Random* Source BOM's for various Builds - both 4U and Euro

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koshi
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Post by koshi » Mon Oct 24, 2016 6:43 pm

Guys would you know if BOM for ResEQ in 4U (CGS202) is the same as R*S in Euro?

Also, can't find mouser cart for '73 filter (CGS77) if you happen to have one please give me a shout.

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Post by GryphonP3 » Tue Oct 25, 2016 2:24 pm

Anyone have a proper BOM for the haible trapezoid VCA and string filter? The available BOMs and silkscreens on the PCB have quite a few differences.. I'' just inching through them following the silkscreens right now, so a tested bom for the current R*S pcbs would be great. Dont need a mouser cart or anything, just a list of the parts and amounts of each needed would make life easy.
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the bad producer
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Post by the bad producer » Tue Oct 25, 2016 4:45 pm

Are these the original PCBs?

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Post by GryphonP3 » Tue Oct 25, 2016 5:41 pm

the bad producer wrote:Are these the original PCBs?
Nope, I was referring to Ralf's PCBs. I think the Trapezoid is old stock though. Juergen never posted a BOM unfortunately. Dragonfly Alley guys posted a bom but it is very different from whats on the silkscreen.
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the bad producer
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Post by the bad producer » Wed Oct 26, 2016 4:02 am

Ah, didn't know they had re-released the String...

The OG build thread has notes on the Trap, that's where I got my info, no condensed BOM as such, but it's all there IIRC

http://electro-music.com/forum/topic-43206.html

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R*S Serge Resonant EQ/Wavemultipliers

Post by Vortex » Wed Dec 07, 2016 6:35 am

Hello everyone,

I am new to the forum, this is my first post

I am a Serge owner and looking to expand my system.

I'm want to buy the R*S Res EQ/Wavmult although I cannot find build doc on the R*S site or on here, and since it has the feedback pot, which is important to me, I need to know how to connect it up to the panel PCB and CGS PCB?

Can anyone help?

Thanks

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synchromesh
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Re: R*S Serge Resonant EQ/Wavemultipliers

Post by synchromesh » Sat Dec 10, 2016 6:36 am

There's the build document for the Euro version, but it doesn't really answer your question about the feedback.

The MW topic for the Euro version has some discussion of the feedback.

Ralf mentions in the announcement topic:
tobb wrote::eek: 'feedback', is this just the output connected to the input?
Kind of, there's an active mixer circuitry (using Burr-Brown OPA2134) on the component pcb, with the feedback knob you can dial in how much feedback you want.
So perhaps the feedback circuitry is contained entirely on the "component" (i.e. panel) PCB, with no direct connection to the CGS board.

But I guess your best bet is to message Ralf and ask him for the wiring diagram. :tu:

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Post by harolddonnelly » Tue Dec 27, 2016 11:44 pm

For the DSG build I noticed that you can use 50K or 100K Pots, can anyone speak to which one would work better?

http://randomsource.net/docs/RandomSour ... SG_mk2.pdf

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Post by johnnywoods » Sat Jan 07, 2017 4:00 pm

Here's a mouser cart for the Carnivore:

https://www.mouser.com/ProjectManager/P ... b2d51f3407

I use the classic blue bananas instead of white... this includes everything except power headers and pots/knobs.

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Post by johnnywoods » Sat Jan 07, 2017 6:02 pm

Here's a cart for the lpg/timbre section for Donks:

http://www.mouser.com/ProjectManager/Pr ... c450ed7dac

Doesn't include knobs/pots or the vactrols.

Might want to double check the trimmers and caps... I'm not so good at ordering those tbh :-/

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mrkva
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Post by mrkva » Tue Jan 10, 2017 6:03 am

Gotta say the BOMs are pretty terrible on these (at least the ones I went through so far). I am noticing a lot of mistakes and inconsistencies between the boards I received and the PDFs online.

For example now I am reading VCFS BOM (http://randomsource.net/docs/RandomSour ... e_VCFS.pdf) and cannot figure out how am I supposed to mount 2n3904 transistors, since there is no footprint for them on my PCB (v1.02). Numbering of bypass caps is completely different then in the BOM as well.

Carnivore BOM is missing any info about the noise transistor and has incorrect amount of trimmers listed (needs 5, but there are 4 100k in the BOM).

VCFQ BOM has 200R trimmer for V/Oct, but on PCB, I only found marking for 100R trimmer. I will follow the Eurorack version which has 200R trimmer, but...

RC hasn't been responsive on e-mail. I kinda have to say that I expected more (at least better prepared BOMs) for such pricey kits.

