MUFF WIGGLER Forum Index
 FAQ & Terms of UseFAQ & Terms Of Use   Wiggler RadioMW Radio   Muff Wiggler TwitterTwitter   Support the site @ PatreonPatreon 
 SearchSearch   RegisterSign up   Log inLog in 
WIGGLING 'LITE' IN GUEST MODE

Greater trigger voltage
MUFF WIGGLER Forum Index -> Expert Sleepers  
Author Greater trigger voltage
Analog>Plugins
I was just looking into how to boost the trigger volume/voltage for say my Arp Odyssey. It does like a hefty voltage to trigger it. So I was thinking one of these?

http://www.synthesizers.com/q118.html

But then I thought Doh! Maybe the new cable mod would increase the voltage enough to give more trigger power?
os
Quite possibly. What interface are you using?
Analog>Plugins
I use the 2408mk3 Motu, do you think your simple cable mod would work though insted?
os
Have you tried the headphone outputs? They're supposed to be much higher voltage on that interface.

An easy thing to try would be a cable wired
T -> T
R -> S
S -> nothing

which in theory doubles the voltage swing, versus a traditional 'floating ring' Silent Way cable.

Or you could try the Silent Way AC Encoder cables (though of course you'd have to use Silent Way AC Encoder too).
Analog>Plugins
Yeah I figured out using the headphone trick.... only problem is that I have a Pro 1, Odyssey, Yamaha Cs-30 and a modular to control.

If I was using say output 7 on the Motu 2408mk3 just for trigger and not for cv/volts pitch control would there really be a need to use the AC plgin if it's just for increasing the trigger power?
os
The voltage doubler circuit relies on AC input to work.

But like I say, you could try a TRS->TS(nothing) cable first, without AC Encoder.
Big G
Analog>Plugins wrote:
I was just looking into how to boost the trigger volume/voltage for say my Arp Odyssey. It does like a hefty voltage to trigger it. So I was thinking one of these?

http://www.synthesizers.com/q118.html

But then I thought Doh! Maybe the new cable mod would increase the voltage enough to give more trigger power?


Neither. The Q118 has 5V Gate and Trigger outputs. The 2408 has barely <5V signals.

ARPs with a "system interface" require >10V Gate AND Trigger. On the Odyssey II the Gate may work on less than 10V as it is switching a transistor, but the Trigger is ac coupled into CMOS logic running on +15V. That means that you have to exceed 2/3 the power rail to pass the logic threshold and there will be a tolerance on that. You are not going to get that level voltage with smoke and mirrors, you need at least a 12V powered circuit (15V is better) and a simple transistor switch.

The ARP Axxe has a relaxed spec, requiring a >8V Trigger because it is going into a transistor switch.

The transistors can be modified to switch at a lower voltage with one resistor value change, but you cannot change the CMOS threshold.
One solution might be to add transistor switching inside the Odyssey using its power supply and drop the input thresholds to about 3V, then it will work with almost anything.
Analog>Plugins
Yeah think I will try that idea OS, I did buy some insert cables as I was worried that using normal jacks might fry my 2408mk3.

How I've wired it (still to be tested) at the moment is the stereo end of the insert lead coming from an output on the 2408mk3 and then one of the two mono ends going into the synth with the other mono end going nowhere.

My brain hurts when it comes to cables, so simple yet I don't think I'm hard wired to think that way lol.
os
Big G wrote:
the Trigger is ac coupled into CMOS logic running on +15V. That means that you have to exceed 2/3 the power rail to pass the logic threshold and there will be a tolerance on that.

The 2408mk3 has a nominal output range of 9.2V (+/-4.6V), so the voltage doubler circuit I posted on the other thread ought to produce 18.4V, which should work then.

Analog>Plugins wrote:
I did buy some insert cables

That's not the same - that gives you
T->T
R->nothing
S->S
and
T->nothing
R->T
S->S

You want a cable that uses T & R (and ignores S) to maximise your voltage swing.
Arnoid
os wrote:
An easy thing to try would be a cable wired
T -> T
R -> S
S -> nothing

which in theory doubles the voltage swing, versus a traditional 'floating ring' Silent Way cable.



