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

[shot]

For level calibration you need 1.228V RMS between pin 2 and 3, not between pin 1 and 2
if I'm not mistaken....

Huh... you got me thinking... I believe it's beetween ground and hot...
Can someone confirm this?

 

[shot]

bump!

 

[horizonsound]

Ground (Pin 1) and Hot (Pin 2). Seemed to work for me.
Tell me if it's wrong.

By the way, this thing smokes on a kick drum and snare!

 

[mus1k_freak]

how would i wire the switch section of the board if i want gain reduction only? i dont care to much about in and out, and for a clean simple build ide like to eleminate those switches, do i just jump pin four to pin 1?

 

[EmptyMusicBox1]

hi everyone !

I have question about the C11 caps on the horizonsound's pcb , it's not present ! It's normal ?



Please somebody can post a clear picture of the PCB mount ? i don't find the problem of mine ! it's just for compare

thanks !!!

 

[abechap024]

@shot
I believe the original DBX manual http://adn.harmanpro.com/product_documents/documents/607_1324058678/160-161%20Calibration%20Procedure_original.pdf states between pin 1 and 2 and tie pin 3 to ground. Though Really, since your just are calibrating both to eachother its not *that* important as long as you have the same reference point to both. I would try to go through it again. If something isn't 100% on it probably OK as long as its in the ballpark.

@EmptymusicBox1

C11 can be either 0.33uF or 1.8uF it will effect the low end slightly (the sidechain will respond to the low end more with the 1.8uF so some people might just want to leave the 0.33uf in ) It is changed because the impedance around the VCA changed to optimize for the THAT 2180 chip and that of course changed the cut off frequency for a given capacitor value.

Also that would be fun to see how to change the attack and release times, though I haven't looked into it yet. Please share if someone experiments with this!

 

[shot]

@shot
I believe the original DBX manual http://adn.harmanpro.com/product_documents/documents/607_1324058678/160-161%20Calibration%20Procedure_original.pdf states between pin 1 and 2 and tie pin 3 to ground. Though Really, since your just are calibrating both to eachother its not *that* important as long as you have the same reference point to both. I would try to go through it again. If something isn't 100% on it probably OK as long as its in the ballpark.

My problem is that R79 is not in the ballpark! But I'll try again for sure.

And what about this situaton I have with missing signal on the minus leg of the output (pin3)? Positive signal is ok, but it's inverted counterpart is just missing... I have cca -20db on the input leg of the R92 and after that it's gone.

 

[abechap024]

@shot
I believe the original DBX manual http://adn.harmanpro.com/product_documents/documents/607_1324058678/160-161%20Calibration%20Procedure_original.pdf states between pin 1 and 2 and tie pin 3 to ground. Though Really, since your just are calibrating both to eachother its not *that* important as long as you have the same reference point to both. I would try to go through it again. If something isn't 100% on it probably OK as long as its in the ballpark.

My problem is that R79 is not in the ballpark! But I'll try again for sure.

And what about this situaton I have with missing signal on the minus leg of the output (pin3)? Positive signal is ok, but it's inverted counterpart is just missing... I have cca -20db on the input leg of the R92 and after that it's gone.

Thats fine. A lot of electrically balanced output stages aren't a perfect "out of phase" signal on the neutral leg. But it still balances perfectly.

ps also try switching chips around and different chips if you have them to see if the voltages clear up.

 

[mus1k_freak]

i turned on my clx for the first time, got my power rails set right, put the ic chips back in but i have no output all i get is a loud hum, doesnt seem to change with any of the controls either, the gain reduction meter and below and above lights seem to be working correctly but i only get a constant hum out, any ideas?

upon first start up diode cr15 smoked so i replaced it and cleaned the board with alcohol and now it seems fine, i wonder if i burned out the 2n4037 transistor? i have 40v drop across r90 does that seem high?


Also looks like q8 and q14 are switched,  I'll order some new ones a day that might solve my problem

 

[hotel valkenburg]

;D soooo psyched got it fired up today. no smoke! it sounds awesome on bass cant wait to get some drums going tomorrow.
nice easy clean build. had some fun making a 1/2 width case from an old digi002r. its a little junky looking but i like it.
I might even do the wood panels.

thanks again abe for the support and your hard work!! and congrats on the new offerings!

Jordan

 

[abechap024]

i turned on my clx for the first time, got my power rails set right, put the ic chips back in but i have no output all i get is a loud hum, doesnt seem to change with any of the controls either, the gain reduction meter and below and above lights seem to be working correctly but i only get a constant hum out, any ideas?

upon first start up diode cr15 smoked so i replaced it and cleaned the board with alcohol and now it seems fine, i wonder if i burned out the 2n4037 transistor? i have 40v drop across r90 does that seem high?


Also looks like q8 and q14 are switched,  I'll order some new ones a day that might solve my problem

Yes, lucky for troubleshooting, if you are getting no sound the signal path is pretty easy....one opamp the VCA then the opamps and output stage.. I would bet the new transistors will sort it out.
Good luck

 

[usekgb]

Quick question.  I have a pile of 15V-0-15V mains transformers sitting around.  They rectify up to 20V per leg, and after a couple volts lost to regulation, I should still be able to hit the target of 15V per rail.  Would I be cutting it too close?

