Pedal I/O 1U Noise w/ Chase Bliss Pedal

Hi, I recently got the Pedal I/O 1U to use with my favourite guitar pedal, Chase Bliss’ Dark World.

I have a 7U case and the 2nd Gen Audio board, so I connected the Pedal I/O directly to the audio board, and used the 1/4" jacks to run unbalanced TS cables from the case to the pedal and back. I had a sample of a piano playing (from the ER-301) running through the signal path.

Unfortunately, no matter how much I played with the signal levels on the sound source, the Pedal I/O, and the Dark World itself, I could not get a relatively clean signal of the pedal. It was very dark and very, very noisy with lots of digital artifacts (sound of the pedal processing) when the signals were raised to a high enough level to hear the effect.

Has anyone faced something like this? Any suggestions?

Thanks in advance!

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Interesting! Have you tried using only a cable (no pedal) connected between the 1/4" send and return? Is it still noisy then?

Hi thank you for your response!

I just tried your suggestion and when I patch the cable between send/return, the noise is gone: there is a clean sample playing. So I guess we could say that it’s not the Pedal I/O itself but the interaction between it and the Dark/World (D/W).

I also experimented more, and found that if I bypass the effects on the D/W (just running it through the pedal w/o effects turned on) the signal is basically just as clean as when self-patching the send/return in the case. But as soon as I turn on either the D/W side of the effect, the heavy noise/digital processing sounds are introduced again.

I’m powering the D/W with a standard Amazon-bought 9v (500mA) tip-negative adapter plugged into a Furhman power brick. From what I understand, this should be enough to power the pedal. The D/W manual says it requires “200mA or more. If you use a ‘standard’ outlet of 100mA, the pedal will not function properly.” But I’m pretty sure that means my adapter can handle it.

It also says input impedance of D/W is 1M, and output impedance less than 1k. I don’t know enough to understand what this means and if it could be the problem of compatibility with the Pedal I/O.

Just had an idea as I was writing this. Instead of going through the Pedal I/O, I just used a 1/8" to 1/4" cable directly from the ER-301 into the D/W and then 1/4" to 1/8" back into my Headphone 1U. Crazy thing–it fixed it. Now the noise and the digital artifacts are gone. It sounds way better. The only thing is that it sounds like the signal is overloading the D/W on some of the louder peaks. I’m wonder if I can just limit those peaks in the 301 because this signal is way cleaner.

Any idea what the problem is between the Pedal I/O and the D/W?

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I suspect the D/W might not like to have the input mixed with the output. Do you have the Pedal I/O MIX knob on maximum wetness? Also, have you optimized the SEND and RETURN levels?

Hi again, thank you for this.

I did try 100% wet, and to optimize send and return levels from the beginning. (By optimize, I imagine you mean adjust the knob levels, correct? There’s no other kind of optimizing feature that I’ve missed in the manual, is that right? :slight_smile:)

I’ve tried again after your last message 100% wet and to adjust the send and return levels, but unfortunately it has not helped.

With Mix at 100% wet, no matter what increments of Return and Send I set, the signal is either (1) too weak to register any of the effect from the pedal or (2) too noisy for the effect to be usable–there’s much more noise than effect.

Unless I’m missing something, I’ve literally tried everything in terms of knob settings on the Pedal I/O.

Thank you again for all your suggestions. If you have any more, please do let me know.

Any help is very much appreciated.

Let’s try to eliminate each variable:

  1. Send your signal from Pedal I/O SEND to Dark World and connect the D/W output to a guitar amp, if possible. If you don’t have a guitar amp, see if you can borrow one. If not possible, you could try an audio interface. See if the noise is present.

  2. Now try the reverse - guitar into D/W and D/W output into Pedal I/O RETURN. Any noise?

  3. You can also try plugging a guitar directly into the Pedal I/O RETURN to see what that does.

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Thank you kindly for troubleshooting with me. I truly appreciate it.

Unfortunately, my return-window was closing on the Pedal I/O and because I only bought it to use with the D/W, and couldn’t get it to work after days and hours of experimenting, I had no reason to keep it. So I sent it back to the shop for a refund.

Too bad.

In any case, thanks again!

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@Dasein1980 - I’m experiencing exactly the same problem you’ve described with the Pedal I/O 1U noise! Only difference is I’m using a Microcosm pedal, but the description you’ve given above is exactly the same. The Microcosm input itself (0% Send, 100% return) is clean, however when I send any signal to the pedal I get noise, just as you’ve described above.

Don’t Dark World and Microcosm both have line/ instrument level switching? Are you sure it’s set to instrument level? You could just be overdriving it, if it’s set to line.