SB4000 Support Thread

The is the official support thread for the SB4000 project.  Documents related to the build (assembly, calibration, templates, etc.) will begin to trickle in over the next week or so.

I ask to please keep this thread clean and friendly.

All further questions, issues, comments, etc - please refer to this thread.

BOM:

https://www.dropbox.com/preview/SB4000_REV4_BOM_2020.pdf?role=personal

Quad VCA BOM:

https://www.dropbox.com/preview/QVCA_REV2_BOM_2020.pdf?role=personal

Build Manual (UPDATED 2/28/2011): (Approx. 13 Megs)

https://www.dropbox.com/preview/SB4000_ASSY_DOC_REV3.pdf?role=personal

Frontpanelexpress File for Parmetal (Machining Only, No Text)

https://www.dropbox.com/preview/SB4000_REV5_PARMETAL.fpd?role=personal

Note: for Modushop you can modify the mounting hole locations

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Update*

Send/Return - There seems to be alot of confusion on how this gets wired.  Well, there is no set way, it should be wired whichever way works for your rig.  It is an UNBALANCED signal. 

Typical way is to tie both "sends" on the board together and tie both "returns" together as well.  Then, connect the "sends" to a 1/4" TS connector and same with the "returns"  This will allow you to now send a mono unbalanced signal out of the compressor to your board, and also send a mono unbalanced signal to the compressor for ducking.

Alternatively, you could wire the "sends" and "returns" to an XLR connector (ie: the "sends" to XLR Pin 2 and the "Returns" to XLR Pin 3), but then you'll need a "Y" cable to break them back out to 1/4" TS.

QUAD VCA Boards:

Please note typo in the silkscreen on the VCA boards (BOM is correct) -  should be a 0.1uF Film Cap, not 4.7nF.  If using the QUAD VCA boards, you must install JMP8 & JMP9 on the backside of the main board.  All of the components within the VCA boxes on the SB4000 main board are not to be populated.  VR1/VR2 would be best changed to 10K, however you can leave it at 50K if you'd like.  Turn the pot fully counterclockwise to start, and then slowly turn clockwise to calibrate for unity Gain (the target resistance is 5K, so for a 50K pot you won't have to turn it much)

For remaining changes to SB4000 Main Board, see the Quad VCA BOM above.

Calibrating for lowest THD with Quad VCA boards:

Easiest way to calibrate THD is feed a 1K test tone into compressor and look at the return signal with a freq analyzer in your DAW.  (I recommend to download Blue Cat's Freq analyzer for this.)  Distortion node will be seen at 2K, adjust until 2K node is as low as possible.

Engage the "External In" so the sidechain is disabled (Of course be sure there is no external signal being fed to the external input). 

Adjust DTRIM Pots (VR3/VR4 on Main Board) for lowest THD.  Then turn front panel gain knob to Max (lower the input signal as required so signal doesn't clip).  Now adjust the 50K Pots on the VCA boards for lowest THD.  Return front panel gain knob to 0.  You will need to repeat this process a few times until lowest THD is achieved.

Wow I just built this & it only took me 15 minutes!

Sorry, just wanted to be the first to respond hear! 
Can't wait to get this project going! ;D

Cheers
Sean

Mike, the pdf version has a number at the bottom of the first page selected in green (68k). Any reason for this?

Just want to check it does not relate to a number to 'be confirmed'.

skot_e said:

Mike, the pdf version has a number at the bottom of the first page selected in green (68k). Any reason for this?

Just want to check it does not relate to a number to 'be confirmed'.

Click to expand...

No, it's fine.  Don't know why it's highlighted.  Probably just remnants from me checking it.  I'll fix it in a bit.

Hi Mike, I've done quite a bit of part sourcing today and have a few questions and remarks ;

- Do you have any (mouser) part numbers on the 2-3-4-5 pin connectors, or a keyword on which to search? Can't seem to find them
- When searching for D1-D24, the best result is Vishay 1N4151TAP instead of 1N4148. Will these ones be fine?
- U22 on the BOM says IC, REGULATOR, NEGATIVE, +12V FIXED, 1A, 2%, TO-220. This +12V should be -12V, not?
- For U25 will a NTE1549 (mouser) work instead of the LM3916 specified in the BOM? I checked the pinouts on the datasheets and they are the same.
- PWR LED, SW1, SW2 and XFMR are available through mouser as well

Tsane said:

Hi Mike, I've done quite a bit of part sourcing today and have a few questions and remarks ;

- Do you have any (mouser) part numbers on the 2-3-4-5 pin connectors, or a keyword on which to search? Can't seem to find them
- When searching for D1-D24, the best result is Vishay 1N4151TAP instead of 1N4148. Will these ones be fine?
- U22 on the BOM says IC, REGULATOR, NEGATIVE, +12V FIXED, 1A, 2%, TO-220. This +12V should be -12V, not?
- For U25 will a NTE1549 (mouser) work instead of the LM3916 specified in the BOM? I checked the pinouts on the datasheets and they are the same.
- PWR LED, SW1, SW2 and XFMR are available through mouser as well

Click to expand...

1) You can use pretty much any .1" connector type.  They don't have to be the bolt down.  You can use the crimp molex kind if you want to, there's plenty of room on the board.  I used the "bolt" type because they're cheap and require no special crimping tools (which most people probably don't have).

