Klangwerk modifications

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DGTom
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Klangwerk modifications

Post by DGTom » Fri Feb 05, 2010 2:14 am

Cat-A-Tonic wrote:
DGTom wrote:I really like my Klang Voice.... which is a bastardized, modded to all hell Klangwerk, I rewired its insides so it operates as seperate balanced modulator, VCO & wave shaper.
How about giving us the details about said mods and bastardizations in a new thread?
Pretty please; with sugar on...
As requested :D

First off; all the usual disclaimers apply, mod at your own risk, warrenty goes out the window etc. etc.

I'll add to that these mods shouldn't be performed if a) you already like the KW as is b) you don't have and/or aren't familiar with the schematic.

Before starting take the time to really study & understand the innards of the Klangwerk, there's lots going, a few expensive parts & you really want to be sure that once you start you know what you are doing. That being said, one of my main aims in performing these mods was that they were 100% reversiable, everything can be un-done & it doesn't require any major chnges to the PCB.

The main caveat; you lose the ability to have an AC coupled balanced modulator, we're going to remove that switch & re-use part of the cct. to do another job, so, if you need / want AC coupling in the KW, then these mods arn't for you. This wasn't a problem for me %80 of the time I use this module as a turbo charged VCA because I love the gain on the input & the Mix knob on the output.

So, lets look at the changes to the panel;

Image

As I said, the switch for AC / DC on the carrier is gone. In its place is the output for the internal Carrier VCO. By removing S1 we get access to the output of the internal Waveshaper @ S1-3, this gets its own output on the panel.

In order to get signal into the waveshaper 2 capacitors have to have one leg lifted, wired together & connected to a socket on the panel;

Image

Its not pretty, but, it does the job.

Image

This connetion is made as a track on the PCB, but we're using that for something else now.

Image

this pic shows the back of the S1 pads. The blue wire has a 1K resistor in line with S1-1, more of that later. The purple wire is connecting the track that usually feeds those 2 caps to S1-2, fast tracking the Ext. Carrier signal into the AD633, bypassing the wave shaper which now has access on the panel.

That blue wire is the output of section A of IC1, a basic inverting amp with 0 gain, I've used this to buffer the output of the 8038 function generator that is used for the Internal Carrier VCO.

You get access to this signal at a via underneth one of the trim pots;

Image

The via is tiny so I soldered a thin resistor leg in there & soldered the wire onto that.

Then R17 gets one leg lifted & the VCO goes into the op-amp;

Image

Again, not real pretty.

One thing I still need to do, I'm an idiot for not doing it to begin with, is tack an attenuator onto the waveshapers CV input.

Hope this is of use to anyone else who, like me, wished they could use each part of the KW for differant jobs. I really like the waveshaper, which is similar in some ways to the old Serge waveshaper, based around the LM3900. I also find it really usefull having another simple VCO, even tho its not that the best at low frequencies, great if I need a simple FM source or a percussive noise.

& here's a cheap & nasty demo of the 3 differant sections, one at a time then all together.

http://dl.dropbox.com/u/252415/Klangvoice.mp3

first 30secs is a tri from the Blacet VCO into the waveshaper, please excuse the silences / cable clicks, this was an afterthought I didn't have time to edit it down. Anyway, after 30secs is the Internal VCO, by itself, then CV'd by a Binary Zone. You can hear it shit itself when the CV goes to low; I'm a big fan of clicks & pops so this is no big deal for me, I think of it as a mid/hi VCO.

Then I switch to the Main out, external / internal carrier, using the waveshaper on either / or etc. etc. One thing that is really cool is the internal envelope follow can really freak the VCO out, its lots of fun to FM a VCO with the KW VCO, then feed the FM'd sound into the ring mod, using the waveshaper on an oscillator that is feeding the Folds CV on the CGS Wave Multiplier is good value as well :D

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Post by Cat-A-Tonic » Fri Feb 05, 2010 7:46 am

DGTom, Thank you for posting this with pictures and instructions. :hail:

I'll have a look through the schematic and see what I can suss.

It sure would be cool if it was possible to add the I/O for the wave shaper
and the output of the carrier VCO without having to sacrifice the AC functionality of the balanced modulator.

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Post by DGTom » Fri Feb 05, 2010 8:33 pm

No problems.

I guess I didn't mind getting rid of the AC/DC switch, I never like the way it worked, & I still can't for the life of me figure out if there is anything that differant an AC couple carrier would do :hmm:

I must be missing something, but when I tried a bunch of patches before doing the mods, it seemed to me the way I use it I wasn't going to lose much.

but, I think you'd could keep it if you just wanted the Waveshaper I/O, or, you added a little add-on board with an op-amp buffer for the VCO out. Seeing as how the 8038s cost about $20 a piece, I figure its worth protecting it a little :emt:

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Post by Cat-A-Tonic » Sun Jun 20, 2010 10:47 pm

Am I right in thinking that the output for the wave-shaper is connected to the S2-1/S3-2 pad?
This pad also appears to be connected directly to +15v.

