Arp Odyssey ..Help Needed :)

[Captain Proton]

Hi Peeps,

Loving my Arp in as much is legal that a man can love his Arp Odyysey he he....

I do have a problem that I am unsure of how to fix though. Oscilator 1 tracks nicely but oscilator 2 is out of sync i.e not quite 1V/Oct.

Am using Silent Way by Expert Sleepers which basically uses the Motu 2408mk3 as a midi to cv convertor and makes up retunes the synth regardless of how unstable the tuning is.

This works great as I use oscilator one as a reference for Silent Way to tune the Arp. But Oscilator 2 is about -20% of a note to +20% of a note over 5 octave range which makes it hard to sample.

Does anyone know how to adjust the 1v/oct curve of either of the oscilators so I can bring it in line. I suck at schematics so treat me as though I am a bit thick with any explanation he he.

Thanks in advance

[golden beers]

how is it if you unplug the CV/GATE inputs and just play the keyboard? still out?

[Martin Dubka]

Unplug the CV and using the keyboard to bring both oscillators in line.
I do this by using a strobe tuner.

Play the lowest note, tune it.
Play the highest note and adjust the small trimpot inside the hole to the right of the fine tune slider.
When you play the lowest note again it will be slightly out so retune it with the slider. Play the highest note, retune it with the trimpot, etc, etc until both ends of the keyboard are perfectly in tune.

Repeat the whole process for the 2nd oscillator. Note - the lower trimpot on Osc2 is for fine-tuning the intervals when playing duophonically. I never really bothered with this...

Now try your CV set-up again and report back...

[Captain Proton]

Cheers for the infor guys, problem is my arp keyboard is a bit broke. One of the oscilators plays at a constant pitch but when I hold down a key and then hold down another key the 2nd oscilator tracks that pitch fine.

I'd just spent a load of money on replacement sliders . Maybe I should rack the Odyssey in an Oak type modular case.

Anyhow I was wondering would this tuning technique work over CV as surely it would be the same as using the keyboard built into the synth?

Will try to tune it later today, cheers for the advice

[Captain Proton]

Ok I've calibrated my 1/volt cv to oscilator 1 which should be tracking just nice. here is an audio file with starting on low C with oscilator 2 tuned to oscilator 1.

I then go up each octave over 5 octave range, you can hear how oscilator 2 drifts as I go up the octaves. On the last octave I tune oscilator 2 to oscilator 1 to show how far out it's gone.

After this I just have oscilator 1 on it's own in to show tuning.

[Captain Proton]

Here is a pic of the Arp.

Could a kind soul explain what the adjustments 1, 2 and 3 do? I'm going to wing it and have a go now at tuning, but not sure what the difference between 2 and 3 are?

[golden beers]

Originally Posted by Captain Proton

I'd just spent a load of money on replacement sliders

did you try something like this first

[Captain Proton]

I thought of that but the synth was in bad condition and the sliders even more so. I mean they were just sticky very hard to move and made a lot of noise.

I'm starting to think if maybe there is a way to have access directly to each oscilator CV by way of turning the Odyssey into a semi modular?

It seams I can tune oscilator 2 by using potentiometer 3 as shown in my pic.... but only using the built in keyboard. Doesn't work over CV though which is odd. Seems it must just calibrate the keyboard.

Think it's time to open her up again...will ost a pic of the insides.

[golden beers]

Originally Posted by Captain Proton

I thought of that but the synth was in bad condition and the sliders even more so. I mean they were just sticky very hard to move and made a lot of noise.

dude, thats just dust and dirt. any electro-mechanical contact cleaner aerosole would've fixed that

[Captain Proton]

Oh well, these were brand new made for Arp type sliders.... so should last a while longer.

I must be able to adjust the CV/Volt reference for each oscilator on the circuit board for cv use?

[Martin Dubka]

Originally Posted by Captain Proton

Here is a pic of the Arp.

Could a kind soul explain what the adjustments 1, 2 and 3 do? I'm going to wing it and have a go now at tuning, but not sure what the difference between 2 and 3 are?

I already explained...

1 is osc1 hi track.

2 is osc2 hi track.

3 is the duophonic interval tuning.

[Captain Proton]

Sorry dude, was getting ahead of myself again. Thank you for the explanation.

It looks like those adjusters won't adjust the cv/volt amount. I have however just opened her up again and found some other adjusters:


1: VCO 1 V/Oct (which is also 1 on the other pic)

2: VCO 2 V/Oct (is 2 on other pic)

3: VCO 1 Freq Cal (gotta be it)

4: VCO sencond voice (same as 3 on other pic, as already mentioned must be to tune duovoice)

5: VCO 2 Freq Cal (I hope this works lol)

Apologese for being a bit dense on all of this.

[Captain Proton]

Not sure what I did... but it seems to have magically sorted itself out.

Tracks lovley now It's good to get to know your synth inside and out I suppose.

[golden beers]

Originally Posted by Captain Proton

Not sure what I did... but it seems to have magically sorted itself out.

Tracks lovley now It's good to get to know your synth inside and out I suppose.

if it fixed itself after you open and close it that means you have a dry solder joint or dirty connection somewhere. if this is that case i would get out the old bashing stick to locate the problem.

[Captain Proton]

Yeah you are probably right, it is a very old machine for sure....think I might send it off to get surviced and possibly modded to be more like the 2600 with patch inputs/outputs.

Such a lovely elestic wet boigny sound to this synth. Complements the Pro 1 and CS-30 just nicely. 3 very different sounding synths covering most of the area I need.

Just got to finish building this Oakley Modular lol.

Tracks over 7 octaves using Motu 2408mk3 and Expert Sleepers Silent Way plugin. My Kenton could only dream of that sort of stability in tuning.

[toolstudio]

Originally Posted by Captain Proton

Oh well, these were brand new made for Arp type sliders.... so should last a while longer.

I must be able to adjust the CV/Volt reference for each oscilator on the circuit board for cv use?

Hi,

I'm just looking for replacement sliders. There were some on EBay, but not yet.

Where did you get yours ?

wolfgang

[Captain Proton]

Roland, JUNO, Korg, Synth items at low prices on eBay.co.uk