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

Q: using a sequencer module in conjuntion with a CV keyboard
MUFF WIGGLER Forum Index -> 5U Format Modules  
Author Q: using a sequencer module in conjuntion with a CV keyboard
Dave Peck
A question for those of you who are using a hardware CV sequencer module in conjuction with a CV keyboard .... How are you choosing whether the oscillators in your system are being fed the output from the sequencer, the output from the keyboard CV, or a sum of both (so you can use the keyboard to 'transpose' a running sequencer)?

Some kind of switch module? A precision unity summing mixer module to add both CV signals before the osc 1V/oct inputs? Manually repatching every time you want to change the routing?

I'm surprised that most sequencer modules don't seem to include an input jack for a 1V/oct input from a keyboard, and a three position toggle switch to select whether the sequencer is outputing the sequencer signal, the keyboard CV input signal, or a sum of both. So how are you guys working around this?
diophantine
I would guess most often it is just manual re-patching.

While I don't do this sort of thing often, at least with the Q106 (and, IIRC, the Zeroscilltor) you've got two 1V/Oct inputs on the VCO.

The Synthasystem sequencer (not 5U, but closer to 5U in style than any other format) actually has a CV input that gets added to the output of the first row. I've never used it outside of testing, but that's mostly because I've never used a keyboard with it. (The VCOs also have two 1V/Oct inputs.)

It always struck me as odd that the 960 lacked such a feature. But then again, maybe it was because the 901a and 921a both had 3 1V/Oct inputs.
JohnLRice
I usually just patch things up as I need/want them each time although I could use a sequential or other switch.

All of my big knoby sequencers have transpose inputs so it makes things easy: Moon 569, GRP R24, Division6/Mattson SQ816 (eurorack), and I used to have a Synthesizers.com Q119.

If I remember correctly when I had a Q960 I scratched my head a few times on how to do a typical sequence transpose, and I think I was spoiled by the Q119 which I had first. The MOTM-300 VCOs only have a single 1v/oct input and I really needed something like a precision adder module but I never got one.
suitandtieguy
there's an app for that:

Dave Peck
JohnLRice wrote:

All of my big knoby sequencers have transpose inputs so it makes things easy: Moon 569, GRP R24,.....



A-ha! I was looking for that on the GRP and didn't see them. Now I do.
JohnLRice
Dave Peck wrote:
JohnLRice wrote:

All of my big knoby sequencers have transpose inputs so it makes things easy: Moon 569, GRP R24,.....



A-ha! I was looking for that on the GRP and didn't see them. Now I do.
thumbs up And, you can use one row to transpose another (if it's not part of the same grouping), no need to do modifications like I did to my 569! w00t
Raven_Martin
I bought an intellijel unity mixer specifically for this purpose. Requiring the V/oct CV to stay precisely scaled, there's not actually many modules that can reliably mix two signals at unity. However, I now use a cirklon which is very efficient at routing any midi controller anywhere in the studio, including outputting as CV. Would be overkill just as a keyboard router though!
Leverkusen
I am using the circlon with midi too to do this but I think the Mos-Lab CP3 does this with its switches for CV routing.

https://www.mos-lab.com/cp3
suitandtieguy
Raven_Martin wrote:
there's not actually many modules that can reliably mix two signals at unity.


i use .1% tolerance resistors in the Active Multiples for this very reason. the other option was scaling trimers and i think that's less reliable.
bwhittington
A Moon 590v/vi set is a nice option for voltage summing.
diophantine
suitandtieguy wrote:
i use .1% tolerance resistors in the Active Multiples for this very reason. the other option was scaling trimers and i think that's less reliable.

I'm a big fan of using precision resistors in these situations as well. Costs less than a decent trimpot, no one's ever gonna mess it up, and I don't think I can trim a 10-turn trimpot to be any more accurate than a .1% resistor in that sort of situation.
Dave Peck
... so it's looking like it is as I suspected, that only a few sequencers have an input for adding a keyboard (or other) CV source and provide precision summing of that signal with the sequencer's signal. And that the default work-around for many wigglers seems to be an external precision summing mixer and manually patching and unpatching the KYBD and SEQ signals from the mixer inputs to select either or both signals.

