Search found 220 matches

by groove
Sun Feb 23, 2020 10:38 am
Forum: Music Tech DIY
Topic: Decoupling Cap Position/ Type
Replies: 26
Views: 1655

Re: Decoupling Cap Position/ Type

Is there any practical difference between film, MLCC and ceramics for bypassing? I used poly box caps on some early circuits because they had 5mm lead spacing and now I am wondering if these perform worse than ceramics for bypass duties. I think I read somewhere that ceramics have very low ESR and t...
by groove
Mon Jan 06, 2020 3:32 pm
Forum: Music Tech DIY
Topic: Mackie Powered Monitor Trouble Shooting
Replies: 8
Views: 1167

Re: Mackie Powered Monitor Trouble Shooting

If there's a ground connection through a terminal/screw, you might try cleaning this contact and tightening it - that was the issue with an M-Audio B5a I had with a similar symptom.
by groove
Thu Jan 02, 2020 8:06 pm
Forum: Music Tech DIY
Topic: DIY JPTR 8 clone *** New VCO Core Picture ***
Replies: 422
Views: 51806

Re: DIY JPTR 8 clone *** New VCO Core Picture ***

Happy new year, Boogie! Glad to hear you are still around and working on this project. Looking forward to the release, and wishing you all the best.
by groove
Tue Jul 30, 2019 8:50 pm
Forum: Music Tech DIY
Topic: DIY JPTR 8 clone *** New VCO Core Picture ***
Replies: 422
Views: 51806

Hi Boogie,

Is this project still live?
by groove
Fri Jun 21, 2019 5:24 pm
Forum: Music Tech DIY
Topic: Project PRO2021 - A Pro-One keyboard synth
Replies: 1281
Views: 76140

Noise bleed to outputs, sequencer/arp not working

I had mine open today and made a bit of progress. On the sequencer / arp not clocking correctly: I had D116 in backward. DOH! fixed. I thought I had fixed the bleed of the Noise/Ext into the output when master volume is down all the way. I noticed today it's following the cutoff of the filter, so if...
by groove
Fri May 31, 2019 4:26 pm
Forum: Music Tech DIY
Topic: Project PRO2021 - A Pro-One keyboard synth
Replies: 1281
Views: 76140

Hey Pete, I posted the silkscreens for the boards on the Github page a while back. Print those out on the biggest paper you have and use that to find your components :). Thanks, will do. I managed to fix the bleed: I reflowed the solder on the noise pot and cleaned the flux again, and it's good to ...
by groove
Thu May 30, 2019 8:16 pm
Forum: Music Tech DIY
Topic: Project PRO2021 - A Pro-One keyboard synth
Replies: 1281
Views: 76140

groove, did you ever get your bleed issue fixed? No, and I've been away from it for a bit. I cleaned flux (again), replaced the 5532, and looked around as best I could for a bad value resistor somewhere but I don't see anything that looks off. Bit hard to tell against the schematic - I didn't take ...
by groove
Fri May 17, 2019 10:48 am
Forum: Music Tech DIY
Topic: Project PRO2021 - A Pro-One keyboard synth
Replies: 1281
Views: 76140

I finally finished my build and did calibration. I have just to oil the wooden end CAPS(avoiding rehashing the jokes) and add the knobs, once I'm positive I won't have to remove the boards (see below). What a project, this was an easy build and it sounds awesome! I love the build quality of the case...
by groove
Fri May 03, 2019 10:38 pm
Forum: Music Tech DIY
Topic: Project PRO2021 - A Pro-One keyboard synth
Replies: 1281
Views: 76140

Sparky wrote: I'd like to report that I'm at the "Go have a beer!" stage in assembly! :banana: :bananaguitar:
Looks awesome, nice work!

I finally unboxed last night - kit looks AMAZING. I managed to find a few minutes to put the PSU together tonight. Looking forward to the rest.
by groove
Tue Apr 16, 2019 12:22 am
Forum: Music Tech DIY
Topic: Triangle core symmetry and pitch stability
Replies: 12
Views: 1302

since the charge up voltage is the same as the discharge voltage, Va is constant, and C stays constant. R1 + R2 is almost constant, except for the variation in diode "resistance" as the current through them change as the pot is turned. it doesnt matter where the pot is set, the resistance through o...
by groove
Mon Apr 15, 2019 6:26 pm
Forum: Music Tech DIY
Topic: Triangle core symmetry and pitch stability
Replies: 12
Views: 1302

Triangle core symmetry and pitch stability

I have been playing around with a triangle core oscillator in a circuit simulator. I breadboarded it today and was a bit surprised to see that the pitch is rising when I move the symmetry/shape pot connected to the diodes toward either end of its range (pitch rises toward either extent). I tried cha...
by groove
Fri Mar 29, 2019 4:28 pm
Forum: Music Tech DIY
Topic: PWM changing pitch of VCO
Replies: 17
Views: 1229

Re: PWM changing pitch of VCO

I have been building up a saw core vco on my breadboard, learning about all the various sub circuits and wave shaping. I have found some great resources and schematics that have increased my understanding exponentially (sorry, pun). I've hit a snag on what appeared to be the easiest waveform to sha...
by groove
Thu Mar 21, 2019 9:30 am
Forum: Music Tech DIY
Topic: Project PRO2021 - A Pro-One keyboard synth
Replies: 1281
Views: 76140

