unity gain buffer?

Started by zeppelinchld, March 21, 2007, 02:04:05 AM

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zeppelinchld

i need to make a unity gain buffer but im kinda confused about what it is

jonathan perez

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dont build something if you dont even know what it is.
no longer the battle of midway...(i left that band)...

i hate signatures with gear lists/crap for sale....

i am a wah pervert...ask away...

zeppelinchld

well i was hoping that someone here could explain it to me so that i could build one

km-r

Look at it this way- everyone rags on air guitar here because everyone can play guitar.  If we were on a lawn mower forum, air guitar would be okay and they would ridicule air mowing.

black mariah

Quote from: thebattleofmidway on March 21, 2007, 02:05:32 AM
search

dont build something if you dont even know what it is.

Have any of your replies been anything beyond snarky one-liners?

jonathan perez

#5
nope, ive got anger problems since the robbery...

come to think of it, check out all my recent posts/replies.

nothing but snarky one liners.

every forum needs a grumpy somethinoranother.  ;)
no longer the battle of midway...(i left that band)...

i hate signatures with gear lists/crap for sale....

i am a wah pervert...ask away...

calculating_infinity

Quote from: zeppelinchld on March 21, 2007, 02:04:05 AM
i need to make a unity gain buffer but im kinda confused about what it is


Here you go buddy.  I cant help you personally other than finding this.  Laters

Quote from: Mark Hammer on June 16, 2005, 11:22:19 AM
That means that it:

a) Provides no gain (i.e., signal level out = signal level in), hence "unity gain" (gain = 1)

b) Provides a lower impedance for the next device to "see" than if the next device was "looking at" the signal source instead (hence "buffer).

http://www.diystompboxes.com/smfforum/index.php?topic=34230.0

Ge_Whiz

Okay chaps, slowly step away from the snark. Let's all chill, relax, take a deep breath, and...

Quote from: zeppelinchld on March 21, 2007, 02:04:05 AM
i need to make a unity gain buffer but im kinda confused about what it is


...ask the real question, which is, "If you don't know what a unity gain buffer is, why do you need to make one?"

You'll get a much more helpful response if you tell us what you are trying to do, whether there is a problem that you need to solve, or why you think you need a unity gain buffer. Alternatively, you could ask, "Can anyone please direct me to a schem for a unity gain buffer?" and we probably wouldn't blink an eye, other than to reply with a flurry of "The SEARCH function is your friend...".


MartyMart

If you need one or two for the long cable runs to and from your pedalboard and amp
then swing over to AMZ's site ( above left ) there's a few buffers there.
If your first pedal is a Boss/Ibanez etc which have a buffer then there's no need at that point.
They help with long cable runs to keep your tone/impedance alive  :icon_wink:
"Success is the ability to go from one failure to another with no loss of enthusiasm"
My Website www.martinlister.com

GibsonGM

Buffer:
Gain = 1
Input Z = high
Output Z = low
Can be useful, can change your tone in ways you won't like if you're not careful - can also preserve your tone and make a crappy ckt. sound good while driving long cable runs.

Go to AMZ, read up.

:icon_mrgreen:
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MXR Dist +, TS9/808, Easyvibe, Big Muff Pi, Blues Breaker, Guv'nor.  MOSFace, MOS Boost,  BJT boosts - LPB-2, buffers, Phuncgnosis, FF, Orange Sunshine & others, Bazz Fuss, Tonemender, Little Gem, Orange Squeezer, Ruby Tuby, filters, octaves, trems...

petemoore

i need to make a unity gain buffer but im kinda confused about what it is
  It is an active circuit, buffer.
  the active can be BJT, Jfet, Mosfet, OA, Ge...
  high input impedance, and low output impedance generally speaking.
  Almost 1:1 gain, or no gain, but it may sound like gain if it is preventing gain loss, or if the active input [of the next circuit in the chain] it is driving...makes a higher gain sounding output.
  Because because because because, because of the wonderful things it does.
  You likely have buffers in your signal chain if you have a 'modern' stompbox which uses a momentary switch to switch the bypass/buffer circuitry [like Boss, Ibanez, Dan-O etc. etc.
Convention creates following, following creates convention.

zeppelinchld

thanks for the feedback.
well i know this is a stompbox forum but im making one for a guitar preamp
im working on replicating jerry garcias tiger wiring and it asks for a Unity-gain buffer Pre-amp low z output by John Cutler
if anyone is familiar w/ this buffer please send me a schematic.

GibsonGM

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MXR Dist +, TS9/808, Easyvibe, Big Muff Pi, Blues Breaker, Guv'nor.  MOSFace, MOS Boost,  BJT boosts - LPB-2, buffers, Phuncgnosis, FF, Orange Sunshine & others, Bazz Fuss, Tonemender, Little Gem, Orange Squeezer, Ruby Tuby, filters, octaves, trems...

zeppelinchld

i hav searched google and i cant get any unity gain schematics.
i hav plenty of info on the actual guitar

Gus

emitter follower, cathode follower, source follower

people left hints with the fet switching efffects

Paul Perry (Frostwave)

http://www.generalguitargadgets.com/index.php?%20option=content&task=view&id=156&Itemid=190

The links there explain all.

And if you want to make a small one & put it in a cable at the guitar, this is the way to go:
www.till.com/articles/PreampCable/index.html  Don Tillman knows his stuff, trust me.

oldrocker

#16
I think a simple explanation would be IMHO.  When an effect is bypassed it's louder than when the effect is engaged.  I could be wrong but I would think a unity gain buffer would be built inside that same box as the effect that's not loud enough to balance the bypass volume.  Any other buffer could be built separately outside in its own enclosure or in the guitar itself like a Strato Blaster.  I'm not positive, but this is my impression.