Search found 1854 matches

by devinw1
Fri Jan 22, 2021 3:47 pm
Forum: Music Tech DIY
Topic: Fake TL074 chips in circulation
Replies: 23
Views: 659

Re: Fake TL074 chips in circulation

dubtoms wrote:
Fri Jan 22, 2021 1:22 pm
I guess I know why I've had issues with recent builds... Probably not a good idea to source op-amps from Aliexpress :)
Yeaaah.. definitely a minefield on that site man. Some good, some bad, some absolutely awful.
by devinw1
Fri Jan 22, 2021 11:35 am
Forum: Music Tech DIY
Topic: Fake TL074 chips in circulation
Replies: 23
Views: 659

Re: Fake TL074 chips in circulation

Yikes. COVID delay/ripple effect I assume? A little but not the main cause. On average Semiconductor usage grows by about 5% per year so you need to build new fabs every year. But it's definitely boom and bust. The memory people feel this the most as their fabs are the most expensive, but building ...
by devinw1
Fri Jan 22, 2021 12:42 am
Forum: Music Tech DIY
Topic: Fake TL074 chips in circulation
Replies: 23
Views: 659

Re: Fake TL074 chips in circulation

I just ordered a bunch of 74s from Tayda at the start of this week. Glad I saw this, I'm gonna giive them a close look over just to make sure. I have a giant batch of TL072s from Tayda. I'll take a look too. I had been buying 074s from them, but then realized in bulk (100+), Mouser was cheaper than...
by devinw1
Fri Jan 22, 2021 12:41 am
Forum: Music Tech DIY
Topic: Fake TL074 chips in circulation
Replies: 23
Views: 659

Re: Fake TL074 chips in circulation

Should we be worried about 074s and 072s going scarce for some reason? All ICs will be going scarce for at least the next year. Current semiconductor demand far exceeds supply, as the automotive industry is discovering and having to cut back vehicle production significantly. Most fabs are already a...
by devinw1
Thu Jan 21, 2021 6:20 pm
Forum: Music Tech DIY
Topic: Fake TL074 chips in circulation
Replies: 23
Views: 659

Re: Fake TL074 chips in circulation

Should we be worried about 074s and 072s going scarce for some reason?
by devinw1
Tue Jan 19, 2021 12:40 pm
Forum: Music Tech DIY
Topic: Holiday week proto: The sequel to B1; B2 Kick Bass module
Replies: 15
Views: 523

Re: Holiday week proto: The sequel to B1; B2 Kick Bass module

Thanks h0wser! I'm working on the build documentation right now, probably 75% done. Just have to knock out the final BOM and get panels in and we should be golden.
by devinw1
Tue Jan 19, 2021 12:37 pm
Forum: Music Tech DIY
Topic: TR-606 - is there any clone in DIY format?
Replies: 192
Views: 26400

Re: TR-606 - is there any clone in DIY format?

thanks. the kick and hats sit really well in the mix. a complete 606 in euro would be sweet I'm working on basically what is a DR110 with all voices in euro right now. The DR110 is very similar to 606. This would be just the voices, no sequencer. Figured I'd mention it though! Any news on this? :pa...
by devinw1
Mon Jan 18, 2021 11:54 am
Forum: Music Tech DIY
Topic: resetting this 555 AD envelope generator
Replies: 6
Views: 194

Re: resetting this 555 AD envelope generator

You could just use a BJT or JFET to drain the cap (C3) when issued with the reset pulse.
by devinw1
Sun Jan 17, 2021 4:00 pm
Forum: Music Tech DIY
Topic: 4 Channel Quadrature LFO
Replies: 15
Views: 505

Re: Sneak preview, new module progress

Heck yeah, I was wanting a full size analog oscope module for my rack!

:D :D :D
by devinw1
Fri Jan 15, 2021 5:06 pm
Forum: Music Tech DIY
Topic: LM339 Pullup resistor value
Replies: 15
Views: 201

Re: LM339 Pullup resistor value

Does transition time refer to the steepness of the rising edge, or the delay in responding to changes on the inputs? Either way, I'm only using it to clock a sequencer at "musical" rates, so I doubt the sort of lag this might cause would matter much here. yeah, the former. The capactive load seen b...
by devinw1
Fri Jan 15, 2021 11:53 am
Forum: Music Tech DIY
Topic: LM339 Pullup resistor value
Replies: 15
Views: 201

Re: LM339 Pullup resistor value

As guest mentioned, the transition speed will increase with a lower pullup, but will draw more current in the off state. 150k is pretty huge. That will make a pretty miserably slow transition, but for this maybe it is OK? The LM339 is not a particularly high speed comparator, but for example the tra...
by devinw1
Fri Jan 15, 2021 11:48 am
Forum: Music Tech DIY
Topic: Experience with cheap panel manufacturer in china?
Replies: 11
Views: 360

Re: Experience with cheap panel manufacturer in china?

