Looking for something to build (a harmonizer type effect)

[dfx_pedalpcbs]

Anyone know of any harmonizer circuits out there worth doing and possibly able to be controlled with an expression pedal or is that done in the realms of digital land?

[blackieNYC]

(I bought a Behringer harmonizer and I love it.)

[iainpunk]

all harmonizers are digital, the only analog thing that comes close is ring modulation, but i don't think you are seeking a ring modulator.
a ring modulator creates the sum and difference frequencies between teh input and the carrier (internal tone generator).

cheers, Iain

[11-90-an]

all harmonizers are digital, the only analog thing that comes close is ring modulation, but i don't think you are seeking a ring modulator.
a ring modulator creates the sum and difference frequencies between teh input and the carrier (internal tone generator).

cheers, Iain

you *can* use a PLL to generate harmonics but... the signal quality will be compromised quite a lot since everything would end up as square waves (albeit heavily filtered ones)

[iainpunk]

all harmonizers are digital, the only analog thing that comes close is ring modulation, but i don't think you are seeking a ring modulator.
a ring modulator creates the sum and difference frequencies between teh input and the carrier (internal tone generator).

cheers, Iain

you *can* use a PLL to generate harmonics but... the signal quality will be compromised quite a lot since everything would end up as square waves (albeit heavily filtered ones)

hmm, yes, i totally forgot that. but its not really the clean harmony you'd seek from a harmonizer pedal.
if you make something like a Blue Box, you can get away with the square waves!

cheers, Iain

[dfx_pedalpcbs]

ok thanks guys

[Mark Hammer]

The Electronics and Music-Maker "Harmony Generator" will produce a variety of intervals, using CMOS counter/divider chips and a 4046 PLL to start from.  I've never been able to get mine working.

In the late '70s, A/DA produce a floor-pedal harmonizer, that used 44 different chips.  It was probably the largest floor pedal ever made in a cast-aluminum enclosure, and certainly the first non-rackmount harmonizer.

Usable harmonizers tend to be digital, largely because separating the true pitch information from everything else is complicated, even if the waveforms generated don't necessarily need to be replicas of the input (i.e., square-waves at designated intervals).  One wonders if something like an Arduino or Raspberry Pi Zero could do the requisite pitch interpretation and drive simple analog oscillators to achieve reliable and accurate harmonies.

[11-90-an]

M.H., might that harmonizer be this?

https://www.premierguitar.com/articles/Inside_the_ADA_Harmony_Synthesizer

And it seems from tharticle that it's polyphonic too... cool...

[mozz]

Isn't vibrato part of the sound of harmonizing? Doesn't a tuner pedal or clip on detect the fundamental? How about a transistorized version of a Magnatone pitch shift.

[Mark Hammer]

M.H., might that harmonizer be this?

https://www.premierguitar.com/articles/Inside_the_ADA_Harmony_Synthesizer

And it seems from tharticle that it's polyphonic too... cool...

Yes, that's the beast.  Because it uses bucket-brigade chips to achieve pitch-shift, rather than attempting to identify the specific pitch of the input note, it can be polyphonic.  Note that the Chase Bliss Thermae also uses bucket-brigade chips to achieve polyphonic "pitch jumps" in its repeats, although it does not "track" pitch to provide simultaneous harmonies. 

In the late '70s, EHX released the Hot Foot controller that could twist knobs, using a foot treadle.  The "killer app" for it was to manipulate the delay-time control on a Memory Man to achieve pitch bending, similar to what a Digitech Whammy pedal does in the digital domain.  Again, it could only change pitch after you played something, not concurrently.

[iainpunk]

Isn't vibrato part of the sound of harmonizing? Doesn't a tuner pedal or clip on detect the fundamental? How about a transistorized version of a Magnatone pitch shift.

magnatone vibrato is not like a harmonizer, a harmonizer creates notes a fixed ratio from the input, the vibrato is changing the frequency a very small bit up and down. if you put a clean path parallel to that vibrato circuit, you get the famous uni-vibe sound, where a harmonizer creates a chord.

tuner pedals look for zero-crossings to determine the fundamental of the note played

cheers, Iain