That seems really strange to me. Perhaps because I'm coming from a keyboard player background and think of a hardware sequencer as an 'extra' in a modular synth, something to augment the keyboard, it just seems to me that a precision KYBD summing input, with a switch to select SEQ/KYBD/BOTH should be a pretty standard and important feature on a sequencer module.
Squattamolie
I had some issues years ago with this, so I bought an STG Active Mult and it solved them all nicely. I was hesitant at first to spend the $ on "just a mult" but once I did, I was glad (still have it, won't sell it, use it in every patch). I have two full STG Time Suite sets, and two Q960s - 90%+ of my patches have both keyboard CV and sequencer CV going to pitch, and I never run into pitch issues. I actually want a 2nd Active Mult, will add one at some point.
bwhittington
Dave Peck wrote:
... so it's looking like it is as I suspected, that only a few sequencers have an input for adding a keyboard


The large non-clone sequencers that I can think of, the Q119, Moon 569 and GRP R24, all have it. I think the Modcan sequencers all have it? Are there others that don't? The 960's don't, but they are emulating a legacy concept. Makes sense for it not to exist on the 1-2U sequencers, trade-offs being what they are. Seems like there are a fair number of good choices for this though?
Dave Peck
I have noticed that several quantizer modules do include a precision adder, often labeled a 'transpose' input. Since these modules often get used in conjunction with sequencers, this would work just as well as having it on the sequencer. Still seems odd that a lot of sequencers don't have it.
Rex Coil 7
Ok, I'm game for tossing out the most mockable question .. smile.

If I understand this question properly, why can't a spdt on-on-on toggle be used to select v/oct cv source (applies to Q106 usage)?

Each throw wired to each v/oct source, with one of the throws summing both sequencer and manual voltages?

If I understand the new Q174/Q175 modules the "add" input is easily used for sequnce transposition.

Perhaps I've oversimplified the images of the setup and/or question here in my mind and am not seeing the situation correctly? With the collective experience that has responded so far, I have to wonder if I'm seeing things incorrectly since my answer seems too obvious and simple by comparison. That having-been said, help a fella out and show me where I've stepped on my dick here.

Thanks ... smile
Rex Coil 7
..... Adding to that, in my view of this all cv sources would be actively buffered. But, with the Q106 is it even necessary? Especially if using portamento/glide (not many slew circuits track super well over 3 or 4 octaves that I am aware of).
Dave Peck
Rex Coil 7 wrote:


...Each throw wired to each v/oct source, with one of the throws summing both sequencer and manual voltages?


yes, the two switch positions that select only the sequencer or only the keyboard are simple - it's that third switch position that selects a precision unity gain mix of both signals added together that's the tricky part, and the one that seems to me like it's practically a necessity to make a sequencer module really useful, but that's based on the way I would use a sequencer.
Rex Coil 7
Dave Peck wrote:
Rex Coil 7 wrote:


...Each throw wired to each v/oct source, with one of the throws summing both sequencer and manual voltages?


yes, the two switch positions that select only the sequencer or only the keyboard are simple - it's that third switch position that selects a precision unity gain mix of both signals added together that's the tricky part, and the one that seems to me like it's practically a necessity to make a sequencer module really useful, but that's based on the way I would use a sequencer.


Yea, but ... well ... there's this ......

Rex Coil 7 wrote:
..... Adding to that, in my view of this all cv sources would be actively buffered.


I would agree, but as I said in the REST of my post you partially quoted (see above) .... an active buffer would fix this (DIY? Perhaps?) Take a look at how the Dot Com Q174 has that "ADD" input ... a buffered input which places an active buffer between sources/destinations that isolate each of those from one another, fixing the unity gain issues.

thumbs up
MUFF WIGGLER Forum Index -> 5U Format Modules  
Page 1 of 1
Powered by phpBB © phpBB Group