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

[jplebre]

Crap got the wrong meters, didn't I? http://www.hairballaudio.com/shop/product_info.php?cPath=25&products_id=59
That's what I get for rushing

 

[abechap024]

Crap got the wrong meters, didn't I? http://www.hairballaudio.com/shop/product_info.php?cPath=25&products_id=59
That's what I get for rushing

Those will work but are noticeably "slower" and you have to use a 10k resistor instead of 3k3. Or just ship them back and get the right ones.

 

[abechap024]

Hey guys

So completed mine. Time to polish the little things now
Anyone else followed the suggestion to change the cap? (0.33uF)?

I managed to pull the sound I wanted from some snares exactly like the 160's I remember, but for the life of me the kicks just loose all body and get clicky, as if it wasn't fast enough (but this beast is that fast).

Eg. I can match the example in the sound cloud to 99.99%

I did do a silly mistake and installed the BC550 on the RMS section the wrong way around. I'm assuming the "timing cap" is the 22uF tantlum, maybe I damaged the cap?

Ideas before I start hacking at the board?

J

I would use 1.8uf for the 0.33uf cap like I stated before, maybe its the actual kick / kick sample that you are compressing that is clicky itself? If you wanted more bass out of it , you could use a 0.33uf cap, that would let the compressor not react so much to the lows.

 

[jplebre]

tried it on a handfull of kicks and pretty much all of them became thin and weightless (loosely describing as loss of low end)
but except for one kick it simply wasn't fast enough and this is pretty darn fast compressor. Or maybe it's fine. I'll compare it with a 160 some point soon I hope.

Meanwhile I may socket the caps and give it a go.

I've been on the soundcloud groupdiy page is there someone that could pretty please post a kick setting there?

For the meter! RIght! I could raise the meter but only to halfway! I'll try with 10k too. thanks!

 

[nuclues]

I'm a bit confused about the measuring method at the powerrails- maybe it's my bad English:
I can measure 15 volt at the plus and minus points,where i put the black lead (com) of my multimeter at the minus point and the red lead of my multimeter at the plus point.
Is it the correct Way to measure?
I ask because I read that some put the Black lead on the G point at the powerrails and the red on the minus or plus and measure from that, and if I dó that I got something like 0-1 volt out of that.
Right now I got 15 volt at the 15 volt points and around 50 volt at the 24 points
Best from Nick

 

[jplebre]

Hi Nucleus

No, you have to measure witht he black probe on G. Red probing +15 should yeld a positive voltage, on -15 a negative voltage.
Check your DMM setting, You should be on V DC, not AC, and probes on the correct place (V+Com)

Then adjust the trimmers.

Seing 50v on the 24v rails though. What are the voltage (AC this time around) on your CT points?

 

[nuclues]

Thanks jplebre- I send you a virtual beer for helping me
Now I have 15 v at the minus and plus point and around 27 v at the 24 v points.Measured with the black lead at G and red lead at minus or plus.
I've measured in DCv mode.Still it doesn't give meaning to my brain why I should measure with the black lead at the ground point,because the pcb it's not connected to the chassis yet so there's no ground connection to the outside of the unit.
Thanks again for your help JPL
Best from Nick

 

[jplebre]

I've measured in DCv mode.Still it doesn't give meaning to my brain why I should measure with the black lead at the ground point,because the pcb it's not connected to the chassis yet so there's no ground connection to the outside of the unit.

to the best of my understanding, or how I interiorized this, this "ground" is a reference level.
may or may not be the same as a power ground or the earth, although it is?

This ground will be the CT as well.

(bit rusty, trying to grab most of these principles but there's so many variables).

Cheers for the beer

 

[jplebre]

Right socketing the caps - more roundy goodness for the kicks, but not an extreme difference.
And I just noticed something:

Rev3board:, meter still without the "callibration" resistor, RMS callibrated, i/p at 0.011v
- I do not have 15/-15 on the ratio pot. but on the threshold and o/p pot. Did I misread the info a few pages back?
- R43 does nothing. Ratio, on the other hand, only does "compression on/off" and then very little if no change from 1.3ish to +inf
What exactly was the "mod" on rev2?

Or is this just my unit? :shock:

edit I don't have LED attached and I just saw on original schem the ratio is tapped onto that
Edit 2: Above/below led do not interfere with ratio, back at schematic for me

 

[jplebre]

freaking great sounding unit.