Edit: talking about 4U versions
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mrkva
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Post by mrkva » Tue Jan 10, 2017 10:10 am

Continuing... TGTSH BOM is missing to mention 470 ohm resistors, so watch out for that. There is inconsistency regarding the zener diode, where PCB (and half of BOM) asks for 5,1V, but description states 5,6V.
And ChaQuo has three extra 1n4148 in BOM, but nowhere to be found on PCB.
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Post by nordlead » Wed Jan 11, 2017 1:04 pm

If you find any errors in the BOMs, simply send me an Email (rather than PMs here or on FB or posting here) specifying exactly what is wrong. Usually I'm able to fix that within a few hours.

And please consider that this is DIY - I spend a lot of time preparing the build docs, usually more than 2 days for a pdf, however, errors and typos cannot always be avoided - I'll update the docs whenever suggested parts change or errors are spotted.

The same is of course true for the Haible pcbs - as Jürgen used to point out, do not merely rely on the BOM (being error free).
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clorax hurd
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Post by clorax hurd » Wed Jan 11, 2017 2:17 pm

nordlead wrote:And please consider that this is DIY
If it's DIY then the schematics should be included in the building docs.

You mention JH, but for those projects there are schematics available, so the builders can check the context of the parts in question.

But I wonder what exactly should people "do themselves" without schematic. Should they just guess? Or reverse-engineer the pcb into schematic to be able to think about the circuit and the correct value?

I believe that if kits are sold without schematic, then the BOM, silkscreen and documentation should be perfect.
Last edited by clorax hurd on Wed Jan 11, 2017 2:45 pm, edited 2 times in total.

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mrkva
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Post by mrkva » Wed Jan 11, 2017 2:20 pm

nordlead wrote:If you find any errors in the BOMs, simply send me an Email (rather than PMs here or on FB or posting here) specifying exactly what is wrong. Usually I'm able to fix that within a few hours.

And please consider that this is DIY - I spend a lot of time preparing the build docs, usually more than 2 days for a pdf, however, errors and typos cannot always be avoided - I'll update the docs whenever suggested parts change or errors are spotted.

The same is of course true for the Haible pcbs - as Jürgen used to point out, do not merely rely on the BOM (being error free).
Hello,
as mentioned in our e-mail conversation – I did contact you about the missing info by e-mail. Didn't get a reply, so I decided to try to source the information from the community.

I also sell DIY kits and I know how much time it can take to prepare a good documentation. I actually spend half a day just taking pictures for the step-by-step tutorial, then I give the kits to beta-testers to check for any possible errors and spelling errors. Granted, they are much simpler kits then yours. Here is an example: http://knowledge.lom.audio/guides/elektrosluchminicity

I think it might be helpful if you could provide the schematics – it would make the BOM "debugging" process simpler and it wouldn't force me to rely on BOM as you suggest. Because now I am not sure whether I should trust BOM or PCB layout.

Regards,
Jonas
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mrkva
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Post by mrkva » Wed Jan 11, 2017 3:06 pm

And I have to add, I am sincerely thankful for the work you're doing! The boards and panels are very well made.
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nordlead
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Post by nordlead » Wed Jan 11, 2017 4:31 pm

mrkva wrote: VCFS BOM (...) cannot figure out how am I supposed to mount 2n3904 transistors, since there is no footprint for them on my PCB (v1.02).
VCFS 1.02 is a new version with improved layout - I've just uploaded a new build doc for VCFS 1.02 (4U): No more (hand-matched) transistors, only BCM847DS. The BOM also now reflects a new reference build (with some slightly radical choices).
mrkva wrote:Carnivore BOM is missing any info about the noise transistor and has incorrect amount of trimmers listed (needs 5, but there are 4 100k in the BOM).
Thanks, fixed now: http://randomsource.net/docs/RandomSource_Serge_Carnivore.pdf
mrkva wrote:VCFQ BOM has 200R trimmer for V/Oct
BOM (200R) is correct - 100R was a printing error on the pcb.
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Post by nordlead » Wed Jan 11, 2017 4:43 pm

mrkva wrote:And I have to add, I am sincerely thankful for the work you're doing! The boards and panels are very well made.
Thanks! :guinness:

Oh, one more note re the VCFQ - a few days ago I've been testing another build and gained some insights:

For perfectionists: matching the 220p capacitors gives a nice edge in peak resonance. However, it will probably be hard to notice without a scope and a 1:1 comparison.

I never really cared about tracking, however, I was surprised to find that I could get the VCFQ to track over 5 octaves and a bit. Anyone tried this? Not sure if this related to any part choices ...

