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diablojoy
Joined: Sep 07, 2008 Posts: 809 Location: melbourne australia
Audio files: 11
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Posted: Tue Jul 16, 2013 6:26 pm Post subject:
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Andy love the look of the white boards , these are self etch ? wow
the whole thing looks absolutely great .
Quote: | I may put a PDF together with complete details and PCB foils for all the "carrier" boards and 40 series modules (along with corrections to the ARP service manual - quite a few mistakes there!) |
that really would be fantastic and very generous of you looking forward to it. _________________ In an infinite universe one might very well
ask where the hell am I
oh yeah thats right the land of OZ
as good an answer as any |
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Broadwave
Joined: Feb 16, 2007 Posts: 347 Location: Manchester UK
Audio files: 6
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isak
Joined: Dec 13, 2009 Posts: 847 Location: Israel
Audio files: 18
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Posted: Wed Jul 17, 2013 1:30 am Post subject:
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Hi Andy,
Looking foreword for the ody and the 2600 files.
Cause of you I become a big Arp fan!
Thank you for revealing the Arp world to me! _________________ http://www.myspace.com/mgmtrance |
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xpmtl
Joined: Aug 10, 2007 Posts: 162 Location: Brussels, Belgium
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Posted: Wed Jul 17, 2013 3:06 am Post subject:
Re: Arp Boards |
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AndyR1960 wrote: |
I'm taking a break form building for a while, but I'm currently drawing up an Odyssey clone, which, I'm glad to say is a whole lot simpler |
_________________ http://sdiy.xpmtl.net |
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forbin
Joined: Jan 29, 2009 Posts: 120 Location: Fremantle, Australia
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Posted: Wed Jul 17, 2013 9:39 pm Post subject:
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Looks fantastic! The screwdriver sitting on the keyboard is a nice touch... |
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Broadwave
Joined: Feb 16, 2007 Posts: 347 Location: Manchester UK
Audio files: 6
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Posted: Thu Jul 18, 2013 2:03 am Post subject:
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Still have a problem with the VCF mixer - distorting!
I've increased the input resistors from the standard 100k to 330k (to compensate for the fact that I've swapped the 4012 for a 4075)... just wondering if I should take them up to 680k or more as on the Odyssey (0-5v waveforms, but 0-10 or +/-5 for the 2600) or ditch the passive mixing and put an op-amp in there... no cigar yet.
GRRRRRR!!!!! |
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isak
Joined: Dec 13, 2009 Posts: 847 Location: Israel
Audio files: 18
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Broadwave
Joined: Feb 16, 2007 Posts: 347 Location: Manchester UK
Audio files: 6
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Posted: Thu Jul 18, 2013 2:29 am Post subject:
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@Isak, thanks for that... but I've solved the problem
Just found out that it wasn't the VCF mixer that was the problem... I was using a 15v gate from my modular for the AR envelope, which in turn was pushing the VCA too hard... DUH!
Dropped the gate voltage down to 10v, now sounds great... I LOVE the ADSR exp control of the VCA, it really give the amp a kick. |
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isak
Joined: Dec 13, 2009 Posts: 847 Location: Israel
Audio files: 18
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Broadwave
Joined: Feb 16, 2007 Posts: 347 Location: Manchester UK
Audio files: 6
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isak
Joined: Dec 13, 2009 Posts: 847 Location: Israel
Audio files: 18
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Posted: Sun Aug 25, 2013 1:57 am Post subject:
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Quote: | I ended up copying the tracks from a pretty bad photo of the back of a genuine 4072 module, then painstakingly sorting out where the components should go from the schematic that's available. |
wow man, crazy job!
Looks a beauty, for sure sounds a beauty!
YouTube Vids!!!!!
