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frijitz
Joined: May 04, 2007 Posts: 1734 Location: NM USA
Audio files: 54
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Posted: Wed Sep 03, 2008 2:57 am Post subject:
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/mr wrote: | AndyR1960 wrote: | I'll try and get some audio samples up today. |
If you can, make a recording of some other separate VCO as well with the same equipment, for a comparison. |
What???? Data so other people can hear what you're talking about? No. |
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ericcoleridge
Joined: Jan 16, 2007 Posts: 889 Location: NYC
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Posted: Wed Sep 03, 2008 8:55 am Post subject:
Re: ARP Odyssey Oscillators |
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Tim Servo wrote: | Luka wrote: | tim will your design have 10Vpp waveshapes or will it be the same as andy's board and range from 5-6 |
Well, both, really.
Tim (making waves) Servo |
How about the ring mod chip? Just wondering, although I'm sure it would be easy enough to add on. |
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Tim Servo
Joined: Jul 16, 2006 Posts: 924 Location: Silicon Valley
Audio files: 11
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Posted: Wed Sep 03, 2008 3:05 pm Post subject:
Re: ARP Odyssey Oscillators |
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julianw wrote: | That's GREAT news you're putting together a PCB run based on the Odyssey VCO.
Tim Servo wrote: | Well, I have a secret source for some 5910s. We'll see if they come through. |
I took a look at the auction Peake mentioned, they sell 6 x PN5910 for $9.90 (+ $17.90 postage to the UK!) = $27.80 Total for myself
However, in the listing it says they sell 100 for $89 and 500 for $228.
You could definitely make some money, and save everyone else money, if you could sell this rare part along with the PCB, it seems like the only obscure component. |
I'll try my hardest to come up with a supplier for this part. HOWEVER, I'd much rather come up with an easy to find (and less expensive) sub. I've got two cross numbers to check now, so it looks very likely that we won't need 5910s. Still, the 5910 will be the "benchmark" for sound, behavior, stability, etc. I want these things to sound and feel as much like my stock Ody as possible.
One interesting note about the waveform levels: the stock Ody can easily use the VCOs as modulation sources (VCO 1 can mod VCO 2 through the S/H mixer). A "proper" waveform centered around 0V will sound very different when used for FM, so this is one case where you might prefer the original 0 to 5V (or 6V) square and saw waves for trill and sweep effects. Of course, for vibrato you still want a wave centered around 0, and the Ody's LFO does that just fine.
Tim ("Proper") Servo |
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Tim Servo
Joined: Jul 16, 2006 Posts: 924 Location: Silicon Valley
Audio files: 11
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Posted: Wed Sep 03, 2008 3:14 pm Post subject:
ARP Odyssey Oscillators |
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The Ring Mod chip is indeed a very easy one to add. This is all very preliminary, but what I have planned is a single VCO board with the features of VCO 1 (audio/LFO sw) and VCO 2 (sync input), and space to add the digital ring mod. Get two, populate the ring mod on one, and you're off and running. Of course, you'll have to patch or jumper the square wave from the other VCO into the ring mod, but that's an easy task.
Tim (off and running) Servo |
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rjd2
Joined: Sep 02, 2007 Posts: 236 Location: philly
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Posted: Wed Sep 03, 2008 4:23 pm Post subject:
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great news tim! that's awesome. im assuming you will cross-reference the part you are replacing the 5910 with? if i were to build, i would also shoot for as faithful as possible. |
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loss1234
Joined: Jul 24, 2007 Posts: 1536 Location: nyc
Audio files: 41
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Dego
Joined: Apr 22, 2008 Posts: 139 Location: Sweden
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Posted: Wed Sep 03, 2008 10:58 pm Post subject:
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I would love a pcb as well Tim |
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Broadwave
Joined: Feb 16, 2007 Posts: 347 Location: Manchester UK
Audio files: 6
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Posted: Fri Sep 05, 2008 12:32 pm Post subject:
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Odyssey VCO Samples removed from forum... needed the attachment space, sorry. Last edited by Broadwave on Tue Mar 02, 2010 3:47 am; edited 3 times in total |
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Broadwave
Joined: Feb 16, 2007 Posts: 347 Location: Manchester UK
Audio files: 6
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ericcoleridge
Joined: Jan 16, 2007 Posts: 889 Location: NYC
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Posted: Fri Sep 05, 2008 12:50 pm Post subject:
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Wow!! These are so right on! They sound amazing. I can't wait to try them out now.
AndyR1960 wrote: | For got the pic... Duh! |
What are these? They're just single VCO versions of the dual VCO you posted originally? |
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frijitz
Joined: May 04, 2007 Posts: 1734 Location: NM USA
Audio files: 54
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Posted: Fri Sep 05, 2008 12:54 pm Post subject:
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Could someone please post some comparison sound clips demonstrating the special characteristics of this VCO? Thanks.
