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

[Songguy]

Hi abe,

I'm thinking about installing a LED along with the switch I'm using to select stereo mode. Any ideas on wiring up an led, can this be done?

Best,
Chris

 

[abechap024]

Hi abe,

I'm thinking about installing a LED along with the switch I'm using to select stereo mode. Any ideas on wiring up an led, can this be done?

Best,
Chris

Of course, just wire the led and current limiting resistor to a power rail and the other side of a double pole switch

 

[Trench Recordings]

Will this power transformer work for a dual unit ?

http://ca.mouser.com/Search/ProductDetail.aspx?R=VPT36-1390virtualkey55310000virtualkey553-VPT36-1390

I'm ordering stuff from Mouser for other projects, might as well combine and save shipping

-Dave

 

[abechap024]

Will this power transformer work for a dual unit ?

http://ca.mouser.com/Search/ProductDetail.aspx?R=VPT36-1390virtualkey55310000virtualkey553-VPT36-1390

I'm ordering stuff from Mouser for other projects, might as well combine and save shipping

-Dave

looks good!

 

[eparg]

What is everyone using to mount the pcb to the case? I'd prefer not to drill if at all possible. Has anyone used something like this before?

http://www.wlanparts.com/product/EZSNAP-5-3/PCB-Mount-Nylon66-48mm-standoff-for-3mm-hole-3M-adhesive-4-pack.html

 

[jplebre]

that went terribly wrong with me on pedals so decided to take 45min to drill
any drill will probably do the trick for 4-40 thread and you can get one of those stepped drill bits for a £10

 

[Winetree]

Pedals get thrown around. I don't drill cases anymore. I use the nylon 3M PC mounts on all my projects.
On microphone Power Supplies, I'll JB Weld the transformer brackets to the case.
Neat and strong no problems so far.

 

[Majestic12]

I have a problem on the calibration process on one channel of my dual unit.

I can't get the voltage at the end of R79 down to -0,011V as stated in the manual. I can turn the trimmer to any position I like, the voltage is stuck to +2,4mV
when in Input Mode.
The channel is working perfectly and all the other calibration steps are performed. Does anybody know what to do ?

I already checked the trimmer and its working perfectly. No problems on the second channel.

 

[ffarrell]

My 1u  stereo 160vu clone. 

 

[sidewalkmantra]

REV 3: excuse me but when in inserting a polarised cap in C21- what polarity is insert 1 for this cap? It appears to be unmarked on the board.

Thanks in advance
Gordon

 

[late]

Finished my second unit. But i have problem with output gain. It not increase the output, it just give more distortion. Could it be vca problem? Because i have old black cans and both channel have same problem.

 

[baadc0de]

Finished my second unit. But i have problem with output gain. It not increase the output, it just give more distortion. Could it be vca problem? Because i have old black cans and both channel have same problem.

Is it a 202 or 200 VCA?

 

[late]

Finished my second unit. But i have problem with output gain. It not increase the output, it just give more distortion. Could it be vca problem? Because i have old black cans and both channel have same problem.

Is it a 202 or 200 VCA?

200 series black. It is marked "vca" and it is potted. So i cant see inside. Bought them from ebay some month ago Sound is very distorted.


Edit:

Tested with another vca and it work. Weird that both are broken. Seller told in ebay listing that they are tested.

 

[abechap024]

REV 3: excuse me but when in inserting a polarised cap in C21- what polarity is insert 1 for this cap? It appears to be unmarked on the board.

Thanks in advance
Gordon

A polarized cap is supposed to be inserted there...Check the cap, if its one of my kits it looks like an electrolytic but is a bi-polar electrolytic (just like the originals) orientation doesn't matter.

 

[abechap024]

Finished my second unit. But i have problem with output gain. It not increase the output, it just give more distortion. Could it be vca problem? Because i have old black cans and both channel have same problem.

Is it a 202 or 200 VCA?

200 series black. It is marked "vca" and it is potted. So i cant see inside. Bought them from ebay some month ago Sound is very distorted.


Edit:

Tested with another vca and it work. Weird that both are broken. Seller told in ebay listing that they are tested.

Did you make sure to use all the correct resistors (the ones not with the (T) next to them? Also make sure the That 2180 circuit isn't installed, sounds like a control Voltage problem...

 

[late]

Finished my second unit. But i have problem with output gain. It not increase the output, it just give more distortion. Could it be vca problem? Because i have old black cans and both channel have same problem.

Is it a 202 or 200 VCA?

200 series black. It is marked "vca" and it is potted. So i cant see inside. Bought them from ebay some month ago Sound is very distorted.


Edit:

Tested with another vca and it work. Weird that both are broken. Seller told in ebay listing that they are tested.

Did you make sure to use all the correct resistors (the ones not with the (T) next to them? Also make sure the That 2180 circuit isn't installed, sounds like a control Voltage problem...

Yes. It worked well with different vca.

 

[baadc0de]

I got mine to work with an original 200 (silver can, unpotted) VCA. Somehow I managed to fry the meter TL071, the RMS section of TL082 and the meter emulation ICs.

Btw, the "low noise mod" added about 10dB of noise for me.

 

[abechap024]

I got mine to work with an original 200 (silver can, unpotted) VCA. Somehow I managed to fry the meter TL071, the RMS section of TL082 and the meter emulation ICs.

Btw, the "low noise mod" added about 10dB of noise for me.

the low noise mod is only for rev 2....did you have rev 2 or 3? anyway thanks for reporting your success!! nice to hear. how is the hiss noise? i hearrd the silver cans are maybe a little hissier, but dont know it it will bother me

 

[baadc0de]

I got mine to work with an original 200 (silver can, unpotted) VCA. Somehow I managed to fry the meter TL071, the RMS section of TL082 and the meter emulation ICs.

Btw, the "low noise mod" added about 10dB of noise for me.

the low noise mod is only for rev 2....did you have rev 2 or 3? anyway thanks for reporting your success!! nice to hear. how is the hiss noise? i hearrd the silver cans are maybe a little hissier, but dont know it it will bother me

I do have a (pair of) rev 2 boards that's why I was surprised that it ended up being counter-productive. I'm getting about -70dBFS noise residue on my system (TC Konnekt 48). Looking at the analyzer, it is mostly 60hz harmonics with some hiss, bot not too much. Since I have to replace the fried ICs I took from the other channel to troubleshoot / fix the first channel, I didn't sand down and close the case yet, I expect the noise to drop somewhat from that. Maybe shield some cables going to pots and switches too.

Thanks for the project, it's really great. I would also recommend it to newbies wanting to learn compression.. the LEDs are extremely helpful and absence of attack / release makes it easier to dial in what you want. Maybe not the best tool for all jobs, but I'm liking the usual suspects of bass, kicks and snares, some vocals (especially dynamic mics over tube amps, gives them back some pop).

 

[late]

Yes the silver cans are little bit more noisier. I have both silver and black. I like more black cans and they sound more like an original 160vu. I have two silver and one black (unpotted) they work well. But those two potted black cans not work. Sound is so distorted, is it possible that dbx have made different sorts of black cans for different units. Or are they just broken?