CLX-VU Build Thread (DBX 160VU ) UPDATE: REV 3

[abechap024]

Actually taking your cue I was able to get it down to 10mb using acrobat.
Thanks!

 

[slowbass]

Great work, thanks for the manual !
So, it's not a good idea to use the "optional psu" part for a dual clx or can it work ?

 

[Rob Flinn]

hey Abe

Which meter should one order from HAirball to fit Danderloos cases ?

Also I'm guessing that one of each type of switchbank is needed ?

 

[abechap024]

Hi Rob,
Yes you will need one of each switch-bank and http://hairballaudio.com/shop/product_info.php?cPath=25&products_id=64 meter the 1ma smaller one.

Cheers,
Abe

 

[thebigskinny]

Just looking at the case wondering about the switch banks. Don't you only need one switch bank per unit?
Oh and Abe , I got the parts kits, very well packaged and documentation is great.  Just have to get some bits here an there!!!

 

[Rob Flinn]

Just looking at the case wondering about the switch banks. Don't you only need one switch bank per unit?
Oh and Abe , I got the parts kits, very well packaged and documentation is great.  Just have to get some bits here an there!!!

1 switchbank per channel.

If you build a stereo one you buy one of each.  so the extra switch on one of the banks is the mains on/off & on the other bank it is a stereo link

 

[sr1200]

Started my build last night. got the board almost completely stuffed and have some questions...

1) R29 and R28 arent on the THAT build BOM.. do I need them?
2) The caps at the right sid eof the power supply on the board and schem say 10uf 16v the BOM says 25V (im guessing the 25s will work)
3) C16 on the board says trim and no value, its not on the BOM either (jumper?)
4) Anyone tried to wire this bad boy using a Lorlin rotary switch?

 

[abechap024]

Started my build last night. got the board almost completely stuffed and have some questions...

1) R29 and R28 arent on the THAT build BOM.. do I need them?

Nope you don't need them if you are building a THAT chip build.  R29 biases the discrete VCA positive supply and R28 is part of the discrete vca symmetry circuit

2) The caps at the right sid eof the power supply on the board and schem say 10uf 16v the BOM says 25V (im guessing the 25s will work)

yep they will work and wont mind as much on your first power up while you adjust your voltages if they are more than 16v for a bit.

3) C16 on the board says trim and no value, its not on the BOM either (jumper?)

No, that is to trim the 22uf timing capacitor. chances are you will never need it, unless you want to experiment with different timing capacitor values and a switch. So do not jumper it, if you do it will short out your rms unit.

4) Anyone tried to wire this bad boy using a Lorlin rotary switch?

very possible
you would need a least a 3pole/3position (so a 4pole 3 pos would work) .
You could also just wire it up to always be in GR mode. then you wouldn't even need a switch. Thats where my meter usually stays...
Good luck!

 

[dandeurloo]

Hey Guys, just wanted to give you a update on the compressor. I got a chance to finally fire mine up today.  I did a few tweaks but not much.  Basically I just put a new meter scale in the meter and re calibrated the meter.  Abe your PDF is wonderful!  

(NOTE****If you are gonna use one of the scales form ABE's pdf you need to make it 50% the size of the pdf.  I found that to work pretty nicely compared to the DBX 161 I have here.)


Ok, so after changing the few things with the meters I got to running sounds through the CLX.  Right from the start I was impressed!  Its very much a DBX 160 vu sound.  I have a 161 here that I tested it next to and a pair of 160x's and a slew of other greta compressors.  All of the DBX compressors have the same kind of sound but the VU's both just have ablot more vibe.  The attack time or something is more musical.  Plus when the VU's really grab down the Snap sound of the compressor is much more pleasing the the 160x's.

(NOTE*** I test all the compressors by multing them on my patch bay and then running them to different channels on ,y folcorm so it was a pretty Apples to Apples Comparison.)

Anyway the long and short of it is the CLX sounds great.  The CLX is a little brighter and more present then the 161 VU.  I have a few ideas why that may be.

1. Balanced vs. Unbalanced?
2. Brand new parts vs. 40 year old parts
3. THAT chip vs. OLD DBX chip.  

I didn't try this because I am very happy with the sound of the compressor but if you want to try and get even closer to the vintage vibe I think I would try and mis adjust the trim on the that chip so it is a little dirtier. I think that would make the CLX so close you would have a hard time picking them out if you get you thres, ratio matched up.

