Buchla 258b Clone Project

3vcos · Joined: Oct 26, 2006 Posts: 107 Location: California

I thought Buchlas were usually 1.2 v/oct not 2 v/oct........
(...I thought)

blue hell · Posted: Mon Aug 18, 2008 3:55 pm Post subject:

As in 1 mV / cent ... hmm ...

synthi · Joined: Jul 20, 2007 Posts: 29 Location: Spain

Yes, 1.2V/8va... I think that is. can you confirm, Mike?

So those original 258s would be a great adition for an EML 101 wich is also 1.2V...

Synthi

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

303monkey · Joined: Mar 11, 2008 Posts: 65 Location: NODNOL

Hi there peake
Do you have PCB's for sale for this project?
Personally I would be interested in this project, namley the one closest to the original.
Could you keep me up to date on the progress

Peake · Posted: Thu Aug 28, 2008 1:10 pm Post subject:

Nothing is going to be for sale. From me, at least Laughing

loss1234 · Posted: Thu Aug 28, 2008 9:32 pm Post subject:

will there BE artwork though?

thanks

Peake · Posted: Thu Aug 28, 2008 9:48 pm Post subject:

I'm working on at least four DIY projects at the moment in addition to this, so it's going slowly. Check the original post for any updates and artwork.

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

hey Peake in the other thread you were going on about buchla power supplies and their instability and multiple power lines or something.

I have been looking at some buchla schematics (257 in particular as i'm going to try build it soon) and it just appears that module has 2 power feeds, one for the module and one for the LEDs. Was this what you were talking about?

So will this module need a 15v line and a 12v?

Peake · Posted: Thu Aug 28, 2008 10:07 pm Post subject:

It's going to need a super-secret vintage Buchla power supply. I cannot possibly disclose the specifics.

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

hehe fair enough
guess that means im out then
might try build the verbos one instead

Peake · Posted: Thu Aug 28, 2008 10:22 pm Post subject:

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

chill friend
i didnt really read through the last thread properly.. i guess. I coudlnt really tell what was going on and avoided it most content except vague stories of chips power suppies and possibilities of potential buchla noises that some-one (ie yourself) claimes are it and a bit Smile

and im interested... Internet mis-communication angst is meh, i try avoid it.

im not really sure why you post so much about this if your going to keep most of it secret. could you confirm the power secret? i'm just trying to do some research on it and was curious about the 12/15 v lines.

loss1234 · Posted: Fri Aug 29, 2008 5:07 am Post subject:

i gotta agree with LUKA...the other thread was vague as well about the PSU. no one really ever answered what was so odd about it or even what the name of it is.

I think if someone could answer this it would let a lot of people know if they really can get this working OR not.

i dont think any offense was meant but as Luka says, this thread makes people think there is a PROJECT going on that they can GET as artwork or a pcb eventually.

if it is a strictly personal project, i apologize, but if not, i am willing to TRY and meet all the weird power requirements.

What i am wondering though is Doesnt a PSU just provide power? at a specific amount of AMPS and a specific amount of VOLTS? beyond a weird amount of volts and amps, what is SO WEIRD about this PSU? Many of us would love to know

thanks

no harm intended

Smile

Peake · Posted: Fri Aug 29, 2008 9:28 am Post subject:

Edit: Everyone who thinks it's funny to ask questions answered in the original post should most certainly build something else.

loss1234 · Posted: Fri Aug 29, 2008 10:00 am Post subject:

"
Buchla 200e uses a 12volt wallwart that goes through DC-DC converters to get the +/-15 and +5 volt lines. These are switching supplies.

The supply Mike is talking about is linear, just very old. I has a 48 volt centertapped transformer. It was made before IC regulators were invented. As such, it uses 741 opamps and discrete transistors to regulate the +/-15 and +5 voltages.
"

this was the only answer i could find in the other post that mentioned the specific power supply. but it was a quote from someone else.

am i looking at the right post? is there a NAME for this psu or is just part of the 200 system?

Peake · Posted: Fri Aug 29, 2008 10:04 am Post subject:

Edit: Everyone who thinks it's funny to ask questions answered in the original post should most certainly build something else.

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

funkyfarm · Posted: Fri Aug 29, 2008 5:21 pm Post subject:

Peake · Posted: Fri Aug 29, 2008 7:15 pm Post subject:

I don't see any big deal in crossfading from sine to saw or square- I just set it at either sine or saw and make music from there. The crossfade is not a critical feature to me, as the FM is best sine-to-sine. Others may find go-room in between. I'd enjoy hearing any novel applications.

Peake · Posted: Tue May 24, 2011 2:02 pm Post subject:

Completed, 3 years later. Don Buchla did not answer my emails regarding whether I could release the new PCB artwork, so sorry, NOT AVAILABLE. Added L-1's waveform switching concept (works great, thanks a bunch for the neat idea, an extremely good observation!).

shawn · Joined: Dec 13, 2005 Posts: 209 Location: savannah

Tease.

CJ Miller · Joined: Jan 07, 2007 Posts: 368 Location: 127.0.0.1

Wow!

First I was like Shocked

But then I was like Rolling Eyes

Then I learned to crossfade between them!

Shocked

I hope this answers your question.

decaying.sine · Joined: Aug 31, 2009 Posts: 92 Location: New Haven, CT, USA

Fun. I love trying to track down these old parts like the uA726HC.

Sounds like a great project Mike.

CJ Miller · Joined: Jan 07, 2007 Posts: 368 Location: 127.0.0.1

Yes, the tri-sine FM is luscious. But I have been thinking of a psuedo-Buchla crossfading VCO based on wavetables - probably more gritty than luscious! This is based on my own naive interpretation of the Buchla philosophy of designing the controls first, and then filling in the circuitry. Mind you, I am not a very skilled musician, nor engineer.

But I am thinking of a versatile high-frequency VCO driving two different wavetables, with some crossfading between them. Looking at my sketches of it does remind me of the Buchla 2xx VCOs, though it probably would not sound like them.