Ian |
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ericcoleridge
Joined: Jan 16, 2007 Posts: 889 Location: NYC
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Posted: Fri Sep 05, 2008 1:11 pm Post subject:
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I think these samples illustrate, at least, how well the osc sync and ring mod sound. I'm sure oddy VCOs are not the only VCOs that sound like this when synced-- but I've built several different DIY VCOs where the sync sound isn't even close to what's illustrated in the samples above.
I suppose it depends on what kind of sync sound you're looking for, but for me, the odyssey sets the standard for "osc sync" sound. |
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loss1234
Joined: Jul 24, 2007 Posts: 1536 Location: nyc
Audio files: 41
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Peake
Joined: Jun 29, 2007 Posts: 1113 Location: Loss Angeles
Audio files: 3
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Posted: Fri Sep 05, 2008 1:45 pm Post subject:
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Yeah, these will make hella cheap wide-range VC LFOs, with reset. Sweet... _________________ We are selling emotions, there are no emotions in a grid. -mwagener
"IC 741. Sometimes you don't want fidelity." -Small Bear Electronics Catalog |
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rjd2
Joined: Sep 02, 2007 Posts: 236 Location: philly
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Posted: Fri Sep 05, 2008 3:15 pm Post subject:
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awesome news, andy. you are helping me get that much closer to the dream of an arp-based modular set. |
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Broadwave
Joined: Feb 16, 2007 Posts: 347 Location: Manchester UK
Audio files: 6
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Posted: Fri Sep 05, 2008 4:03 pm Post subject:
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ericcoleridge wrote: | Wow!! These are so right on! They sound amazing. I can't wait to try them out now.
AndyR1960 wrote: | For got the pic... Duh! |
What are these? They're just single VCO versions of the dual VCO you posted originally? |
These are separate VCO's, no ring mod (can be easily modified though). The dual board that I posted earlier is for my Oddy clone project
Andy. _________________ Kronos 2-88, Kronos 61, Studiologic Sledge V2/SL, Broadwave ARP 2600EX, Broadwave 18U ARP based Eurorack Modular, Broadwave Minimoog Clone, GEM S2 Turbo.
Synth DIY Projects
Musical Doodlings |
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loss1234
Joined: Jul 24, 2007 Posts: 1536 Location: nyc
Audio files: 41
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Broadwave
Joined: Feb 16, 2007 Posts: 347 Location: Manchester UK
Audio files: 6
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Posted: Sat Sep 06, 2008 1:37 am Post subject:
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To be honest, I had no idea that Tim Servo was also working on these VCO's (as we say in England - you wait all day for a bus, then two come along at once).
I've owned several Oddy's in my time (as well as a 2600), and always regretted selling them, which is why I'm so passionate about recreating one.
I'm surprised that they've been ignored for so long, and it wasn't until recently that I had the confidence to do anything like this - I only picked up a soldering iron for the first time last year, but thanks to this forum I've learned a great deal
There is something "special" about the Oddy VCO/RM combination that I've never been able to recreate. The sync on other VCO's tended to be very weak, and no amount of tinkering seemed to improve things. The Oddy Ring Mod, isn't a true Balance Modulator, it's just a couple of CMOS gates used in an "exclusive or" set-up - so you can also use it for processing gates/lfo's etc.
I'll be posting info on the 4023 VCF (White Face Oddy, 12db) and the 4035 (their infamous Moog VCF) soon, maybe today if I get the time.
The 2N5910, *can* be replaced with a 2N3906 - I've tried this and it works, although it does seem to draw a bit more current. The main problem I have is the 1.87K Tempco - I'm looking into this... I've seen something around where a guy used 2 SMT tempcos, but I can't remember where, so I'll be Googling for the next few hours
Andy. _________________ Kronos 2-88, Kronos 61, Studiologic Sledge V2/SL, Broadwave ARP 2600EX, Broadwave 18U ARP based Eurorack Modular, Broadwave Minimoog Clone, GEM S2 Turbo.
Synth DIY Projects
Musical Doodlings |
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Luka
Joined: Jun 29, 2007 Posts: 1003 Location: Melb.
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Broadwave
Joined: Feb 16, 2007 Posts: 347 Location: Manchester UK
Audio files: 6
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Posted: Sat Sep 06, 2008 2:57 am Post subject:
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Hey Luka, thanks!
Yup, that's the guy - and this is the page I remember:
http://modularsynthesis.com/am/am.htm
I see no reason why this won't work, and I've just ordered 20 of each SMT - I'll let you know how it goes.
Andy. _________________ Kronos 2-88, Kronos 61, Studiologic Sledge V2/SL, Broadwave ARP 2600EX, Broadwave 18U ARP based Eurorack Modular, Broadwave Minimoog Clone, GEM S2 Turbo.
Synth DIY Projects
Musical Doodlings |
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a.b.o.z.
Joined: Feb 07, 2007 Posts: 351 Location: Zagreb, Croatia
Audio files: 7
G2 patch files: 4
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Posted: Sat Sep 06, 2008 5:14 am Post subject:
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I'm a noob and I'm not a shame of it.
