Impedance matching

David Rogerson · From: Victoria, Australia

I have a Goodrich model 60 matchbox that I use occasionally. Because the effect is very subtle I'm what the wondering the difference is sound wise between this unit & Little Izzy, which I believe is also a buffer. I am using an Emmons '81 push pull through a Quilter Steelaire.

Craig Baker · From: Eatonton, Georgia, USA - R.I.P.

Hi David,
I thought someone would have jumped in here to answer your question. Though I have never had a Matchbox, I understand that they are a well made unit.

One of the advantages of Li'l Izzy is that it plugs directly into the guitar, eliminating any cord. Even a short piece of quality cord has some amount of capacity which can attenuate the high notes and overtones. Personally, I believe the direct plug-in is why Li'l Izzy will provide the greatest sound possible from your Push-Pull Emmons and Quilter amp.

Li'l Izzy has been gaining loyal fans for 40 years now, and we still promise to buy it back if you're not delighted. Thank you for your post David.

Best regards,
Craig Baker 706-485-8792

cmbakerelectronics@gmail.com

C.M. Baker Electronics
P.O. Box 3965
Eatonton, GA 31024
_________________
"Make America Great Again". . . The Only Country With Dream After Its Name.

David Rogerson · From: Victoria, Australia

Thanks Craig. I appreciate your prompt reply & while as you say, you aren't familiar with that particular Goodrich unit my original question remains un-answered.
When I originally purchased that item from Scotties some years ago, the advice was to use 2 for maximum matching - 1 at the guitar & the other at the amp input. Perhaps Jim Palenscar may like to offer a comment here.

Jack Stoner · From: Kansas City, MO

I've had a Goodrich Matchbox and a Lil Izzy. Both do the job. I now use a Goodrich MatchBro which has a low Impedance output both when not using the dobro simulator function of the unit and when using the dobro simulator function. Considering I use a Hilton Volume Pedal, I'm not sure either is really needed. I don't hear any difference either with the Matchbro between the guitar and volume pedal or just going direct from the guitar to the volume pedal (my Franklin has Lawrence 710 pickups).

You don't need one at the amplifier. There is no "matching" needed at the amplifier end.

Lane Gray · From: Topeka, KS

If you're gonna use two, the second one goes at the output of the volume pedal.
Since I like the "tone suck" of the pot killing highs as the volume drops, I often run my Izzy there
_________________
2 pedal steels, a lapStrat, and an 8-string Dobro (and 3 ukes)
More amps than guitars, and not many effects

Jack Stoner · From: Kansas City, MO

Only needed on a Pot volume pedal. A Hilton (and some others) are low impedance output so a device that buffers and outputs a low impedance is not needed.

Craig Baker · From: Eatonton, Georgia, USA - R.I.P.

David,
The proper use of any buffer, as Jack mentioned, is directly before any cords. (not after a cord, such as would be the case at the input to an amplifier.)

There is no "matching" being done here, and none is needed. The purpose of a buffer is to protect your guitar's tone by making certain that no high impedance signals are followed by a guitar cord, or other device which may contain capacity that would roll off the highs and overtones. Again, as Jack mentioned, unlike pot type volume pedals, the active pedals already output a low impedance signal making the second buffer unnecessary.

With any buffer, the higher the impedance of your pickup, the more you will notice the improvement in tone. Some players love buffers and won't play without them, while others wouldn't think of investigating a different idea. Since you already have the Matchbox, with our guarantee you can personally compare the two products with no risk or obligation. If you'd like, I'll set a Li'l Izzy aside for you to try.

Thank you David, and best regards,
Craig Baker 706-485-8792

cmbakerelectronics@gmail.com

C.M. Baker Electronics
P.O. Box 3965
Eatonton, GA 31024
_________________
"Make America Great Again". . . The Only Country With Dream After Its Name.

Georg Sørtun · From: Mandal, Agder, Norway

The "matching" that some mention (and some say is iÅ•relevant), is "close enough for comfort" with a typical PSG PU in the 15 to 22 kiloohm range followed by a buffer with an input impedance (resistive load) of around 500 kiloohm. This about 1 to 25 ratio place the Q-factor for the RCL circuit (that is the PU) to the upper end of the PU's frequency range, which is where we want it for "clear highs". Those who want to check the Q-factor "effect" with its peaks and dips, may try changing the load on the PU - I believe that's what the "Z" control on a BlackBox does (?).

I have a MatchBox and a SteelDriver III (same thing), and they present a 500 kiloohm load to the PU - perfect for most PUs. I prefer a little lighter load on the PUs, so I most often use a Boss LMB3 as buffer - that's a 1 megaohm load.

Main thing is that a good buffer represents a constant load on the PU, whereas going directly via a pot-VP means the load is varying with VP travel.

Having a buffer right after a pot-VP pretty much eliminates any effects the cable into the amp and the input impedance of the amp itself may have on the resulting "tone" in a passive VP setup. I don't use a buffer there, as the low-ohm VP and short cable I use means any advantages of having a buffer after the VP are inaudible.

David Rogerson · From: Victoria, Australia

Craig, thank you for your generous offer but at this stage I will pass on it. I only use the Goodrich unit occasionally ( eg recording) & don't regard it as an important part of "my sound" at this stage. I was just curious about any difference & if I can get to the Dallas show next year maybe I can hear one of your Little Izzys in person.

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