Resonant Lopass Gate PCB's (New Batch 4/29/12)

djthomaswhite · Joined: Nov 22, 2007 Posts: 140 Location: Orange, CA

For those looking for boards, there will boards available for everyone that pays in advance to get in on the order. A message will go out to all who have expressed interest when that time comes.

NEWS!!!

My 1st Revision 2 Prototype has been completed. I am sending it to the other 2 beta-testers tomorrow so I an get some additional feedback. I will also be posting some new youtube videos of my freshly built unit Saturday or Sunday this weekend. Let me explain how I almost lost my mind tonight first...

I built my unit. Clean, pro soldering job... quality components... wired it with 3 audio and 2 cv inputs... Plugged it in and it didn't work (at all). The switch was popping loudly, no audio would feed through and the rest of my modular cabinet was shorting out. Scary... but due to the fact the traces don't have solder mask, are "were" too close together in some places I had mistakenly "flicked" a teeny-tiny blob of solder between positive power and ground when filling a "Via" hole. 2 hours after un-soldering all my wires and testing IC's etc I discovered this almost microscopic mistake. Not, the LPG Rev.02 works like a charm!!! The only mistake I could find was that I need to switch the wiring to the Resonance pot as I somehow got it backward. I guess the fact that in my rush I ordered Audio Taper pots for my test units doesn;t help much either though (sweep is way short).

I built this version with the standard VTL5C3 so you will all see how that goes in the Youtubes. I can say that the resonance with VTL5C3's is WAY different to the resonance with VTL5C4's. When moving towards self-oscillation the VTL5C3 has a bit of delay. When in filter mode, flipping the Deep Switch allows for below hearing range and up so you can go as low as you'd like to offset the delay. But, in "Both mode" and Amplifier Mode" the LPG sounds just like what I have heard of the originals. I'll try to make a few videos to showcase all the modes with the VTL5C3's. I do not have any plans to make videos beyond that. Once these things are working you can test other Vactrols on your own and share with us here at the forum. I need to get the boards ordered and produced once testing is complete. That will be my focus. The beta Testers (Fonik and 23 is Good) will hopefully post their results here, and hopefully they will match mine!

Thanks for tuning in and staying interested in this project. The mixer section works, the inverted CV output works (even though the level of CV input to the CTRL input does drop a bit when plugging a cable to the inverted CV), and the resonance section all work. There are no pops when switching modes, nor are there any pops beyond normal when pluggin in or removing jacks. I AM EXCITED to have this revision working! We are getting really close to being able to produce the PCB's. Hang in there folks!

More to come soon,

Thomas

djthomaswhite · Joined: Nov 22, 2007 Posts: 140 Location: Orange, CA

The PCB is shaping up to almost finished... Here are two Youtubes showing off all the modes of the Lopass Gate Clone PCB. Watch in High Quality Mode if your connection is fast enough.

These LPG's are capable of such a wide range it is really hard to capture all they offer in a couple of videos, but here goes anyway:

Video #1

Video #2

Specs: VTL5C3's, Deep Switch Mod, Resonance is use, Dual mixer stage in use with 3 audio ins with pots and 2 cv ins (1 with pot, 1 direct) and one inverted CV output.

Enjoy! PCB's were mailed to the two beta testers yesterday to see if they find errors I didn't. Otherwise, payments should be starting in about 1-2 weeks time. I will send invoices to those who are interested. Thanks!

Thomas

Luka · Joined: Jun 29, 2007 Posts: 1003 Location: Melb.

nice demos
wish every project had videos like that

how good does the resonance sound in the first video!
i havent heard resonance on a lpg before, i like it
i think i might modify my design to include it now
originally i thought if buchla didn't include it why bother but these videos totally proved those thoughts false. thanks thomas

numbertalk · Posted: Sun Oct 05, 2008 7:34 am Post subject:

Wow, thanks so much for the videos and all the work you've put into this. So impressive. Can't wait to get my boards!

parasitk · Joined: Sep 21, 2008 Posts: 69 Location: NYC

Great vids! With the resonance up it does sound similar to the Wiard Borg 2 - very cool. Very Happy

fluxivity · Joined: Oct 05, 2008 Posts: 2 Location: alexandria

Please put me in for a couple of boards.
Thanks
Paul

apemandan · Joined: Sep 21, 2008 Posts: 8 Location: UK

I'd like two boards on your next run if possible. Thanks!

Luka · Joined: Jun 29, 2007 Posts: 1003 Location: Melb.

i like this design
put me down for 4 thanks

c00lcollector · Joined: Sep 28, 2008 Posts: 10 Location: New York Metro

I'll take 4....

Appliancide* · Posted: Sun Oct 05, 2008 7:09 pm Post subject:

I'll take two of these for sure.

Thanks!

djthomaswhite · Joined: Nov 22, 2007 Posts: 140 Location: Orange, CA

Hi gang,

Thanks for the first orders. Invoices will be sent likely this week sometime depending on day job schedule. In the meantime, here are my two FPE Panels for:

1. Single LPG (efficient 1U design)
2. Single LPG (expanded 2U design)
3. Dual LPG (same as 2 1U's in series with switching jack, and leaves off the "Deep" switches)

Hope you enjoy!