On dual board. There is only one 1v/oct input? How do you control other VCO?
Confused.
Ivan |
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ericcoleridge
Joined: Jan 16, 2007 Posts: 889 Location: NYC
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Posted: Thu Oct 16, 2008 10:42 am Post subject:
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AndyR1960 wrote: |
Yup, that's the guy - and this is the page I remember:
http://modularsynthesis.com/am/am.htm
I see no reason why this won't work, and I've just ordered 20 of each SMT - I'll let you know how it goes.
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Did this work out for you Andy?
You also mentioned just substituting a 1K for the 1.87K, right? Wouldn't a 2K be closer? But neither of these allows it to track *perfectly*?
I'm just buying some parts now to assemble this board, and I'm wondering what to do about the tempco. |
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Broadwave
Joined: Feb 16, 2007 Posts: 347 Location: Manchester UK
Audio files: 6
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Posted: Thu Oct 16, 2008 3:52 pm Post subject:
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ericcoleridge wrote: |
Did this work out for you Andy? |
Unfortunately no... I found the solder joint between the SMD's too fragile (even though I encased them in epoxy), just way too fiddly.
2 x 1K Tempco's in series work and track fine, and that's what I'm using now.
Andy _________________ Kronos 2-88, Kronos 61, Studiologic Sledge V2/SL, Broadwave ARP 2600EX, Broadwave 18U ARP based Eurorack Modular, Broadwave Minimoog Clone, GEM S2 Turbo.
Synth DIY Projects
Musical Doodlings |
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numbertalk
Joined: May 05, 2008 Posts: 992 Location: Austin, TX
Audio files: 5
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Posted: Fri Oct 17, 2008 9:22 am Post subject:
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Hi Andy,
A few questions:
1) What are the critical/timing caps in this circuit - just the 680pfs? Any others that should be polystyrene? Would you say that 1000pf works better than 680pf?
2) EDIT: Think I found it - it was a 2N5172, which you have replaced with 2N3906, right? Wasn't finding a corresponding one for the other oscillator because this one is part of the ring mod circuit. What is the unlabeled transistor in your layout - the one right beneath the 330K resistor and above the left-hand/VCO 1 PW Adjust trimmer? Odd, because I can't seem to find this in the Arp schematics and don't see a corresponding one on your board for VCO 2.
3) How would you properly calibrate the 3 trimmers for each VCO?
4) 2K Tempcos (instead of the 1.87Ks) from Bridechamber would work fine for each oscillator circuit without changing any other component values in the circuit?
5) EDIT: Never mind - confused this with the other project mentioned here. I see this board does have the ring mod circuit. You mention there's no ring mod on this board but there is a ring mod output pad. How could you mod this board to get ring modulation out of this pad?
6) EDIT: Found the schematic and it looks like all 3 would be B100K, right? Still wondering why you have 5 instead of 6, though. What value and taper type would you suggest for each of the pots? Also, I see 5 pots on your board in the photo you posted, but it seems there should be 6 - 3 (Coarse, Fine and Manual PW) for each oscillator. On this note, if I wanted to add an attenuator for the FM input, what value and taper would you suggest for that?
7) Finally (thanks for your patience), the Osc 1 Audio/LF switch switches the module between operating as an audio oscillator versus an LFO, right?
Thank you!! |
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Broadwave
Joined: Feb 16, 2007 Posts: 347 Location: Manchester UK
Audio files: 6
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Posted: Fri Oct 17, 2008 10:27 am Post subject:
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numbertalk wrote: | Hi Andy,
A few questions: |
Phew... Ok I'll see what I can answer...
1. Just the 680pf for timing (1000pf should be fine, although the osc frequency will just be a bit lower.
2. Ooops... that's a 2N3904
3. Put both coarse & fine controls to minimum and adjust the VCO Freq Trimmer to give 20Hz. Put both PW controls to minimum and adjust PW Trimmer for 50% pulse (Square wave). The scale trimmer is a bit more awkward - Play octaves on your keyboard, and adjust trimmer until you get an octave difference - I always set up another oscillator to play bottom C, tune the osc you're adjusting for minimum beat frequency, and play an octave higher... adjust the scale trimmer then play bottom C again... retune for zero beats and play an octave higher again... re adjust the trimmer (keep doing this until the osc is scaled correctly, can take some time though)
4. a 2K tempco should work fine, there's plenty of leeway in the scale adjustment to cover the difference.
5. Not sure what board you're talking about - The original Dual VCO details I posted has the Ring Mod built in.
6. I used 100k Lin for all the controls... ARP used 100k Log for the FM attenuators.
7. That's right.
Andy. _________________ Kronos 2-88, Kronos 61, Studiologic Sledge V2/SL, Broadwave ARP 2600EX, Broadwave 18U ARP based Eurorack Modular, Broadwave Minimoog Clone, GEM S2 Turbo.
Synth DIY Projects
Musical Doodlings |
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