2x 12BH7 oscillator

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

Moderators: luketeaford, Joe., lisa, Kent

Post Reply
User avatar
Chrome Dinette
Common Wiggler
Posts: 190
Joined: Sun Feb 03, 2008 9:14 am

2x 12BH7 oscillator

Post by Chrome Dinette » Sun Nov 30, 2008 11:19 am

I haven't built anything for a while, but I found this easy and fast project here:

http://electro-music.com/forum/viewtopi ... 121#209121

I used 24vdc and added extra, switchable capacitors to vary the range of the oscillators.

Image
Image

youtube:


User avatar
Kent
Large Member
Posts: 11884
Joined: Thu Mar 06, 2008 10:17 am
Location: Vienna, Austria

Post by Kent » Sun Nov 30, 2008 12:17 pm

Hey, if it is 24VDC can one run it off of the +/- 12VDC that Eurorack provides?

User avatar
Cat-A-Tonic
Lobsters love Muff
Posts: 3734
Joined: Mon Feb 04, 2008 12:03 am
Location: Yokohama, Japan

Post by Cat-A-Tonic » Sun Nov 30, 2008 5:35 pm

Crystal radio sets used variable capacitors that are continuous like a potentiometer.
I always thought it would be cool to use one of those as a super range control.

I understand in this situation you are just switching between low and high, and then fine tuning with the 100k pots.

It looks like a cool little noise maker, but without voltage control of freq. I don't feel all that inspired to build one (especially with my hulking backlog).

User avatar
Soy Sos
Dub Surgeon
Posts: 4614
Joined: Thu Apr 03, 2008 9:38 am
Location: Pittsburgh, PA USA

Post by Soy Sos » Sun Nov 30, 2008 5:54 pm

Pittsburgh Guitars cable in pic #2 haha!
You're playing tomorrow @ Gooskies?
Around what time does your band hit?


User avatar
Chrome Dinette
Common Wiggler
Posts: 190
Joined: Sun Feb 03, 2008 9:14 am

Post by Chrome Dinette » Sun Nov 30, 2008 6:51 pm

Cat-A-Tonic wrote:Crystal radio sets used variable capacitors that are continuous like a potentiometer.
I always thought it would be cool to use one of those as a super range control.

I understand in this situation you are just switching between low and high, and then fine tuning with the 100k pots.

It looks like a cool little noise maker, but without voltage control of freq. I don't feel all that inspired to build one (especially with my hulking backlog).
I will probably build a keypad with trimpots to control this/make it more useful.

I am pretty sure the variable caps are mostly in the very low pf range, not sure how much adjustment that would give.

User avatar
wetterberg
Super Deluxe Wiggler
Posts: 7673
Joined: Thu Jul 24, 2008 5:31 pm
Location: Copenhagen, Denmark.

Post by wetterberg » Sun Nov 30, 2008 7:18 pm

@Kent the orig. schematics dictate +12v, so you should be able to do that... just don't know how much it draws...

User avatar
Kent
Large Member
Posts: 11884
Joined: Thu Mar 06, 2008 10:17 am
Location: Vienna, Austria

Post by Kent » Mon Dec 01, 2008 12:11 am

It seems quite 'doable'. Another project for the workbench!

User avatar
Chrome Dinette
Common Wiggler
Posts: 190
Joined: Sun Feb 03, 2008 9:14 am

Post by Chrome Dinette » Mon Dec 01, 2008 6:47 am

wetterberg wrote:@Kent the orig. schematics dictate +12v, so you should be able to do that... just don't know how much it draws...
I was thinking the same thing. You could run one heater on each 12v rail. I'll stick a current meter in line later and see how much it draws total.

User avatar
Chrome Dinette
Common Wiggler
Posts: 190
Joined: Sun Feb 03, 2008 9:14 am

Post by Chrome Dinette » Mon Dec 01, 2008 6:48 am

Kent wrote:It seems quite 'doable'. Another project for the workbench!
It was very easy/fast.

I mainly built this because I hadn't built anything for a while, it looked easy, and didn't require a high voltage supply(I am currently out of high voltage filter caps).

User avatar
fluxmonkey
Super Deluxe Wiggler
Posts: 1832
Joined: Sat Oct 18, 2008 10:05 pm
Contact:

Post by fluxmonkey » Mon Dec 01, 2008 8:48 am

thanks for posting those samples... i'd seen the schemo and wondered what it'd sound like.

b
www.fluxmonkey.com

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

User avatar
Soy Sos
Dub Surgeon
Posts: 4614
Joined: Thu Apr 03, 2008 9:38 am
Location: Pittsburgh, PA USA

Post by Soy Sos » Wed Dec 03, 2008 11:32 am

BTW, I went to see Chrome Dinette's band the other night.
Cool band and dude has some seriously sick guitar tones!
Rock on!!
:sb:

Post Reply

Return to “Music Tech DIY”