SOLVED Need some ears to help me with a client’s concern about some ‘fizzle’

[KR Sound]

I built a Dane and a circuit that’s basically the Lightspeed side and he’s concerned about this fizzle sound that I can barely hear.

https://on.soundcloud.com/B6qMhXm1vpW3L6Ri7

Right at 10 seconds and 28 seconds he says.

He just sent it back to me so I’m going to see if I can reproduce this ‘sound’, but is this a bit much or what? ¯\_(ツ)_/¯

 

[Nostradoomus]

Yeah it's a nothingburger unless you are zappa's central scrutinizer

 

[Locrian99]

Yeah it's a nothingburger unless you are zappa's central scrutinizer

Gtfo of the white zone!

 

[Feral Feline]

Distinct at time-codes Nostrodoomus pointed out, and again @ 50 and elsewhere.

I'm using headphones, and it's distinctly there, a sort of phasing sound on the decay's middle of a single held note; the fizzle cuts off abruptly just before the note itself drops out.

I can't say there's anything wrong with the circuit or op-amp choice because I honestly don't have enough experience to know, but that "fizzle" is there and I would NOT say it's insignificant. It may not be prominently in your face, but it's more than inconsequential — can you test it at stage volumes in a mix? Doubt it would be heard most contexts, but during an intro or interlude that has long sustained single notes where the rest of the band drops out — I think it'd be heard, then.

 

[Noodles]

Yeah it's a nothingburger unless you are zappa's central scrutinizer

....or Eric Johnson.

If the customer wants to buy a Hotcake-style circuit, run the other way.

 

[jesuscrisp]

Honestly, I can't tell and I'm super sensitive to thus kind of stuff. But just to check, could you share the schematic? Maybe running it at higher voltage helps otherwise. But sometimes people are just people.

 

[Nostradoomus]

Honestly, I can't tell and I'm super sensitive to thus kind of stuff. But just to check, could you share the schematic? Maybe running it at higher voltage helps otherwise. But sometimes people are just people.

WIth headphones on it's pretty apparent. I'm guessing there's some crossover distortion or something happening with the amount of op amps and diodes in those 2 circuits. Once @KR Sound gets it back we can suss it out, might be coming from just the lightspeed side but who knows.

 

[jesuscrisp]

WIth headphones on it's pretty apparent. I'm guessing there's some crossover distortion or something happening with the amount of op amps and diodes in those 2 circuits. Once @KR Sound gets it back we can suss it out, might be coming from just the lightspeed side but who knows.

Maybe some issue with overlapping or parallel traces. Those circuits really aren't complex though...

 

[jwin615]

Need $25 in power supply filtering.

 

[Nostradoomus]

I finally found a youtube demo of an opamp drive where someone holds notes out. You can hear the same thing happening here, go to about 7:15 with headphones on and listen to the fizzle out on the decay

 

[KR Sound]

Here’s another audio recording of him playing the PPCB Fordoble Boost where he’s getting the same sound. Same circuit I guess.

https://on.soundcloud.com/eLTbZcuJA9DCe4NUA

 

[Nostradoomus]

are we sure his amp doesn't have crossover distortion

 

[jesuscrisp]

Are you sure your OPA2134s are legit BTW?

 

[KR Sound]

Are you sure your OPA2134s are legit BTW?

Ya, they are direct from Mouser. Im going to swap in some 072s when I get it just to see if anything’s different. I have a couple other OPAs coming from Mouser for another project on Thursday also

 

[Aentons]

I can hear it no problem. Stuff like that makes clean reverb and delays sound trashy. It reminds me of the bleed you get on bypassed TS9.

 

[pbrommer]

I can hear it no problem. Stuff like that makes clean reverb and delays sound trashy. It reminds me of the bleed you get on bypassed TS9.

I’m listening through my crappy iPhone speakers and hear that decay. It sound thought I heard it before he even clicked the pedal on. It sounds like a really weird frequency that the guitar/amp/pedal resonance at to have weird responses.

But I don’t know a thing. I just play for fun, build pedals/amps/guitars at a slightly above terrible level.

 

[KR Sound]

The dude actually wrote to Brian Wampler about it. Wow. I don’t even.

“
I was thinking more about the fizzle sound and sent a message to Brian Wampler to pick his brain… he actually got back to me lol

Here’s what he said about those fizzles


“The fizzle sound: I think it’s just a result of a non inverting soft clipping arrangement, where you have multiple diodes in series, which raises up the clipping threshold a bit.

Try removing some diodes, i.e. one diode in one direction, 2 in the other. You can also just filter out more highs, both in the LP filter after the first OA, and in the tone control section.
Also, you don’t need that last 1uf after the volume, you’re already blocking DC from the 1uf after the second op amp.

If you do the diode changes, you’ll likely need more volume since the 25k tone pot and the 100k volume pot creates a big voltage divider, making the output signal smaller. You might consider buffering before the volume pot, or change the values of the tone control so you can use a smaller tone pot.”

 

[Nostradoomus]

Someone had to speak to the manager

 

[Synchrony Pedalworks]

Wow! I am impressed with the resourcefulness of the client.

I also listened to the sound clip. If you hadn’t have told me that the fizzle was there, I would have not identified it.

I will do client work too, but this gig is still a hobby. If I was in this situation, I might consider refunding him the cost, minus the shipping, and call it a day. It may be more hassle to satisfy the client’s wishes.

 

[KR Sound]

Wow! I am impressed with the resourcefulness of the client.

I also listened to the sound clip. If you hadn’t have told me that the fizzle was there, I would have not identified it.

I will do client work too, but this gig is still a hobby. If I was in this situation, I might consider refunding him the cost, minus the shipping, and call it a day. It may be more hassle to satisfy the client’s wishes.

Ya, I’ve already offered that but he doesn’t want his money back. Yet at least

 

[Noodles]

Ya, I’ve already offered that but he doesn’t want his money back. Yet at least

Maybe get Wampler to suggest this to him