Thanks,
Zach

 

[usekgb]

Scratch that last question.  I won't be able to get the 24V rails with my transformer.  Duh!

 

[mus1k_freak]

I swapped out those 2 transistors and bazinga! works and sounds great! super squishy for sure! still needs to be calibrated as i dont have an oscilloscope, but even not calibrated it sounds pretty awesome! cant wait to get it dialed in!

i turned on my clx for the first time, got my power rails set right, put the ic chips back in but i have no output all i get is a loud hum, doesnt seem to change with any of the controls either, the gain reduction meter and below and above lights seem to be working correctly but i only get a constant hum out, any ideas?

upon first start up diode cr15 smoked so i replaced it and cleaned the board with alcohol and now it seems fine, i wonder if i burned out the 2n4037 transistor? i have 40v drop across r90 does that seem high?


Also looks like q8 and q14 are switched,  I'll order some new ones a day that might solve my problem

Yes, lucky for troubleshooting, if you are getting no sound the signal path is pretty easy....one opamp the VCA then the opamps and output stage.. I would bet the new transistors will sort it out.
Good luck

 

[usekgb]

Ok.  I have a question regarding my last question.  Assuming that I use a 15-0-15 mains transformer, and get +-20V instead of +-24, how much would this realistically hurt the performance of the two output transistors?  I read on here somewhere that Abe has used voltages ranging from 20V to 30V without any harm, but how was the actual performance at these different voltages?  Thoughts?

Cheers,
Zach

 

[brewbacca]

Hey everyone, I just finished putting my unit together and I've learned that I hate putting molex connectors together . Here's what happened on first start up:

Lights came on, no smoke, no nasty noises, so far so good. I ran a bass through my clx and I was definitely able to get the compression working.

Here's my initial issues:

- There's a slight crackling/noise effect that gets louder when I add gain.
- The (standard hairball) meter seems backwards, but maybe it's supposed to be that way? In GR mode, the needle hovers around zero with no sound going in, and in in/out modes, the needle pegs. It looks like it's wired correctly.

Here's where the sadness begins: In channel 1 I, very stupidly, thought I would see what happened when I flipped the pots connector, and well, bad things happen. Now the above light is always on and when I use any ratio the sound cuts out. I'm assuming I blew a chip or transistor.

I should note that I left out R30 since it wasn't included in the BOM.

Anybody run into any of this? I've been reading through the thread while building this thing, but there's a lot in there, so please forgive me if I missed anything.

Thanks!

 

[brewbacca]

Ok, after a couple hours of sleep, I tried switching out the IC between the boards, and got some good results when I switched out the LM301's from the RMS. I still need to calibrate, but both sides are now seemingly working. The meter still seems backwards and there's still some noise on the output. I do have R109 installed (didn't catch to leave that out). I took all the IC's out to calibrate the power rails, and found that R101 on channel 1 doesn't seem to be adjusting anything. Could I have blown out this trimmer when I switched the pot connector direction? R101 on channel 2 successfully adjusted the +15 rail.

 

[berkleystudios]

I swapped out those 2 transistors and bazinga! works and sounds great! super squishy for sure! still needs to be calibrated as i dont have an oscilloscope, but even not calibrated it sounds pretty awesome! cant wait to get it dialed in!

i turned on my clx for the first time, got my power rails set right, put the ic chips back in but i have no output all i get is a loud hum, doesnt seem to change with any of the controls either, the gain reduction meter and below and above lights seem to be working correctly but i only get a constant hum out, any ideas?

upon first start up diode cr15 smoked so i replaced it and cleaned the board with alcohol and now it seems fine, i wonder if i burned out the 2n4037 transistor? i have 40v drop across r90 does that seem high?


Also looks like q8 and q14 are switched,  I'll order some new ones a day that might solve my problem

Yes, lucky for troubleshooting, if you are getting no sound the signal path is pretty easy....one opamp the VCA then the opamps and output stage.. I would bet the new transistors will sort it out.
Good luck

dude that looks awesome! turned out great!

 

[Spencerleehorton]

Got my pcbs, time to starting building!

Regards

Spence.

 

[EmptyMusicBox1]

hi everyone !

I have question about the C11 caps on the horizonsound's pcb , it's not present ! It's normal ?



Please somebody can post a clear picture of the PCB mount ? i don't find the problem of mine ! it's just for compare

thanks !!!

hi Guys !!

i have find my problem on the CLX board ! the CA 3083 was dead !!! n0w the Comp work ! !!!

- Question :

How i can wire an Asymetric Input fot he CLX board ? i wire the pin 2 to the pin 1 and i use the pin 3 for the audio ?

How i can adapt 2 VU LED meters and Where on the PCB : the first for the Input/ Output and the 2nd for the audio compression ?

i can use any VU led METER for that ?

for exemple :


my project : http://groupdiy.com/index.php?topic=51894.msg708838#new

thanks