more highs with opamp buffer? can someone explain?

[hilbi]

This week I built the amz super buffer, see this thread http://www.diystompboxes.com/sboxforum/viewtopic.php?t=30917&start=0&postdays=0&postorder=asc&highlight=

I tested these two configurations below.

Configuration 1: Strat - 12ft cable - amp

Configuration 2: Strat - 12ft cable - buffer - 20ft cable - amp

I found out that configuration 2 had more highs the configuration 1, my expectation is that it should be the same.

Is the difference because the guitar pickup sees an impedance of 2M7(buffer) in config 2 instead of the 1M impedance (amp) in config 1?

Test equipment:
Fender Strat
George L Cable
Fender Hot Rod Deville amp
AMZ Super buffer

[Oliver]

Hello,

the reason for that ist, that the calbe capacity sucks hights from Your guitar Pickup.
The Buffer avoids that = very simple explanation..

bye
Oliver

[hilbi]

correct, but the same cable is used (12ft) to guitar amp as to the buffer, so they would both suffer the same losses before it hits the high impedance circuit.

right?

[zachary vex]

yes.  the high input impedance is taking the load off of the pickup/cable combination and preserving highs, and then the output is low impedance so it drives the other cable length with no further losses into the amp's 1M input z.

[zachary vex]

correct, but the same cable is used (12ft) to guitar amp as to the buffer, so they would both suffer the same losses before it hits the high impedance circuit.

right?

no, it's not just the cable capacitance... it's pickup's output impedance that's involved as well.

[hilbi]

ok thanks for your input.

So it is *normal that i experince these extra high's with the buffer use?

How does the pickup's output relate to the amps input and how to the buffer. Is there a good reading available? I would like to understand this a little bit more.

* I want to keep my original guitar signal to shine through as much as possible, so are these highs already in the guitar and not just added by the circuit?

[Hevimies]

So it is *normal that i experince these extra high's with the buffer use?

* I want to keep my original guitar signal to shine through as much as possible, so are these highs already in the guitar and not just added by the circuit?

Yes, it is normal, and the highs are already in the sound but they are sucked out because of the impedance of the cable and pickups and capacitance of the cable.

[Oliver]

Hi,

on the other Hand:

for my Taste - most Guitaramps have plenty of highs..
And most buffered Pedals like Boss and Ibanez take some dynamics.
No one will hear that, if You play a gig, but For myself, the Amp reacts
in another way and sounds more open for me, without a buffer...

Maybe, that a good buffer doesnt influences the dynamics, but i dont like to try that - beeing satisfied with my Tone like it is.

cu

Oliver

[hilbi]

OT:I used to use an true bypass system all the way, so in total about 40 ft george L cable, some george l patch leads and connectors.

But it didn't sound ok, both with strat and tele it sounded like my guitars had a cold ( picture: a human being talking with nose closed between two vingers)

Just adding one ibanez pedal inbetween would already sound way better, allthough they rolled off some high as well.

That's why i built this buffer.

[petemoore]

Guitar cavity real estate permitting...
 You could put a buffer in the guitar, on a DPDT/500k switch/pot. You pull up / push down the knob for buffer / bypass.

[seanm]

Great info about buffers. I always wondered why my opamp based pedals sounded more trebley.....

Question about the super buffer. Why 4 opamps rather than 2? I find that 1 is usually *almost* good enough. Wouldn't 2 give enough headroom? I am planning on building one to drive a long cord.

[petemoore]

I got motivated enough to make the lazy mans Buffer...an OA buffer, 4558 OA or something like that.
 Works great too, I was experiencing what I knew forthe first time as cable capacitence / tone loss, didn't sound very good At5 All either, this fixed it. I was running over 50' and about 4-5 boxes, all TBypass.