# Pendulum Harmonic Tremolo



## phi1 (Mar 31, 2022)

I wish I was cool enough to make this enclosure. This pedal belonged to my neighbor as a kliche build that he’d bought on reverb. It was not working, and he was more interested in having me make a klon similar to my own build’s look and mods, so we did that. I’m sure the kliche could have been repaired, but we decided it’d be fun to re-build with a pendulum circuit. Cool effect to go with the hydro-dip.

I’d been curious to try this one to see how it compares to the Jon Patton Cardinal tremolo I’d built. They have some similarities, but each have their own sound. The cardinal seems a bit warmer in the top end, maybe due to some caps on the jfets G-D, or just the jfet topology in general. The frequencies of the hpf and LpF are different. These can be adjusted by capacitors, and though I tried the pendulum with theoretically the same frequencies as the cardinal, it didn’t sound quite the same. Not in a bad way though, both sound cool. Stock, the pendulum has more mid-scoop and a more phasey character, while the cardinal doesn’t scoop the mids, and the phasing sound is more subtle. Bringing the HPF cutoff frequency on the pendulum down brings it closer to the cardinal, but still not the same.  There’s other factors, like jfets vs op amps, or how the ldr attenuation is situated in the circuit, that may contribute to the different overall sound. 

I ended up making a little vero board to switch between 2 HPF settings. Stock 6n8, and then the dip switches bring in a 3n3 in parallel, bringing the total to around 10n. The difference isn’t crazy drastic, but enough to make a difference. Stock is a bit more scooped and phasey, with the 3n3 added the mids back a bit. (Both 1&2 of the dip sw are tied together, it’s just what I had handy. Could have made even more C settings but this was enough for me).  I added solder to the cap in socket after I was done selecting.

Overall a fun and satisfying build. One more thing to note, which has been discussed on other reports is to physically adjust the led/ldr spacing to get the right balance between the two sides. After I play with it some more it will go back to my neighbor, since I already have the cardinal.


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## Dan0h (Mar 31, 2022)

Your vero add on is awesome love the dips. I might try the same thing as I wasn’t aware of the Phasey-ness of this build until I had ordered the board.


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## phi1 (Mar 31, 2022)

You could do something by similar in the LPF side, after socketing and checking I just went with the HPF cap switch. If I would have thought of it sooner, could probably put the 1uF cap on the underside of the board, maybe bent 90deg. That way, the vero doesn’t have to be above the cap like mine (kind of unsteady since the leads to pcb are long.


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## Dan0h (Mar 31, 2022)

phi1 said:


> You could do something by similar in the LPF side, after socketing and checking I just went with the HPF cap switch. If I would have thought of it sooner, could probably put the 1uF cap on the underside of the board, maybe bent 90deg. That way, the vero doesn’t have to be above the cap like mine (kind of unsteady since the leads to pcb are long.


I had planned on socketing the caps and trying a few out based on another post I saw. For some reason my Tayda order has been stuck “Packing” almost a week now. That’s never happened before, they must be slammed right now. But once I have the parts I’ll try some things out.


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## phi1 (Mar 31, 2022)

Any chance you ordered Uv print or custom drilling? I’ve had stuff stuck in packing because there was a problem with the files in the dashboard.


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## almondcity (Mar 31, 2022)

Dan0h said:


> I had planned on socketing the caps and trying a few out based on another post I saw. For some reason my Tayda order has been stuck “Packing” almost a week now. That’s never happened before, they must be slammed right now. But once I have the parts I’ll try some things out.


I think Tayda is super backed up, or may be in the middle of their holiday. I ordered DHL shipping on an order a week ago and it's still packing. Last time I ordered that shipping it was at my door in 3 days


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## almondcity (Mar 31, 2022)

This is one of the coolest paint jobs I've seen!


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## Dan0h (Mar 31, 2022)

almondcity said:


> I think Tayda is super backed up, or may be in the middle of their holiday. I ordered DHL shipping on an order a week ago and it's still packing. Last time I ordered that shipping it was at my door in 3 days


Agreed and same story for me. I always pay up for the fast shipping and it always arrives insanely quick considering how far away it is. Let’s hope they wrap things up this weekend.


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## Dan0h (Apr 2, 2022)

almondcity said:


> I think Tayda is super backed up, or may be in the middle of their holiday. I ordered DHL shipping on an order a week ago and it's still packing. Last time I ordered that shipping it was at my door in 3 days


Says my order is on the way due to arrive Tuesday. Hope they got yours out the door as well. Enjoy new parts day!


