Search found 415 matches

by ricko
Wed Jun 23, 2021 11:57 pm
Forum: Eurorack Modules
Topic: Wavefolders, what are the basic variations?
Replies: 19
Views: 643

Re: Wavefolders, what are the basic variations?

KSS: :yay: One kind of waveshaper is the modulus function: e.g. CatGirlSynth's Modulo Madness or my fricko Rasp. But is it a "wavefolder"? But if you allow modulus, you might also allow saw frequency doublers and window-comparator-based things, and the term loses its meaning. To me, a "wavefolder" h...
by ricko
Wed Jun 09, 2021 1:19 am
Forum: Music Tech DIY
Topic: History of Synth DIY: Opinions requested
Replies: 119
Views: 2725

Re: History of Synth DIY: Opinions requested

We're coming up on ten years in business serving synth DIY and still feel like noobs. [we are very grateful for all of your continued support!!] We've re-opened our brick and mortar shop outside Boston, and have this amazing blank white staircase wall leading up to our second-floor front door. We w...
by ricko
Wed Jun 09, 2021 1:05 am
Forum: Music Tech DIY
Topic: History of Synth DIY: Opinions requested
Replies: 119
Views: 2725

Re: History of Synth DIY: Opinions requested

I would add magazine articles, datasherts, theses and patents, for DIY in the 70s. In Australia, Electronics Today International lead the way in the mid 70s, ultimately with the 4600 and 3600 synths. I recall the boy Ken Stone putting some circuit ideas in too. (The ETI publisher later went on to ma...
by ricko
Thu Jun 03, 2021 7:36 pm
Forum: Music Tech DIY
Topic: What does the Memristor mean for synth design?
Replies: 16
Views: 1547

Re:

Much of the past year has been spent on developing circuits to mimic memristors (MMC) and memcapacitors (which don't actually exist yet) Back then, what did you use? Did any of the circuits find their way into Non Linear Circuits offerings: I get the impression you are more taken by the chaos than ...
by ricko
Thu Jun 03, 2021 8:13 am
Forum: Music Tech DIY
Topic: What does the Memristor mean for synth design?
Replies: 16
Views: 1547

Re: What does the Memristor mean for synth design?

Does anyone have an update on this? .... Are there any memristors available as single precise component, like a resistor? I saw this lot's press release some time ago : https://knowm.com/products/discrete-m-sdc-memristor-dip-6-pack I have NO IDEA whether they work or not, but they do seem to be wha...
by ricko
Thu Jun 03, 2021 2:40 am
Forum: Music Tech DIY
Topic: What does the Memristor mean for synth design?
Replies: 16
Views: 1547

Re: What does the Memristor mean for synth design?

Does anyone have an update on this? I see from youtube videos that more devices are being found to have memristor-like behaviours in sweet spots. For example, lamps and thermistors. I am not so much interested in crossbars or memory or neurons as in the behaviour where (in effect) a high frequency s...
by ricko
Tue Jun 01, 2021 9:56 pm
Forum: Music Tech DIY
Topic: Recommendations for a complete DIY rack
Replies: 103
Views: 2383

Re: Recommendations for a complete DIY rack

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 ...
by ricko
Mon May 31, 2021 12:54 am
Forum: Music Tech DIY
Topic: Recommendations for a complete DIY rack
Replies: 103
Views: 2383

Re: Recommendations for a complete DIY rack

I (re-)started off with that 100% DIY attitude, and it really held me back. Everyone is different, of course. The problem was that it took so long to get a sound out, and there always seemed to be something missing or not done: do I do the midi converter before the vco? Do I do the VCA before I have...
by ricko
Mon May 31, 2021 12:34 am
Forum: Modular Synth General Discussion
Topic: Is there such logic function?
Replies: 10
Views: 497

Re: Is there such logic function?

