Recommendations for a complete DIY rack

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Pr0fBi0
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Re: Recommendations for a complete DIY rack

Post by Pr0fBi0 » Tue Jun 01, 2021 4:13 am

yay! with a combination of removing and re-soldering parts, and using some isopropul alcohol to clean off excess flux (i didn't add extra, but from all the re-soldering it was building up) I was able to get my quad vca functioning on all channels. That's when i realized that the release on my ADSR envelope was acting like it was on full all the time no matter what the knob was set to. tore that apart and re-flowed all the solder joints and now it works perfectly.

I also added a Erica synths midi to cv module the other day and thought I broke something, but it turns out the midi keyboard I was using was outputting on chnl 11 which was why the modules midi light lit up but the gate light wasn't working. after reflowing everything twice I finally decided to hook up my circuit to the midi in and it worked first try. just shows you....make sure your are using the proper test parameters before you assume something is broken.

parts for my vco should be here tomorrow, then I can try tuning that and setting the trims on my filter, which seem to be way off now.

anyone got any tips for the cables to connect guitar pedals. should i just buy some cheap 4 foot guitar cables, cut off one end on each and wire on 1/8th inch plug so I can have cables to run out to my pedals and back in using the AI stomp box adapter?

got a turing machine, lfo, and an output module on order. probably going to sit on all that for a month before i decide to add some mutable stuff

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Re: Recommendations for a complete DIY rack

Post by EATyourGUITAR » Tue Jun 01, 2021 10:04 am

Big thumbs UP on your learning experience. Out of all the posts to the DIY section these are the ones that make my day. You are learning to solve problems. You are building the equipment you want to make music. Someday you will be designing modules from scratch.

To convert the 1/4 to 1/8 the best way is a format jumbler. That is a blank panel drilled for jacks. The strain on a 1/4 cable will destroy the 1/8 jack unless you are extremely careful. This is why format jumblers are the way. Synsi or doepfer sell metal panels you can drill. You can also cut scrap steel from old appliances if you want it %100 free. All you do is connect all the sleeves together. Connect a 1/4 tip to a 1/8 tip. Super easy build. You can also DIY a dual attenuators on a blank panel if you don't already have one. If you need to bring the signal level up from guitar pedals going into eurorack you can DIY a gain stage with a volume knob from a single opamp on strip board. this is good practice to design your own stripboard layout from schematic. Use a TL072 or TL082. You could even use TL071. The eurorack header is 0.1 inch pin spacing so it will drop in directly to a stripboard layout. Add 10uf caps and 47R resistors as fuses and RC filter. A fixed gain amp would be a 22K input resistor with 100K in the feedback loop of an inverting opamp. The output resistor is 1K. Super simple DIY for $4 total in parts.
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Re: Recommendations for a complete DIY rack

Post by Ayab » Tue Jun 01, 2021 10:33 am

I have to say that KSS gave some golden advice about utility mixers and patch cables. Maybe the mixers he described seem a bit complicated but I would cut and paste KSS's post at least for later reference. He knows his stuff. I agree that sub-mixers are key to really interesting patches. Utility modules seem less exciting than sound making modules at first but mixers are really important. As are mults or stackables.

Lots of great advice here but the mixers thing just resonates with my experience of modular. It is also (usually!) really easy to build small useful circuits. Electro-Music is another great forum with lots of circuits to look at.

KSS's mixer with switched CV or Audio channels by a dual pole switch - one pole to switch the CV capacitor another pole to switch a resistor on the pot for lin/log response. Combined with the up/down mixer switching - very useful. Genius!

As KSS suggests with utility patch cables you can build some very useful things from simple circuits and this can free up using other modules. I think you could do with a White noise circuit - an easy diy self build is a simple transistor noise circuit. If you are a guitarist you may want to try to trigger the synth with an Envelope Follower circuit (lots of diy versions available). I would also recommend a glide/slew

If you want to use your modular as more a playable expressive synth (and from midi) then someone mentioned delayed vibrato LFO is a must (MFOS do one too). This will sow the mind seeds in your mind for the same general principles for controlling all the possibilities of your modular from CV and Gate! Wavefolding, ring modulation (maybe your pedals do this), exciting filter types and combinations (via mixers).