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## almondcity (Apr 2, 2022)

Dan0h said:


> Says my order is on the way due to arrive Tuesday. Hope they got yours out the door as well. Enjoy new parts day!


I just submitted a ticket for my DHL order that still hasn't shipped in over a week. Meanwhile my next order with slow shipping shipped today. Baffling


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## fig (Apr 2, 2022)

Beautiful pour and build. I'm also very appreciate of the build notes as I have this one coming up soon.


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## phi1 (Apr 2, 2022)

Thanks! Wish I could take credit for the finish, this was a re-gut of a broken pedal. I think the effect is a nice match for it.


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## jesuscrisp (Apr 3, 2022)

Nice build! Built the Pendulum myself and the midscoop really bothered me. Ended up putting a 4n7 cap across the volume pot and changing the output cap to 68n, that got rid of the huge emphasis on the treble and bass, now it's rather transparent in terms of EQ. Found it unusable with drive and fuzz pedals before, now it works like a charm.


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## Boba7 (Jul 1, 2022)

phi1 said:


> I wish I was cool enough to make this enclosure. This pedal belonged to my neighbor as a kliche build that he’d bought on reverb. It was not working, and he was more interested in having me make a klon similar to my own build’s look and mods, so we did that. I’m sure the kliche could have been repaired, but we decided it’d be fun to re-build with a pendulum circuit. Cool effect to go with the hydro-dip.
> 
> I’d been curious to try this one to see how it compares to the Jon Patton Cardinal tremolo I’d built. They have some similarities, but each have their own sound. The cardinal seems a bit warmer in the top end, maybe due to some caps on the jfets G-D, or just the jfet topology in general. The frequencies of the hpf and LpF are different. These can be adjusted by capacitors, and though I tried the pendulum with theoretically the same frequencies as the cardinal, it didn’t sound quite the same. Not in a bad way though, both sound cool. Stock, the pendulum has more mid-scoop and a more phasey character, while the cardinal doesn’t scoop the mids, and the phasing sound is more subtle. Bringing the HPF cutoff frequency on the pendulum down brings it closer to the cardinal, but still not the same.  There’s other factors, like jfets vs op amps, or how the ldr attenuation is situated in the circuit, that may contribute to the different overall sound.
> 
> ...


Very nice build!

I wonder about the HPF section of the pendulum. It seems the cutoff frequency is 1950Hz, which seems very high, as I remember both the Cardinal and the Twin Peaks tremolos use a cutoff frequency of about 750Hz

The LPF section seems a bit more standard (400Hz, the cutoff chosen by the Zeppelin tremolo. Cardinal uses 150Hz and Twin Peaks 650Hz)

So I wonder if the HPF is part of the problem, as a lot of build reports mention sound issues. Put a 10n or 12n in parallel with the stock 6n8, and I think the sound would improve a lot. Or am I missing something? @PedalPCB, did you chose that cutoff frequency with another circuit or in mind, or just listening to the sound?


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## phi1 (Jul 1, 2022)

I recommend socketing both the HPF and LPF caps and experimenting. On my dip switch, I ended up with only 3n3 in parallel with 6n8. Higher caps sounded nice too, just taste at that point. 

Matching the Cardinal cutoff frequencies didn’t make it sound identical to my ears. 

Also mess with the led/ldr placement, it has a big impact on the gain and balance between bass/treble. 

IMO the stock pendulum setting doesn’t sound bad, pretty cool actually, more of a noticeable phasey effect.


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## Robert (Jul 1, 2022)

The values were chosen audibly for the maximum about of swoosh.   

It seems some folks prefer to reduce the phasing effect, but that's part of the charm of a harmonic tremolo for me.

There's nothing wrong with toning it down if that's what you prefer.


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## swelchy (Jul 1, 2022)

Sweet dip!... I did a swirl recently.... non dip.... pour over


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## Robert (Jul 1, 2022)

I built a little contraption a few years ago to do "spin art" on an enclosure.

I may have gotten a little carried away with my choice of motors, you should have seen the enclosure fly off of that sucker.   😵‍💫😵


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## phi1 (Jul 1, 2022)

@swelchy very cool! Nice job. Maybe this one was poured, I don’t know haha. The housing was salvaged from a broken pedal so I didn’t do the finish.


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