Gonna check this out... Since I discovered the Esi esp1010 is also dc coupled, only the range goes from -2.84V to 2.84V...
Would be nice if I can double the voltage using that cable configuration because 2.84V is just not enough for gate's...

With the ac encoder & voltage tripler I'm getting 7V at max but it's still a bit unstable in the lower part (0-1V)...
os
Arnoid wrote:
With the ac encoder & voltage tripler I'm getting 7V at max but it's still a bit unstable in the lower part (0-1V)...

That's why the AC Encoder has a 'Min Out' setting, so you can avoid that low voltage region (where the diodes don't conduct).
Arnoid
That's useful I will set the min range on 1V then
Tough it would be nice I can double the voltage without using the AC encoder an cables using that cable you mention above.. -5,6V to 5,6V would be a nice working range smile
Analog>Plugins
+/- 14.8volts from main outputs on Motu 2408mk3 should be more than enough to trigger the gate/trigger on the old power hungry Arp Odyssey smile

Think I might get a Motu 24 i/o now that this cable voltage doubling thing worked out nice.
Analog>Plugins
Ok now this is really weird, I've calibrated the Pro 1 with the new cables that put out double the voltage but it's calibrated itself to 2v per octave exactly?

How can that be, really odd. Getting no more range than the using an insert cable which runs at half the voltage.

I am finding that on the Pro 1 the extra voltage is bleeding through from the gate/trigger cv into the Cv..er..Cv if you know what I mean.

Have measured with a volt meter and it's definitely 2v per octave right now and the calibration graph looks the same with the standard insert cable as it does with the double voltage cable...crazy huh?
Analog>Plugins
Yep, I fired up another cable and replaced it with the previous one that had the job of controlling the filter input on the Pro 1. Before it could never quite open up the filter fully and with the new cable it is the same.

But checking the voltage on the voltmeter it is indeed double so I'm confused for sure.
os
You're using the AC Encoder plug-in, right?
Analog>Plugins
No I just wired them up in answer to your reply post:

Quote:
An easy thing to try would be a cable wired
T -> T
R -> S
S -> nothing

which in theory doubles the voltage swing, versus a traditional 'floating ring' Silent Way cable.


The voltage has doubled as measured on Voltmeter, but the synth still reacts as though it hasn't?

Just using straight Voice Controller for controlling mono synth i.e gate, cv and env to filter input.

This is all on a MOTU 2408mk3
os
How odd. Are *all* the cables linking the interface and the synth wired that way? I can imagine it might cause problems if not (confused grounds).

You might even need to use the same kind of cable to get the audio back from the synth into the interface.
Analog>Plugins
As in are all the cables linked to the 2408mk3 of the new 'wired for double voltage' type? If so then no as I still use it for lesser audio duties like the hardware insert for my analog echoboy.

I will try it though.

Very odd behaviour....I mean your cable idea works in theory as the voltage is doubled. It must be a grounding thing like you say. I will do some experimenting.
sine
Sorry to step in, Analog>Plugins...
I just wanted to report, on my Motu 1224 1-8 'low voltage' outputs I get 4 octaves with the Motu-advised wiring:
T -> T
R -> nothing
S -> S

I just tried 'wired for double voltage':
T -> T
R -> S
S -> nothing
Now I get more than 7 octaves! Is this ok for the interface? I know you wouldn't recommend it if it weren't, but just curious. It's such a simple way to double voltage. Thanks.
Analog>Plugins
Man that is odd how it works for you but not for me on the pro 1. Mine is calibrating itself to 2v/octave?

Have taken all the non double voltage cables out and it still has no affect even though I can see double the voltage on the cables. Will try the Odyssey tomorrow to see if it's a Pro 1 thing.
Mans
sine wrote:

I just tried 'wired for double voltage':
T -> T
R -> S
S -> nothing
Now I get more than 7 octaves! Is this ok for the interface? I know you wouldn't recommend it if it weren't, but just curious. It's such a simple way to double voltage. Thanks.


I would like to know as well?
os
I think the best answer is "it depends". It's probably not advisable if there are other options.
MUFF WIGGLER Forum Index -> Expert Sleepers  
Page 1 of 1
Powered by phpBB © phpBB Group