps - http://www.powerstream.com/Wire_Size.htm - so I am guessing I am good, but I would rather not guess.

Use what I got, or go shopping?

 

[minor_glitch]

How critical is it to clean the board after soldering?  I'm using Kester 245.
It claims to be 'no clean' but should I still try to clean it up a bit?

 

[sr1200]

ok, so im wiring up #2 tonight, i get the PS hooked up, fire it up and get reasonable tolerance for what is supposed to be there (11.88 and 15.20 +/- )

I hook up he wires from the PS to the main board, fire it up just to see if the light comes on (for my "ITS ALIVE!!!" ritual)

and BAM!!! (literally) the 5534 on the right VCA explodes.  Im not talkin burns up, im talking EXPLODES sending shrapnel across the room and blowing the top off the chip.  I have no clue where to start trouble shooting this kinda thing.... im hoping it was just a bad chip.  Im thinking if something was that F'd up perhaps both the left and right would have blown.... so upon further inspection of the  remnants of the chip i notice the little dot is missing... hmmm  DUMB ARSE me put the chip in backwards! DOH!  So LFMF (learn from my fail) and check the dots before firing it up! LOL

 

[snipsnip]

reversing polrity on things tends to make them explode.

you should know this from watching science fiction alone!

 

[Ptownkid]

reversing polrity on things tends to make them explode.

you should know this from watching science fiction alone!

Haha, indeed!

 

[ruckus328]

Hey I don't see anything on the BOM for the DBX unit/units. How many are in the project? I might just be missing it because I am uncertain what to look for.

http://dl.dropbox.com/u/4740474/SB4000_Production/SB4000_REV4_Part_Numbers.pdf

Because DBX202's are a mod, standard design uses THAT2180 or THAT2181's and BOM reflects this.  If you're using 202's you need 2 of them for the audio VCA's.  You'll still need 2 THAT2180's or 2181's for the sidechain (doesn't matter which one or what grade)

 

[Harpo]

Hey I don't see anything on the BOM for the DBX unit/units. How many are in the project? I might just be missing it because I am uncertain what to look for.

http://dl.dropbox.com/u/4740474/SB4000_Production/SB4000_REV4_Part_Numbers.pdf

Because DBX202's are a mod, standard design uses THAT2180 or THAT2181's and BOM reflects this.  If you're using 202's you need 2 of them for the audio VCA's.  You'll still need 2 THAT2180's or 2181's for the sidechain (doesn't matter which one or what grade)

...and for DBX unit/units, make sure you know what type of modular VCA you're asking for. Looking at some threads, you seem to be looking for the 'gold can' VCAs DBX202C, coming with different parameters than the 'black can' VCAs DBX202. There are some other VCAs for this type of footprint around, namely the 'silver can' DBX2001, the 'blue can' THAT2002N, THAT2002R, THAT2002T or the 'open frame' DBX202X, DBX202XL, THAT202R, THAT202XT, THAT202XTC or THAT2002T1, all with more or less differing parameters for control voltage law, supply, max.i/o-current, ...

 

[ruckus328]

How critical is it to clean the board after soldering?  I'm using Kester 245.
It claims to be 'no clean' but should I still try to clean it up a bit?

Yes personally I would, it literally takes 2 minutes, just pour some alcohol over it and/or dunk it.  It's up to you if you want to do it, but first off - it looks like Sh*t if you don't.  Secondly, it's harder to notice bad solder joints.  Thirdly, depending on solder used the flux residue can often be sticky, which means dust, etc is going to cling to your board like a fly trap.

However....

There's no such thing as "no clean solder", I don't care what Kester or anyone else says.  Notice in thier literature where it says (should be ok for most applications).  Well, we've had major system failures at my plant due to this supposed no clean crap, resulting in catostrauphic failures on equipment sent abroad (which was not an easy or cheap fix - try getting equipment back through Algerian customs, in the end I had to go over there, but that's another story).  That was high voltage stuff, but we've seen issues with small signal here as well.  Now everything gets cleaned, whether no clean flux is used or not.  Anyways, "no clean" flux leaves a slightly conductive parasitic residue, when you start to get into high impedances is, you've basically formed a conductive path around your entire board, and it's juuuuuust conductive enough that all kinds of fun things can happen.  Would there be issues with a design like this?  I can't say, probably not, but for the 2 minutes it takes it's not something I'd gamble on, especially on something that's supposed to be high end audio.

You're probably going to need something a little more agressive than isopropyl alcohol though if using "no clean", I'd try methanol (any hardware store).