A Rampage or similar type module like DUSG. This is diy version of the popular "maths" module - very flexible module for Glide Envelopes, LFO, Oscillator, Comparator, trigger delay and more.

I am beginning to find the more generative aspect sequencers, digital and analog logic, CV feedback (KSS's mixers would be great for this sort of stuff), switching, chaos.

What you are doing so far seems like a better choice to me than a Moog Mother as it will ultimately be much more flexible and you can try unusual configurations. Check out the collection of patches in the "Book of Unusual Things" (not sure if that is the right name, sorry) which is a collection of patches from the Wiggler forum.

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Re: Recommendations for a complete DIY rack

Post by Pr0fBi0 » Tue Jun 01, 2021 12:03 pm

EATyourGUITAR wrote:
Tue Jun 01, 2021 10:04 am
To convert the 1/4 to 1/8 the best way is a format jumbler. That is a blank panel drilled for jacks.
I may modify this idea and use a spare pedal enclosure and get a few long 1/8 patch cables. Already trying to think about saving hp...
Ayab wrote:
Tue Jun 01, 2021 10:33 am
I have to say that KSS gave some golden advice about utility mixers and patch cables. Maybe the mixers he described seem a bit complicated but I would cut and paste KSS's post at least for later reference. He knows his stuff.
Yeah I've already re-read his post like 5 times. I got like 3 sentences in the first time and my eyes glazed over. Too many things I didn't understand all at once. I'm starting to get what the mixer he described is doing, but I'm finding I'm really having to watch YouTube videos on modules to start understanding what things do what.
If you are a guitarist you may want to try to trigger the synth with an Envelope Follower circuit (lots of diy versions available).
Great idea, I wouldn't have thought about using something like that.
I would also recommend a glide/slew
I'm still trying to wrap my head around slew.

If you want to use your modular as more a playable expressive synth (and from midi) then someone mentioned delayed vibrato LFO is a must (MFOS do one too).
Could this be patched by running an envelope with a slow attack into the speed of an lfo. Maybe that wouldn't work if you couldn't control the Lin/log of the attack.
A Rampage or similar type module like DUSG. This is diy version of the popular "maths" module
I just saw a video on the rampage today. I'm starting to think about these kind of utility modules as an effect pedal for your signal or cv path. Right now I'm severely lacking these things as I only have one envelope and no LFO. I do find myself using envelopes as modulators in soft synths more than LFOs. so anything to get more envelopes is up my alley.
What you are doing so far seems like a better choice to me than a Moog Mother as it will ultimately be much more flexible and you can try unusual configurations. Check out the collection of patches in the "Book of Unusual Things" (not sure if that is the right name, sorry) which is a collection of patches from the Wiggler forum.

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Re: Recommendations for a complete DIY rack

Post by KSS » Tue Jun 01, 2021 6:37 pm

Pr0fBi0 wrote:
Tue Jun 01, 2021 12:03 pm
I'm still trying to wrap my head around slew.
Slews are like bar hoppng on a Friday or Saturday night.
Most analog slews are based on what electronics calls R/C. A resistor feeding into a capacitor and going beyond it to somewhere else in the patch.

People are the signal. The Bars are the 'capacitors' and traffic is the resistor on the way to the bar.

Early in the evening the bars are mostly empty and work just hit quitting time so traffic is heavy. But you and your buddies get past the traffic and find a mostly empty bar. So you go in and sit down. You and your buddies aka signal has been diverted into the bar aka capacitor, and begin filling it up. A few people are leaving and they're the small signal coming out of the slew at first. As more people get tothe bar and come in, it's becoming crowded. Some people look in at the door and say no way, lets go on to the next bar. The capacitor is filling and less input signal is being diverted. So the slew output is getting higher as the evening goes on. Traffic is less too as the commuters are gone now and the mid evening roads are mostly clear.

