Hello everyone. Happy new year. May this one be better for all.
I would like to ask you what do you think could have gone wrong after following this simple schematic- layout and having no sound out of it.
http://aletheia.co.jp/kawaikoji/2010/04/24/thing-modulator%E3%83%AC%E3%82%A4%E3%82%A2%E3%82%A6%E3%83%88/
My solder joints are good (I've built and repair several pedals and pre amps), there is proper continuity in my circuit and I've used a couple of different 100uf caps and LMC 567 ics.
Actually there is an oscillation sound on the out, but there is no guitar sound coming from the in. Both in and outs are properly grounded on the chassis.
Does the schematic actually work?
Thanks in advance
Use the audio probe and check that the input signal is getting to pin 2.
Use the multimeter and check there's 9v at pin 4, and 0v at pin 7.
Actually I checked with an oscilloscope the in and the out. And of course I 've checked all grounds. Pin 4 takes around 1V after the 100k resistor- 1uf cap junction.
100k at pin 4 (power) seems real unlikely.
Agree with Paul, the 100k is limiting the current to below the device's minimum. A 10k there will put it in range.
I have to admit that I tried with either omitting just the 100k resistor and both cap and resistor on the supply, but the result is the same, just noisier. No guitar sound coming from the out. The oscilloscope showing a much smaller signal using a 1k, 1V sinewave
Quote from: MikeA on January 01, 2021, 05:02:05 PM
Agree with Paul, the 100k is limiting the current to below the device's minimum. A 10k there will put it in range.
Thanks Mike. I will try it too.
I'm having trouble understanding what the output should sound like when it's working. This is a tone decoder hacked to make a ring modulator? The output is the phase detector of a PLL, with the center frequency set by the external pot controlling the VCO. Input is an audio signal. Would that make a ring mod?
<EDIT: Apparently it does! Clearly I don't know ring moduators. https://www.diystompboxes.com/smfforum/index.php?topic=104440.20 >
People say that it sounds weird, in a good way for some, and that it's a verified schematic. The thing is I can't tell since there is no actual mixed signal coming out. Just faint noise without any guitar.
Google seems to think people have made this before. There's even an Instructable! There's even an video sample. Looks like this guy added a single op-amp. But states the circuit is based on Tim Escobedo's Thing Modulator
- https://www.instructables.com/Ring-Modulator-Pedal/
Bravos dis this also, and made a video! It sounds like like a ring mod.
- http://beavisaudio.com/beavisboard/projects/bbp_567Mod.pdf
- https://youtu.be/EArcT20xSeY
Ooh here's another! This one is fun to listen to. Looks like this was modded. Seems like they added a light sensitive control that is either mixing or engaging the effect and he's controlling the effect with his. I wonder if there's a schematic?
https://www.youtube.com/watch?v=OcWauvJM1j4
Looks people have been talking about this here for years: https://www.diystompboxes.com/smfforum/index.php?topic=46995.0
It works just fine, I've made a few with different strategies for "carrier suppression" and noise. The 100k value is correct, and if course you can noodle with it. 100k/100u got rid of a ton of the oscillator whine. Super cool, albeit limited.
Thanks everybody for the input, it seems like a a verified project, but could you please help me a bit more and tell me where could I have a problem and mine doesn't function? There are no voltages available to compare. I seriously doubt that all 5 of my ICs are bad. The Beavis audio one is totally different and it uses the LM567 . My version uses the LMC567. Totally different IC.
Nearly sorted. A bad solder joint and either a bad 100k resistor or 100uf cap. The joint was a very slight mistake around pin 3 (in) and then nothing really was coming from the out, but the oscilloscope was showing that there is good signal on pin 3. I omitted both voltage cap and resistor, and with 9V it was working. Noisy but very interesting. So from now on it's just a matter of experimentation with different caps and resistors. I guess an input voltage of around 3-4 Volts would be ideal, since 9 is way too noisy and 1 doesn't really start the IC. I insist. We 're talking about the LMC567 (the CMOS version of LM567).
After sorting completely this version I will try the instructable one since it combines a Lo Pass filter around the out, for much better control of the signal. There is also this interesting version as well.
https://electro-music.com/forum/post-226159.html
Thanks again for the input and advice. Cheers.
ps. After a bit of voltage supply experimentation on pin 4, I decided that for my guitar taste it works better with a voltage between 3.5V - 5V
QuoteA bad solder joint and either a bad 100k resistor or 100uf cap. The joint was a very slight mistake...
Of course it's a bad joint, it almost always is with newer members. The allure of blaming things on a bad part can waste a lot of time, remember this in the future. And no, not a slight mistake, a huge mistake, preventing you from using the device.
Also, the LM567 and LMC567 are not totally different at all, what are you talking about? They're the same, one is CMOS, it's lower power so lower noise/carrier. Same pinout even, same technique/hack, which comes from Tim Escobedo, sans surprise.
I totally accept my initial mistake, but it's weird that it doesn't work with the schematic resistor - cap combination and this continuous trial-error thing made me solder carelessly. Is there a possibility that a series of 5 ICs have different specs (maybe because they are cheap ebay ones)? What is the correct voltage on pin 4 for such a project (and maybe on pin 5 and 6)? Any idea? For the time being I've started the instructable version. The basic version is cool but quite uncontrollable in a way.
sorry to be so grumpy.
Quoteweird that it doesn't work with the schematic resistor - cap combination
QuoteIs there a possibility that a series of 5 ICs have different specs (maybe because they are cheap ebay ones)?
These ICs are for outdated technology, there's a good chance they're the same ICs Escobedo and Dano and everyone else were using, although they might be out-of-spec. How anyone outside of weirdo DIY music gear world ends up with a stash of these in the 21st Century, I don't know. Are dedicated tone decoder ICs still used for something? I can't imagine these do anything µC don't. I have a few in my stash, I'll try throwing something together on the breadboard in the next few days and report back.
Sorry to hear it doesn't work, the Thing Mod is a lot of fun. You couldn't really gig with these pedal designs in a loud club or bigger, but they're cool if noise is part of the aesthetic, or if you can finesse a gate/adsr that works for your playing.
I think you're right about outdated ICs. It wouldn't be the firs time to find an out of spec one (I remember a bb combo some time ago for a chorus). If you try with a voltage supply of around 4V you may discover that the noise is not so bad. And yes it's fun for certain passages. Maybe the other schematics are more developed.
well, there is always this difference:
Comparison Table
DEVICE NUMBER DESCRIPTION
LMC567 Low power tone decoder
LM567, LM567C General-purpose tone decoder with half oscillator frequency than LMC567
(please don't bite.)
Just for your interest.
I found some time to make some changes. So for the thing modulator what works for me is changing the 9v resistor to 1k (100uf for the coupling cap is ok). The rest of the circuit works fine.
Then for the instructables circuit (ring modulator and low pass filter combined), change the LPF input resistors of 100k and 4.7k from the modulator IC out, to just a 100nf cap from the IC1 out straight to the IC2 input. (And maybe the 10uf supply cap of the op amp to 47uf- at least that's what I did). It works much better that way for me.
Cheers.
^ glad you got it working! Time to make some weird sounds now ;D