Pedal Output Impedance

Killens84

Killens84

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Sep 3, 2008
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#1
I recently bought a Way Huge Pork Loin, and just saw in the manual where it says the output impedance is < 25k ohms. That’s quite a bit higher than most other high-quality pedals I’ve seen. That makes me a little worried about high-end loss when the pedal is active, since I run a 15-20 foot cable to my amp after my pedalboard. Is the output impedance in the manual accurate, is it a typo, or am I reading that wrong? Here’s the link to the manual...
https://vidweb.aws.marketlive.com/jimdunlop_vid/text/content/pdp/manuals/WHE201.pdf
 
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#2
I have the Pork Loin. I'm not really tech savvy enough to say if the output impedance is correct. However, to my ears, the Pork Loin sounds fantastic with a bass guitar. I don't notice any high end loss at all. Of course, you may find otherwise. Let me know what you find out.
 
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#4
Yes it is, at the midpoint of the volume control. At either end, the impedance drops (down to a couple hundred ohms at full volume). This is because it uses a 100k volume pot, like a big muff. At midpoint you have a voltage divider of 50k in parallel with 50k, yeilding 25k output impedance.
 
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#5
jw23mind said:
Yes it is, at the midpoint of the volume control. At either end, the impedance drops (down to a couple hundred ohms at full volume). This is because it uses a 100k volume pot, like a big muff. At midpoint you have a voltage divider of 50k in parallel with 50k, yeilding 25k output impedance.
Click to expand...

Wow, that’s interesting. So as long as my volume control is in the lower or higher end of its range, the output impedance will be low? I think my volume knob is only around 8:00 or so. It’s pretty low, because that’s where I achieve unity gain. Maybe 9:00 at the most.
 
#6
jw23mind said:
Yes it is, at the midpoint of the volume control. At either end, the impedance drops (down to a couple hundred ohms at full volume). This is because it uses a 100k volume pot, like a big muff. At midpoint you have a voltage divider of 50k in parallel with 50k, yeilding 25k output impedance.
Click to expand...

Very good!:thumbsup:

It's worth noting that placing the level pot at the output is fairly common with a lot of pedals. The output pot on the Pork Loin can be changed to a 5K or 10K for lower output impedance, because the output opamp (LM833n) can drive 2K loads without difficulty.

-Frank
 
#8
Thanks for all the input. I ended up ordering a TC Electronic Bonafide buffer to put after the Pork Loin, which is at the end of my signal chain. It’s 1 meg input, and 100 ohms output. That’ll give me peace of mind, if I’m plugging into a passive DI or running a long cable to my amp. It was probably ok without the buffer, but my analytical side likes for the numbers to look good.
 
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