In the actual slew there's a single 'bar'-capacitor and a single resistor. The resistor is usually variable aka a knob that you can set. Which means you control how the traffic flows. Aka how fast the people get to the bar for their evening drink. Traffic is going into and out of the bars in the city on a weekend night. The bars decide how many get in before they say we've reached capacity, and no one else can come in until someone else leaves. Which means the people -traffic- moving from bar to bar -the signal- is now full strength at the output too. It just took the time for the bars to fill up for it to reach this point.

That's a slew. The output follows the input but is delayed for a few drinks by a capacitor diverting the signal to charge it up. Once its charged up the output matches the input. While it's charging up the output is less than the input. Betcha didn't know the signals in your synth were doing a bar crawl through your circuits!!
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Re: Recommendations for a complete DIY rack

Post by ricko » Tue Jun 01, 2021 9:56 pm

Pr0fBi0 wrote:
Tue Jun 01, 2021 4:13 am
yay! with a combination of removing and re-soldering parts, and using some isopropul alcohol to clean off excess flux (i didn't add extra, but from all the re-soldering it was building up) I was able to get my quad vca functioning on all channels. That's when i realized that the release on my ADSR envelope was acting like it was on full all the time no matter what the knob was set to. tore that apart and re-flowed all the solder joints and now it works perfectly.
You know what may be really useful to do?

Make it part of your routine to look at all your solder joins through a loupe, as a pre-power-up inspection. Any join that looks blobby or grotesque (hot solder hitting cold metal) or missing or enclosing a blob of rosin or flux or whatever, or sitting on top of a thick puddle, or with a whisker shorting to a neighbour, I reheat. And, unless it is a small board, I inspect it a second time to confirm the reheats work and catch things I missed first.

(The worst is "dry joints" where the solder has not attached but may sit in contact: the board can work in one position, but then move it and the flexing of the board disconnects the solder: very hard to disgnose when symptoms come and go.)

Since I started this close inspection, with a cheap plastic monocle loupe in one eye, not only do I get far fewer strange functional bugs, but my soldering has improved.

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Re: Recommendations for a complete DIY rack

Post by Rex Coil 7 » Tue Jun 01, 2021 10:43 pm

ricko wrote:
Tue Jun 01, 2021 9:56 pm
...You know what may be really useful to do?

Make it part of your routine to look at all your solder joins through a loupe, as a pre-power-up inspection. ..... Since I started this close inspection, with a cheap plastic monocle loupe in one eye, not only do I get far fewer strange functional bugs, but my soldering has improved.
... this is good workmanship, plain and simple. I use a #10 loupe .. it's saved me from plenty of headaches ... :tu:
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Re: Recommendations for a complete DIY rack

Post by Pr0fBi0 » Tue Jun 01, 2021 11:47 pm

Omg...just set up a "basic patch" and used all 15 patch cables I've bought so far.....



Monologue is clock and sequencer, sine and square out of Bermuda into vca. Volca sample synced to monologue and output is going into the mixer at the end and Ableton is providing reverb and echo.

I need to get some cables to connect my pedals and also get more patch cables...and the trims on my filter are way off. Going to have to toy with those

Also I have a serious lack of modulation sources. Really just one envelope. going to address that next, then maybe another voice.

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Re: Recommendations for a complete DIY rack

Post by Pr0fBi0 » Wed Jun 02, 2021 12:01 am

KSS wrote:
Tue Jun 01, 2021 6:37 pm
Pr0fBi0 wrote:
Tue Jun 01, 2021 12:03 pm
I'm still trying to wrap my head around slew.
Slews are like bar hoppng on a Friday or Saturday night.
Most analog slews are based on what electronics calls R/C. A resistor feeding into a capacitor and going beyond it to somewhere else in the patch.