I'm thinking about adding this output for the wave-shaped VCO and calling it done.
Would this require any additional buffering circuitry?

Please advise.

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Post by DGTom » Sun Jun 20, 2010 11:17 pm

Its S1-3.

S2 is a logic switch so to speak, it doesn't carry any audio, it just tells the NOR gate what to do which in turn controls the flow of signal thru the analog switch IC5.

Here;

Image

you can see the end of a wire sticking out from the solder in the top right hand side, above the silver cap, thats the wire on the other side of the board going to the green banana on the panel.

I think its fine to go straight from the LM3900 - or rather, its output cap, plenty of other modles do. I use that section alot & havn't noticed any wierdness.

However that signal is a little on the tame side, its by no means too low or noisy, but, next to the straight output of the Blacet VCO it needs a little extra gain. I generally use Channel D on the Quad Mix or the Klangs input, or you could add a gain cct. to turn it up a little.

One of my favourite KW patches is; Twin T drums -> Waveshaper & modulation inputs. Waveshaper out into Carrier input. Fantastic for making cheesy bongo / tom sounds sound like they have broken skins :sb:

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Post by Cat-A-Tonic » Mon Jun 21, 2010 11:37 am

I punched the panel, and wired it up tonight. :party:

It was dead easy thanks to you DGTom. :hail:

It works like a charm too.
Now my Klangwerk doubles as a VCO with VC wave-shape!
Both the oscillator and the wave-shaper still get modulated by the envelope follower on the signal input.
:banana: :goo: :banana:

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Post by DGTom » Mon Jun 21, 2010 8:31 pm

:yay:

That waveshaper is cool, getting at the KW guts really made it so much more usefull for me.
Cat-A-Tonic wrote:Both the oscillator and the wave-shaper still get modulated by the envelope follower on the signal input.
That is one of my favourite things :sb:
you can get some awesome feedback loops going.

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Post by Cat-A-Tonic » Tue Jul 27, 2010 9:38 am

I don't know why i didn't try this sooner,
but sending your audio into the External Carrier Input
allows you to send it through the VC wave-shaper
and out through the (added) Carrier Output.
This disables the internal VCO of course.

This is such an easy mod, and yields so much :sb: .

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Post by cerebrosis » Fri Nov 04, 2011 5:20 pm

Just did this and Im very pleased. You can have the osc running and at the same time use the rest of the klang as a vca, wow.

Thanks guys

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Post by Cat-A-Tonic » Fri Nov 04, 2011 9:25 pm

I'm thinking there is one more space on my panel that I could put a jack in,
and it would be awesome to bring the internal Envelope Follower to an output.

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Post by cerebrosis » Sat Nov 05, 2011 10:56 am

Yeah that would be great. :tu:

Man this module is very powerful.

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Post by Cat-A-Tonic » Tue Nov 08, 2011 8:52 pm

Just to make sure I'm reading the schematic correctly, I'd like to ask a second opinion.

For the Envelope Follower output...

Am I right in thinking that pin 9 of IC8 (3900) is the best location to tap the full envelope output?

and that the junction of R23 (100k) and pin 14 of IC2 (324) is the best place to tap the attenuverted envelope output (from the Freq. section)?

I assume it would be wise to add a 100 ohm resistor to any additional output in order to protect ICs from accidentally connecting 2 outputs together.

(edited for typo: wrong IC #s)
Last edited by Cat-A-Tonic on Tue Nov 08, 2011 10:38 pm, edited 2 times in total.

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Post by DGTom » Tue Nov 08, 2011 9:09 pm

:tu:

Maybe, remove R20 / lift it where it connects to pin #14 of IC2 & use a switching jack, so, no output plug hooked up & you have bizness as usual, but once you jack in to get the processed EF CV it removes it from the VCO control path.

Edit;

Pin #9 of IC8 (LM3900)

Pin #14 of IC2 (LM324)

junction of R23 / R20


adding a 100R - 1K to your new output.

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Post by Cat-A-Tonic » Fri Nov 11, 2011 9:57 am

I just wanted to report that the Envelope Follower output mod is a total success!

I went ahead and used DGTom's idea of the switching jack to remove the envelope from the VCO Frequency CV mix when a plug is inserted.

I cut the trace between R23 and R20.
Junction of R23 & pin 14 of IC2 goes through a 100 ohm resistor on its way to tip of new Env.Follower jack.
R20 goes to switch of new jack.
New jack gets connected to ground.

I took the opportunity to recalibrate the Frequency range too.

