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Transpose Utility Module - who can handle pitch transpose?
MUFF WIGGLER Forum Index -> Eurorack Modules Goto page Previous  1, 2, 3, 4, 5, 6  Next [all]
Author Transpose Utility Module - who can handle pitch transpose?
frankbuss
Ok, sounds like a plan cool I cleaned it up a bit and removed the quantizer. There are just too many possibilities and it is not really related to the transpose function, and would make it more expensive with a microcontroller and DAC. I think would be better to use a separate module for it which just quantizes a signal.

But I used an idea which was posted earlier in this thread, with a master-sum channel, and two switches, to add the CV-out signal to the master-sum, and another switch to add the master-out to the other 4 sum channels (which means there are 4 possible combinations). This reduces the external wiring a lot, if you want to use it for the initial use case posted in this thread, adding a CV signal and a pot to up to 4 CV signals in parallel.

In addition each sum channel has 2 inputs, for adding signals individually to each channel.

With the master out and the 2 CV-outs (same level on both CV-outputs, but individually buffered, and short-circuit protected, as all the other outputs), it is possible to cascade multiple of these modules in different ways, to transpose more than 4 channels.



If this is ok, I'll change the circuit diagram. I would still use the OPA4180, with very low offset voltage and "zero-drift" function, and 0.1% resistors, which should result in better than 1 mV accuracy.

Would be my first module, so initially I would sell it just for the parts cost to anyone who wants to try it. Only requirement would be to tell me if it works as expected, or if there are problems, in which case you could send it back and I will refund you. But I don't expect problems for such a simple module.

Only remaining question is a nice name for it. What about "Frank's Sum"? nanners
SlyFrank
Looks great. 1 mV or better accuracy is what is needed (ideally) for such a module, so this would be an amazing transpose module. I'd be happy to be a beta-tester and either build it and test it (as long as I was provided a PCB & BOM) or buy it and test it pre-built.

And, yeah, totally agree - quantizing seems to be an unnecessary add-on for this module. That can be done easily elsewhere. Somewhat similar in function to the Doepfer A-185-2 Precision Adder (which also has no built-in quantizer), but the Doepfer is only one channel (so would need 4 of them = 24 HP total), and this module would be far better, i.e. 4x A-185-2s in 24 HP would not come close to 1x of this module in 8 HP!

Cheers Guinness ftw!
gimber
Count me in, looks great.

I didn't fully grasp the earlier discussion about the knob/cv source, but it'd be really useful if that switch would jump in whole volts so it'd be an octave switch as well.

You could give it a black panel and call it Black Adder Dead Banana
frankbuss
gimber wrote:

I didn't fully grasp the earlier discussion about the knob/cv source, but it'd be really useful if that switch would jump in whole volts so it'd be an octave switch as well.


Well, this would be the task of the external quantizer, or MIDI-to-CV generator. But I could add a voltmeter:



This doesn't require an expensive DAC, just a small one Euro PIC microcontroller could do it. But the displays with such small digits are a bit expensive, I found only this at Digikey for EUR 5.24:

http://rohmfs.rohm.com/en/products/databook/datasheet/opto/led_display  /numeric/lb-303ak.pdf

But it might be worth the price, to have an accurate measurement. Would be 10 mV accurate, which is about 1/8 semitone with 1V/octave. So you could select the +/-5V range and then adjust exactly to full octaves yourself.

Alternatively I could add two switches instead of the display: one 3 position switch for selecting +/manual/-. When manual is selected, then the pot is used. Otherwise another switch is used: 1V/2V/3V. The first switch decides if it is +1/+2/+3V or -1/-2/-3V. But I think the voltmeter is more flexible and would even allow you to adjust exactly for chords etc.

PS: in this draft I added two slots on each edge, because with all the jacks with lots of possible cables, it might be not stable enough with just one screw on each side. Found a name for it, too: "Sum & CV". How boring is this hihi
gimber
I was just thinking about what happens when the cv source range switch was flipped among the different ranges. If the change was in whole volts and you were using it to feed the transpose input, everything would stay in tune, just switch octaves.

The voltage display is interesting, but I would just as soon leave it out to have a simpler module.

Then again I'd also be happy with a 4hp module with no cv source and one set of inputs. twisted

frankbuss
gimber wrote:
I was just thinking about what happens when the cv source range switch was flipped among the different ranges. If the change was in whole volts and you were using it to feed the transpose input, everything would stay in tune, just switch octaves.