Anyway, some more things I'd like to report with forumites, to see if anyone experienced this:
- Ratio was working fine today (i know analogue gear can be temperamental, but damn!)
- @Abe, what's that via next to the O/p and the pcb standoff hole? seems that if I put a nut there the o/p stage goes into cutoff.
- with the hairball vu I can't get the meter to go to 0 even with 10k resistor. The TL opamp gets incredibly hot as well after a few turns of the trimmer.
Any other ideas before I get some 1mA meters my way?

 

[eparg]

freaking great sounding unit.

Anyway, some more things I'd like to report with forumites, to see if anyone experienced this:
- Ratio was working fine today (i know analogue gear can be temperamental, but damn!)
- @Abe, what's that via next to the O/p and the pcb standoff hole? seems that if I put a nut there the o/p stage goes into cutoff.
- with the hairball vu I can't get the meter to go to 0 even with 10k resistor. The TL opamp gets incredibly hot as well after a few turns of the trimmer.
Any other ideas before I get some 1mA meters my way?

I had two bad tl071's, I would try buying new ones and popping them in. I couldn't get my meter to zero before I replaced the tl071's. Triple check the orientation of the tl071. If its getting hot that is a bad sign, mine is barely warm.

 

[jplebre]

eparg, this with normal vu meters, not amperometers?
thanks

 

[berkleystudios]

creating my BOM now for a stereo unit. Where are yall sourcing the NTE292/ CA3083???? digikey isnt stoked and neither is mouser...

 

[jplebre]

kingston I got a few spare from ebay - littlediode (UK)

 

[eparg]

eparg, this with normal vu meters, not amperometers?
thanks

I'm using the hairball 1ma meter

 

[tfp]

Hi Abe,

Finally finished my CLX today with VCA200 and it is sounding great, just three questions to be sure:

Calibration of R34 didn't do anything noticable for the distortion, I used a couple of programs for testing, but the differences when turning a lot of times where not visable for me?

For the rev 2 build is it for the Hairball 1ma meter: 1k or 3k3?

What is the average noisefloor what you guys are measuring, I am getting about -76dB with gain at 0.

Thanx for the build, really great and looking forward to use it in the studio!!

RJ

 

[abechap024]

Hi Abe,

Finally finished my CLX today with VCA200 and it is sounding great, just three questions to be sure:

Calibration of R34 didn't do anything noticable for the distortion, I used a couple of programs for testing, but the differences when turning a lot of times where not visable for me?

For the rev 2 build is it for the Hairball 1ma meter: 1k or 3k3?

What is the average noisefloor what you guys are measuring, I am getting about -76dB with gain at 0.

Thanx for the build, really great and looking forward to use it in the studio!!

RJ

Cool just reread and noticed you did it with the 200 discrete vca. Black can or silver?
1ma meter is 3k3.
noise floor should be down around -90 or so (that is with that chip) is it hiss or hum noise floor?
r34...were is your distortion at? also you have to turn it a lot and watch like on rmaa, watch for the 2k or 3k overtones and there will be a little sweet spot.

 

[jplebre]

Hey guys

took the CLX for the studio today. Regardless of being close to the 160, everyone loved the darn thing.
I'm going to be mixing with a veteran some point in the next coming weeks and he has an army of 160's. He asked me to bring mine, should be fun!

I still think something is fishy with the ratio. It's like it should be a log pot instead of linear or soemthing too sensitive to start with and then almost no change at all, and 1:4 trimmer there's no difference CW to CCW (rev3).

J

 

[plektra]

Hi, I'm having some issues with the rev.3 kit and Purusha's front panel. For those who aren't familiar with this, the panel has got a subpanel to mount the switch assembly and ratio & gain pots. The problem is that subpanel is too thick for the pots, which are not tall enough to be able to fasten the nuts. I was thinking of getting rid of the whole subpanel and use regular standoffs for mounting the switch assembly, but I would have to add some through-holes to the front panel for the standoff screws.

If people have had similar issues, how have you solved this out? I could switch to longer pots, but the whole idea of attaching the switchbank only using the mounting via pots doesn't actually really convince me, I'm looking for some more robust way to do it.

Some photos:
http://capstanaudio.files.wordpress.com/2013/06/photo-13-6-2013-22-19-43.jpg
http://capstanaudio.files.wordpress.com/2013/06/photo-13-6-2013-22-20-03.jpg

 

[baadc0de]

Had the same box here but no problems encountered. I had some pots with longer thread it seems... I think Piher from banzai. The switch assembly is definitely robust enough when mounted that way, our box is in use for quite some time and no problems or loosening up yet.