Output Impedance Question

[les_chupacabra]

So we want high impedance inputs and low impedance outputs.

Typical input impedance values seem to be from 500k to 1M (ZVex SHO = >5M)

What's considered "low" impedance? I think vintage Rats are around 1k but I've also seen pedals w/ a couple hundred ohm output impedance.

I was just looking at the Moog Phaser and its input impedance is 1M and output = 5000 ohm = 5k ohm.

Is that likely to cause any problems? Just stick a buffer/booster after it and call it good?

Thanks!


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AUDIO IN 1/4" phone jack - accepts any instrument-level or line-level audio signal from -16 dBm to +4 dbm. Input impedance is one megohm.

AUDIO OUT 1/4" phone jack - -4 dBm nominal output level. +8 dBm absolute maximum output level. Output impedance is 5,000 ohms.////

[Eric H]

The general "rule" is to have the input-impedance -at least- 5 times greater than the output (preferably 10 times). so in the case of the moog an input impedance of 25k would probably be adequate .  You would need a buffer (DI) with many recording consoles.

[brett]

Hi.  

output = 5000 ohm = 5k ohm

That could (maybe) be an issue for driving a fuzzface or Miss Piggy, which have about 10k of input Z.  Most other pedals that I can think of have much higher input Z.

cheers

[les_chupacabra]

So what really matters is what comes next in the chain? And anything that's greater than 25k (5k*5) would be fine?  Great - sounds like it shouldn't cause any problems - this would be inline w/ a couple other guitar pedals but no fuzzface (at this point) - not really at a console but that's good to know.

Thanks!

[Eric H]

So what really matters is what comes next in the chain?

Yes

And anything that's greater than 25k (5k*5) would be fine?  Great - sounds like it shouldn't cause any problems - this would be inline w/ a couple other guitar pedals but no fuzzface (at this point)

just put the fuzzface at the start of the chain

- not really at a console but that's good to know.

Older consoles generally had 2k mic inputs, a lot of newer consoles without input transformers run from 10k to 22k.

-Eric

[les_chupacabra]

Thanks for the info.  Very helpful!

John