I want to see _________________ http://www.myspace.com/mgmtrance |
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steffensen
Joined: Jul 11, 2012 Posts: 103 Location: Sweden
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Posted: Sun Aug 25, 2013 2:21 am Post subject:
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What a beauty! Good job! |
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diablojoy
Joined: Sep 07, 2008 Posts: 809 Location: melbourne australia
Audio files: 11
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Posted: Sun Aug 25, 2013 2:41 am Post subject:
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orsm work we should all be in awe. _________________ In an infinite universe one might very well
ask where the hell am I
oh yeah thats right the land of OZ
as good an answer as any |
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emmaker
Joined: Aug 10, 2007 Posts: 12 Location: Portland, OR
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Posted: Mon Aug 26, 2013 12:59 pm Post subject:
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Quote: | Truthfully? I think it may be ambitious for a first project... but Zthee's TTSH comes on a complete single board (except for the 3 VCO modules), so it's certainly easier to do than messing around with separate boards (23 PCB's in mine!). |
I actually think your way of doing individual boards is better. With one board it could get screwed up bad enough to have to scrap the whole thing. With individual boards only the module that is hosed can be replaced. There are going to be a few hobbyists whose skills won't be up to what's required for this project and will probably trash their board. |
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THeff
Joined: Sep 01, 2006 Posts: 229 Location: Florida
Audio files: 33
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Posted: Mon Aug 26, 2013 7:41 pm Post subject:
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Hi Andy,
I just checked out your pictures on Flickr and you do fantastic work! My DIY ARP-2600 works very well but but can't touch the panels and cases you have made...excellent!
I just made four 4035 filters for a current project from your layout and they work great.
Thanks for posting your DIY projects!
Regards,
Theff |
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Broadwave
Joined: Feb 16, 2007 Posts: 347 Location: Manchester UK
Audio files: 6
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Posted: Tue Sep 03, 2013 11:13 pm Post subject:
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THeff wrote: | Hi Andy,
I just checked out your pictures on Flickr and you do fantastic work! My DIY ARP-2600 works very well but but can't touch the panels and cases you have made...excellent!
I just made four 4035 filters for a current project from your layout and they work great.
Thanks for posting your DIY projects!
Regards,
Theff |
Thanks for your kind words Theff, much appreciated.
I set out 5 years ago with the though of building one, but didn't have any clue where to start - That's when I started dabbling with Odyssey VCO's etc and realised that it was a possibility.
Most of the stuff I've done is pretty crudely put together, but I went all out for the 2600 project as I wanted it to look as good as I could get it - I was initially put off by the price of having the panel laser cut and the screen printing, but I'm really pleased with the result - I seem to spend more time looking at it than playing with it
I'm currently working on the 3620 duophonic keyboard clone (the controller I've built is "ok", but just not quite right). Unfortunately, I had to pay a fair amount for decent and clear documentation as the available schematic downloads for the 3620 are unreadable... It should be completed by the end of the week, but I'm a bit concerned about what capacitors to use for the keyboard S&H. Standard metalized poly caps work well in the 4015 S&H module, but I'll have to see if they're good enough for the keyboard. |
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LFLab
Joined: Dec 17, 2009 Posts: 497 Location: Rosmalen, Netherlands
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Posted: Wed Sep 04, 2013 10:55 am Post subject:
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Styroflex or Silvermica? Alternatively, wima has a line of caps intended for applications involving short pulses, not sure what parameter is optimised in these.
edit:
Checked and those are the fkp1, not really suitable, big, and aimed at high power electronics. |
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roglok
Joined: Aug 28, 2010 Posts: 202 Location: uptown
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Posted: Fri Sep 06, 2013 9:07 am Post subject:
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great work, andy |
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DES
Joined: Feb 28, 2003 Posts: 794 Location: New Jersey
Audio files: 8
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Posted: Sat Sep 07, 2013 7:03 am Post subject:
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Wow! That is impressive! _________________ Dave
www.davesneed.com |
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diablojoy
Joined: Sep 07, 2008 Posts: 809 Location: melbourne australia
Audio files: 11
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Posted: Sun Sep 08, 2013 6:04 pm Post subject:
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Andy I would recomend using polystyrene for sample and hold circuits
Rushonline capacitors are a good source for these and close to you. _________________ In an infinite universe one might very well
ask where the hell am I
oh yeah thats right the land of OZ
as good an answer as any |
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Broadwave
Joined: Feb 16, 2007 Posts: 347 Location: Manchester UK
Audio files: 6
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Posted: Sun Sep 08, 2013 11:40 pm Post subject:
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diablojoy wrote: | Andy I would recomend using polystyrene for sample and hold circuits
Rushonline capacitors are a good source for these and close to you. |
Thanks for the info, they've got 500n in stock
I'm currently using a good quality metalized poly, which seems to work ok, I've just got to sort out a slight problem I have with the upper voice generation circuit (not scaling to 1v/oct)... I thought I'd just need to change a few resistor values to bring it in line, but it's having a knock-on effect to the main lower voice cv out.
