Buchla(ish) 258(ish)

From circuitbending to homebrew stompboxes & synths, keep the DIY spirit alive!

Moderators: Kent, luketeaford, Joe.

Post Reply
User avatar
J3RK
Super Deluxe Wiggler
Posts: 6801
Joined: Tue Dec 22, 2009 12:46 pm
Location: Seattle

Buchla(ish) 258(ish)

Post by J3RK » Tue Dec 28, 2010 5:48 pm

It looks like we'll probably hit the mark, so here's the address again:




Thanks!
:party:








I will ship to your Paypal address unless you specify otherwise in the transaction notes. Please don't PM me with these unless there is some problem preventing you from doing so through Paypal. (harder to keep track of)

I think this should work fairly well. Please post any questions you have here, and I'll get the mod list and build notes up ASAP. All components are labeled with values (recommended values/parts) on the board. I'll try to make a list though sometime soon.

Thanks for all the interest and support. I can't wait to see what people do mods-wise :sb:

Will post some new audio demos, mod lists, and other notes soon.




<original first post here>

Hey,

So Mark said he didn't mind me doing a run of these. I'm working on some improvements, both practical (like adding a proper power connector,) and luxury (hoping I can shrink it and cram two on a board...) I'd also like to figure out an alternative to using the 3080 OTA IC. Mark went discrete for this, which seems reasonable, but if anyone can think of an easy alternative, or if nobody cares about using a 3080 (and therefor not have perfect tri-symmetry) then I'll just keep it the way it is in that department.

I really haven't had any issues. I'm sure my symmetry isn't perfect, but the sine sounds good to me. I'd like to amplify it a bit, so I'll see if I can get the output closer to non-Buchla spec. (10V P2P)

I estimate that I can have a new layout for this by sometime next week, and could send it out shortly after that. I always manage to forget some small item, and need to revise, so I'm going to check it, have someone else check it, a few times before getting them made.

I'll document any changes from the current layout, fix any issues (I've already fixed the expo-converter orientation and things like this.) So it should be a fairly simple build. I'll test before sending them out, and then after that, everyone will be on their own. I don't mind fielding the odd question here, but one condition of this was that people don't start asking Mark about them. :help: :mrgreen:

So, I'm thinking about doing a simple run of 50. I'd like to gauge interest, so if you want one of these (or think you might,) let me know. Then when I have the design finalized (in a week or so,) I'll ask for orders, then send it out, and get them shipped out immediately upon return. There is a 2 week turnaround with the board maker I use, so my rough estimate is that we could have these in our hands in around a month.

I'm posting here first. If I don't get the target 50 I'm looking for, I'll cross post to Electro-Music. This is my first full run, so that's why I'm starting with 50. I don't want to get overwhelmed the first time out.

Thanks!

Oh, and just to be absolutely clear, these are roughly 258 based. Triangle core, VC waveshape Mutant-Pseudo 258 boards. They are 1V/Oct, not 1.2V/Oct. If you want the real thing this isn't it, but it's pretty close. That said, I LOVE the sound of my prototype. I'll see if I can whip up a raw demo this evening. (I've combined mine with a wave folder to create a super-bastardized-mutant-pseudo-258/259,) but I can just get an output from the pseudo 258 portion.

Here's what mine sounds like combined with the folder:

http://home.comcast.net/~r3cogniz3r/More258.mp3

It's being FMed a bit by a Teezer, otherwise it's the mutant combo.
Last edited by J3RK on Thu Aug 30, 2012 1:03 pm, edited 10 times in total.

User avatar
decaying.sine
Broken <--> Fixed
Posts: 5397
Joined: Wed Jun 03, 2009 10:05 pm
Location: New Haven, CT USA

Post by decaying.sine » Tue Dec 28, 2010 5:51 pm

I'd be interested in 2 PCBs. Nice work on this project.
Brian
"I must create a system or be enslaved by another mans; I will not reason and compare: my business is to create." William Blake

"Vactrols ringing, Dude." "Thank you Donny"

User avatar
reignbear
Super Deluxe Wiggler
Posts: 1170
Joined: Sat Dec 19, 2009 7:12 pm
Location: Long Beach/santa ana

Post by reignbear » Tue Dec 28, 2010 5:55 pm

nice sounds! :hail:

User avatar
Hi5
Super Deluxe Wiggler
Posts: 2703
Joined: Sun Dec 07, 2008 4:03 pm
Location: chicago

Post by Hi5 » Tue Dec 28, 2010 6:12 pm

depending if there are 2 per board I am down for 2-4 boards.
Good to see this cloned! Thanks!

User avatar
J3RK
Super Deluxe Wiggler
Posts: 6801
Joined: Tue Dec 22, 2009 12:46 pm
Location: Seattle

Post by J3RK » Tue Dec 28, 2010 6:16 pm

Hi5 wrote:depending if there are 2 per board I am down for 2-4 boards.
Good to see this cloned! Thanks!
Worst case, I could always put a pin-strip on it, so that multiple boards could be layered with common power.