In other news, the bender factory is up and running! I'm tellin you guys these things are buuuuutah! I thinking if there is any demand I will sell them separately for people wanting to build other custom keyboard instruments, upgrades etc..: THIS. I would definitely be interested in another set or ...
by groove
Tue Mar 19, 2019 9:57 am
Forum: Music Tech DIY
Topic: Project PRO2021 - A Pro-One keyboard synth
Replies: 1281
Views: 76140

Yes on knobs, please.

pete
by groove
Mon Mar 11, 2019 1:22 pm
Forum: Music Tech DIY
Topic: Marbles meltdown smoke
Replies: 45
Views: 2973

collumn2016 wrote:Using Eagle you can select where the 3.3v lines go, so followed that around and apart from lifting more pins on the stm the only thing left that i can see is C2.
The 0402 C1 looks like a good thing to rule out early, especially if you have another to replace it.
by groove
Wed Mar 06, 2019 10:56 pm
Forum: Music Tech DIY
Topic: Project PRO2021 - A Pro-One keyboard synth
Replies: 1281
Views: 76140

Re: Shared Mouser Cart

A quick edit that I've discussed with Janne about: The 4 connectors for attaching the VCO boards to the main B board I found out can only go 1 orientation, so I changed to a different (and actually cheaper) connector. I haven't updated the BOM yet because I haven't tested them yet but I'm 99.9% the...
by groove
Tue Mar 05, 2019 6:17 pm
Forum: Music Tech DIY
Topic: Project PRO2021 - A Pro-One keyboard synth
Replies: 1281
Views: 76140

Shared Mouser Cart

I uploaded the complete BOMs with Mouser Pns. https://github.com/devinw1/PRO2021 I imported both BOMs into one shared project in Mouser. Obviously use at your own risk - I did no verification other than the import. EDIT: link removed, I am updating the cart per recommended replacement connectors. I...
by groove
Thu Feb 21, 2019 11:39 am
Forum: Music Tech DIY
Topic: Lexicon LXP-15 Bridge Rectifier Help Needed
Replies: 9
Views: 1181

Replaced the rectifier with this: https://www.mouser.com/ProductDetail/833-2KBP04-BP Seems to be working good now, but the rectifier gets kinda hot. It’s rated for 165C max, so that’s good, but I see now that the current might be low (2A). I don’t see anything else on Mouser with a compatible packa...
by groove
Wed Feb 13, 2019 7:50 pm
Forum: Music Tech DIY
Topic: Project PRO2021 - A Pro-One keyboard synth
Replies: 1281
Views: 76140

devinw1 wrote:BTW, tentative order window for this run is Sunday 02/24! :sb: :sb:
sent a deposit this morning. Thanks for all of the work you put into this. I really love that it is a complete keyboard!

pete
by groove
Sun Feb 10, 2019 8:41 pm
Forum: Music Tech DIY
Topic: Why so much TL072 ?
Replies: 55
Views: 7006

Asia is all over fakes. That are only 0.3V-3V uSec vs 13V stated in a datasheet. I don't think there is another trusted source to buy ICs these days except major like Mouser or Digikey. Other cheap places are like Russian Roulette. Especially Tayda and Aliexpress (most pirated one). Do you have any...
by groove
Tue Jan 22, 2019 12:35 am
Forum: Music Tech DIY
Topic: How long did it take youto learn surface mount soldering?
Replies: 51
Views: 2477

Re: How long did it take youto learn surface mount soldering

Love to hear your stories and where the challenges are. through-hole is a known thing, in the sense that there's a standard spacing to it. SMT is a different beast. It's not a monolithic "surface mount" category of difficulty. There are easily soldered SMT sizes like 1206 and 0805, and SOIC chips. ...
by groove
Fri Jan 18, 2019 3:04 pm
Forum: Music Tech DIY
Topic: Breadboard brand recommendations
Replies: 5
Views: 520

Rumour has it the 3M boards are made by this company who sell direct, if you are in the US, which I am not: http://www.assemblyspecialist.com/WebStore/breadboards.html Thanks for the replies, everyone. I ordered one board from Assembly Specialist - I'll report back when I've had a chance to use it ...
by groove
Thu Jan 17, 2019 6:25 pm
Forum: Music Tech DIY
Topic: Breadboard brand recommendations
Replies: 5
Views: 520

Breadboard brand recommendations

I spent a few hours putting together a Moog ladder filter on a breadboard the other night and when I finished it didn't work. I got monkeying around and realized at some point that several connections were loose to the point of being able to pull the parts right out or having so much wiggle they wer...
by groove
Thu Jan 17, 2019 3:14 pm
Forum: Music Tech DIY
Topic: SEM filter 24db/oct
Replies: 14
Views: 1346

anyone? :cloud: I wasn't going to answer since I am a novice, but since nobody else has and you threw out the second call, I will bite. Maybe someone can shred this and shed some light. If I were to breadboard this(see below), I would venture to guess: Try switching between the points to the right ...
by groove
Thu Jan 10, 2019 7:35 pm
Forum: Music Tech DIY
Topic: Question about the 3340 VCO datasheet
Replies: 19
Views: 1281

Hi, I have couple of questions regarding this matter. I’m building a triple 3340 Vco that I intend to use inside a stand-alone monosynth. It will have keyboard, arpegiator, quantisers, so I’m thinking about ways of making them rock solid in terms of pitch stability. I’m so worried about this that n...

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