Buchla 100 clones: 158, 180, 140, 156, 106, etc. DEMOS

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sines
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Post by sines » Thu Sep 26, 2019 10:43 am

lasesentaysiete wrote:sines
I use the 1.5A version of this to power 20u worth of modules:

https://www.mouser.es/ProductDetail/Bel ... CISNKQ8%3D
I ordered the 1.5A version, now thinking I should have got the 3A version, but managed to switch the pinout for DC:DC converter I had to power all of these. I may modify this to get -15V and use it to power some CGS modules [Noise, Sample & Hold, Sub mixer] and convert them to 4U :drunkbanana:

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lasesentaysiete
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Post by lasesentaysiete » Thu Sep 26, 2019 10:48 am

sines
looks great. I heard some nice sounds of yours on Instagram too :tu:

I run all of this from a 1.5A PSU with no problems:

Image

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sines
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Post by sines » Thu Sep 26, 2019 1:20 pm

lasesentaysiete wrote:sines
looks great. I heard some nice sounds of yours on Instagram too :tu:

I run all of this from a 1.5A PSU with no problems:


Nice! Given that I have two or three other supplies for the 200 series modules I have on the back burner, I should be able to do just fine for now.

One thing I was thinking; I wanted to have the 144 +158 VCOs split up by using a pair of SPDT On - None - On switches for each, so that one could be fed from a Sequencer, and the second, to be used as a modulator. I should be able to just drill two holes beside the center hole for the existing switch, and wire them each separately, correct?

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Post by rosch » Thu Sep 26, 2019 7:28 pm

I've never come across Tiny Jax before, they look like they work with normal 1/8" euro patch cables, correct?

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sines
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Post by sines » Thu Sep 26, 2019 8:36 pm

rosch wrote:I've never come across Tiny Jax before, they look like they work with normal 1/8" euro patch cables, correct?
This explains all of the differences between these similar looking jacks.
viewtopic.php?p=1429841

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Post by rosch » Fri Sep 27, 2019 5:17 am

Thank you!

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sines
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Post by sines » Fri Sep 27, 2019 10:22 am

lasesentaysiete wrote:sines
looks great. I heard some nice sounds of yours on Instagram too :tu:

I run all of this from a 1.5A PSU with no problems:

Image
I received the 1.5A PSU which was nice and hefty. I wired up a similar Power One supply for my MCI console [which is overkill, but, needed to be done] so I think I can handle this. I'm just wondering, if I want to take this out of the country someday, wouldn't I be better served with a switching power supply, such as these?
https://mou.sr/2nRrgGE

Technically the Power One supply can be set for other countries, but that requires rewiring and I'd like to not have to worry about it, and just use an IEC cable with a passive adapter instead of also lugging around a transformer in case I need to go mobile.

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lasesentaysiete
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Post by lasesentaysiete » Fri Sep 27, 2019 11:05 am

sines
I guess SMPS makes sense if you will be using different mains voltages. I have no experience powering an entire system with one, though.

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Post by rosch » Sun Sep 29, 2019 12:35 pm

Sorry got to unload all my noobie questions here in this thread. How do people convert their fpd file to inkscape dxf? When I export from frontpanel designer I only get the holes and the centers, but none of the graphics / text.

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lasesentaysiete
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Post by lasesentaysiete » Sun Sep 29, 2019 1:01 pm

rosch wrote:Sorry got to unload all my noobie questions here in this thread. How do people convert their fpd file to inkscape dxf? When I export from frontpanel designer I only get the holes and the centers, but none of the graphics / text.
You will not be able to edit the graphic on the fpd files. I can send you the PDF.

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Post by rosch » Sun Sep 29, 2019 2:47 pm

Ah thanks that would be nice!

(The problem is not ordering from Schaeffer, albeit probably i would prefer the blue colour. If I could print them out 1:1 that's enough, b&w to make my own amateur screen prints. So thanks for the offer, should I pm you my email? for now one would suffice for me in order to cut a panel and check back that the size is correct so I can be sure when I cut the wood for the cabinet this week :grin: I only have the PSU board so far just like to check the measurements against an original print for now)

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Post by guitarfool » Thu Oct 03, 2019 8:13 pm

146 and 112b are now available at Modular Addict (as well as restock of the ones they ran out of). :nana:

So I need a BOM for the 146 :wink:

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Post by lasesentaysiete » Fri Oct 04, 2019 2:07 am

guitarfool wrote:146 and 112b are now available at Modular Addict (as well as restock of the ones they ran out of). :nana:

So I need a BOM for the 146 :wink:
The new BOMs will be ready today. Sorry for the wait.

The most important part for the 146 is the switch:

https://www.mouser.es/ProductDetail/gra ... cycode=EUR

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lasesentaysiete
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Post by lasesentaysiete » Sat Oct 05, 2019 9:19 am

I finished this today:

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christie
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Post by christie » Mon Oct 07, 2019 3:55 am

Looks great, can't wait to try one.

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Post by Delabelle » Mon Oct 07, 2019 5:39 am

lasesentaysiete wrote:
guitarfool wrote:
The most important part for the 146 is the switch:

https://www.mouser.es/ProductDetail/gra ... cycode=EUR
Stock = 0 and available 16-Dec-2019

Any alternative?

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lasesentaysiete
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Post by lasesentaysiete » Mon Oct 07, 2019 6:07 am

Delabelle wrote:
lasesentaysiete wrote:
guitarfool wrote:
The most important part for the 146 is the switch:

https://www.mouser.es/ProductDetail/gra ... cycode=EUR
Stock = 0 and available 16-Dec-2019

Any alternative?
there may be an alternative source, but that is the only switch I could find that fit this application.