^Exactly. JLC and such are used to doing films and custom silks all day, but batch your PCBs on a huge piece of stock with other customers...that's part of their efficiency. There's really nobody doing that with metal work AFAIK. So, most shops, even if they are not outsourcing for the silkscreen wi...
by devinw1
Thu Jan 14, 2021 6:29 pm
Forum: Music Tech DIY
Topic: Experience with cheap panel manufacturer in china?
Replies: 11
Views: 360

Re: Experience with cheap panel manufacturer in china?

...Some sort of JLCPCB/PCBway equivalent but for aluminium panels, ideally with options for anonoized aluminium and brushed aluminium. Thanks! This does not exist. I used to use Chinese vendors for getting panels anodized and then laser etched, but it's not particularly cheap per so. In resonable v...
by devinw1
Thu Jan 14, 2021 1:50 pm
Forum: Music Tech DIY
Topic: Experience with cheap router from china for panel making?
Replies: 2
Views: 115

Re: Experience with cheap router from china for panel making?

There's a whole thread on this already. https://www.muffwiggler.com/forum/viewtopic.php?f=17&t=235904&hilit=cnc A couple of us are successfully making prototypes on cheap CNC routers, but more like in the $500-$800 range. The REALLY cheap ones are essentially worthless for doing metal. They are flim...
by devinw1
Thu Jan 14, 2021 12:11 pm
Forum: Music Tech DIY
Topic: Holiday week proto: The sequel to B1; B2 Kick Bass module
Replies: 15
Views: 523

Re: Holiday week proto: The sequel to B1; B2 Kick Bass module

Pretty soon I think. I'm requoting some of my production panels right now and this is in the mix.!
by devinw1
Wed Jan 13, 2021 11:44 am
Forum: Music Tech DIY
Topic: Triangle VCO current source?
Replies: 6
Views: 190

Re: Triangle VCO current source?

Yeah, a OTA such as the LM13700, CA/AS3280 or a current-output VCA like the 2164 are probably the most common and least exotic.
by devinw1
Wed Jan 13, 2021 1:52 am
Forum: Music Tech DIY
Topic: my first 303 clone
Replies: 15
Views: 520

Re: my first 303 clone

Love it. So is that 303_98 as in 1998? You've been at this a hot minute eh?!! (Label me completely not shocked at that fact if it is true due to your depth of knowledge!) :sb:
by devinw1
Wed Jan 13, 2021 1:48 am
Forum: Artist Discussion
Topic: Exceptional rap...
Replies: 148
Views: 8510

Re: Exceptional rap...

Brad s wrote:
Tue Jan 12, 2021 7:32 pm
I'm right there with you, my friend.

Let's have another, shall we?

:sb: :guinness:
by devinw1
Wed Jan 13, 2021 12:33 am
Forum: Music Tech DIY
Topic: Holiday week proto: The sequel to B1; B2 Kick Bass module
Replies: 15
Views: 523

Re: Holiday week proto: The sequel to B1; B2 Kick Bass module

Whipped out a demo video tonight. I'm slowly getting the hang of doing these, but still suck at it. lolz.

by devinw1
Tue Jan 12, 2021 7:24 pm
Forum: Artist Discussion
Topic: Exceptional rap...
Replies: 148
Views: 8510

Re: Exceptional rap...

Man, I've been binging on Doom hard for the past week. My god that guy was good. RIP.
by devinw1
Tue Jan 12, 2021 1:48 pm
Forum: Music Tech DIY
Topic: Utility Mixer I
Replies: 9
Views: 267

Re: Utility Mixer I

Nice one! Harald reigns as the productivity champ here on Muffs diy!
by devinw1
Tue Jan 12, 2021 12:33 pm
Forum: Music Tech DIY
Topic: a440 mixer schematic advise
Replies: 7
Views: 240

Re: a440 mixer schematic advise

Oh, I didn't know you wanted more than 1 signal. You CAN add signals with a non-inverting configuration, but it is more complicated, and you would add feedback resistors. But, things are not as clean cut. So, yeah, that's why it's easiest to add with an inverting summer, at the virtual ground point....
by devinw1
Mon Jan 11, 2021 7:35 pm
Forum: Music Tech DIY
Topic: a440 mixer schematic advise
Replies: 7
Views: 240

Re: a440 mixer schematic advise

If you don't want any gain, the simplest thing would be to just use a buffer (since that seems like what you are trying to do is buffer the high pass filter you have created with the 1u cap right? So that first part would be like this:
buff.png
buff.png (2.87 KiB) Viewed 52 times
by devinw1
Sun Jan 10, 2021 2:00 am
Forum: Music Tech DIY
Topic: Self syncing VCOs
Replies: 22
Views: 601

Re: Self syncing VCOs

Hahah, goddamn. That's pretty funny

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