Do it yourself crew in the house?

[TubularCorporation]

6 hours ago, sweepstakes said:

Jesus could I get a BOM order right the first time just ONCE in my life?

I love those little SMT LL4148s. They're so cute that I don't even mind how they roll around all over my workspace.

I've heard rumors that it's possible to get one right, but I've never seen convincing evidence.

[Limo]

52 minutes ago, TubularCorporation said:

I've heard rumors that it's possible to get one right, but I've never seen convincing evidence.

Sighs in the general direction of his impressive stockpile of incorrectly purchased components.

[TubularCorporation]

I was looking for a specific unusual capacitor value in that box a couple weeks ago (because I'd forgotten to order them when I ordered parts fro something) and when I finally actually found some they were so old that the label on the bag had faded completely off.  I've got wrong parts going back to like 2007 in there.

 

During the quarantine I've been hoarding small boxes so I can eventually organize all of my extra parts with little dividers between orders of magnitude (so say for resistors I'd cut strips of cereal box for 10 ohms, 100 ohms, 1k, 10k etc and then fold them around the bags of all of the resistors in that range so I could easily grab the strip and pull the entire range out of the box to look for a specific value - when I built the Kijimi I had to do that to keep track of everything and it was a quick way to find stuff quickly but still have it all crammed into a box as tightly as I could to save space), but the thing is the old unsorted parts box goes back long enough now that for things like electrolytic capacitors that have a shelf life I'd almost have to sort them by age too, so I could use the old ones for things that weren't important or prototyping stuff.

 

Then I get lazy and don't do it at all.

[Hautlle]

I totally bought one of these storage drawer things at least a year and a half ago and made a spreadsheet with all of my inventory at that time. Since then I haven't tracked hardly any of the parts I've bought or used. I also still haven't put a single fucking thing in that drawer and keep all my stock in the plastic bags they came in stacked inside a few little cardboard boxes that some of my first parts buys probably came in...

 

[Limo]

I only started out two years ago and kept an Excel sheet straight from the start. It really helps, except that I don’t always trust what it says. “Do I really have 28 thonkicon jacks? Better round them all up and count them just to be sure.”

Tedious.

[user]

Glad I’m not alone in never getting an order right the first time and dealing with the tedium involved in keeping track of/organising your inventory. 
 

Installed a ltc1799 (variable clock osc that TubularCorporation pointed me towards in another thread) in the Yamaha dd11 that crossed my path a couple weeks ago. 
Of course it was all working (although the crunchy percussion I was hoping to liberate from the dd’s fizzy intestines was mostly dominated by clock whine until I realised it was probably wise to ground to pot controlling the ltc) until I hooked up a keystep and the dd11 threw a midi error and then refused to work with the ltc anymore. It still runs fine with the original clock source so all is not lost, hopefully. 
 

Here’s a short video of the dd doing its best 90s autechre imitation, bit like seeing a middle aged Japanese businessman singing ABBA at a karaoke bar, it’s nothing but good intentions and misdirected passion/frustration. 

Turn down the volume, lots of nasty high frequencies! 
 

Spoiler

IMG_3605.MOV

 

[Limo]

I lost my PCB manufacturing virginity today. Played around with using Fritzing to transfer a schematic to breadboard, which was ... painful, but still beat erasing and redrawing on graph paper, maybe, then figured, what the hell, let's try to design a PCB for it, then figured, what the hell, let's have it manufactured.

Used seeedstudio because a tutorial on the internet told me too. 

Now let's hope I didn't fuck things up.

(the schematic was for a simple dual VCA, btw).

[TubularCorporation]

 

4 hours ago, Hautlle said:

I totally bought one of these storage drawer things at least a year and a half ago and made a spreadsheet with all of my inventory at that time. Since then I haven't tracked hardly any of the parts I've bought or used. I also still haven't put a single fucking thing in that drawer and keep all my stock in the plastic bags they came in stacked inside a few little cardboard boxes that some of my first parts buys probably came in...

 

I have a small storage drawer that I found some place, too.  The only thing that's in it are dozens of screws that got misplaced and then turned up weeks later after I forgot what they belonged to.  All my parts are in bags in boxes, except a bunch of electrolytic caps I got a while back and never use becuase they're 18v and it seems like I always need 25v these days.

 

I've also gotten in the habit of ordering a few extra of every cheap part when I build something, so that I can build up a stock of spare parts, but then not feeling like digging through the spares to see what I have on hand already next time I place an order, especially since the parts I DO have extras of are all really cheap anyhow so it only costs a couple dollars at most to be lazy.  And then I add on a few extras again and the box of random parts gets bigger.

[sweepstakes]

1 hour ago, user said:

a middle aged Japanese businessman singing ABBA at a karaoke bar, it’s nothing but good intentions and misdirected passion/frustration. 

I feel personally attacked

[TubularCorporation]

1 hour ago, user said:

Glad I’m not alone in never getting an order right the first time and dealing with the tedium involved in keeping track of/organising your inventory. 
 