User avatar
Luka
Super Deluxe Wiggler
Posts: 5412
Joined: Tue Jul 15, 2008 9:15 am
Location: melbourne

Post by Luka » Tue Dec 28, 2010 6:17 pm

ill grab 2 (depending on price)

User avatar
Luka
Super Deluxe Wiggler
Posts: 5412
Joined: Tue Jul 15, 2008 9:15 am
Location: melbourne

Post by Luka » Tue Dec 28, 2010 6:18 pm

J3RK wrote:
Hi5 wrote:depending if there are 2 per board I am down for 2-4 boards.
Good to see this cloned! Thanks!
Worst case, I could always put a pin-strip on it, so that multiple boards could be layered with common power.
please do

User avatar
rico loverde
Super Deluxe Wiggler
Posts: 4036
Joined: Fri Aug 06, 2010 10:40 am
Location: Portland, Oregon

Post by rico loverde » Tue Dec 28, 2010 6:21 pm

I'd like 2 pcb's if ya make them. Thanx.
works for Darkplace Manufacturing

User avatar
Rod Serling Fan Club
aquatic hitchhiker
Posts: 3760
Joined: Mon Dec 14, 2009 12:13 am
Location: MNTN

Post by Rod Serling Fan Club » Tue Dec 28, 2010 6:24 pm

I'll take 2 for sure, 4 if the price is nice.

User avatar
sduck
experimental use of gravity
Posts: 14372
Joined: Wed Feb 18, 2009 6:03 pm
Location: Vortepexaion, TN, USA

Post by sduck » Tue Dec 28, 2010 6:26 pm

I'll take 2 or 4 depending on your total numbers.

User avatar
J3RK
Super Deluxe Wiggler
Posts: 6801
Joined: Tue Dec 22, 2009 12:46 pm
Location: Seattle

Post by J3RK » Tue Dec 28, 2010 6:28 pm

I estimate them being in the $20ish range shipped. I'll play with the numbers a bit, and see if I can offer any discounts for multiple board orders. I'm not trying to majorly cash in on this, but if I can get a small return on the investment and time investment, then I'm quite happy indeed. I may be able to get them out for less, but that's just an estimate. The factors would be one or two per board, and how much time the rework takes. My main goal is to get a properly working, and easy to build single. The double would be secondary, (but I'd like this too so I could do both saw and pulse versions on one board.) I'll post updates as things progress.

User avatar
J3RK
Super Deluxe Wiggler
Posts: 6801
Joined: Tue Dec 22, 2009 12:46 pm
Location: Seattle

Post by J3RK » Tue Dec 28, 2010 6:33 pm

Wow, just judging by the response already, I don't see any issues moving forward. I'll start refining the design today or tomorrow, and see how possible a double will be. If I just take the schematic, and redesign the board, I think it shouldn't be a problem, though it may take a slightly higher initial time investment. If I take the current one, I could have a usable single version in a day or two.

I'm wondering which would be better for this run. I can easily make this one layer-and-mount-friendly to stack boards. A dual would be pretty cool though. :despair:

Well, I suppose I should just start on both. I can refine my current one quickly, start on a brand-new double, and see how things progress. If the double starts taking too long, the other will be ready to go in its place.

Anyway... :goo:

User avatar
jonkull
Lowest Common Denominator Patcher
Posts: 2506
Joined: Mon Nov 24, 2008 7:02 pm
Location: Burbank, CA

Post by jonkull » Tue Dec 28, 2010 6:35 pm

I'd like 2 (or 4) of these as well.
If only someone would invent a synth that would allow the end user to determine the functionality. You could pick which functions were important to you in 'modules'. A 'modular', if you will. - Stretta

User avatar
jarvis
concerned with insignificances
Posts: 731
Joined: Mon Aug 17, 2009 12:49 pm
Location: Chicago

Post by jarvis » Tue Dec 28, 2010 6:38 pm

do you have an idea of what the board size would be? I'd love to make a parallel-mount euro version

User avatar
parasitk
Learn to swim
Posts: 4956
Joined: Thu May 15, 2008 11:47 am
Location: Pennsylvania
Contact:

Post by parasitk » Tue Dec 28, 2010 6:41 pm

I'm definitely interested in a pair, but don't have the money for anything right now.

If you do a second run I will be there! :party:

User avatar
J3RK
Super Deluxe Wiggler
Posts: 6801
Joined: Tue Dec 22, 2009 12:46 pm
Location: Seattle

Post by J3RK » Tue Dec 28, 2010 6:42 pm

jarvis wrote:do you have an idea of what the board size would be? I'd love to make a parallel-mount euro version
The current single version (basically my version of Mark's layout,) is on a 3"x5" board. So, they could be done if you have a deep enough case.