I think your input function is B AND NOT(A) This is the same as NOT( NOT(B) OR A) IIRC which could be implemented with a couple of diodes for the OR and a transistor for each NOT (plus some resistors.) However, the rub is that logic signals need to be in perfect synch for logic operations to work. E...
by ricko
Thu May 06, 2021 7:34 pm
Forum: Music Tech DIY
Topic: Minor issue with Frequency Central Envelope
Replies: 12
Views: 358

Re: Minor issue with Frequency Central Envelope

Did the LED ever come on? Maybe it just the wrong way round. You can try without soldering anything: put hold the terminals of a spare LED (that you have tested to work in series with the same resistor value as the module) against the solder points on the back of the board, * if it lights then the o...
by ricko
Thu Apr 29, 2021 6:28 am
Forum: Music Tech DIY
Topic: Transistor Based Low Pass Gate schematic?
Replies: 55
Views: 2680

Re: Transistor Based Low Pass Gate schematic?

... Then, We'd *still* need to add any effect* that the CdS memory effect is having on 'Vactrol' throughput. *And we need to study the CdS resistance to do that. "Need to"? Hmmm. You seem to be saying that the smart or proper way to characterize a system like Vactrols is by white box methods (analy...
by ricko
Wed Apr 28, 2021 10:50 pm
Forum: Music Tech DIY
Topic: Advice sought: what to do about supplier who wont send
Replies: 2
Views: 281

Advice sought: what to do about supplier who wont send

Does anyone have any advice? 8 months ago, I bought a certain PCB from a well-known US music shop, including the additional postage to get to Australia. About US $120 using PayPal. After this: radio silence. No tracking number. After enough time, I raised a Paypal dispute, and next day they contacte...
by ricko
Wed Apr 28, 2021 7:49 am
Forum: Music Tech DIY
Topic: ExpoDAC VCO
Replies: 14
Views: 550

Re: ExpoDAC VCO

Why not use a 24-ish -bit audio DAC to drive the integrator?

The Sabre ES9023P chip would provide 2 channels, and only costs $2. I guess one would have to figure out how to drive it with blocks of data, and turn off any fancy filtering.
by ricko
Wed Apr 28, 2021 7:06 am
Forum: Music Tech DIY
Topic: Transistor Based Low Pass Gate schematic?
Replies: 55
Views: 2680

Re: Transistor Based Low Pass Gate schematic?

The memory effect of CdS is not too different from dielectric absorption in capacitors. Which means using a capacitor to duplicate its effect makes sense. . I don't really see that for LED responses are like simple RC curves. images.png The attack is weak and gets relatively less in effect on loud ...
by ricko
Tue Apr 27, 2021 6:16 pm
Forum: Music Tech DIY
Topic: buzz on 220v plug ?
Replies: 5
Views: 214

Re: buzz on 220v plug ?

Here in Australia, we have 240V 3pin AC power standard. So it may be similar to Europe. It used to be common in live music situations to make "earth lifters": double adaptors where the middle earthing pin was removed. This was to remove ground loops, causing "hums" or (rarely) "buzzes". You would on...
by ricko
Tue Apr 27, 2021 5:38 pm
Forum: Music Tech DIY
Topic: Transistor Based Low Pass Gate schematic?
Replies: 55
Views: 2680

Re: Transistor Based Low Pass Gate schematic?

I made a couple of stabs at simulating aspects of vactrol responses at https://electro-music.com/forum/topic-22769.html, back when they were getting super-expensive. The simple circuit is probably enough (the complex one looks strange to me now: what is that transistor doing?) At the least, it shows...
by ricko
Thu Apr 22, 2021 11:11 am
Forum: Music Tech DIY
Topic: Hifi Tone control Ic (TCA740) as VCF?? (or TCA730 as VCA?)
Replies: 5
Views: 2334

Re: Hifi Tone control Ic (TCA740) as VCF?? (or TCA730 as VCA?)