Will mention this in the next version of the doc, too ...
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Post by mrkva » Wed Jan 11, 2017 5:10 pm

Great, thanks for the updates. Can you please explain why you decided to omit the 15pF and 270pF in the VCFS? The reason I am asking is that I already soldered them in, according to the old BOM... :help:

Also, really looking forward to the NTO!
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Post by nordlead » Wed Jan 11, 2017 5:57 pm

mrkva wrote:Great, thanks for the updates. Can you please explain why you decided to omit the 15pF and 270pF in the VCFS? The reason I am asking is that I already soldered them in, according to the old BOM... :help:
This is a bit of an esoteric topic - the build was an experiment. In the small caps were used for compensation, i.e. to prevent the op-amp from self-oscillation. They do, however, slightly affect the sound - lowering the (very) high frequencies a bit. So leaving these out (and using a fancy modern op-amp like the ones specified) preserves the heights - whether you hear this (or only see on a scope of analyser) is a different story ... the 270pF (presumably - I didn't extensively check this) smoothens / slews the CV, so I guess this will be most noticeable when you use audio rate ("geometric") CV signals, e.g. like from a DSG mk2 ... the old setups (slow op-amps and caps) will not produce / handle sharp edges and corners, but will "soften" out. I like to keep the waveforms edgy and crisp and to soften them only when needed / intentional, which is why I experimented leaving these out (and liked the result). OPA2134 and 2227 seem to be able to handle this without extra compensation (which is surprising as they are way faster and tend to self-oscillate more easily than the old op-amps - however, a good PSU might be essential here, not sure if this is the case with a poor psi ...). So in the end it's a matter of taste (or obsessive-compulsive disease ;-)

Oh, and having the caps in means your version is basically like every single one built in the last few decades, so nothing to worry about ...
mrkva wrote: Also, really looking forward to the NTO!
pcbs are in production ... :party:
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Post by listentoaheartbeat » Thu Jan 12, 2017 4:53 am

nordlead wrote:I never really cared about tracking, however, I was surprised to find that I could get the VCFQ to track over 5 octaves and a bit. Anyone tried this? Not sure if this related to any part choices ...
I've always carefully calibrated my builds of the VCFQ (Euro version) and were able to get 4-5 octaves of proper tracking (+- 10 cent across octaves) with all of them.

BTW, another topic: I think it would be helpful to note in the VCFQ build docs that unwanted oscillations by the opamps may also cause resonance clipping due to reduced headroom (while being invisible themselves on a basic scope).

Just encountered this with a new build. I was getting a clipped sine wave in self-oscillation until I installed 82pF in the CS position marked in an early version of the build doc.

The results I was getting were completely different than any issues with oscillations I had before, it really just looked like a consistently clipped sine at any cutoff freq setting.

I wonder if this is the issue some of the people are facing that complain about not being able to get clean sine waves in self oscillation!

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Post by cygmu » Thu Jan 12, 2017 7:23 am

That is an interesting thought.

This demo of the VCFQ on a Creature panel

shows the filter oscillating at around the 8.00 mark. You can clearly see, and just about hear, that the wave is not a sine but clips at the top. As Yoris says in his description of the video: "Hard to get a pure sine out of it. You can control overloading the filter with the gain, but if you turn it to far down you lose self-oscillation in higher frequencies."

My build of the CGS board is much the same. It has to be worth trying the stabilising caps.

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Post by listentoaheartbeat » Thu Jan 12, 2017 9:26 am

cygmu wrote:That is an interesting thought.

This demo of the VCFQ on a Creature panel

shows the filter oscillating at around the 8.00 mark. You can clearly see, and just about hear, that the wave is not a sine but clips at the top. As Yoris says in his description of the video: "Hard to get a pure sine out of it. You can control overloading the filter with the gain, but if you turn it to far down you lose self-oscillation in higher frequencies."

My build of the CGS board is much the same. It has to be worth trying the stabilising caps.
Here's a sweep of the sine (BP > IN) that I get when I set VC Q fully CW and dial up GAIN to about 9 o'clock (just before the clipping kicks in):

https://dl.dropboxusercontent.com/u/423 ... _sweep.wav

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Post by cygmu » Thu Jan 12, 2017 3:17 pm

Very clean!

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Post by listentoaheartbeat » Thu Jan 12, 2017 6:31 pm

cygmu wrote:Very clean!
Indeed! There is a similar discussion in another thread, I've posted more results there (so I won't further derail this thread):

viewtopic.php?p=2438301#2438301

And as a little extra, here is a video of the VCFQ tracking quite well over four octaves:

http://dl.dropboxusercontent.com/u/4237 ... acking.mp4

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