Installed a ltc1799 (variable clock osc that TubularCorporation pointed me towards in another thread) in the Yamaha dd11 that crossed my path a couple weeks ago. 
Of course it was all working (although the crunchy percussion I was hoping to liberate from the dd’s fizzy intestines was mostly dominated by clock whine until I realised it was probably wise to ground to pot controlling the ltc) until I hooked up a keystep and the dd11 threw a midi error and then refused to work with the ltc anymore. It still runs fine with the original clock source so all is not lost, hopefully. 
 

Here’s a short video of the dd doing its best 90s autechre imitation, bit like seeing a middle aged Japanese businessman singing ABBA at a karaoke bar, it’s nothing but good intentions and misdirected passion/frustration. 

Turn down the volume, lots of nasty high frequencies! 
 

  Hide contents

 

IMG_3605.MOV 50.84 MB · 1 download

 

 

 

 

That sounds great!

 

It might just not work with MIDI when you change the clock speed, the one thing I've installed a variable clock in is an olfd Behringer multi-effect and if you turn the clock down low enough the front panel controls won't even respond anymore, much less MIDI.

 

Try this, I have no idea if it's a good idea because I just thought of it, but it makes sense I think:

 

Install the variable clock and set it by ear to the point where it sounds closest to normal, then send it some MIDI and see if it works reliably.  If it DOES, you can measure the resistance across the pot and wire up a switch that will select between the pot and a fixed resistor of the value you measured, so at least you can switch it to a semi-stock ode with MIDI.

 

Alternatively, since those pads are just simple piezo discs under rubber, you could almost definitely wire in jacks that would let you trigger the pads with external audio.  You'd also probably want to add some pots to adjust the inputs so you could use line level safely, and if you think you might use CV you'd definitely need to do more work, but for audio you PROBABLY wouldn't burn anything up with simple input jacks and passive volume controls wired up in parallel with the piezo discs.

 

EDIT: I haven't actually tried that myself so if you try it and your DD11 dies you've been warned!

Edited July 24, 2020 by TubularCorporation

[user]

21 hours ago, sweepstakes said:

I feel personally attacked

I’m sorry, shared a bunch of meals with young Asians heavily into karaokebars over the last few months, must have left a mark. ; D 

 

21 hours ago, TubularCorporation said:

That sounds great!

 

It might just not work with MIDI when you change the clock speed, the one thing I've installed a variable clock in is an olfd Behringer multi-effect and if you turn the clock down low enough the front panel controls won't even respond anymore, much less MIDI.

 

Try this, I have no idea if it's a good idea because I just thought of it, but it makes sense I think:

 

Install the variable clock and set it by ear to the point where it sounds closest to normal, then send it some MIDI and see if it works reliably.  If it DOES, you can measure the resistance across the pot and wire up a switch that will select between the pot and a fixed resistor of the value you measured, so at least you can switch it to a semi-stock ode with MIDI.

 

Alternatively, since those pads are just simple piezo discs under rubber, you could almost definitely wire in jacks that would let you trigger the pads with external audio.  You'd also probably want to add some pots to adjust the inputs so you could use line level safely, and if you think you might use CV you'd definitely need to do more work, but for audio you PROBABLY wouldn't burn anything up with simple input jacks and passive volume controls wired up in parallel with the piezo discs.

 

EDIT: I haven't actually tried that myself so if you try it and your DD11 dies you've been warned!

Thanks!

I think you’re right about the lower clock speed being the source of the midi error, and it seems hooking up the keystep coincided with one of the wires running from the pot breaking which explains why things were wonky after that even with no midi connected and everything runs fine with the original tl installed (in a rare case of foresight I soldered a pinheader on the board where the original lt was so I could easily go back and forth for troubleshooting purposes). 

Was redoing the wiring and soldering that’s coming from the small ltc pcb to the dd11, might finish tonight but decided to take a quick break after getting frustrated with soldering tiny bits of stripped wire to make the necessary bridges. 
 

For the trig mod I was considering to just measure the voltages the pads send out when I whack em real good and see what a safe margin would be for sending the triggers. 
Also hoping to get individual outs, maybe put some caps to filter out the nastiest clock whine. If this goes somewhat successfully I’ll attempt cv control of the ltc pot. 
If everything is still working by then I might start looking for some further bends but for now not gonna mess with the ic’s, don’t want to break it rn. 

[TubularCorporation]

Hope you get it working, because those examples sounded great!

 

I guess A nice thing about the LTC PCB is if you break the DD-11 you can pull it out and install it in something else.

I had to start learning some basic Python today to get a thing working.  It's easier than I expected.

[sweepstakes]

1 hour ago, user said:

I’m sorry, shared a bunch of meals with young Asians heavily into karaokebars over the last few months, must have left a mark. ; D 

Hehe, all good - yeah, I had a bit of a karaoke phase about 5 years ago, and 

22 hours ago, sweepstakes said:

good intentions and misdirected passion/frustration

are basically my exact psychological GPS coordinates.

[user]

On 7/25/2020 at 10:02 PM, TubularCorporation said:

Hope you get it working, because those examples sounded great!

 

I guess A nice thing about the LTC PCB is if you break the DD-11 you can pull it out and install it in something else.