The TCA 740 has been used before in synths: the Variophon used it in the tone control of at least two of its modules. The bass side is used for VCFs (with overlapping range to give some kind of presence boost, and the treble side is used for two VCAs (which are used for dynamics but not to cut off t...
by ricko
Fri Apr 16, 2021 2:04 am
Forum: Music Tech DIY
Topic: Making pcb front panels in KiCAD
Replies: 3
Views: 845

Re: Making pcb front panels in KiCAD

Here is some extra information to help newbies to FPD (i.e. me) use Front Panel Designer with KiCad, in order to make synth panels from PCB material. There may be better/other ways to do it, and import/export is improving in KiCad. 1. DFX. This is a vector graphics format that supports multiple laye...
by ricko
Tue Apr 13, 2021 10:54 am
Forum: Eurorack Modules
Topic: Best Bargains in Eurorack
Replies: 107
Views: 9612

Re: Best Bargains in Eurorack

Behringer 305 (P EQ + stero mixer + A440 + headphone outs) and 150 (delay LFO + ring modulator + noise + S&H) (Probably the 172 as well (delay + phaser + delay LFO) but I have never tried it.) For assembled: Taabak For DIY: Elby, FCUK, Majella, Barton, and the usual suspects. (Not SMD and too tightl...
by ricko
Tue Apr 13, 2021 5:35 am
Forum: Music Tech DIY
Topic: ETI 4600
Replies: 52
Views: 4243

Re: ETI 4600

cnicht wrote:
Mon Apr 12, 2021 4:34 am
A quick question on the design if I may?

Do the pins bridge the X-Y crossover point or do the pins contain resistors/diodes?
On a 4600, the pins (and points) do not have diodes or resistors. The matrix is a big mult.
by ricko
Sun Apr 11, 2021 7:48 am
Forum: Music Tech DIY
Topic: PCBs as Front Panels ?
Replies: 307
Views: 33347

Re: PCBs as Front Panels ?

KSS wrote:
Thu Apr 01, 2021 4:04 pm

Of course the best choice would be for the mfr to make a longer, stronger and proper swage. But they feel they've 'solved' the problem with the square boss. It does solve theone problem, but creates another. .
Swage! What a fantastic word!
by ricko
Thu Apr 08, 2021 8:52 am
Forum: Eurorack Modules
Topic: Pitch to CV options (I know I know, but can it be DONE??)
Replies: 32
Views: 1719

Re: Pitch to CV options

Most pitch trackers are going to get weird when the input signal goes silent. Normally you'd also pair them with an envelope follower and a VCA to silence the mess (on the Disting, the algorithm includes an envelope follower). There is a kind of module called "track and hold": it keeps the last not...
by ricko
Wed Apr 07, 2021 9:51 am
Forum: Eurorack Modules
Topic: Frequency Central appreciation thread
Replies: 54
Views: 1646

Re: Frequency Central appreciation thread

You should check out Arley Dynamics. It's essentially a CEMvelope with an integrated VCA in 6 HP. Uses all tall trimmers, so it's a bit easier to tweak than standard alpha pots w/ Davies 1900 knobs. Yes. And the big thing it does right is having a gain CV on it, which is a way to get dynamics. Rick
by ricko
Wed Apr 07, 2021 12:04 am
Forum: Eurorack Modules
Topic: Frequency Central appreciation thread
Replies: 54
Views: 1646

Re: Frequency Central appreciation thread

I built a CEMvelope and a CEMosc, and they both were nice builds with no drama, and the modules have worked as expected, at what seemed to be the most features compared to others at that price point (this was a year or two ago.) I wish they had some more imaginative or unique features, perhaps. (I a...
by ricko
Tue Apr 06, 2021 7:10 am
Forum: Eurorack Modules
Topic: best euro modules to create violin, viola, cello sounds
Replies: 130
Views: 7750

Re: best euro modules to create violin, viola, cello sounds

Pretty: a touch of the Crouching Tiger cello, too!

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