Check your Impedance!

[metropolis_4]

All this testing with the HX Stomp really has me amazed at how huge a difference input impedance has on the sound and the way the attack feels. Here's a quick (and suuuuper dirty) test I recorded showing some examples. I'm going to be using this a lot more from now on. There's a lot of potential to pull back in the mix or poke out more in the mix depending on the song.

I like the softening of the attack of 70k on the Tele, but on the Les Paul I'm split. I think if I was playing lots of palm muting or percussive stuff on the low strings I'd prefer 1meg, but I'd prefer 136k to round off jangly stuff like high arpeggios, or even down super low for stuff like cocktail jazz hour behind a piano.

If you haven't messed with it before, it's something that's definitely worth checking out that can have a major impact on tone and feel.


Here's a breakdown of the guitar and impedance settings for the clips:

1. Telecaster
   1. 70kOhm
   2. AUTO
2. Telecaster
   1. 70kOhm
   2. AUTO
3. Les Paul
   1. 136kOhm
   2. AUTO
4. Les Paul
   1. 136kOhm
   2. AUTO

Nothing else was changed in the signal path other than the input impedance. Amp model was the Divided Duo with a York 112 Blue IR. Red Squeeze comp in front (mix 47%) and an EQ after the amp (+10db@200Hz | +2.7db@6.2kHz).

(Please excuse the sloppy timing and tuning. I recorded guitars first just to listen back for myself to hear what the differences sounded like when I wasn't playing... then thought it would be fun to add drums/bass to hear a mix... then thought I might as well share here)

 

[Badonkey Kong]

Cool test! I agree on the Tele preference but a little more split on the Les Paul clips. But I'm listening on crap speakers at the moment that tend to round of the highs anyway. Thanks for sharing. Not sure i want a new rabbit hole to dive down at the moment

 

[DrewJD82]

No u.

 

[la szum]

AUTO sounds better to my ears. Sorry.

AUTO also seems to have more dynamic range.... lowering the Input Impedance looks
to be compressing the signal a bit and muting the attack and chime of the Tele.

 

[jay mitchell]

For folks whose modelers don't have variable input impedance, there's this: Dragster Load Correction
If you're averse to spending ca. $70 for a few bucks' worth of parts, it's a trivial project to build one: you place a potentiometer of ca. 1meg or greater value between your guitar's output and ground. Voila! Infinitely variable load impedance.

 

[the-trooper]

If you haven't messed with it before

Messed with it a lot. Just went back to auto.

 

[metropolis_4]

No u.

Sorry, "Check yor impedance!"

 

[James Freeman]

Way too "chimy" on AUTO with the Tele, almost screechy.
The Les Paul is less susceptible to that, but also benefits from the lower impedance.
In my opinion form what I hear.

 

[Stone]

I often play around with Impedence to what sounds better for me, and Its not always on auto Ive used 70, 90 and 136 as well with great results, but depends on the guitar pickups and what and where is in the chain
YMMV

 

[metropolis_4]

Way too "chimy" on AUTO with the Tele, almost screechy.
The Les Paul is less susceptible to that, but also benefits from the lower impedance.
In my opinion form what I hear.

Those were my feelings too. The Les Paul I could see using either one depending on what I'm going for. But I'm not a fan of that Tele sound on AUTO.
It felt really abrasive and hard playing too.

That was with the amp presence at 0 and tone around 5, so there really wasn't anywhere else to go if I was just depending on the amp settings to get rid of that screech.

Lower impedance settings respond more like my Kemper to me. I'm wondering if one of the things I love about the feel of the Kemper might be a difference in the input impedance?

 

[jay mitchell]

In addition to shunt resistance, guitar pickups are sensitive to shunt capacitance. Variable capacitors are typically larger than pots and can cost more as well. Here's one example that would work: VARIABLE AIR CAPACITOR . Another way to experiment with this is to build or buy different-length cables made from the same wire. Longer cables have more shunt capacitance.

 

[la szum]

.
It felt really abrasive and hard playing too.

That's what a Telecaster do!!

 

[the-trooper]

I'm not a fan of that Tele sound

Follow the words of wisdom written here, disregard everything before and after them, that is how you fix your issues.

 

[HotRats]

Tried auto or different values but I always come back to fixed 1 mega Ohm (or whatever is helix highest value)

I don't use fuzz pedals.

 

[la szum]

Lower impedance/more compressed settings respond more like my Kemper to me. I'm wondering if one of the things I love about the feel of the Kemper might be a difference in the input compression?

Sorry. Can't help myself. Just that one of the noteworthy qualities of the Kemper is that more compressed/rounded off/squished
nature.

 

[Bob Zaod]

I don't really get too technical about that stuff but I will see if messing with it does anything for me. I do change guitars a couple times a night from P-90's to HB's etc etc..

 

[bigcupholder]

An EQ block would be more flexible in the sense that you still get a clean DI for re-amping in case you went too far with killing the treble. It would react differently when you roll down your volume knob, but I'm not sure either way is better than the other in that sense.

 

[Desertdweller]

This is a good tip. When I had a HX Stomp, I didn't like it until I set the input impedance to the highest option possible. For some reason the "auto" wasn't quite right for me either.

Here's a quick snip from the manual on this topic:

Input Settings Page 2 Knob 1
In-Z
HX Stomp has an impedance circuit on its Main L/R
inputs that affects tone and feel by loading your
guitar's pickups as they would by an effect pedal or
amplifier. A lower value will typically result in some
high frequency attenuation, lower gain, and an overall
"softer" feel. A higher value provides full frequency
response, higher gain, and an overall "tighter" feel.

 

[metropolis_4]

An EQ block would be more flexible in the sense that you still get a clean DI for re-amping in case you went too far with killing the treble. It would react differently when you roll down your volume knob, but I'm not sure either way is better than the other in that sense.

Maybe? But input impedance seems to have much more of an effect besides just a shift in EQ. Lower values make the attack feel softer and rounder.

Even if I could dial in something similar with an EQ It's way faster and easier to just dial it up in the input on the Stomp, plus that way I don't have to take up a block with an EQ (there are only 8 blocks to begin with).

 

[bigcupholder]

Maybe? But input impedance seems to have much more of an effect besides just a shift in EQ. Lower values make the attack feel softer and rounder.

Even if I could dial in something similar with an EQ It's way faster and easier to just dial it up in the input on the Stomp, plus that way I don't have to take up a block with an EQ (there are only 8 blocks to begin with).

Good point about the block limits on the Stomp. If it does what you want, by all means go with the simpler option.

The lower impedance is not doing anything other than rolling off high end though. There's nothing nonlinear about about the response of a lower input impedance itself. It's the compression or distortion later in your preset that's reacting differently.