If you want what's in my picture though - search for that (4 pin): 282834-4 (The last digit is the number of pins)

2) Use a 1N4148.  Just a regular old 1N4148, nothing special:

http://www.mouser.com/ProductDetail/Fairchild-Semiconductor/1N4148TA/?qs=sGAEpiMZZMtldOIVIVqa3SMPQXB85PA9Snp4653ZGO0%3d

3) Yes, my bad I will fix it.  It should say -12V.

4) Hmm.... Yea I saw that guy before as well.  It looks like a knockoff for the LM3916.  But they don't give much info on that datasheet.  I think it should work ok, but I can't say for sure.  I mean, I don't think you're gonna blow anything up, just can't say how it will perform compared to the LM3916.  Never used anything from that company before, National Semi makes good stuff.  Strong chance you're gonna have to go to digi for a few items.  If you find yourself doing so, go with the LM3916.

5) Yes all those should be available through either Mouser or digikey.  You don't have to use those particular switches or LED, those are just what I'm using in my pic, and what my front panels are machined for.  If you find something else with the same specs and same mounting hole size as what I listed on the BOM that you like more, then go for it.

The simple solution is to get the whole parts kit! ;D However; you should be able to easily find most of the parts at most suppliers.

Here is a detailed BOM for you guys in the US.
As mentioned above and in the attached file, if you're looking to buy the whole kit with most of the parts the easiest thing to do is buy it from Ptownkid, the bundled price is excellent.

SB4000 US BOM (XLS)
SB4000 US BOM (PDF)

Azone, wonderful job, very detailed!

The only things I noticed upon quick glance are SK1,SK2, & SK19 are required to build the bargraph.  You can't assemble it without them.

Honestly though I would highly recommend moving all of the sockets to the required area.  There's alot of IC's, and I can't imagine hard soldering all of them (and it's not very good for them, there's a risk of damage).  If you hard solder them and have any issues debugging the unit would be a nightmare.

ruckus328 said:

1) You can use pretty much any .1" connector type.  They don't have to be the bolt down.  You can use the crimp molex kind if you want to, there's plenty of room on the board.  I used the "bolt" type because they're cheap and require no special crimping tools (which most people probably don't have).

If you want what's in my picture though - search for that (4 pin): 282834-4 (The last digit is the number of pins)

2) Use a 1N4148.  Just a regular old 1N4148, nothing special:

http://www.mouser.com/ProductDetail/Fairchild-Semiconductor/1N4148TA/?qs=sGAEpiMZZMtldOIVIVqa3SMPQXB85PA9Snp4653ZGO0%3d

3) Yes, my bad I will fix it.  It should say -12V.

4) Hmm.... Yea I saw that guy before as well.  It looks like a knockoff for the LM3916.  But they don't give much info on that datasheet.  I think it should work ok, but I can't say for sure.  I mean, I don't think you're gonna blow anything up, just can't say how it will perform compared to the LM3916.  Never used anything from that company before, National Semi makes good stuff.  Strong chance you're gonna have to go to digi for a few items.  If you find yourself doing so, go with the LM3916.

5) Yes all those should be available through either Mouser or digikey.  You don't have to use those particular switches or LED, those are just what I'm using in my pic, and what my front panels are machined for.  If you find something else with the same specs and same mounting hole size as what I listed on the BOM that you like more, then go for it.

Click to expand...

Thanks, I'd like to get everything from one supplier, because of ridiculous shipping costs when ordering for a low amount of money . Might just split the parts up in two and order one part from mouser and the other from digikey.

Ptownkid said:

The simple solution is to get the whole parts kit! ;D However; you should be able to easily find most of the parts at most suppliers.

Click to expand...

I would if there didn't exist such a thing as customs who overcharge on import taxes ;D. If I get an overview for a total cost and it's coming near your kit, I'll strongly think about ordering that instead

The only things I noticed upon quick glance are SK1,SK2, & SK19 are required to build the bargraph.  You can't assemble it without them.
Honestly though I would highly recommend moving all of the sockets to the required area

Click to expand...

Done. Any time the BOM is updated the document will be rev'd but the link & filename will remain the same

Rukus, have you compared builds with just THAT chips against the DBX 202 alternative?

What differences does it make to the unit? Does it make it more usable for one application that the other? eg. better for drums or mixes with DBX202, etc. More noisier, etc.

Also, with Ptown's kit, does it make this mastering grade, or what do you need to make this compressor mastering grade?

canidoit said:

Rukus, have you compared builds with just THAT chips against the DBX 202 alternative?

What differences does it make to the unit? Does it make it more usable for one application that the other? eg. better for drums or mixes with DBX202, etc. More noisier, etc.

Also, with Ptown's kit, does it make this mastering grade, or what do you need to make this compressor mastering grade?

Click to expand...

Whether you use THAT2180/81's or DBX202's is a matter of personal preference.  DBX202's are going to have a more distorted vintage type of sound.  To some that is desireable, to others it is not.  I personally prefer THAT2181's over the DBX202's.  DBX202's have been extinct for years.

Again, what is "Mastering Grade" is a matter of personal preference.  All of the components in his kit are high grade.

I knew the kit pricing was better than self sourcing...

but yet...pre orders are trickling in very slowly, are people not interested, or waiting on something? I won't be able to do this for only a handful of people, far too much money.

Cheers

Im certainly in, just waiting on the sale of a bit of kit to fund it.

Should be able to send payment this week.

Thanks
Jake

I'll buy one fairly soon. Money's just tight at the moment. This is the worst time of year for me money-wise.

Joe

I had a feeling that there may be quite a few people just gathering funds, I just wanted to find that out.

End of the month is always the worst for me and the wife has a conference this weekend.