Still scratching my head on this one |
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diablojoy
Joined: Sep 07, 2008 Posts: 809 Location: melbourne australia
Audio files: 11
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Posted: Mon Sep 09, 2013 2:46 am Post subject:
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Quote: | Thanks for the info, they've got 500n in stock |
holly crap Andy 500nf thats going to be physically quite large in a polystyrene cap. I have some 330nf polystyrenes - they are about the size of a sub c battery so yeah they are going to be big
last ones i used in a sample and hold were 10nf
(the MFOS 1v/oct keyboard circuit and rays sample and hold also) _________________ In an infinite universe one might very well
ask where the hell am I
oh yeah thats right the land of OZ
as good an answer as any |
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Broadwave
Joined: Feb 16, 2007 Posts: 347 Location: Manchester UK
Audio files: 6
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Posted: Mon Sep 09, 2013 6:11 am Post subject:
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Yup, they're big... The original 3620 Keyboard used BIG Polycarbonates, the polyester ones I'm using are fine for testing, but the voltage drop over time is not really acceptable.
But, at least I found the problem I had with the second voice CV scaling... It's the keyboard I used (converted from a matrix scanner - the carbon switch pads introduce too much additional resistance when a second note is played, causing havoc with the resistor chain).
I tested the PCB with the keybed from my Odyssey and it works fine... Looks like I'm going to have to build my own with J-Wires etc or get two MIDI CV converters - one low note and one high note priority... I can't see either being easy. |
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diablojoy
Joined: Sep 07, 2008 Posts: 809 Location: melbourne australia
Audio files: 11
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Posted: Mon Sep 09, 2013 3:00 pm Post subject:
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Ah those damn pesky carbon pads
I have been getting keybeds from old home organs (usually for free)
so they are the bendy wire types. good for low note priority using rays circuit hmm but you want upper and lower note priority . so just a simple resistor chain based system wont work.
not sure if either of these will get you where you want to be but
maybe this ?
http://electro-music.com/forum/topic-29746.html
and / or
http://www.muffwiggler.com/forum/topic-75544.html
However maybe 2 resistor chains running opposite directions to each other could be utilised if you could come up with a way of preventing the second note on each being involved for each one , thinking lots of magnetic micro reed switches so probably painful to implement and to set up.
edit : oh or 2 of these one set to low note priority and one set to high note priority and a standard midi keyboard of course
http://www.kentonuk.com/products/items/m-cv/prosolo.shtml _________________ In an infinite universe one might very well
ask where the hell am I
oh yeah thats right the land of OZ
as good an answer as any |
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Broadwave
Joined: Feb 16, 2007 Posts: 347 Location: Manchester UK
Audio files: 6
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Posted: Mon Sep 09, 2013 10:42 pm Post subject:
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diablojoy wrote: | Ah those damn pesky carbon pads |
Just bought some silver conductive paint - apparently less than 0.2r per cm, so I'll give that a try on the PCB pads and bubble contacts.
The ARP 3620 keyboard is duophonic from a single resistor chain - It derives the upper voice by detecting the voltage difference between the two notes played... that voltage difference is passed though a standard S&H and then mixed with the lower CV to produce the second upper voice - quite a simple but elegant design.
Kimber Allen, here in the UK, is going strong and still sell 2 pole "make" contact block assemblies - I'm waiting for them to get back to me, but I suspect they'll be expensive, but probably still cheaper than two Kenton Solo's |
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