Search found 1065 matches

by oldcrow
Thu Apr 29, 2021 11:03 am
Forum: Music Tech DIY
Topic: CEM3310 equivalent circuit
Replies: 45
Views: 12027

Re: CEM3310 equivalent circuit

The Real MC wrote:
Wed Apr 28, 2021 9:39 pm
You're not the only one with job changes.

I just accepted a new job with Lockheed Martin and am bound for Orlando FL.
Congrats on the new job! Though that is going to make the drive to AHMW a bit longer...or will it? ;)

Crow
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by oldcrow
Wed Apr 28, 2021 2:36 pm
Forum: Music Tech DIY
Topic: CEM3310 equivalent circuit
Replies: 45
Views: 12027

Re:

KSS wrote:
Sat Feb 24, 2018 2:18 am
Crow, the panel shows trig, but it's not on the schematic?
This is only 3.2 years late, but my trig jack is just a capacitor to the gate. 0.1uF or so gives long enough of an impulse to trigger an A/D cycle. Oh, and there is a reverse blocking diode for the negative-going transient.

Crow
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by oldcrow
Tue Apr 27, 2021 10:47 am
Forum: Music Tech DIY
Topic: CEM3310 equivalent circuit
Replies: 45
Views: 12027

Re: CEM3310 equivalent circuit

After a long hiatus, I have returned. It only took 3.5 years after being hired, but now that I have control of my department at work things are less hectic and I can get back to synthesizer stuff. ;) Thanks Massimo for that awesome analysis of the EG and the lovely OBX-4!

Crow
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by oldcrow
Wed Apr 24, 2019 2:35 pm
Forum: Announcements - Please read!
Topic: Mike has passed away.
Replies: 916
Views: 122503

RIP Mike :waah:
by oldcrow
Mon Aug 06, 2018 9:40 pm
Forum: Music Tech DIY
Topic: crOwBX 8-voice
Replies: 247
Views: 27883

The board has provisions to set it up like a stock OBX card with the 2-pole LPF. I am trying to finalize the docs for this board as there are a number of revisions, but in this case you omit the DG508 and strap a jumper across the JP6 "OBX" pads near The (optional) notch trimmer T15. I'll have more ...
by oldcrow
Fri Jul 06, 2018 4:43 pm
Forum: Music Tech DIY
Topic: crOwBX 8-voice
Replies: 247
Views: 27883

That kickstarter seems under-funded for assembled boards.
by oldcrow
Tue Jul 03, 2018 3:24 pm
Forum: Music Tech DIY
Topic: crOwBX 8-voice
Replies: 247
Views: 27883

Hey folks,

The last eight weeks have been crazy 12-hour workdays (including some weekends) but I now have 5 days off and all remaining boards will be shipped in that time. Sorry for the delays, the bonus is new BoMs will also be ready.

Crow
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by oldcrow
Fri Apr 27, 2018 2:40 pm
Forum: Music Tech DIY
Topic: Old Crow Crowminius for Eurorack DIY build
Replies: 28
Views: 2992

Just make sure the fuses are set as noted in the source file. I use the avrdudess program which has settings for them, although you can also put them on the CLI/command line in a shell window. The .hex file should have these fuse settings and show up in the GUI when the file is loaded. Crow /**/ Cod...
by oldcrow
Sun Apr 22, 2018 12:50 am
Forum: 5U Format Modules
Topic: CS80 filter in 5u format
Replies: 27
Views: 3837

The MOTM-480 and RR-480 aka MOTM 480 mkII are the result of me spending a long time hand-selecting parts to test as a CS filter in place of the Yamaha parts in my CS-80. In the end, I got it as close as can be brought into this world. The thing to remember is, the filter is only one part of a much l...
by oldcrow
Wed Mar 28, 2018 9:17 am
Forum: Music Tech DIY
Topic: crOwBX 8-voice
Replies: 247
Views: 27883

Sure, I'll get some prepared over the long weekend. --Crow
jean_schön wrote:crow, will you be putting up noise PICs for sale? or would someone burn one for me?
by oldcrow
Tue Mar 27, 2018 3:44 pm
Forum: Music Tech DIY
Topic: crOwBX 8-voice
Replies: 247
Views: 27883

I do provide pads for an axial tempco part on the newer rev boards as well. As I'm thinking of this it should be an easy solution to piggyback a 1k Akaneohm Tempco 3300ppm/°C on the LS318 like done on many other designs... Piggyback it from Pin 2 to Pin 7 of the LS318 et voilà... Then you could even...
by oldcrow
Tue Mar 27, 2018 3:38 pm
Forum: Music Tech DIY
Topic: crOwBX 8-voice
Replies: 247
Views: 27883

Please note, the v2.3/v2.4 voice boards do not use LS318s, or DIP matched transistor parts at all. These use LM3046MX (SOIC14) or FMB3904 (SOT23-6). The older parts are just getting too rare, so I try to keep actively-produced devices as options. The LM3046 is on the last time buy list, which is why...
by oldcrow
Tue Mar 13, 2018 8:42 am
Forum: Music Tech DIY
Topic: crOwBX 8-voice
Replies: 247
Views: 27883

