Author Topic: Low Impedance, Wireless, and Buffers, Oh My!  (Read 234 times)

lbpesq

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Low Impedance, Wireless, and Buffers, Oh My!
« on: February 06, 2018, 12:06:29 AM »
I've been looking for a used Sarno Music Systems Steel Guitar Black Box in all the usual places for a while.  One finally turned up on reverb and I grabbed it.  That got me thinking.  I know that one of the advantages of low impedance pickups like our Alembics is that tone isn't lost over long cable runs.  However, if I use a wireless system from the guitar to the pedal board, and the wireless receiver now outputs the signal that goes through the pedal board and on to the amp, is the receiver similarly outputting a low impedance signal?  I would think the receiver's output would be the same whether the guitar plugged into the transmitter was low or high impedance.   If so, can I measure this with a multimeter? 


I'm really looking forward  to A/B-ing  running wired/wireless into the SGBB, then into the pedal board.    I've never tried one, or even seen one in real life, but I've read tremendous reviews of the SGBB.


Bill, tgo
« Last Edit: February 06, 2018, 12:47:01 AM by lbpesq »

cozmik_cowboy

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Re: Low Impedance, Wireless, and Buffers, Oh My!
« Reply #1 on: February 06, 2018, 03:58:20 AM »
"I would think the receiver's output would be the same whether the guitar plugged into the transmitter was low or high impedance. "

You are correct, Sir.

Peter
"Don't take life so serious; it ain't no ways permanent"

Pogo

adriaan

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Re: Low Impedance, Wireless, and Buffers, Oh My!
« Reply #2 on: February 06, 2018, 04:17:31 AM »
The lack of signal loss over a long cable with your Alembics is due to having an onboard preamp. Without an onboard preamp, the weak signal  of a low-impedance pick-up actually suffers a lot from long cables.

Zut8083

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Re: Low Impedance, Wireless, and Buffers, Oh My!
« Reply #3 on: February 06, 2018, 11:45:49 AM »
Ahoy, Bill,

I hope I didn't mess up your point, but would you test two of your guitars, one Alembic and (a) passive guitar()s, perhaps using single coil and humbucker signals, as the experimental and the control cohorts, respectively, to address your hypothesis?  Also the first thing that I thought of when you said "wireless receiver" was the Air Force Base scene from "Spinal Tap".  If you played out in places buffeted by a lot of common EM interference/commerce, do y'all think there would there be a difference between the efficiency of buffered/pre-amp'd signals remaining intact vs. passive signals getting to your wireless emitter intact given the different areas of the instrument's circuit and their incomplete shielding at all frequencies (e.g. exposed strings/tuning machines, microphonic pickup/potting issues, or potentially incomplete cable/cavity shielding)?  Thanks!  Cheers.

jwright9

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Re: Low Impedance, Wireless, and Buffers, Oh My!
« Reply #4 on: February 06, 2018, 12:00:48 PM »
Ahoy, Bill,

I hope I didn't mess up your point, but would you test two of your guitars, one Alembic and (a) passive guitar()s, perhaps using single coil and humbucker signals, as the experimental and the control cohorts, respectively, to address your hypothesis?  Also the first thing that I thought of when you said "wireless receiver" was the Air Force Base scene from "Spinal Tap".  If you played out in places buffeted by a lot of common EM interference/commerce, do y'all think there would there be a difference between the efficiency of buffered/pre-amp'd signals remaining intact vs. passive signals getting to your wireless emitter intact given the different areas of the instrument's circuit and their incomplete shielding at all frequencies (e.g. exposed strings/tuning machines, microphonic pickup/potting issues, or potentially incomplete cable/cavity shielding)?  Thanks!  Cheers.

Zut, do you suffer from Over-analysis Paralysis?


cozmik_cowboy

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Re: Low Impedance, Wireless, and Buffers, Oh My!
« Reply #5 on: February 06, 2018, 01:41:31 PM »
The guitar feeds the transmitter.  The transmitter transmits through the air; impedance is not involved.  The receiver receives said transmission with no knowledge of its source, and sends it on it's merry way at whatever impedance it sends at.  Ergo, guitar impedance cannot effect receiver output.

Peter
"Don't take life so serious; it ain't no ways permanent"

Pogo

Zut8083

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Re: Low Impedance, Wireless, and Buffers, Oh My!
« Reply #6 on: February 06, 2018, 02:52:38 PM »
Dear jwright9,

In no way, shape, or form.  Thanks for your concern, though.
« Last Edit: February 06, 2018, 03:32:20 PM by Zut8083 »

lbpesq

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Re: Low Impedance, Wireless, and Buffers, Oh My!
« Reply #7 on: February 06, 2018, 03:48:34 PM »
Yea, I figured the same as Peter.  So can I test the receiver in some manner to determine the output that is feeding into everything else?  I checked the spec sheet on the wireless and it doesn't seem to include this info. 

By the way, while I love the Spinal Tap reference, I've never had any interference issues with my current wireless.  It is a relatively new system called the PRA WIC.  They also have an extended low frequency version for bass and another for computer recording.  Excellent unit.

Bill, tgo     

PUPPET SHOW
                            And Spinal Tap

Zut8083

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Re: Low Impedance, Wireless, and Buffers, Oh My!
« Reply #8 on: February 06, 2018, 04:19:56 PM »
Nice touch with the marquee. :D

"We've got a bigger dressing room than the puppets?!"

edwin

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Re: Low Impedance, Wireless, and Buffers, Oh My!
« Reply #9 on: February 08, 2018, 12:18:54 AM »
The beauty of the Black Box is when you plug a passive guitar directly into it. The variable input impedance lets you dial in all kinds of tones.