I don't know how to do this without a microcontroller, because e.g. when there is a range +/-1V and the pot has selected 0.5V, when you change it to +/-2V, the output voltage would be 1V, not 1.5V.

And right, maybe the voltmeter makes it too complicated. You could always use the second output and a cheap Chinese $3 multimeter from eBay to measure it exactly hihi

But now that you mentioned that it might be useful to change octaves, maybe it would be a good idea to add two 3 position switches? One for -1V, 0V, +1V and one for -2V, 0V and +2V. With these switches you can quickly change the octave from -3V to +3V in 1V steps, and the pot value would stay in tune. Or maybe a rotary switch with multiple positions.

SlyFrank
gimber wrote:
Then again I'd also be happy with a 4hp module with no cv source and one set of inputs. twisted



This is _exactly_ what I have been wanting. I assume that the single IN at the top is for the transposing voltage, which is added to all 4 of the INs (sequences or whatever) and the resulting 4 sums go out the 4 OUTS.

But I'm happy with whatever direction this goes, so long as that core functionality is there. The extra bells & whistles (switches, etc) are certainly nice (and I would definitely buy it), and I understand how octave switching would be useful, but this 4 HP mockup is very elegant.
Zephod
I'd certainly be interested in building/testing a few prototypes of these - should be excellent to use with Tuesday :-)
gimber
SlyFrank wrote:


This is _exactly_ what I have been wanting. I assume that the single IN at the top is for the transposing voltage, which is added to all 4 of the INs (sequences or whatever) and the resulting 4 sums go out the 4 OUTS.


Yep, it would simply add the top input to the four other inputs. My first thread ever here was about wanting to design a module like this but I never had the time to figure it out. It's exciting to see something similar coming along!
aroom
guys, there is already a 3 voices option in 2 hp ready to be backed if you are interested.

I mean, take two of this module and you'll have 6 voices in 4 hp

edit :

check kay_k posts on this thread :

https://www.muffwiggler.com/forum/viewtopic.php?p=2606997#2606997

https://www.muffwiggler.com/forum/viewtopic.php?p=2609402#2609402


I'm gonna pick up his custom made module tomorrow at the post office. Unfortunately I won't be able to test and report because I'll be off for 10 days in the Faroe Island, without my modular
aroom
regarding frankbuss project, I think that it's great to have more option if you go with a larger form factor than 2 hp

I like the switch option, but personally I would like to have one switch per output.
gimber
aroom wrote:
guys, there is already a 3 voices option in 2 hp ready to be backed if you are interested.

I mean, take two of this module and you'll have 6 voices in 4 hp

edit :

check kay_k posts on this thread :

https://www.muffwiggler.com/forum/viewtopic.php?p=2606997#2606997

https://www.muffwiggler.com/forum/viewtopic.php?p=2609402#2609402


I'm gonna pick up his custom made module tomorrow at the post office. Unfortunately I won't be able to test and report because I'll be off for 10 days in the Faroe Island, without my modular


If that's the case then great! Those posts don't really describe the module (other than a potential 1u version) and the video is shot in the dark, so the kay_k module is a little unclear. Is it described somewhere else?
SlyFrank
gimber wrote:
aroom wrote:
guys, there is already a 3 voices option in 2 hp ready to be backed if you are interested.

I mean, take two of this module and you'll have 6 voices in 4 hp


If that's the case then great! Those posts don't really describe the module (other than a potential 1u version) and the video is shot in the dark, so the kay_k module is a little unclear. Is it described somewhere else?


Is this the module? http://www.modulargrid.net/e/other-unknown-wk1

If it is, then I may be misinterpreting or misunderstanding this module, but from what I see this module can be used for transposing 1 sequence per module - there is only one output in the mixer. So 4 modules would be needed = 8 HP. It's a 3:1 buffered mixer, so one input can be the sequence, one input can be the transposing voltage, the third input I dunno. But what I am talking about (and what I think gimber is too) is being able to add a single transpose voltage to 4 different sequences simultaneously. So each sequence + transpose voltage combo will need its own output = 4 outputs. This only has one output. And only one sequence + transpose voltage combo.

Maybe I am not grasping this... I found this on MG by clicking the link in that YouTube video.

