Buffer questions..Do I need one?..what are they for?

[rosssurf]

I have been playing guitar for many decades and rarely use more than one pedal in the chain between my guitar and amp..usually a Dunlop Wah( 53Q?..? I think) because I play with rack effects. my live rig chain consists of the following

PRS's, Les Pauls, and sometimes Strats into -wah - Korg rack tuner - Egnater ie4 preamp - Rocktron intellifex - VHT stereo 2/50/2 kt77 powered power amp- into a stereo Bogner 4x12.

I recently have built a few pedals with true bypass switching that I use with my home rig such as the Ross Compressor, BSIABII, Fetzer Valve, and Vulcan for my home rig. all have true bypass switching.

Questions

1) What does a buffer do?
2) Do I need one for my live rig?...Home rig?
3) Is a buffer unnesicary with true bypass switching?

Is there a buffer build that is recomended
Thanks in advance

[Mark Hammer]

Read this:  http://www.petecornish.co.uk/case_against_true_bypass.html

Then ask yourself if your tone is acceptable to yourself.  If it is, fine.  If not, maybe you need a buffer at some point.

[slideman82]

You usually match impedances with buffers, they don't have gain, just means a high impedance at the input and low impedance at the output. If you want to see what happens, just plug all your rig bypassed, and the turn on a buffer, so you'll notice high frecuencies lost because the guitar cable appear now. There's one in GGG, well, several, try all 3 if you want!

[Ripthorn]

Jack Orman has lots of cool, simple buffer circuits on his site.  From the sound of it, your live rig should be just fine (the rack effects probably already have buffers).  As for your home rig, you might want one if you chain up too many pedals, even true bypass ones, but with just a few, it won't matter too much.  A buffer is basically a high input impedance/low output impedance device which helps prevent signal loss over long cable runs, etc.

[R.G.]

You usually match impedances with buffers,

Audio buffers MISmatch impedances to limit signal loss or selective loss of some frequencies. Matching impedances is only useful for maximum power transfer. Most audio circuits - power outputs being the big exception - are concerned with maximum voltage transfer, not power transfer. As such, they are concerned with the load impedance being much larger than the source impedance.

they don't have gain

Some buffers have gain, although many do not. It's the impedance thing that matters about buffers, not the gain.

just means a high impedance at the input and low impedance at the output.

This is correct.

If you want to see what happens, just plug all your rig bypassed, and the turn on a buffer, so you'll notice high frecuencies lost because the guitar cable appear now.

This is correct.

[rosssurf]

Wow...you guys are great. I am now " in the know" about buffers thanks to all for the quick and helpfull posts and the link!

My next question is (See my latest post) in this same forum " How do I make my MXR Flanger quieter, and without a loss of signal "

[iaresee]

First half of this clip is no buffer, second half is Jack Orman's leaky transistor buffer in negative ground configuration:

http://dl.getdropbox.com/u/870088/sounds/name-that-effect.mp3

That's the only change. Admittedly it turns the sound to crap. But it serves to highlight all the high end content that disappears down a long cable run (~45' of it in this case). The buffer was at about the mid-point, running at 9V.

I got all excited when I heard this is cans on Friday night but I've since thought perhaps I don't care as much as I thought. I'm building the Super Buffer this week. The lack of unity gain on the leaky AC128 was disappointing. I'm still torn. But my initial reaction was a big "I need a buffer"...

[slideman82]

You usually match impedances with buffers,

Audio buffers MISmatch impedances to limit signal loss or selective loss of some frequencies. Matching impedances is only useful for maximum power transfer. Most audio circuits - power outputs being the big exception - are concerned with maximum voltage transfer, not power transfer. As such, they are concerned with the load impedance being much larger than the source impedance.

they don't have gain

Some buffers have gain, although many do not. It's the impedance thing that matters about buffers, not the gain.

just means a high impedance at the input and low impedance at the output.

This is correct.

If you want to see what happens, just plug all your rig bypassed, and the turn on a buffer, so you'll notice high frecuencies lost because the guitar cable appear now.

This is correct.

Excellent! So I got a 6? (I was generalising!)