The Kassutronics slope has EOC and EOR gates.
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A mix of life and build progress todayā¦
I received a Tayda order the other day that replenished some stocks as well as helped me get the last few bits for a couple of projects. The triple splashback delay is a head scratcher when it comes to the controls and I will need to toy with it a bit before I feel like I actually know what Iām doing. I went ahead with the crunchy spring reverb and just stuck to the resistor values printed on the PCB. It works pretty much as expected - as far as I can tell. Iām sure my hackjob on the spring tank probably did a number on the sound quality but I bet it also leads to āunique audio characteristicsā which is a fancy way of saying it sounds crap 
It also forced me to try crimping some Molex plugs - which I really need to do more of. If anyone knows of a good assortment kit please let me know.
I need to do a fairly hefty mouser order next to get parts for the performance oscillator, the noodle toaster, the wave shaper, the morse code module, and the kassutronics slope (thanks @BenRufenacht !). I have been attempting to make the North Coast Synthesis fixed sine bank, but for some reason cant get the circuit to work. I thought I cooked my Typoon module but it turns out there was just a loose wire - so now it is still not 100% functional but at least usable and fun to play with.
We have been looking for electrical engineers at work for some projects so I recommended we check out the Ohio State University Engineering Design Showcase. I thought it was going to be a huge waste of time until we found a team who built a functional R2D2. One of those team members agreed to come in and talk to us yesterday and seems very excited about the projects we have in store. Hopefully he can teach me a thing or two.
I found out they also have an electronics club on campus with a well equipped lab. I might sneak in at some point and use their PCB oven for my Tides and Kinks modules.
A good friend of mine at work wanted to go see TWRP and Magic Sword, so I thought I would tag along. Then he got covid and I ended up going by myself. It was a really great show if a bit lonely. I love Magic Sword and TWRP knows how to put on a show.
I snapped a picture of Commander Meouchās pedal board because I couldnt help myself.
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Wave shaper is functional! Wellā¦ the 0 octave control and CV are. Iāll take it though! The volume mix knob is switched around - but I knew I had a 50/50 chance with that one going in. Hopefully hooking up the other six outputs wont be too much of a hassle.
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Its not going to win any beauty contests but my fixed sine wave generator bank has 8 different wavelengths going on now. Its based on the MSK 010 Fixed Sine Bank - North Coast Synthesis Ltd. design. The biggest annoyance with building this one has been the shoddy quality of the stripboard its on.
I have the space to add four more frequencies but it would be fun to mix things up a bit. I have a whole TL074 available for monkey business. I also have this IR reciever/flickering LED cluster that I could mess with (no remote though, sadly).
Any suggestions for another voltage source or two?
I do have a couple of LDRās kicking aroundā¦
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What sort of dark magic is this?
I imagine I am just being messed with and that it does indeed matter - and that the negative supply should go where the minus is.
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After a little poking around the schematics, I see a full bridge rectifier - so perhaps it is safe after all. I guess Iām just used to all of the op-amps requiring -12 to function properly.
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Itās still +/- 12V (minus a diode drop on each side, so closer to +/- 11.4V).
Yeah, nothing appears to be using -12 V in that.
I think I have seen modules with a clever power circuit that takes a cable plugged either way and in either case sends Ā±12 V to the right places. Canāt give you any details but Iād imagine itās a somewhat complicated bit of circuitry. Iād rather just use diodes and have it simply not work if the cableās reversed.
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With the full bridge rectifier as in the schematics, it does that, nothing complicatedā¦
If you plug the ribbon one way, one pair of diodes is always conducting.
If you plug it the other way, the other pair of diodes conduct and ācrossesā the two voltages.
Only drawback is the voltage drop.
Now go ahead and plug it in with the cable shifted one row of pins and test the limits of this āeither wayā statement. O the lengths developers go to to avoid using keyed connectorsā¦
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Keyed connectors wonāt always save you from reversal, but yeah, they do pretty much prevent offset errors.
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I am currently eyeballing a used 350$ MS-20 on facebook marketplace.
halp.
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Iād rather use a totally foolproof boxed header, butā¦
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I put a 1222 together thinking to myself āFinally - Iāll get a nice clean toneā. When I plugged it into my stripboard based test PSU, it sounded fantastic. Then when I plugged it into my case - the ripply sound that I get on the high end that has been plaguing me with all of my other oscillator builds is STILL there!
Iām starting to think that the FC Routemaster is just crappy. Iām not exactly sure what to do. I might need to drop 150$ on a used HP oscilloscope from the FB marketplace so I can get a better look at what is going on since my little yellow one does not seem up to the task. In the meantime I guess Iāll take the power supply out of the case.
Pretty demoralizing.
The Routemaster IS crappy, according to
For whatever reason they didnāt use a ground plane. And then they routed the ground all around the Horn and back when it could have been routed directly.
Added: Oops, I now see you replied to that so obviously not telling you anything you donāt know.
But if it sounded fine with the test PSU and bad with the Routemaster, that surely suggests it really is the supply.
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Yeah itās a piece of crap PCB design. Iāve notified Rick Holt of it on various media, but heās just been ignoring it. A real shame.
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I always just assumed that it was my lack of soldering skill that was the issue so it is pretty disheartening to hear that they are in fact THAT bad.
I might be in the market for some PCBs @TimMJN XD
Though this does leave the question of what to do with the 3 that I have already built. I suppose I could attempt that grounding trick to bridge the two ends of the loop. I dont know if trying to get in contact myself will do any goodā¦ squeaky wheel gets the grease and all that.
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yeah I have replaced most of my Frequency Central power boards . my friend that helps me make stuff work found that problem with the ground , no plane and the trace being inadequate . not that their stuff is bad just that you will move beyond the beginner stage real quick and need more power and more reliable power .
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https://frequencycentral.co.uk/
as a matter of opinion [ I own them ] they have some really great modules .
easy to build and not to expensive .
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