People are the signal. The Bars are the 'capacitors' and traffic is the resistor on the way to the bar.

Early in the evening the bars are mostly empty and work just hit quitting time so traffic is heavy. But you and your buddies get past the traffic and find a mostly empty bar. So you go in and sit down. You and your buddies aka signal has been diverted into the bar aka capacitor, and begin filling it up. A few people are leaving and they're the small signal coming out of the slew at first. As more people get tothe bar and come in, it's becoming crowded. Some people look in at the door and say no way, lets go on to the next bar. The capacitor is filling and less input signal is being diverted. So the slew output is getting higher as the evening goes on. Traffic is less too as the commuters are gone now and the mid evening roads are mostly clear.

In the actual slew there's a single 'bar'-capacitor and a single resistor. The resistor is usually variable aka a knob that you can set. Which means you control how the traffic flows. Aka how fast the people get to the bar for their evening drink. Traffic is going into and out of the bars in the city on a weekend night. The bars decide how many get in before they say we've reached capacity, and no one else can come in until someone else leaves. Which means the people -traffic- moving from bar to bar -the signal- is now full strength at the output too. It just took the time for the bars to fill up for it to reach this point.

That's a slew. The output follows the input but is delayed for a few drinks by a capacitor diverting the signal to charge it up. Once its charged up the output matches the input. While it's charging up the output is less than the input. Betcha didn't know the signals in your synth were doing a bar crawl through your circuits!!
That is the most complex and in depth analogy anyone has used to describe something for me. So I get the concept, what is a typical use case?

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Re: Recommendations for a complete DIY rack

Post by KSS » Wed Jun 02, 2021 12:56 am

The two most visible uses of slews across synths is portamento or glide and envelope generators. But they can also be used as filters. Using the bar crawl again, the drinkers are filtered from the non-drinkers who just want to run around the town from place to place.

When used with a comparator slews can become oscillators and timers. Feed 10 volts to a slew, send its output to a comparator set to 5V and use the comparator with one of the vtrig to Strig patchcords to make a ramp oscillator 10 people walk single file into the bar. The comparator is the bouncer. He lets 9 in but with the tenth he says everybody has to leave. The Strig took the 10V to GND aka 0V when the comparator read 10V at the slews output.
Since the slews no longer at 10V, the comparator shuts off and the bouncer starts letting people into the bar again,

As a timer, the bouncer tells his buddy to do something when he lets the tenth person into the bar. His 'buddy' is whatever else in your patch is waiting on some time to pass. Because everybody can't get through the door at once. And the bouncer has to check their ID, which takes little time for each one.

If you read the Makenoise MATHS module manual, you'll see plenty of other examples. MATHS is a couple slews, some comparators and some mixers.

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Re: Recommendations for a complete DIY rack

Post by Ayab » Wed Jun 02, 2021 9:59 am

Anyone who uses a bar analogy for a slew explanation gets a high score. That was quite lengthy explanation - bit vicarious? :hihi: KSS you need to go out for a drink man! :guinness:

Eatyrguitar I must make a format jumbler like that also a great idea.

OP for more cables you can buy a bunch of shielded cable and bare mono jacks. Get some clear heatshrink too so that they can be toughened and also the utility patch cords you make as KSS advises can have a label heatshrunk to them.

Delayed modulation patch is: LFO is fed to input of VCA and AR generator connected to VCA's control input. When gate is applied to the circuit the AR is gated on and the VCA responds to the applied envelope and the LFO comes through the VCA. The delayed modulation output would normally modulate pitch.

This is the collection of Muff' Wiggler patches etc.. The book of bad ideas, I referred to (wrongly) before. Link: http://bit.ly/1oz2zaI

I think your system could do with a sample and hold too - for completeness. I love sample and hold but these have serious voltage droop so more for effects than for pitch critical situations.

My favourite portamento is the Glide in the TB303 which is meant to be a single pole LPF not a slew circuit - this is something I have yet to experiment with.

