MUFF WIGGLER Forum Index
 FAQ & Terms of UseFAQ & Terms Of Use   Wiggler RadioMW Radio   Muff Wiggler TwitterTwitter   Support the site @ PatreonPatreon 
 SearchSearch   RegisterSign up   Log inLog in 
WIGGLING 'LITE' IN GUEST MODE

[IN STOCK] Eurorack 4hp THAT2180-based Audio VCA
MUFF WIGGLER Forum Index -> Music Tech DIY Goto page 1, 2, 3 ... 15, 16, 17  Next [all]
Author [IN STOCK] Eurorack 4hp THAT2180-based Audio VCA
negativspace
This is a single THAT2180 VCA on a 4hp Eurorack panel. The PCB is similar in size to my other 4hp modules and it should work just as well in shallow cases & skiffs. It has a log CV response and is AC-coupled, so consider this one to be for audio only. As you'd expect from a THAT chip, it sounds fantastic. Another compact, "clean audio" module to go along with the mix.

Unlike most of my small-board projects there's no room on this one to add the MOTM power header or mounting holes. I'll still be happy to sell you boards without panels, but you're on your own as far as getting them into your preferred format is concerned. The pots are set 1" on center & are Alpha 9mm-type parts if you choose to go with board-mounting.

I've reposted littlem4tt's image here, it shows the trace cuts (green) and jumper (blue) that need to be done to rev 1.2 PCBs.



BOM

Resistors
[7] 100k
[2] 20k
[1] 10k
[1] 4.12k
[4] 1k
[1] 330R
[2] 100R
[1] 1KTC SMT

Capacitors
[1] 10uF Electro (audio path)
[1] 4.7uF Electro
[1] 1.5nF Poly Film
[1] 22pF Ceramic
[2] 47uF Electro
[3] .1uF Ceramic
[3] .1uF 0805 SMT

Pots
[2] Trimpot (20k)
[1] B or C50k Alpha 9mm
[2] B100k Alpha 9mm

Semiconductors
[1] 5.1V Zener Diode
[1] TL074B
[1] LME49710
[1] THAT2180B
[1] LM78L05
[2] 1N4001

Misc
[1] 10P 2-row Header
[2] PTC Resettable Fuse (.05h/.1t)
[2] Ferrite Bead
[4] Kobiconn 16PJ138 (Jack)

Calibration Procedure:

1) Red probe to the pad on the PCB marked TP. ("Test Point") Black probe to ground.
2) Set offset control to max CW (full volume) or insert a +5V CV source into one of the inputs.
3) Use the trimpot labelled 'zero' to set the voltage @ 'TP' to 0.000V or as close as you can get.
4) Set offset to max CCW. (off)
5) Use the other trimpot to set voltage @ 'TP' to 305.00mV, give or take ~3mV (~1%).

It should then open fully to unity gain with a +5V CV signal. The 5.1V zener diode should limit the offset + incoming CV sum to ~5.14V, so if you mash it up to the diode's break point you'll get a little bit of positive gain with the unit trimmed to unity at +5.00V. If you want to ensure you get no positive gain, max out the diode by applying a CV signal greater than ~5.3V and calibrate to unity at that point.

If you like distortion I encourage you to tweak the trimpots to taste as you can really overdrive the chip by setting the zero-point (step 3) to a positive value. (*this is from memory so forgive me if I got something backwards...) The 2180 sounds really meaty when you overdrive the shit out of it. This is not a bad distortion module if patched/set up that way. 8_)

Alternative CV sensitivity is possible - you can set it up to accept 8V or 10V signals by changing the zener diode to an appropriate value and trimming as above. A different LM78Lxx regulator can also be used to supply the appropriate voltage to the offset control.
negativspace
Prices
Eurorack Panel: $15/ea [280]
Bare PCB: $10/ea [289]
Shipping: $3/USA, $8/Canada, $10/Overseas
The Paypal address for payment is jcoates42@gmail.com
Reality Checkpoint
Excellent!

Please can you put me down for:

1 x panel

1 x PCB

Shipped to the UK.

Thank you. w00t
Ginko
2 panels and 2 pcbs please again to the UK - and there is a big gap in my euro waiting for your svvcf!!! hihi
woodster
I'm down for 2x PCB and 2x Panel delivery to UK.
Is it possible to add to the Mindreader and 4x4x4 shipment, or will there be too long a wait between them going out?

Ginko really does speak the truth about the SVVCF.
Me, I'm trying to be Discrete hihi
negativspace
Yeah, yeah, I hear you. hihi

This thing was only about two hours away from being done, though. It's been through 3 board revisions and two panel changes. I've got almost $2000 invested in parts and prototypes. It's time to finish it and get it out the door...

The SVVCF is next. There's nothing else on my plate. It's still 2 solid weeks of layout/prototyping away from being ready, but at least I can focus on it now.
EATyourGUITAR
those electrolytic caps look a bit bigger than they need to be. you can get electrolytic caps in

6mm = 100uf
5mm = 47uf
4mm = everything else
negativspace
The supply decouplers are a nice, squat 47uF that I use in several modules and the input coupling cap is an Elna Silmic. Both fill their footprints as shown. I'll reiterate that I've been through 3 prototypes already... hihi
aristote
2xPCB and 2xPanels for me please (+ shipping to France). smile
aristote
2xPCB and 2xPanels for me please (+ shipping to France). smile
Cablebasher
1 x PCB, 1 x panel, shipped to UK.

Thanks.
hv0190
2 x PCBs to Germany,
thanks!
CometxYh1n1egyPt
Hi,
Can you put me down for 1 pcb and 1 panel please.

Thanks,
Luke
gbiz
2 x PCB & 2 x panel please. Also to the UK.
Stab Frenzy
What are the three pots for? Initial gain, input CV attenuation and something else?

Either way I'm down for 2x pcb and 2x panel, might double that before the cutoff though.
analogdata
2 panels and 2 pcbs (to sweden)
Nantonos
One panel and one PCB please (to France).
zodiak
I am new to this format and am interested but couldn't work out how front panel and PCB are fixed together. Is it just the pins on the 3 pots, or am I missing something?
cleaninglady
May i have :

1 x Panel

1 x PCB

Shipping to Australia.

SlayerBadger! SlayerBadger! SlayerBadger!
cleaninglady
zodiak wrote:
I am new to this format and am interested but couldn't work out how front panel and PCB are fixed together. Is it just the pins on the 3 pots, or am I missing something?


Once the pots are soldered into the PCB the pots go through holes in the panel and then are fastened to the panel with the nuts on the pot shafts. w00t
yan6
One pcb and panel shipped to Canada please
apophis93
2 x Panel + PCB, man need to catch up on the stuff I already ordered from you wink
dropmotif
Great! Two PCBs please. US shipping.
negativspace
apophis93 wrote:
2 x Panel + PCB, man need to catch up on the stuff I already ordered from you wink


I sometimes wonder how many of my modules are hidden away in backlogs... most of what I offer are quick builds, though, so maybe not as many as I fear. hihi
negativspace
woodster wrote:
Is it possible to add to the Mindreader and 4x4x4 shipment, or will there be too long a wait between them going out?


These won't be ready to ship for about 6-8 weeks... ~3 for orders, ~3 for manufacturing, ~1 to ship to me, plus any delays that might pop up.
MUFF WIGGLER Forum Index -> Music Tech DIY Goto page 1, 2, 3 ... 15, 16, 17  Next [all]
Page 1 of 17
Powered by phpBB © phpBB Group