ba662 clone

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

Moderators: luketeaford, Joe., lisa, Kent

User avatar
guest
Super Deluxe Wiggler
Posts: 4319
Joined: Mon Aug 19, 2013 11:49 am

ba662 clone

Post by guest » Tue Jan 21, 2014 5:40 am

i just finished making a ba662 clone which is approximately the same size as the original (its a bit taller, will get pictures up soon). i tested it in my x0x, and it seems to work fine. i just wanted to check to see if there would be any interest in a production run of these. i dont know exact price, but it would definitely be less than ebay prices for an original.
openmusiclabs.com

User avatar
Paradigm X
Super Deluxe Wiggler
Posts: 2056
Joined: Tue Nov 02, 2010 5:43 am

Post by Paradigm X » Tue Jan 21, 2014 6:48 am

How well matched are they ? I know my SH09 uses four 'selected' BA662s, although ive no idea what parameters are 'selected'

Excellent initiative tho, many thanks, ill prob grab 4 to keep for spares.

Many thanks
Ben

User avatar
dougt
Super Deluxe Wiggler
Posts: 1125
Joined: Thu Apr 30, 2009 3:47 am
Location: Sillycon Valley, CA

Post by dougt » Tue Jan 21, 2014 7:11 am

There are also "A" and "B" grade originals... I have original BA662As I can sell for $35ea to wigglers by the way...

User avatar
Altitude909
Super Deluxe Wiggler
Posts: 3441
Joined: Wed Aug 24, 2011 5:13 pm
Location: Meesheegan

Post by Altitude909 » Tue Jan 21, 2014 7:39 am

I'm in for sure. Be just as happy to have the board files actually
Last edited by Altitude909 on Tue Jan 21, 2014 7:43 am, edited 1 time in total.

new voodoo
Learning to Wiggle
Posts: 22
Joined: Mon Nov 25, 2013 4:44 pm

Post by new voodoo » Tue Jan 21, 2014 7:40 am

ive got a few but could original poster "guest/openmusiclabs" post a photo?
isnt OpenML who made the Mixtape Alpha? I got one of those..not as flexible as id hoped but im sure you were hampered by physical size restrictions of cassette tape emulation.
pm me w prices anyone who has either new or old, id be buying in a lot of, say, 10, 15, or 20..depending on price.

thanks for notifing us and good luck with your project/clone there!

User avatar
guest
Super Deluxe Wiggler
Posts: 4319
Joined: Mon Aug 19, 2013 11:49 am

Post by guest » Tue Jan 21, 2014 10:47 am

ok, here is a picture next to a ba6110 for comparison (my ba662 was at home).

Image

altitude - i will post board files and such as soon as its all verified.

paradigm x - im using pmp4201 matched pairs, which have an absolute maximum offset of 2mV. im not sure how that compares to the original, as the datasheet seems to be lost in the sands of time. but, im guessing its pretty close, and hand selecting could easily generate A and B varieties.
openmusiclabs.com

User avatar
Paradigm X
Super Deluxe Wiggler
Posts: 2056
Joined: Tue Nov 02, 2010 5:43 am

Post by Paradigm X » Tue Jan 21, 2014 11:20 am

Im guessing they will be closer than the originals!
Not that i know much :lol:

Put me down for four provisionally then please, depending on cost.

Will they be covered out of interest, or raw pcb style like shown?

Cheers guest, legend as always :)

:tu:

Luap
Super Deluxe Wiggler
Posts: 1120
Joined: Fri Nov 30, 2012 6:41 pm
Location: North'ish London, UK

Post by Luap » Tue Jan 21, 2014 12:05 pm

Neat! Any advantage for use in a x0xb0x over the 6110? Or is this really intended for other things?
So, whats next, cloned IR3109's!??

User avatar
negativspace
Manhattan Analog
Posts: 6576
Joined: Tue Apr 13, 2010 2:50 am
Location: Manhattan, KS, USA
Contact:

Post by negativspace » Tue Jan 21, 2014 2:35 pm

I might be interested in a bunch. :hail:

(edit: in my terms a "bunch" would be several hundred.)

schmidtc
Common Wiggler
Posts: 198
Joined: Fri Jan 22, 2010 2:34 pm
Location: Boston

Post by schmidtc » Tue Jan 21, 2014 3:52 pm

Nice work! I'd only want 1 or 2 for Roland spare parts -- haven't seen this chip fail yet, but nice to have just in case.