FYI: I've put up pre-orders for both a backplane with 4 voice boards set and a backplane with 8 voice boards set. These are of course bare board sets. The voice boards are my latest v2.4 type that use the AS3310 re-issued envelope generator ICs. The 2.4 boards are backward-compatible with the v2.0 e...
by oldcrow
Mon Mar 12, 2018 8:22 am
Forum: Music Tech DIY
Topic: crOwBX 8-voice
Replies: 247
Views: 27883

It is in fact a small OLED display. :sb: Given the OBX had presets and autotune, I plan to have the same thing here. The display is not strictly needed, but when I go to write and debug the patch manager program, it helps to have something I can use to show information. Hey Crow, is that a 4 pin SPI...
by oldcrow
Fri Mar 09, 2018 6:24 pm
Forum: Music Tech DIY
Topic: crOwBX 8-voice
Replies: 247
Views: 27883

It is in the preliminary phase, but the control panel will look something like this: https://www.muffwiggler.com/forum/userpix2/6440_8vox_panel_v01_brd_1.jpg The 12mm buttons will all have integral LEDs. The section in the lower right area are individual voice panners which connect to the backplane ...
by oldcrow
Thu Mar 08, 2018 5:00 pm
Forum: Music Tech DIY
Topic: crOwBX 8-voice
Replies: 247
Views: 27883

For those interested, I will be opening a pre-order page on my sales portal later this month for the 8-voice board sets. There will be full sets and as well as partial sets for those with existing voice cards. I am working on the front panel and control boards currently. Delivery of the backplane an...
by oldcrow
Thu Mar 08, 2018 3:47 pm
Forum: Music Tech DIY
Topic: crOwBX 8-voice
Replies: 247
Views: 27883

I did this spacing on purpose to avoid having to resort to creative capacitor lead-bending. ;)
jimfowler wrote:The 8 voice backplane does afford more space. The amount of space is uniform for all voice cards and is the same as the space between voices 2 and 3 on the 4 voice backplane. See attached photo.
by oldcrow
Sun Feb 25, 2018 12:41 am
Forum: Music Tech DIY
Topic: CS-80 YM26600/26700 IC Alternatives
Replies: 14
Views: 1481

I got sidetracked onto other stuff, but I still want to make this thing. It may be better to do a board-level replacement vs. chip-level. --Crow
by oldcrow
Sat Feb 24, 2018 3:10 am
Forum: Music Tech DIY
Topic: CEM3310 equivalent circuit
Replies: 45
Views: 12027

The schematic for the module is slightly different vs. crowbx. With the AS3310 chip being made again, I might make a run of this version for the curious builder, but I will also make a 3310 (chip) version too.
KSS wrote:Crow, the panel shows trig, but it's not on the schematic?
by oldcrow
Thu Jan 11, 2018 12:05 am
Forum: Music Tech DIY
Topic: More stuff from Crow's Atelier: crOwBX -> crOwBX-A
Replies: 8
Views: 771

Right, this card will have its own backplane, etc. It was not meant to work in a crowbx/OBX setup. I will deal with that when I test the board. Changing the resonance control profile is not very hard for either filter. :sb: Just checked the schematics. OBXa voicecard has some signals that are not TT...
by oldcrow
Wed Jan 10, 2018 9:41 am
Forum: Music Tech DIY
Topic: More stuff from Crow's Atelier: crOwBX -> crOwBX-A
Replies: 8
Views: 771

I will deal with that when I test the board. Changing the resonance control profile is not very hard for either filter. :sb:
tobb wrote::tu:

(as drop-in for vintages it will be problematic due to the resonance of the AS3320!)
by oldcrow
Tue Jan 09, 2018 7:13 pm
Forum: Music Tech DIY
Topic: OBX voice card (with non-custom CEM3310 equivalent circuits)
Replies: 1752
Views: 214201

@randel Very very very nice job sir! I will have to get the rackmount stuff finished. :guinness: :guinness: :deadbanana:
by oldcrow
Tue Jan 09, 2018 7:07 pm
Forum: Music Tech DIY
Topic: More stuff from Crow's Atelier: crOwBX -> crOwBX-A
Replies: 8
Views: 771

FYI yes I saw the Behringer UBXA thing. I'll believe it when I see it. 8-) This project is about making cards that work in vintage machines and for the general DIY wanderlust. :sb:
by oldcrow
Tue Jan 09, 2018 7:05 pm
Forum: Music Tech DIY
Topic: More stuff from Crow's Atelier: crOwBX -> crOwBX-A
Replies: 8
Views: 771

More stuff from Crow's Atelier: crOwBX -> crOwBX-A

Heya folks, With the return of certain chips courtesy of Alfa Rpar and Erica Synths, I can now make the crOwBX-A voice card. As with the crOwBX cards, these will be drop-in compatible for vintage machines but also able to be used with my 8-voice backplane. Right now it is a work in progress, but I s...
by oldcrow
Fri Oct 13, 2017 9:07 pm
Forum: Music Tech DIY
Topic: OBX voice card (with non-custom CEM3310 equivalent circuits)
Replies: 1752
Views: 214201

Re: some updates

The 4011 is either defective or the +5V going to it has an issue. VCO tuning issues are usually due to a bad timing cap or bad trimmer. --Crow Some updates about how my crowbx is behaving. VCO2 keeps going out of tune on two out of four voice cards. It takes several days/weeks for the tuning to go b...

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