Muff's Modules & More

solitaryzen · Posted: Thu Feb 10, 2011 10:55 am Post subject: Ummmm - bit of a problem here

Was very excited to finally receive a few blacet modules this week (the big batch won't be arriving until a bit later, which is the stuff I bought from Muff smile

).

Anyway, plugged in the single rack of modules that I have. LEDs come on, all looks good. Plug saw output from vco to Quad vca in, output of vca to soundcard and.... nada. Try other waveform outputs, other vca ins, bypass vca entirely, try different leads, different input on soundcard, make sure I'm able to get output from my arp 2600 using same leads/inputs (which I could). All I could manage was a crackling sound when lead was inserted into modules (VCO & Quad VCA).

I then went and checked all the power connections - all seemed to be plugged correctly & securely. I haven't yet disconnected all the modules & tried reconnecting one by one - will try that tomorrow (it's 3 am & I need to sleeep!!). If anyone has any other suggestions, I'm all ears!

One other thing I noticed right away was that the time base LED on the EG1 was flashing rapidly, and the speed didn't change at all no matter where I set the dial (should this only change when something is connected to the CV in, or does this seem to be abnormal behaviour also). The red out LED on EG1 was contstantly on BTW, as was the blue gate LED on the I/O module.

This is all very frustrating, and I'm hoping there will be a simple solution or something really dumb that I've overlooked when connecting things. Any help would be much appreciated!

Ekofisk · Posted: Thu Feb 10, 2011 1:06 pm Post subject:

It sounds like a power problem

Could your modules be overloading the psu?
I get the same symptoms when something is shorted, or I am exceeding my psu.

Mike Fun · Posted: Thu Feb 10, 2011 2:17 pm Post subject:

Double check the power connections on the modules themselves. The only time I've ever seen this kind of weird behavior has been related to this.

Ekofisk · Posted: Thu Feb 10, 2011 2:19 pm Post subject:

Yeah, also check that all ground wires (the black ones) are in place, and not accidentally come loose somewhere.

tIB · Posted: Thu Feb 10, 2011 2:26 pm Post subject:

have you set the voltage on the psu? (blacet PSU?)

Ekofisk · Posted: Thu Feb 10, 2011 2:46 pm Post subject:

I forgot to change the voltage from 110 to 220 once with one of my Blacet PSUs, and luckily all that got hurt was the fuse. I am pretty sure you wouldn't get any power from a PSU with an incorrectly set voltage. Please correct me if this assumption is way off.

tIB · Posted: Thu Feb 10, 2011 2:56 pm Post subject:

you're probably right though I was assuming it being underpowered not over; that might not blow the fuse.

BugBrand · Posted: Thu Feb 10, 2011 6:48 pm Post subject:

Probably best to strip back, taking all modules out, then just try with one module and build back up again. Maybe start with a VCO - easy to know if that's working or not.

I may be way off, but does the Arp use regular minijacks or Tiny Jacks?
Probably you have some regular minijacks, but worth a suggestion perhaps!

solitaryzen · Posted: Thu Feb 10, 2011 7:11 pm Post subject:

Thanks everyone for the feedback. Now that I've had some sleep I'll revisit the box and have another go.

Yes, I did set the voltage to 240 (that was the first thing I made sure I got right!).

I honestly didn't know of Tiny Jacks. It did actually cross my mind that the jacks might be the problem, but I'm pretty certain they are just standard 3.5 minijacks.

Hopefully I'll report back with some better news later today!

Adam-V · Posted: Thu Feb 10, 2011 7:57 pm Post subject:

If you have no luck, let us know. I'm in Melbourne and can maybe pop over next week (depending where you are) with a multimeter and other assorted testy bits to help you out.

Cheers,
Adam-V

stin-g · Posted: Thu Feb 10, 2011 8:04 pm Post subject:

I'm with everyone else on the power supply thing - Rebuilding and testing as you go sounds wise. What PSU are you using?
Also, and forgive me if this sounds kinda goofy but sometimes I sit down and get a patch going and - nada. After scratching my head for a minute I see that my oscillator frequency is too low to hear. D'oh!
Blacet stuff is solid - you'll be glad to have it when you get it all up and running!

solitaryzen · Posted: Fri Feb 11, 2011 5:49 am Post subject:

Thanks again - very pleased to say I've solved things! Turns out it was power related. Firstly, I noticed straight off today that the ground lead on the VCO connection to the psconn2 wasn't attached. Fixed that, then noticed that the Binary Zone power connector was misaligned. Then to top it off, the psconn2 cable was attached backwards to the PSU (thank you Blacet for idiot-proofing this!). I guess the fellow wiggler I bought the rack off was a bit hasty connecting the modules to the rack before posting - never mind, all is good now smile

Just with the handful of modules I have and a couple of hours of messing about today, I can see that the system I'm heading towards is going to be immense sounding!

I still think I may have an issue with my Quad VCA module (the old one) though. I was told this was the only non-Blacet assembled module. There seems to be some definite cross-talk between the four VCA inputs. Overall the module is quite noisy, though depending on the attenuation settings (of inputs that have nothing connected to them...?) I can reduce the noise. If I have an oscillator output connected to input A for example, I get quite an audible crackling noise even with the attenuation all the way down. Anyone had any similar issues with this VCA?

Adam - are you a friend of Steve W? I think he's mentioned you to me (if you're the one who managed to snag some Roland System 100M racks in recent years). Yes, would be nice to catch up & get some pointers, as I'm a new acquaintance of Blacet (& frac in general).

Ekofisk · Posted: Fri Feb 11, 2011 6:11 am Post subject:

Great you got it sorted!

All the times things have gone silent for me, or (non-intended) strange stuff is happening, I always look around the rack, and if too many lights are on, something is fucking with the power.
The mixer/processor is a good example (you'll be getting this from Muff, right?). When both the red and green lights (+ and -) are on at the same time, something is up.
It usually is something to do with grounding. Grounding-issues can cause some major head-scratchers because things "kind-of" work.

Adam-V · Posted: Fri Feb 11, 2011 9:13 pm Post subject:

sneak-thief · Posted: Sun Feb 20, 2011 12:55 pm Post subject:

solitaryzen · Posted: Mon Feb 21, 2011 9:14 am Post subject:

Thanks - will check all those things.

Channel D is really noisy - even with nothing connected to the module I get a lot of noise (modulating, almost FM or ringmod-like) as I increase the gain control.

oozitron · Posted: Mon Feb 21, 2011 9:41 am Post subject:

"Open channel D" (Man from UNCLE!!!)

Channel D is great for creating distortion. I found it great for running the 808 into, boost it into distortion land, then into a filter for shaping.

Drew