User avatar
Peake
I'm in ur DIY. Filling cases with Buchla
Posts: 7058
Joined: Fri Nov 07, 2008 10:00 pm
Location: Loss Angeles

Post by Peake » Tue Jan 21, 2014 6:22 pm

I've listened to a comparison of an XOX box using a 662 and one using a 6110, and I could hear that the 662 sounded better, to me. The 662A is used in the Roland 121 filter, and I'd love to have at least a dual in my setup.
This is not the place I'd imagined it to be.

User avatar
aladan
Desperately Seeking Sondra
Posts: 551
Joined: Tue Feb 14, 2012 12:52 am
Location: Adelaide, Australia

Post by aladan » Tue Jan 21, 2014 9:15 pm

I'm up for "some" (5? 10? 20?) but it does depend on price. As I see it DougT has set the bar that I think you need to get under...

Cheers,
A.

User avatar
guest
Super Deluxe Wiggler
Posts: 4319
Joined: Mon Aug 19, 2013 11:49 am

Post by guest » Thu Jan 23, 2014 1:31 am

ok, im going to make a small run, and see what people think of them. if all goes well, it will be a readily available thing from OML.
openmusiclabs.com

User avatar
jgb
Wiggling with Experience
Posts: 411
Joined: Sun Nov 07, 2010 5:47 am
Location: Göteborg, Sweden

Post by jgb » Thu Jan 23, 2014 2:53 am

Definitely interested! My old x0xb0x might need one. :)

User avatar
guest
Super Deluxe Wiggler
Posts: 4319
Joined: Mon Aug 19, 2013 11:49 am

Post by guest » Thu Jan 23, 2014 5:37 am

Paradigm X wrote: Will they be covered out of interest, or raw pcb style like shown?
sorry i didnt answer this earlier. im intending to leave them raw PCB style. this is actually not the best way to do it, as oils or moisture could possiblly build up, or the board could short to something else (these are both minor concerns). but, it allows the user to hack the board more easily, and if it needs to be covered, a bit of epoxy, silicone, or clear coat would easily do the job.

i was just thinking that i can also make 3080 clones, although im not sure i can fit them in a DIP8 format. maybe a double stack.
openmusiclabs.com

User avatar
sonicwarrior
Super Deluxe Wiggler
Posts: 3815
Joined: Tue Sep 29, 2009 3:36 pm
Location: Cologne, Germany

Post by sonicwarrior » Thu Jan 23, 2014 6:38 am

guest wrote:see what people think of them.
No word on the price? If it turns out to be cheapish (less than $10) I'm interested, too. When it turns out to be less than $5 I would even buy some for my stock (you never know when you need such things).
Soundcloud
For sale: Jürgen Haible Tau Phaser (MOTM format)

User avatar
guest
Super Deluxe Wiggler
Posts: 4319
Joined: Mon Aug 19, 2013 11:49 am

Post by guest » Thu Jan 23, 2014 8:11 am

i wont know price until i get production figured out. everything will be ready to go in maybe a month from now.
openmusiclabs.com

User avatar
Altitude909
Super Deluxe Wiggler
Posts: 3441
Joined: Wed Aug 24, 2011 5:13 pm
Location: Meesheegan

Post by Altitude909 » Thu Jan 23, 2014 11:31 am

hows the DC offset with this? When I was building x0xb0xes I would put a trimmer and a 10 meg pot next to the 6110 so I could trim out the VCA thud, might be cool to have that on the little board so one could do the same thing

User avatar
minisystem
Common Wiggler
Posts: 165
Joined: Wed Dec 26, 2012 5:16 pm
Location: Toronto
Contact:

Post by minisystem » Thu Jan 23, 2014 11:11 pm

How about a faithful open source clone of the Roland IR3109 next. :)

User avatar
guest
Super Deluxe Wiggler
Posts: 4319
Joined: Mon Aug 19, 2013 11:49 am