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Rotary Switches Rotary Switch PC Mnt 22.5deg

Post by Delabelle » Mon Oct 07, 2019 7:31 am

This one is available 51P22-01-1-16S as a 16 position but you can move the stopblades after the washer. Price is also expensive.

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Cheers

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Peake
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Post by Peake » Sun Oct 13, 2019 1:59 am

I'm building an LA67 191 module for forum user christie. Thanks to everyone for the posts on how to calibrate and what you've encountered. I've of course also encountered the flutter and noise which represent the circuit failing/going out of range etc. If you set the filter frequency to one of these noises instead of crossing it you'll hear interesting things. This is where the module is most vulnerable to external interference. I picked up FM 98 at one point; I know this because they were announcing the station frequency as I listened.

The CV bleedtrhough from fast control voltages can also be significant; run an audio-rate cycling CV into it and it can buzz away and the 1K trimmers won't help. I paralled'd 10M resistors across the first three 22M in each section to increase the available range to no avail.

That's when I started noticing sensitivity to my hand proximity to the PCB. Touching some parts eliminated the CV bleed-through. When the power cable was pulled across the PCB there was significant noise.

christie had seen this sort of thing before and had me put a piece of tin foil over the rear of the PCB and ground it. Amazing difference. Dialing in a noise burst zone then covering the rear changed things significantly, significantly. He also recommended the front panel be more fully grounded than simply through the tinijax so a temporary alligator clip to a standoff did make a difference (note that I have all tinijax grounds wired together and out to the PCB ground). Apparently the front panels don't 100% ground through the tinijax.

We're going to find some copper foil or Mu metal and order it. Will have to look at the module more closely tomorrow but I am theorizing 15mm standoff extensions (M/F), perhaps 20mm, upon which to mount the foil evenly above the panel with holes for things which must protrude, then covering those things with foil as well. Tiny holes in the foil for trimmer access as I expect the 5K trimpots will calibrate more easily under such conditions and the HPF might be able to be set to reach the 20KHz indicated on the front panel without those chaotic bursts, or less of them, hopefully none, we'll see.

christie said I should post our findings and intent so others might try it at the same time if there's any interest. He's using a wooden case so no grounded aluminum boats. Cheers.

Also note: I use a vintage Buchla 200 power supply and I've experienced anomalies others haven't, for example I've built more than one Roman 275 which buzz on my bench but when installed in a case, are silent. I may thus be experiencing more artefacts in my 191 build than others.
I just can't help imagining that this would be better with vactrols

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Post by ndkent » Sun Oct 13, 2019 3:13 am

that 116 is really a 216 circuit?

Ironically I was coating a Roman touchplate PCB with spray today, hoping I have the right kind of spray

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Post by lasesentaysiete » Sun Oct 13, 2019 3:45 am

Peake
I experienced a small amount of noise caused by moving my hand closer to the PCB components, too. Nothing as bad as what you are describing, though. Once the module was installed in a case, the interference went away. Also, I tested with a small 211 PSU and a proper 1,5A linear PSU.

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Post by lasesentaysiete » Sun Oct 13, 2019 3:47 am

ndkent wrote:that 116 is really a 216 circuit?
Its half 112 & half 114. There are optional voltage dividers on the CV outputs for 0-10v range.

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Peake
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Post by Peake » Sun Oct 13, 2019 11:45 am

lasesentaysiete wrote:Peake
I experienced a small amount of noise caused by moving my hand closer to the PCB components, too. Nothing as bad as what you are describing, though. Once the module was installed in a case, the interference went away. Also, I tested with a small 211 PSU and a proper 1,5A linear PSU.
A wood case or grounded aluminum boat?

I just checked and 15mm standoffs just clear the lamp solder terminals and large trimpot dials. People who used discrete transistors will be be able to do 15mm across the entire PCB excepting the big cap, switch wiring, and perhaps the two 100uF caps. 17mm would of course provide a bit of breathing room.

We decided to use original components and sourced some TD101 for the JFET biasing circuits. Due to the distance between pairs in the HPF section it required extending the device's leads so they stand pretty tall and might be exacerbating things. I am not convinced they are required at all and that pairs of voltage matched individual transistors are likely perfectly fine.

I could hear a change in the filter by simply touching the edge of the PCB. A screwdriver touching the trimpot dials, an insulated screwdriver, causes the audible character to change. Touch it with your finger and its much worse.

Likely a combination of long lead TD101 and my setup or particular place on the planet which must be an RF hotspot.
I just can't help imagining that this would be better with vactrols

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lasesentaysiete
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Post by lasesentaysiete » Sun Oct 13, 2019 11:56 am

Peake
I have only used the components listed in the BOM so I cannot say if or how much the substitutions you have made are contributing to CV bleed.

I use a wood case (pictured in this thread) and a Power One type PSU. I would assume that an aluminum boat would be even better.

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Peake
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Post by Peake » Sun Oct 13, 2019 12:26 pm

The thing is there's seemingly no CV bleed when shielding is in place and the noise bursts others have documented also having experienced are diminished by shielding as well. The TD101 bias the P-Channel JFETs which are likely vulnerable...working it out as I go. It would be easy for others to confirm if they touch resistor leads at various points to see if anything changes.
I just can't help imagining that this would be better with vactrols

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