The attached circuits pdf are really simple to build and would cover you for some classic modules I reckon you could do with. Happy to answer questions.
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Some Simple circuits.pdf
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Last edited by Ayab on Fri Jun 04, 2021 9:01 pm, edited 1 time in total.

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Re: Recommendations for a complete DIY rack

Post by EATyourGUITAR » Wed Jun 02, 2021 11:54 am

A square wave into a slew gives you something like a sine. Basically what a filter does. Slew is usually for LFO signals and there is not always voltage control. There are two types of slew. One of them is a linear integrator. The other is an RC low pass filter. A linear integrator will convert a square wave LFO to a triangle. That is the difference.
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Re: Recommendations for a complete DIY rack

Post by devinw1 » Wed Jun 02, 2021 1:05 pm

All these bar analogies, but I haven't been to a bar in over a year due to COVID! 6 packs in the fridge is all I got!


actually that's almost true. This Saturday i went to a restaurant/bar for the first time since March 2020. It was still weird though, masks needed inside and nobody inside except ordering, etc.. Getting there. :guinness:

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Re: Recommendations for a complete DIY rack

Post by abelovesfun » Wed Jun 02, 2021 1:20 pm

Once I get the demo video for the 09 made I can show you lots of uses for Slew :) Should be 1-2 weeks.
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Re: Recommendations for a complete DIY rack

Post by Ayab » Wed Jun 02, 2021 2:26 pm

One more thing: To get a big fat Moog modularish sound I would recommend a CP15 mixer clone in addition to a Moog VCF - maybe even a moog 902 VCA clone too. The fat moog sound we know and love is very much to do with the overdrive associated with these solid state (transistor) modules.

Have also only been to the pub a couple of times in a long time. I still feel like being outside only. Have always thought it is lovely doing the al fresco thing especially in the summer. Great to see people out and about again. There is a good vibe.

But the Indian variant is on the rise. There is now the Vietnamese variant that is even worse!! :sstorm:

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Re: Recommendations for a complete DIY rack

Post by KSS » Wed Jun 02, 2021 4:12 pm

Yes, I probably *do* need a drink after this year and a half of lockdown to various levels!

And I agree that a CP3 mixer is both an easy and worthwhile build. I suggest Rene Schmitz's YASH for the S/H. I noticed a few of the circuits in your PDF could be made with the diode patchcords I described. <--They're really useful!

Outside in Summer you say?
That wold be the site for the corporate team building exercise mgmt called resistance. Where they had the employees all running across open fields, dense forests, mud and even single file, crawling on hands and knees through small cloth tunnels. At the end of the day, everyone innately understood the concept of resistance both series and parallel.

As for why they were on the bar crawl slew in the first place?

They'd been in a meeting all day called capacitance. I wrote this for someone wanting to understand what they were seeing on their meter when they probed a capacitor .These explanations may be long but they're seldom forgotten.
KSS wrote: When you place the probes on a capacitor here's what happens.

Imagine a conference hall with tables and chairs set up on two opposing walls which have the only doors to the outside world. There's a few hundred people milling about in the middle and all over the room having fun interaction and casual conversations. They've all come to this conference room to sort the details of a worker-management contract. The people know each other and business decorum means they really aren't supposed to fraternize. But the boss is away, and without his influence, they mill about and enjoy each others company.

^This scenario depicts an uncharged capacitor. The people are electrons aka workers and 'holes aka Mgmt ;)

Then the boss walks in. <--You put your meter probes on the capacitor, and its battery puts electrical force into the room at the doors behind the two parallel rows of tables at the sides of the room with the doors.

Instantly -as instantly as a few hundred people can move- the workers and mgmt people try to get to their seats! They don't want to be seen breaking the no fraternizing rule by the boss! They run into each other and the room clears as they get to their respective seats in the parallel tables.

The capacitor is now charged. <--Just as you'd expect in a room full of mgmt and workers on opposite sides of a employee contract..

