SOLVED Triangulum Boost High Frequency Noise

[punchy712]

I finished building the Triangulum Boost this weekend and I'm noticing an issue that I'm hoping someone may be able to provide some clues as to what may be going wrong. It's working for the most part in that it turns on and the one knob works as expected. The issue I'm hearing is that when the boost is increased it gets to a point where this really high frequency noise is introduced. I tried recording it but I haven't been able to capture it very well at all and it's also hard to explain in words. It's almost like a high frequency "rattle" that is introduced after a note. Easiest example would be if I were to just palm mute an open E; the palm muted note would be heard and then afterwards there's a trailing high frequency noise. It's like a ping or rattle, almost as if my cab were shaking, but it's not as I've never heard this kind of noise come out of it with any other sort of boost pedal.

In case it helps I'm using a JCM800 with a 4x12 to test it out.

 

[punchy712]

I wanted to look at the frequency spectrum so I plugged into my audio interface to run this test where I just played an open B (on my 7 string), capturing the following:
1. guitar straight in interface: nothing out of the ordinary seen in the frequency spectrum
2. guitar -> Triangulum (bypass) -> interface: small bump in the 16k-18k range
3. guitar -> Triangulum (switched on) -> interface: much bigger bump in the 16k-18k range

The above seems to line up with what I'm hearing, though honestly I'm really surprised there's an effect on the tone with the pedal bypassed.

I've attached the screenshots showing the above and I guess now I have two questions. Is the fact that there's an effect on the guitar input signal with the pedal bypassed a mistake in my build and secondly is this high frequency boost a part of the pedal design or did I do something wrong when building it?

I also found this thread that's discussing a similar issue I think: https://www.diystompboxes.com/smfforum/index.php?topic=128429.0

 

[Betty Wont]

What exact part did you use for the charge pump? Certain versions make audible high pitch noise.

 

[Paradox916]

This is exactly what I was thinking as well.

What exact part did you use for the charge pump? Certain versions make audible high pitch noise.

 

[punchy712]

What exact part did you use for the charge pump? Certain versions make audible high pitch noise.

Is the charge pump IC100 (TC1044SCPA)? If so, this is the part I used: https://www.mouser.ca/ProductDetail/579-TC1044SCPA

 

[Betty Wont]

Is the charge pump IC100 (TC1044SCPA)? If so, this is the part I used: https://www.mouser.ca/ProductDetail/579-TC1044SCPA

Yes, and you should be good there. Sorry, that’s all I have.

 

[Paradox916]

It’s been a while since I played mine, I never plugged it straight into my interface, but I’ll give it a shot and let you know what I experience.

 

[Cybercow]

How physically close is the pedal to the DI box? If the two units are physically close together, try a longer cord between them - say at least 6 feet - to see if the HF noise goes away.

 

[Guilherme Collateral]

Some pedals with charge pumps don't go very well plugged to some audio interfaces (and other pedals) . My Klon and my old Mackie interface gave me the same high pitch noise and was noiseless elsewhere

 

[punchy712]

Thanks all for the replies, really appreciate the help.

The DI box and pedal were far apart (pedal on the floor, DI on my desk)

Also note that the issue isn’t with the interface, I’m hearing the same issue with my amp as well. I used to the DI box just to see if can more objectively see what I’m hearing. I also tried plugging the pedal straight into the amp and same issue.

 

[Erik S]

Even though your pump IC is the correct part and from a reputable vendor, it’s worth trying a swap with another one. Certainly sounds like a noisy IC issue.

 

[mkstewartesq]

Even though your pump IC is the correct part and from a reputable vendor, it’s worth trying a swap with another one. Certainly sounds like a noisy IC issue.

Doesn’t replacing a 1044 with a 7660S variant (I understand the S suffix is important) usually solve these issues? I’ve always heard that the 7660S was functionally equivalent to the 1044 foot operated in such a fashion that it moved the potential whine out of the audio frequency range. I picked up a few myself to switch out the 1044s in my various builds based on that advice, but have not gotten around to actually trying it yet.

Mike

 

[Erik S]

Doesn’t replacing a 1044 with a 7660S variant (I understand the S suffix is important) usually solve these issues? I’ve always heard that the 7660S was functionally equivalent to the 1044 foot operated in such a fashion that it moved the potential whine out of the audio frequency range. I picked up a few myself to switch out the 1044s in my various builds based on that advice, but have not gotten around to actually trying it yet.

Mike

That sounds interesting! First I’ve heard of it though. I just always buy extra in case I get a noisy one. I’ve had luck just swapping to another IC from the same piece of foam.

 

[punchy712]

Thanks @mkstewartesq and @Erik S for the recommendations. I looked into charge pump issues a bit more last night and saw similar suggestions so I'll grab a few options to try out as they're cheap enough. Robert recommended a couple different options here, one of them being the 7660S as you mentioned and the other one being 7660H which runs at 120khz which should be well beyond any audible range.

A more general question, why am I seeing noise introduced by the pedal's circuit when in the chain but bypassed? Is it just EMI from the circuit, like the charge pump, that's getting picked up by the output wire? If that's the case would shielding the output wire in this case help?

 

[jesuscrisp]

It's usually an issue when daisy chaining charge pumped circuits.

 

[mkstewartesq]

It's usually an issue when daisy chaining charge pumped circuits.

it apparently can also pop up when only one pedal has a charge pump, if there is a pedal with a clock downstream. I use a GigRig loop switcher that takes in the inactive pedals completely out of the loop. One of my pedals is a two in one build containing a Cetus and a Tibe Scremaer - I was originally getting whine within that box so I replaced the 1044 in the Cetus with another 1044 and that solved that problem. But, even though they are separated by about four loops, if I run my Cetus at the same time as my MadBean Current Lover, the Current Lover picks up some whine from the Cetus. Which is why I bought some 7660s to swap in the Cetus to see if that fixed it (I’ve just been lazy and need to get off my ass to actually make the swap to see if it works).

Mike

 

[punchy712]

I got some new charge pump ICs today from Digikey this time and I'm happy to report that swapping in a 7660H fixed my high frequency noise issue. I can't hear any side effects from the IC swap, pedal seems to be functioning properly now. I did order another 1044 as well, just in case it was a supplier issue, but I had the same noise in my pedals with it.

Thank you all for the help.