User avatar
Luka
Super Deluxe Wiggler
Posts: 5412
Joined: Tue Jul 15, 2008 9:15 am
Location: melbourne

Post by Luka » Tue Dec 28, 2010 6:48 pm

i think there was some issues with the 258 due to modern components having different tollerances than old ones. this led to the waveshapes being different. perhaps if you could allow for timmers around those components. i remember this being mentioned in the original e-m thread for this module. when i get a chance i could find out more information

User avatar
J3RK
Super Deluxe Wiggler
Posts: 6801
Joined: Tue Dec 22, 2009 12:46 pm
Location: Seattle

Post by J3RK » Tue Dec 28, 2010 7:03 pm

Luka wrote:i think there was some issues with the 258 due to modern components having different tollerances than old ones. this led to the waveshapes being different. perhaps if you could allow for timmers around those components. i remember this being mentioned in the original e-m thread for this module. when i get a chance i could find out more information
That's possible, but I don't know exactly how necessary it is. My goal isn't to make a perfect clone, but something that has the basic meaty sound, and similar ability. I'm not sourcing any hard to find parts or anything like that. The hardest thing in the current version to find is the CA3080, and those are still more or less readily available (though not manufactured.) If I can work out a discrete OTA, I will still have the position for the 3080, just to make it flexible.

Just to give you an idea of what I did for mine: I used 1% resistors, a mix of styrene, mylar, and ceramic caps, an SSM2220 for expo, the CA3080 for OTA, and TL07X opamps. I used 390X and 38XX transistors for everything, and it sounds great. Not saying it sounds even 95% like the real thing, but just listening to some clips here and there, and my module, it sounds good, and FAIRLY close.

The one thing I had in there before was an MPF-102 in place of a 3819, but I broke a lead off re-orienting it, and replaced it with a 3819, and it still sounded just fine.

One thing to note. I don't currently have a CV keyboard or MIDI-CV, so I haven't tried to calibrate it properly for 1V/Oct. Judging by the components used for this though (SSM2220+tempco) I assume it should track pretty well. I know the FMing at least sounds really nice.

I have a sequencer board out for mfg right now that should show up in a day or two, so I can give some tonal things a try, and post the results. If it sounds like anything is lacking, I'll make some adjustments to that portion of the circuit. (I think the tracking is more than adequate though.) Maybe I'll try putting some DC voltages in a volt apart, and test this.

User avatar
J3RK
Super Deluxe Wiggler
Posts: 6801
Joined: Tue Dec 22, 2009 12:46 pm
Location: Seattle

Post by J3RK » Tue Dec 28, 2010 7:18 pm

Off to start working on this now. I'll post any major milestones here. Happy to answer questions, etc. Since the single version is already close to done, I'm going to start moving the schematic into my software now. I'm thinking switching to a full two sided board may help compact this thing.

User avatar
Peake
I'm in ur DIY. Filling cases with Buchla
Posts: 7971
Joined: Fri Nov 07, 2008 10:00 pm
Location: Loss Angeles

Post by Peake » Tue Dec 28, 2010 7:34 pm

I've been thinking of building one or two of these to see how well they match up with the original (would love to have 1V/Octave but don't care about super-matched IC tracking stability etc.; those things are a definite part of the charm).
This is not the place I'd imagined it to be.

User avatar
KNYST
hiding in the forest
Posts: 2936
Joined: Mon Jan 26, 2009 10:09 am
Location: the Taiga, Sweden
Contact:

Post by KNYST » Tue Dec 28, 2010 7:38 pm

I'm in for 1 or 2.
NOISE HEALS.
patch responsibly.
LISTEN | WATCH

User avatar
fluxmonkey
Super Deluxe Wiggler
Posts: 1871
Joined: Sat Oct 18, 2008 10:05 pm
Contact:

Post by fluxmonkey » Tue Dec 28, 2010 7:45 pm

2 for me please, thanks!

bbob
www.fluxmonkey.com

BUILDER FOR HIRE - kits or custom, email me with your needs

djs
Super Deluxe Wiggler
Posts: 1228
Joined: Wed Sep 01, 2010 8:36 am
Location: South Beloit, IL

Post by djs » Tue Dec 28, 2010 8:22 pm

i'd be in for 1 or 2
"Noise is what the Earth is made of" - David Bowie

User avatar
the bad producer
Super Deluxe Wiggler
Posts: 2624
Joined: Tue Mar 17, 2009 8:43 am
Location: Clapton Pond

Post by the bad producer » Tue Dec 28, 2010 8:37 pm

This sounds like a nice project for the new year!
I'd be in for two for sure...
Charlie

User avatar
Rod Serling Fan Club
aquatic hitchhiker
Posts: 3760
Joined: Mon Dec 14, 2009 12:13 am
Location: MNTN

Post by Rod Serling Fan Club » Tue Dec 28, 2010 8:52 pm

Do you plan on doing a run of the 208 as well?

Post Reply

Return to “Music Tech DIY”