Strange amp/expander behavior

[NewtoReeds]

I have noticed when playing my Ciao that there is a strange effect when playing through my fender sidekick 60 or my headphones. It almost sounds like a flanger or phaser pedal type sound is there, it's quite distracting, and I wonder if anyone else has experienced this?

 

[Airy]

How is it wired? As the FX‘s name ”phaser” already implies this seems like a phase problem which is most likely caused by wrong wiring eg when adapting stereo leads to mono or by DIY plugs.

 

[NewtoReeds]

As far as wiring, I don't really know what's going on in the expander, but the manual stated if I was only using one output to use the one marked "left" on the expander. Headphones in the one marked "phones". I had wondered if it may be an artifact of only using one output.

 

[Airy]

Please write in detail what connentions with what plug types you use.
Like:

Expander left out > TRRS stereo jack, cable, TRRS stereo jack > Input 3 of Fender Side Kick 60

BTW: TRRS means „tip, ring, ring, sleve“ and is a 4 pole connection as opposed to TRS which has 3 poles only.

And pls give me a hint what expander you are referring to. Is „Ciao“ the brand of the accordion or the expander?

 

[NewtoReeds]

Please write in detail what connentions with what plug types you use.
Like:

Expander left out > TRRS stereo jack, cable, TRRS stereo jack > Input 3 of Fender Side Kick 60

BTW: TRRS means „tip, ring, ring, sleve“ and is a 4 pole connection as opposed to TRS which has 3 poles only.

And pls give me a hint what expander you are referring to. Is „Ciao“ the brand of the accordion or the expander?

Ruling out the actual firing cable, it's expander left out, into a TRS cable, Input 1 of the Sidekick. Ciao is the midi system developed by SEM and was the branding used on both the accordion and the expander in the States.

 

[dak]

Ruling out the actual firing cable, it's expander left out, into a TRS cable, Input 1 of the Sidekick. Ciao is the midi system developed by SEM and was the branding used on both the accordion and the expander in the States.

The Fender Sidekick looks like an amp with unbalanced mono input connections to me. Do not use a TRS cable with it but a TS cable. I don't know what kind of output the SEM expander has.

 

[Airy]

… expander left out, into a TRS cable, Input 1 of the Sidekick.

When a stereo device offers a „left/mono out“ this means that using only the left output will mix both stereo channels to a mono signal. So, you are doing it correctly.

But as @dak suggested: If the manual doesn‘t tell you to use a so called „balanced“ cable (means TRS) use a simple TS cable eg what e-guitars use.

EDIT:
Overthinking my answer, it is not crucial whether the expander offers a balanced (TRS) or unbalanced (TS) output. The rule is: if ANY ONE of both devices (sending or receiving) offers only the more electrically simple unbalanced (TS) use unbalanced for the connection.
So, even if one device uses the slightly more sophisticated balanced signal processing, this device will also work with the simple unbalanced (TS) cables/plugs.

 

[NewtoReeds]

So, I took another look at the cable, and it is a TS cable. I will have to see if if I have a TRS around somewhere.

 

[dak]

So, I took another look at the cable, and it is a TS cable. I will have to see if if I have a TRS around somewhere.

Why? A TS cable cannot cause a "phaser" effect. It will transmit exactly one signal. If both input and output are actually balanced sockets, it may result in a higher hum (or possibly other noise) than necessary. If there is a mismatch of balanced and unbalanced outputs, it will unbalance the connection properly. If the input is actually a stereo input, it will transmit the signal to the left input and leave the right input dead. If the output is actually a stereo output, it will transmit only the left signal.

So your problem must lie elsewhere. Assuming that the TS cable is operative.

 

[Airy]

@NewtoReeds

• Well, if the cable connection is presumably not the culprit what if you’re listening directly from the headphone output. Do you’re have a proper headphone to test?
• Can you rule out that the amp has a problem? eg plugging in a different sound source which you know is ok

 

[dak]

Which reminds me: classic "phaser" effects can be caused by

a) using a headphone (unbalanced stereo) on a balanced mono output
b) headphone or headphone socket with a broken ground connection: that gives you the difference signal between left and right signal on the headphones, but with different polarity on the left and right side

A corollary of case b) is not plugging the headphone connector in completely.

 

[NewtoReeds]

@dak I do have headphones to test, a budget friendly pair of studio headphones- and I honestly can't rule out that there may be an issue with the amp. I'd like to chase this down as it is making me dizzy when I play.

 

[Airy]

... I do have headphones to test,
... and I honestly can't rule out that there may be an issue with the amp.

You definately know how to sustain tension !

So, what single / isolated device now is generating or revealing the phasing issue?

 

[NewtoReeds]

Amp, expander and accordion are all fine... Just some 60hz hum, I guess over in Germany you would have 50hz him

Just gotta try the headphones and...it's far less pronounced and irritating than it was. Strange, because nothing has changed other than the passage of time. Thanks for the primer on TS/TRS/TRRS though! I had genuinely no idea there were so many types of audio cables!