Post by guest » Fri Jan 24, 2014 5:43 am

thats the second request for the IR3109. i think its just 4 VCAs and an exponential converter inside, so shouldnt be too hard to figure out. i think i have an IR3109 kicking around as well. but, i probably wont be able to make it a drop in replacement, as the circuit will be too large. any suggestions on form factor?
openmusiclabs.com

User avatar
minisystem
Common Wiggler
Posts: 165
Joined: Wed Dec 26, 2012 5:16 pm
Location: Toronto
Contact:

Post by minisystem » Fri Jan 24, 2014 9:57 am

The IR3109 and the BA662 are cloned in the 80017A replacement sold by analogue renaissance. That's a big SIP package.

I'd settle for a smaller SIP package for new designs. I get that it would be next to impossible to cram it all into a DIP compatible package.

Luap
Super Deluxe Wiggler
Posts: 1120
Joined: Fri Nov 30, 2012 6:41 pm
Location: North'ish London, UK

Post by Luap » Fri Jan 24, 2014 12:16 pm

guest wrote:thats the second request for the IR3109. i think its just 4 VCAs and an exponential converter inside, so shouldnt be too hard to figure out. i think i have an IR3109 kicking around as well. but, i probably wont be able to make it a drop in replacement, as the circuit will be too large. any suggestions on form factor?
I believe you have an IR3109 Shruthi filter board? :tu:
Actually I was half joking when I suggested cloning that chip. But I do think they could be popular and find plenty of homes.
It's subjective of course, but these things are in some of the best sounding filters out there.
From factor? Even if a bit larger, I expect if it were somehow vertical, much like your BA662 clone, then it would still fit onto most boards that can use the originals.

Anyway, sorry for going off topic! I'd gladly try out one of your BA662 clones in one of my x0xb0xes. I have a couple of genuine BA662's I can compare with, although my testing wouldn't be the most scientific..

User avatar
guest
Super Deluxe Wiggler
Posts: 4319
Joined: Mon Aug 19, 2013 11:49 am

Post by guest » Sat Jan 25, 2014 6:07 am

I believe you have an IR3109 Shruthi filter board?
yes, very true, but im a bit reluctant to take the shruthi apart! it sounds great in there. thanks again.
openmusiclabs.com

User avatar
Jackdamery
Wiggling with Experience
Posts: 283
Joined: Sat Mar 16, 2013 3:39 pm

Post by Jackdamery » Thu Jan 30, 2014 5:48 pm

guest wrote:thats the second request for the IR3109. i think its just 4 VCAs and an exponential converter inside, so shouldnt be too hard to figure out. i think i have an IR3109 kicking around as well. but, i probably wont be able to make it a drop in replacement, as the circuit will be too large. any suggestions on form factor?
Two SMD LM13700s and a SMD TL071. You could probably get it pretty small. There are four resistors, one between the noninverting input of each gain cell and ground. I was trying to do this a while ago and with some help I measured the internal resistors to be 432 ohms.

Someone pointed out to me it's basically the same filter as the Roland system 100 but condensed into a chip. Hence FET buffers would probably do between gain cells. You can see this configuration if you look at the JP8 high pass filter.

For the expo converter I used Thomas Henry's standard current sucking circuit.

Here's a recording I made, when I built half of it, i.e. 12db attenuation.
Demo of 12db OTA IR3109

User avatar
CJ Miller
Super Deluxe Wiggler
Posts: 4256
Joined: Thu Apr 28, 2011 3:10 pm
Location: Mumfordshire

Post by CJ Miller » Thu Jan 30, 2014 6:10 pm

Nice work!
guest wrote:i was just thinking that i can also make 3080 clones, although im not sure i can fit them in a DIP8 format. maybe a double stack.
The 13600 seems close enough to the 3080, and is still available. But I think there will be interest if you can make an equivalent CA3280.

Money is too tight for me to buy BAs, since I don't really need any. But I can't afford to not buy some CA3280s in the future, since I have several projects on hold waiting for a reliable source. And I know I am not the only one.

Post Reply

Return to “Music Tech DIY”