If we go back to when they were milling about before the boss got there, you can imagine that there was pretty much a solid path of humanity along some crazy line from person to person all the way across the room. If you asked them too pass a bucket of water from one side of the room the other, it could easily be done.

But now with the boss -Named Mr. voltage- in the room, they are facing each other far apart sitting at their parallel tables. No water is going to be passed from one side of the room to the other in this situation!

All the energy that we saw when they were milling around is still present in the room. But the presence of Boss voltage has turned it from kinetic to potential.

A capacitor is literally two two plates of metal, separated by a distance. Old radios used metal vanes in air. The red and tan disc caps on your modules have a thin separator between the two discs. Each disc is attached to one lead. If you look at the photos you took you can see the wire lead like a leg under covers of a bed sheet and blanket.

There are other constructions of capacitors too. Most common besides the discs are thin sheets of metal on either side of a plastic film. The film is then rolled into a pastry roll and a wire is attached to each plate on either side. There are the many right cylinder types you see on your PCBs. Like the 1023's big white ones.

The third capacitor on your PCBs is called a tantalum type. You actually have 2 different styles of these from 4 different companies but we'll get to that distinction later. The tantalum type takes advantage of increased surface area of the two plates by plating all the interior surfaces of a spongy tantalum pellet. It's like a volcanic rock with zillions of holes which increase the surface area/size ratio for greater density. Tantalums are small and very efficient compared to other capacitor types.

But lets get back to the conference room. When yout first touch your meter to an uncharged cap, the electrons and 'holes are milling about between its plates and you get a low resistance reading. But because your meter uses a battery, when you attach it Mr. Voltage sends everyone scurrying to their side of the room. As their density in between the 'tables' aka plates of the cap decreases, the resistance reading goes up. As the area between the plates is emptied, no electrons or 'holes can flow, and your meter gives its over-range reading of "1". Aka more resistance than I can measure at this range.

The last part of the analogy is this. Imagine the exact same scenario in rooms of different size which can hold fewer people or rooms so large they can hold thousands to millions and more people. That's the difference in capacitor value. Small room holding fewer 'people' will get to their tables when the boss walks in quicker than thousands or millions would take to get to theirs in a larger room.

Electrons and holes jump over each other into each others emptied spaces like black and red checkers. <--In the classic model of atomic structure which is now seen to be different in ways we don't need to be concerned about for this project. Electrons carry electrical current, and holes exchange with them due to electrical pressure which we call voltage. The is why Ohms law is E=I*R E stands for Electromotive force. Now called Voltage.

I'll share a super easy way to remember Ohms law -in all its various expressions- when I get back.

For now, when you touch the probes -to an uncharged capacitor- you can imagine workers and mgmt rushing to their seats. And you won't be far off what's actually happening at the atomic level.

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Re: Recommendations for a complete DIY rack

Post by Pr0fBi0 » Wed Jun 02, 2021 11:19 pm

KSS wrote:
Wed Jun 02, 2021 12:56 am
If you read the Makenoise MATHS module manual, you'll see plenty of other examples. MATHS is a couple slews, some comparators and some mixers.
i might have to check out that manual. Everyone keeps saying you have to have maths. which almost sounds like a challenge to me.
Ayab wrote:
Wed Jun 02, 2021 9:59 am
OP for more cables you can buy a bunch of shielded cable and bare mono jacks. Get some clear heatshrink too so that they can be toughened and also the utility patch cords you make as KSS advises can have a label heatshrunk to them.
great idea. I should have done that already. any idea of what gauge shielded wire to get. This would also let me make some cables that are 1/8 on one side and 1/4 on the other to plug in guitar pedals.

on a funny side note, making xlr and instrument cables in high school for my jazz choir group was why I always hated soldering. it wasn't till i got a better soldering iron and soldered small things that i started to actually enjoy it.
I think your system could do with a sample and hold too
yup. a sample and hold is on my ever growing list of things to add.
abelovesfun wrote:
Wed Jun 02, 2021 1:20 pm
Once I get the demo video for the 09 made I can show you lots of uses for Slew :) Should be 1-2 weeks.
Awesome! I'll keep an eye out for it

I finally got out to a bar/restaurant this weekend. first time since getting my shots. was nice. things almost seemed back to normal for a bit.