If this is the module, then it's the same as using the middle section of Links 4x times, although it does use 1/2 the space.
aroom
so for now, the module is custom made from an existing module, the WK1 (https://www.modulargrid.net/e/other-unknown-wk1) from Leipzig West


his designer, kay_k, was able to mod it for me, by cutting some traces and soldering some wires.

this is the concept :




but at the end, he managed to end up with a clearer layout.

the function are :

Inputs

T
1
2
3

Outputs

T (buffered copy from T)
1+T
2+T
3+T


it's smart, because you can chain more than one module with the buffered T output


and kay_k is ready to do a new PCB with those functions, if enough people are interested - check his post about that
SlyFrank
Ah, I see now. Thanks for the explanation. This makes sense now, and I agree that the buffered T output is a smart idea for chaining.

If this was built as a new PCB, I'd definitely be interested.

Cheers Guinness ftw!
aroom
yeah it's great. we just need enough people in and this could be in production.
SlyFrank
I'm in.
gimber
I'm in too. Thanks for clearing this up.
mskala
If this is becoming a "post your transposition modules that people can't actually have yet" thread, maybe I can sneak in this one. Currently held up waiting for the panels, I'm still busy writing the manual, and I have a store opening and another module to start selling before this one will work its way to the front of the queue... but it is in the queue, and I've got a batch of them half-built on my workbench right now.
frankbuss
aroom wrote:
regarding frankbuss project, I think that it's great to have more option if you go with a larger form factor than 2 hp

I like the switch option, but personally I would like to have one switch per output.


I don't know if it would fit, but I should get some jacks and switches from Thonk this week, which I could use for exact dimension measurements.

What would you like to have per output? 0, +1V, +2V? I don't have experience with modular setups, does my -1V, -2V idea even make sense, or would it be better to have just a knob for like 0, +1, +2, +3, +4?

But right, everyone who needs it now, and in 2 HP, should buy the modded module from kay_k. My module might need some more time and planning, but I will do it anyway, just as a simple example for learning how to produce modules.
av500
mskala wrote:
If this is becoming a "post your transposition modules that people can't actually have yet" thread, maybe I can sneak in this one. Currently held up waiting for the panels, I'm still busy writing the manual, and I have a store opening and another module to start selling before this one will work its way to the front of the queue... but it is in the queue, and I've got a batch of them half-built on my workbench right now.


then let me add mine as well smile

it's single channel only, but then it's only 4hp. it's called T43 because it can add or sub up to 43 halftones or ~3.5 octaves in addition to adding input B and adding or subtracting input C if needed.

prototypes haven been built and are being used/tested as we speak

https://www.modulargrid.net/e/vpme-de-t43

aroom
I just received Kay's mod and did this short clip :




It does the job perfectly, does a lot in a small form factor : couldn't be happier.


kay_k told me by mail that he will do a new version from his WK1 with jumper, to be able to switch from the original function from the WK1 (adder + buff mult) to this transpose master function.

If you are interested, contact him I guess. (you'll find his website / infos in this thread)
aroom
mskala wrote:
If this is becoming a "post your transposition modules that people can't actually have yet" thread


hé hé

you can get Kay's mod right now - you just have to contact him


but it's great that all of you are designing and releasing new modules - congrats w00t . I wish I could design my own as well.

mskala brillant! the quantized input is a good idea. I just wonder if you could spare some HP and make it smaller ?


av500 this is fun! so if I understood correctly, you have three inputs (a b c) and 6 switches ?


frankbuss personally I would use one switch per output to select how I want the summing done for each output - like I described in one of my earliest post : to be able to select from input A or B or the CV offset

but who knows. it's maybe smarter to have the octave selection by outputs as well. I don't know.

If I had to choose the range, I guess it would be smart to be able to go at least from -1 / 0 / +1. meaning It could be smart ans as important to be able to go down an octave or two, than to go up.

-2 / -1 / 0 / +1 / +2 would be the top of the top.
av500
aroom wrote:


av500 this is fun! so if I understood correctly, you have three inputs (a b c) and 6 switches ?


correct smile
mskala
aroom wrote:
mskala brillant! the quantized input is a good idea. I just wonder if you could spare some HP and make it smaller ?


To coin a phrase, people's eyes are smaller than their fingers. I don't think making my design physically smaller would be a good idea, for a number of reasons, but it'll be open and others who want to attempt that can try.
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