Processing external signals through the Klangwerk's wavefolder sounds awesome by the way.
I ought to do a demo...

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Post by Cat-A-Tonic » Fri Dec 02, 2011 9:27 am

Here is a demo of the Klangwerk being used as a VC wave-shaper
processing a Blacet VCO (saw) through the Carrier input,
and out the modified Carrier output.
A Micro LFO (sine) controls the wave-shape morphing.
same VCO (triangle) modulates the LFO rate.
Waveshape intensity switch changes 3, 2, 1.

Then...
Improbability Drive Quantized (minor) modulates the VCO frequency.
Waveshape intensity switch changes 3, 2, 1.
Attachments
Klangwerk Waveshaper Demo
Klangwerk Waveshaper.mp3
(1.68 MiB) Downloaded 18 times

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klang demo pics

Post by Cat-A-Tonic » Fri Dec 02, 2011 9:44 am

...and pictures of the patch described above.
Image
Image

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Re: Klangwerk modifications

Post by diophantine » Sat Apr 11, 2020 4:59 pm

A lot of pics are now missing (and obviously this thread is now 8 years old)... but thinking of modifying one (or both) of my Klangwerk modules.

Seems the most popular mod (and the one that seems most interesting to me) is adding an output jack for the carrier wave output - pin 7 of IC1 (probably via a 100R resistor).

I'm not sure if I understand the mod involving removing the AC/DC switch - is it just to be able to have a separate external input to the waveshaper section?

And with the envelope follower... are people tapping that (at IC8 pin 9) as an output, or just setting it up to use an external envelope (via a switched jack)? How useful do people find the envelope follower mods? For supplying an external envelope, seems you could just use a Mixer/Processor to mix/attenuvert two signals into the CV jack. So I assume the goal is just to get an extra attenuverter?

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Re: Klangwerk modifications

Post by Cat-A-Tonic » Mon Apr 13, 2020 9:44 pm

diophantine wrote:
Sat Apr 11, 2020 4:59 pm
with the envelope follower... are people tapping that (at IC8 pin 9) as an output,
or just setting it up to use an external envelope (via a switched jack)?
How useful do people find the envelope follower mods?
For supplying an external envelope, seems you could just use a Mixer/Processor to mix/attenuvert two signals into the CV jack.
So I assume the goal is just to get an extra attenuverter?
These mods allow access to the outputs of
the internal envelope follower,
and the internal VCO.
Both are incredibly useful,
and with space on the panel for those two patchpoints
there isn't much reason not to.

EnvF. jack is connected to junction of R23 where it meets IC2 (yellow wire).
This jack is normalled to R20 (red wire).
There's a trace to cut too.

The VCO out is from S1-3 (orange wire).

I pulled it out to take a pic for Frac community service.
Image
Attachments
IMG_E9932.JPG

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Re: Klangwerk modifications

Post by diophantine » Mon Apr 20, 2020 7:44 pm

Cat-A-Tonic wrote:
Mon Apr 13, 2020 9:44 pm
EnvF. jack is connected to junction of R23 where it meets IC2 (yellow wire).
This jack is normalled to R20 (red wire).
There's a trace to cut too.
Thanks for this, and sorry for my delay!

Yes, I guess S1-C is the best place to tap the internal carrier, otherwise you get the inverted Ext. Carrier when the switch is in DC. Too bad it isn't buffered at S1-C.

It seems, though, that the Env.F jack is an input jack, not an output jack, correct? If it going through a normalled jack, it is to allow replacing the signal for purposes of adjusting the frequency, correct?

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Re: Klangwerk modifications

Post by Cat-A-Tonic » Mon Apr 20, 2020 8:04 pm

diophantine wrote:
Mon Apr 20, 2020 7:44 pm
It seems, though, that the Env.F jack is an input jack, not an output jack, correct?
If it going through a normalled jack, it is to allow replacing the signal for purposes of adjusting the frequency, correct?
No, the Envelope Follower jack is an Output
which is scaled and offset by the attenuverter that would normally control carrier VCO frequency.
The Envelope Follower tracks the signal at the primary input.

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Re: Klangwerk modifications

Post by diophantine » Mon Apr 20, 2020 10:23 pm

Cat-A-Tonic wrote:
Mon Apr 20, 2020 8:04 pm
diophantine wrote:
Mon Apr 20, 2020 7:44 pm
It seems, though, that the Env.F jack is an input jack, not an output jack, correct?
If it going through a normalled jack, it is to allow replacing the signal for purposes of adjusting the frequency, correct?
No, the Envelope Follower jack is an Output
which is scaled and offset by the attenuverter that would normally control carrier VCO frequency.
The Envelope Follower tracks the signal at the primary input.
So, what is the purpose of the normalled Jack and cut trace? That doesn't make sense for an output.

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