I've been running into other problems as well. bought a few PCB and panel sets and i'm having trouble finding chips. and diods. especially surface mount stuff. I know we are probably going to have shortages for a while so i may have to hold off on any mutable stuff for a while. What do you guys do to find substitutes for parts you can't find? I bought the transistor ladder filter PCB that was linked earlier here and i was able to buy all the components except the two transistors.

MMBT3906-7-F
MMBT3904-7-F

are there any tricks to finding substitutes? I learned from building a tubescreamer clone that a jrc4558 could be replaced with a jrc4558d or jrc4558p. does this also apply to the world of synth modules?

I did some searches using digikey's find similar tool and found these

SST3906T116
SST3904T116

those seem to be in stock most places. does that seem like an appropriate substitute?

I'm also guessing chip shortage is why the music thing modular radio music and startup are out of stock everywhere.

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Re: Recommendations for a complete DIY rack

Post by KSS » Thu Jun 03, 2021 12:31 am

octopart.com

alltransistors.com

The trick to making patchcords is to fix your soldering iron in place above your workbench and bring the solder and plug *to* it, rather than the other way 'round. This is how it's done in factories where full automation isn't in place.

Buy long commercial cords, cut them in two and you only have wire one side of 1/4 -3.5 adapter style cables.

Edit: As for MATHS, you may or may not need it. But you do need to will greatly benefit from understand why its such a popular choice. There's no virtue in avoiding things just because other people like them. Just as there's no virtue in choosing something just because other people like it.
Making your own choice is different from avoiding becoming informed. :guinness:
Treat utility modules as stars instead of backup singers.
Treat power supplies like Rockstars instead of roadies!
Chase magic sound, not magic parts.

Pr0fBi0
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Re: Recommendations for a complete DIY rack

Post by Pr0fBi0 » Thu Jun 03, 2021 1:11 am

KSS wrote:
Thu Jun 03, 2021 12:31 am
Edit: As for MATHS, you may or may not need it. But you do need to will greatly benefit from understand why its such a popular choice. There's no virtue in avoiding things just because other people like them. Just as there's no virtue in choosing something just because other people like it.
Making your own choice is different from avoiding becoming informed. :guinness:
oh I don't plan on not being informed. I just like to use things like "you have to have this thing" as a mental exercise to see how one could get by with similar results without it. I think i'm sold on Befaco rampage. as it seems like it does most of what maths does but and can stick to my DIY theme.

The more i look around the more i start to see that the modules that are really popular are the ones that can do multiple things. A lot of the mutable modules fall into this as does maths. I guess that way you don't can mold them to your needs instead of being stuck with only one use and that use not being what you need for a given patch.

i'm also toying with the idea of doing a simple a>b switch 2hp module. just 1 in, 2 out and a switch to control which output. but it could also work as a 2 in one out where your switching the input as well. even i could figure out the wiring for that :razz:

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Jumbuktu
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Re: Recommendations for a complete DIY rack

Post by Jumbuktu » Thu Jun 03, 2021 2:13 am

No particular insights, but these are most of the modules I have built, some from kits, some from PCB / panel bundles:

- Turing machine and expanders (x2) - Thonk kits are super easy to build and the trigger expander is a small and simple SMD to get started on
- Thomas dual LPG: from Synthcube I think? A very old kit with wiring required to the front panel
- Humpback filter - another Thonk kit
- Aperture LPG / filter - Thonk
- Manhattan SVVCF filter - from PCB and panel, own sourced components
- NLC Sloth x2 - PCB and panel - NLC modules are generally great to build, use easily-sourced components
- NLC Timber - PCB and panel
- Ornament & Crime - a fairly difficult SMD build
- Radio Music x2 - Thonk, pretty easy build
- Chord Organ - Thonk, same as Radio Music, different firmware
- VPMDE - Euclidean Circles - a very difficult and tedious SMD build
- Patching Panda Punch - small but challenging SMD build
- Befaco Percall - great module, as are all the Befaco kits. Through-hole kit, but packed into a small space. Important to follow the build guide.
- Befaco VC ADSR x2
- Bastl Noise Squared - simple through-hole kit
- L-1 VC mixer - PCBs and panel, SMD components pre-soldered. Beautiful thick PCBs, well-designed module, super-quiet audio.
- Shakmat Time Wizard - Thonk Kit
- Shakmat Bishop's Miscellany - Thonk kit
- DannySound Cali VCO - Thonk kit
- DannySound Through-zero VCO - Thonk
- Feedback modules One-bit delay - PCB and panel, still building (waiting on components)

One thing I keep learning - kits may seem like a cop-out for an experienced builder, but at least you have all the components. I have been caught out when I source my own components having to pay excessive international shipping for one or two essential components that I couldn't get with my first order. Definitely pays to spend time going though your BOM with Mouser (or anyone else) checking that they have alternatives for out-of-stock components.

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Jumbuktu
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Re: Recommendations for a complete DIY rack

Post by Jumbuktu » Thu Jun 03, 2021 2:26 am

Pr0fBi0 wrote:
Thu Jun 03, 2021 1:11 am
The more i look around the more i start to see that the modules that are really popular are the ones that can do multiple things. A lot of the mutable modules fall into this as does maths. I guess that way you don't can mold them to your needs instead of being stuck with only one use and that use not being what you need for a given patch.
Multi-use modules may appeal to some, but I dislike them. This is one reason I have mixed feelings about Mutable. My original rack was all-Doepfer, and it was a joy to patch because it was obvious how to use every module, there were no codes to remember and everything powered up exactly the same as it was powered down.

Of course, you can just ignore the alternate modes and only use the mode that a module was designed for ... in theory. In practice, just knowing there is another mode in the background is distracting.

Maths is different. At least it is understandable as a combination of two function generators and two offset / attenuator utilities, and it doesn't require any special codes or changes of thinking to use in different ways. I don't have one; I still prefer to have separate dedicated modules for things like slew limiting, scaling and offset and modulation generators.

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KSS
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Re: Recommendations for a complete DIY rack

Post by KSS » Thu Jun 03, 2021 3:05 am

:agree:

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devinw1
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Re: Recommendations for a complete DIY rack

Post by devinw1 » Thu Jun 03, 2021 11:25 am

Pr0fBi0 wrote:
Wed Jun 02, 2021 11:19 pm
bought the transistor ladder filter PCB that was linked earlier here and i was able to buy all the components except the two transistors.

MMBT3906-7-F
MMBT3904-7-F


Yeah, COVID chip shortage is still pretty f**ed up right now. MMBT3604/6 are SUPER white bread SMT transistors, and yet they are out of stock at Mouser even. Good news is they say 7k of the PNP one are coming on 6/24 so we are getting slowly out of this mess.

I just scrubbed all my DIY BOMs last week and found that Mouser had 0 CD40106 which also is an extremely white bread chip. It was kind of shocking.

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EATyourGUITAR
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Re: Recommendations for a complete DIY rack

Post by EATyourGUITAR » Fri Jun 04, 2021 11:36 am

I have 30 units of MMBT matched transistor pairs mounted on DIP6. I would sell them for $1 each. I don't need them anymore. I guess there are better matched transistors out there for a VCO so these are now obsolete.
WWW.EATYOURGUITAR.COM <---- MY DIY STUFF

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devinw1
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Re: Recommendations for a complete DIY rack

Post by devinw1 » Fri Jun 04, 2021 11:50 am

MMBT3906/4 is single transistor SOT 363

You thinking of DMMT?

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