Overall I think the CLX is a hair punchier then the vintage units but still has the grab and release (gooey) you want out of the DBX 160 vu.  It also for some reason seems to have more flexibility in the pots then the 161 VU?  Not sure why but, it seems to cover a little wider range all around then the 161 VU.  By this I mean I have more adjustment range of the compression and shape of the compression. All the way form more to less and everything in between.  

The more I compared the CLX next to the DBX 161 I prefer the CLX.  For somethings I am sure the vintage unit would sound better but I think overall I am glad I own the CLX and my friend has the 161!  I will be using these a lot on Kick and Bass!

Thanks Abe for the project. Now everyone else go finish yours these things are sweet!

 

[sr1200]

OK so i had the thing up and running, sounded pretty awesome squish sauce... i was playing around with the meter (jumping various settings since i didnt hook up the actual switch yet) and bam... dead.  blew the fuse.  Popped in another (no jumpers on the meter pins) turns on for a sec, and blows out again.  Any ideas of what i killed?  Im thinkin I jumped the wrong 2 pins the first time, but now that theres nothing on the switch pins... at a loss.

 

[abechap024]

Hmmmm that is a good question...

Okay so if you were jumping the meter switches there is a number of things that could've possibly gotten blown...

Depending on how you jumped maybe one of the voltage regulators got blown, or maybe the output transistors got blown and thats whats blowing your fuse.

Or an opamp got fried and its pulling too much from your fuse.

Try pulling all the opamps out - see if that helps

try measuring the resistance between your power rails and ground and each other, if its too much lower that 100ohm you got a prob....

 

[sr1200]

Took the chips out. Was playing with the continuity test on my meter and noticed the 2 outside legs of the BC550c (Q2) is short (beeeeeeep) i dont have another bc550c to test against. Does that seem right?

 

[abechap024]

Yep, thats right. That transistor is used more like a diode, hence the shorted legs...

What are the fuses rated at you are blowing? I would start at the transformer and work in.....I'm trying to think of things that would cause a direct short of the power rails to blow a fuse and I can' think of many things. Are your output transistors testing good?

Cheers,
AC

 

[sr1200]

Just took the chips all out and its still blowing 250ma fuses. Upon poppin the probes around. I noticed all 3 ac inputs are open. (open to ground as well). Guess thats normal though.

 

[sr1200]

Im thinkin maybe replace the vr's.  Thete shouldnt be any shorts on the legs of the NTEs right? 

 

[abechap024]

Correct there shouldn't be any shorts on the legs of  the output transistors. Are you using the doide checker to test the transistors? thats a handy way to do it...

replacing the Vrs might be a good idea. You could try taking them out then pluggin it in (with no ICs just to be on the safe side.) That would issolate your problem to VRs or later.

 

[sr1200]

Yep was using diode check and open/short (2 different setting on my
Meter). So i replaced the VRs and GOLD!!!  Only odd thing now is i dont have anything on the pins for the meter and the meter is working....  It didnt do that before to my knowledge.  Lol. Oh and btw. F'n GREAT job on this thing.  Its total liquid squish.  Has a real gooey sound (no other way to describe it). It's just organic. Got kick n snare gettin ponded by these things and the whole kit getting destroyed by the sb4000.  Compression heaven?

 

[abechap024]

Congrats on getting it sorted.

These things are a lot of fun. I've gotten my best personal best Rock mix to date by doing somethings different and using these to gooify-chunkify the bass, somehow on these tracks it really let the kick sit on top but the bass in a way that I've never gotten it to before. Still trying to figure out how it does it! I think the 2nd harmonic distortion has something to do with it.

Anyway nice to hear some success on these units.

Cheers,
Abe

 

[sr1200]

Lets see if i can get this to make sense...

to wire a lorlin 4p 3pos switch to the board (gonna use b# for board point and p#(or letter) for the switch prong/pole/thingy

pA - b2
p1 - jumped to p5/p7/p8
p2 - jumped to p3
p3 - jumped to p2 and out to b1

pB - b6
p4 - jumped to p6
p5 - jumped to p1/p7/p8
p6 - jumped to p4 and out to b5

pC - b3
p7 - jumped to p5/p8/p1
p8 - jumped to p7/p5/p1 and out to b7
p9 - b4

pD/p10/p11/p12 not used

maybe a graphical representation will be easier... (the dotted and dark solid lines are jumpers)

Does this look about right or am I WAY off the mark here?

 

[Rob Flinn]

Nearly there with this project just need to get a few parts tomorrow. 

I'm using a generic PSU board that mnats supplies with his 1176 boards.  Is the best place to take the unregulated +&-24v comes from the inputs to the regs ??