Thomas

PS. FPE and PDF files are attached to allow both PC and Mac users to see them. Maybe we can get some premade at Bridechamber, but it would only be worth it if we wanted to vote for the most popular version. Maybe you have panel ideas and will sort them here too?

PPS. I removed the names of all involved from the PCB. It was getting a bit cluttered and didn't seem right with like 6 or 7 names on there.

1U MOTM Lopass Gate.fpd

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1U MOTM Lopass Gate.fpd

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2U MOTM Lopass Gate.fpd

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TW__Dual_Resonant_LPG.fpd

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FrontDesign [1U MOTM Lopass Gate.pdf

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FrontDesign [2U MOTM Lopass Gate.pdf

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djthomaswhite · Joined: Nov 22, 2007 Posts: 140 Location: Orange, CA

I can't post more than 5 attachments. Here is the pdf file for the dual 2U MOTM panel...

FrontDesign [Dual LPG 2U.pdf

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FrontDesign [Dual LPG 2U.pdf

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djthomaswhite · Joined: Nov 22, 2007 Posts: 140 Location: Orange, CA

Hey guys,

Sorry if any of you received duplicate or triplicate emails. I wanted to make sure not to miss anyone, but I had emails at yahoo, here at electro-music, and in the 2 forums about the boards. Lots to sift through. Thanks to all for the first day of orders. We have the minimum needed to get this off the ground. Invoices will be sent out soon, likely at the end of the week.

Thomas

numbertalk · Posted: Mon Oct 06, 2008 8:27 pm Post subject:

Thank you for all the work. Really impressive.

Antonio T · Joined: Jul 30, 2007 Posts: 9 Location: Italy

Hi

please count me in for 2 (4 maybe) boards...

thanks
at

djthomaswhite · Joined: Nov 22, 2007 Posts: 140 Location: Orange, CA

Gentlemen,

Here is the Revision 3.0 Document Packet for the Lopass Gate project. If you find errors, please let me know. I have never put anything like this together before and hope you find it useful and thorough. Included are:

Schematic
Parts List
PCB Component Overlay
PCB Board Layout
Copper (Top/Bottom) Images
Build Document
Front Panel Files

All are in PDF format where available.

Thomas

PS. There is a possibility that Bridechamber will be willing to make panels for this project. Please examine the 2 included files and post your thoughts on if you would buy panels in that MOTM format or not. My vote if for the 2U version with all the bells and whistles. Thanks!

LPG Rev3.0 Document Packet.zip

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numbertalk · Posted: Wed Oct 08, 2008 6:28 am Post subject:

The 2U deluxe version is what I would want.

phdinfunk · Joined: Jun 04, 2008 Posts: 119 Location: Taiwan

Can it gate DC? Would there be a way to make it able to do so, like the Cynthia module?

vtl5c3 · Posted: Wed Oct 08, 2008 6:57 am Post subject: Re: Can this Module....

No expert here, but I think you'd have to bypass C6 to do that. As far as I can tell, it's there to block DC.

BananaPlug · Posted: Wed Oct 08, 2008 7:59 am Post subject:

Phillip Jeffries · Joined: Aug 23, 2008 Posts: 15 Location: Black Lodge

My vote is for the 1u version, ala Oakley / STG. I'd much rather use an external mixer and save space on the filter, as I do with other filters in my system. And this way I can build two.

numbertalk · Posted: Wed Oct 08, 2008 8:30 am Post subject:

Ok, I'll step out and potentially sound like a dummy, but how would I wire (and could I even wire) 2 of these into a "dual" or even 4 into a "quad" module? Would it be just serially hard-wiring the output of one to the input of the next? Seems to me that would be no different than just building them all separately and manually patching the outs to the ins from the panels in the same way, so I'm guessing there would be more to it than that.

fonik · Posted: Wed Oct 08, 2008 9:57 am Post subject: Re: Can this Module....

djthomaswhite · Joined: Nov 22, 2007 Posts: 140 Location: Orange, CA

IMHO, there is no advantage to a quad unit. The original buchla format was just 4 lpgs in one panel with no internal relatioship. Corre t me if I am wrong here.

So I propose the two units, both being single in design. 4 single units could be placed next to each other and patched up freely. Or, one could make the dual units to have the inboard mixer for audio and pots for control. The same goes for CV sections. After playing with my prototypes I have found that subtle control over audio level and incoming CV is VITAL to re potential of this module being realized. watch my videos and this is evident, mainly with respect tohaving built in resonance. I will build two double units and two more single units for myself and my system.

Frac thoughts... I will not lobby to have a Bridechamber Frac panel as I don'T want to directly effect plan-B, Doepfer or Wiard small format sales. Principle folks, that's all. Thoughts?

Thomas

urbanscallywag · Joined: Nov 30, 2007 Posts: 317 Location: sometimes

I thought Wiard was going to discontinue the Frac series.