 

[buildafriend]

Hey I don't see anything on the BOM for the DBX unit/units. How many are in the project? I might just be missing it because I am uncertain what to look for.

http://dl.dropbox.com/u/4740474/SB4000_Production/SB4000_REV4_Part_Numbers.pdf

Because DBX202's are a mod, standard design uses THAT2180 or THAT2181's and BOM reflects this.  If you're using 202's you need 2 of them for the audio VCA's.  You'll still need 2 THAT2180's or 2181's for the sidechain (doesn't matter which one or what grade)

Oh I see. It won't hurt to have both units so I can find the better of the two. Do you have to change any surrounding resistors or caps to use either the THAT or DBX?

 

[ruckus328]

Oh I see. It won't hurt to have both units so I can find the better of the two.

I'm not sure what you mean by this.  There's 4 VCA's in the design - 2 for the Audio (1 for left and 1 for right), and 2 for the sidechain (1 for left and 1 for right also).

For the audio VCA's, you can use THAT2180, THAT2181, DBX202 Black or DBX202 Gold cans.  I'm sure many other VCA's can be used as well, but those are the only ones I tested and confirmed surrounding component values for.  If you're using any type other than those then you'll have to do your homework around the forum for GSSL mods.

For the 2 sidechain VCA's, you need to use THAT2180 or THAT2181, DBX202 can't be used here.

Do you have to change any surrounding resistors or caps to use either the THAT or DBX?

Yes, always, different VCA's - different surrounding components.  Information is on the schematic, but type of VCA you're using would be helpful to know, can't give any advice or tips without knowing that.

 

[ruckus328]

Hookup wire.

Any minimum I should be looking at for the gauge of the hook up wire between the boards and say the power board or the switches? I have a bunch of #26 in different colors. Should I be using something bigger? Yes, I know about the 14 gauge for the star ground but I am looking at all the other wires.

So, I see the power supply as - Transformers 36.0V CT @ 0.69A 18V  - and looking on the web, see #26 up to 2.2 amps - http://www.powerstream.com/Wire_Size.htm - so I am guessing I am good, but I would rather not guess.

Use what I got, or go shopping?

26 gauge wire is way too small imho.  In some places you could probably get away with it, in others you'll likely see smoke.  You're looking at the wrong column, the one you should be looking at is the power transmission column.  The current carrying capability of wire is determined by both size and external thermal factors.  A bare copper wire all by itself in free air can carry more current than an insulated wire bundled with 10 other wires, as heat builds up from all of them.  If you put 2 amps on 26 gauge insulated wire you probably won't like the results.

22 gauge would be my recommendation for most places. 

For the connection from the main board to the Power Supply, I would use 18 gauge, and definately use 18 gauge for your mains/transformer wiring.  Using 14 gauge wire for your PS grounding is pointless if you cripple the ground connection between the main board and power supply (this needs a good ground connection to the power supply), unless you want hum.

BTW, you can get by with a slightly smaller size wire for you PS ground connection, 16 gauge would be ok too.  The point here is, thicker ground wire = better ground connection.

 

[ripgtr]

On the wire - thanks. Ok, glad I asked!  I will grab some wire next time I go by Fry's - there ain't much else around here, unless someone knows an electronics parts place in Austin.

Oh, and on the chip thing - I put a THAT 1512 in backwards one time (troubleshooting and pulling it out and putting it back, and one time didn't check well enough). Pretty impressive what 15 volts can do.

 

[sr1200]

in regards to my incident last night... what else might have taken a poop from me putting that 5534 in backwards?

my ps is fine  

when i power up im getting smoke from the c42 region.which looks like the right channel of that section

EDIT:  After staring at the schematic trying to find c42, i think im going to replace the 5532 at U1 as well.  My -15 seems to be fine and nothing else on the board seems to be having issues. 

 

[sr1200]

ive traced the prob down to the bar graph.  As soon as i disconnected the 3 wires to the front panel for the BG everything worked (no smoke or explosions lol)

 

[ripgtr]

Meter question - I see how to hook the meter up but have a question on the meter lamp. I can't find a datasheet on this that tells me.

So, the meter is marked + and -. The board is marked the same for the meter and A and K for the lamp. Anode/cathode, got that. I am assuming the markings on the meter apply to both the meter and the lamp, so the Anode would the one on the right (looking from the back) marked -. The + would be K or cathode.

Am I reading this right? I don't want to hook it up backwards.

 

[ruckus328]

Anode (A) is positive, Cathode (K) is negative - always.