I had to start learning some basic Python today to get a thing working.  It's easier than I expected.

Aaaaand it’s gone. 
Setup a fresh bit of perfboard for the ltc and redid the wiring but the dd11 was clearly not receiving a high enough clock rate. As I was fiddling with the pot controlling the ltc frequency I noticed a small puff of smoke rising up from the ltc... Quickly switched the dd off and put back the original clock source. Luckily the dd11 still seems to be working normally but when I measured voltage coming from the voltage regulator the pin that’s supposed to output 5v and that I’d tapped to supply the ltc now gave a reading of over 11v. 
 

I guess the voltage regulator had had enough of my repeated soldering and desoldering and called it quits. 
Ordered a replacement ltc and I’m now looking into sourcing a replacement for the voltage regulator. Hope it’s as simple as putting in a new one because I’m not yet at the point where I’ll be able to trace down the fault if it’s not the regulator itself that’s borked. 
 

Seems I’m very lucky to (apparently) not have caused damage to the ic’s getting 5v from the regulator... 

[sweepstakes]

Whoa, I've never seen the fabled magic smoke before. Congratulations!

[user]

Why thank you! It does feel like quite the achievement. 

[psn]

My Revox died in a puff of smoke a while back. Need to recap it one day. 

[Limo]

No holy smoke for me yet.

But the op amp IC in the DIY spring reverb I’m working on did get *really* hot when I misremembered how to wire up a non-inverting amplifier circuit. Four times. 

[Soloman Tump]

Ive got a great fuzz pedal that someone hand built a few years back, but every time you touch the aluminium outer case it creates a deep HUMMMMM

I have limited diagnostic skills, but i'm guessing that is a stray wire inside and it's earthing out when I touch it?

Can anyone help? I can take the pedal apart and have a look.. if it is just a wire I can probably sort it out, but could it be something else?

[TubularCorporation]

The aluminum case is supposed to be connected to ground, that's what shields it from RF interference.  Maybe when you touch it you're LIFTING the ground in some way. 

 

 

For some reason the Devi Ever peddal I clones has started doing smething really weird.  The "noise" more switch just removes one capacitor from the circuit and toggles an LED on and off.  Worked perfectly for weeks but now when I switch it on the pedal sounds th same and the LED blinks on and off almost rhythmically but not quite.  Completely weird.  Checked the continuity on the switch and it doesn't seem like it's defective, plus it seems unlikely that at least two poles of a 3pDT switch would fail at the same time, but I have no clue what's wrong.  It's a really simple circuit, and I can't figure out what's the matter with it.  Works fine in the regular mode and the other switch for "noise" mode works fine but I can' switch on both to get the insane inverted-dynamics effect I built it for.

[sweepstakes]

On 7/28/2020 at 8:58 AM, rhmilo said:

I misremembered how to wire up a non-inverting amplifier circuit. Four times. 

This is all very familiar and reassuring.

[user]

The voltage regulator I think needs replacing in the dd11 turns out to be somewhat difficult to source. Would it be ok to replace it with one that has the same specs? Doesn't seem too difficult to find regulators that seem to output the same voltages...

Also when doing further troubleshooting could I just disconnect the rest of the dd from the powerboard to see if things are back to normal or would this result in incorrect measurements/readings?

[Soloman Tump]

On 7/30/2020 at 7:36 PM, TubularCorporation said:

The aluminum case is supposed to be connected to ground, that's what shields it from RF interference.  Maybe when you touch it you're LIFTING the ground in some way.

 

So in the interest of science I took this pedal apart.

On the PCB there was a 5-terminal block that had a 2 pronged wire "thing" in, and a 3 pronged wire "thing". I wiggled them and the 3 pronged thing was VERY loose, like, it fell out at the slighted touch.  I doubled over the wires and pushed it in tight.  I tightened up the 1/4" connectors, put it back together, and hey presto! Fully working DIY Valhalla Fuzz pedal.  Was chuffed at sorting that out.

[TubularCorporation]

The first time I ever fixed anything was when I bought a Crybaby pedal in high school and used it at a basement show that night, but the next morning it didn't work.  I couldn't get a ride three towns over to return it so I opened it up and poked around until I figured out the IDC-or-whatever conenctor that connected the jacks, pot and switch to the PCB was intermittent, and I fixed it by making little spitwads with scrap paper and jamming them down into the back of the connector to keepit from wiggling.  It still worked perfectly when I traded it away after college.

[Limo]

Successfully built a Befaco Rampage.

It wasn't difficult, as such, but the two PCBs are *very* crowded so it was a *lot* of soldering. Also, the component holes were very small which makes desoldering nearly impossible. It also means that even the tiniest drop of hot solder can gunk up a hole. Ruined one perfectly good pad that way. Luckily Befaco provide schematics and the traces were clearly visible as well so I could fix it with some wire.

Also nearly blew up one of the two channels with a solder bridge between two of the five(!) pins of the shape pot. This pot is now black, but it seems to work ok.

All in all it was a good lesson in patience and a fine meditative experience that resulted in a lovely module. I  function generators.