buffer pedal help

[msurdin]

Hello everyone,

I build the GGG IC buffer recently. It has made a good improvement to a line of pedals and some long cable s/r runs.
Ive heard this buffer is closer to the Klon type of buffer. Apparently it can boost top frequencies unnaturally, and sometimes be undesirable for high gain units.
Ive been told "Just buy a cornish buffer, it leaves all the frequencies natural"
this led me to ask GGG about the discrete (jfet or NPN) buffer, which I was told has a slight volume loss.

What are my other options, kit wise, to find something closer to what I'm looking for? Ive seen the little Fairy duster buffer pcb kits that claim to be a cornish clone..are these legit?

Thank you

[GibsonGM]

With little fanfare, you could make a JFET buffer - no kit needed, it's so simple.  I'm sure Jack has one on the AMZ site!   I like Mosfets/JFETs for this as they retain the 'natural highs of the guitar', but to me it is not artificial.....very tube-like, chimey....just my opinion.

[msurdin]

Thanks for the advice. Would this also be a good option in a looper strip for effects return to buffer the output?
Seems like the ggg "descrete" links to the amz buffer, does anyone know if the amz does have a volume drop?
Thanks again!

[bool]

All in all I would suggest a BJT buffer over a jfet one, if you want some let's say "naturalness" added back to your signal. Both jfet and BJT buffers will have a small signal volume drop (compared to an opamp buffer).

[antonis]

Well said but, IMHO, an IC (bi-Fet) buffer is more simple and convenient than a discrete FET/BJT combination..

[samhay]

>Ive been told "Just buy a cornish buffer, it leaves all the frequencies natural"

These sort of comments send alarms bells ringing for many of us here. What's an un-natural frequency?

I would stick with the op-amp buffer you alread have. If it is a buffer, then it doesn't boost anything, it just helps to prevent high frequency roll-off due to pickup loading.
The 'Cornish' buffer will do the same, but the voltage gain will be a few % below unity (I doubt you can hear the difference).

[msurdin]

Thanks for the help!
My worry is adding buffers to a send/return TB strip would degrade the sound like boss pedals do.
If that ic buffer works for this I have nothing to worry about.
It does make a major improvement being the first thing the guitar is plugged into.
Ive seen  the amz talked about alot, didn't know how they do against each other

[ashcat_lt]

Yeah, this is just a buffer.  It's not boosting anything.  If it's actually built like the schematic, though, it's probably adding more noise than it needs to. 

There is absolutely no power filtering.  Not a big deal if you run it off of a battery.  With a wallwart - and especially a daisy-chain - it could get ugly fast. 

Then the Vref divider uses really big resistors and can't be filtered itself as is.  That's a different kind of noise, but still a real issue.

Since there's no actual gain here, it might not be a problem by itself, but if there's much compression/OD/distortion downstream, it could make a noticeable difference. 

It would be pretty easy to mod that, if you're interested.

[msurdin]

After reading more into some of the buffer options and what has been said it has poked me to find out more...
Regarding power filtering, noise, and unity gain.
Ive been reading the Singlecoil website about the buffers they have such as the "discreet", "the standard" and "High Definition" http://www.singlecoil.com/buffer.php
Then I saw amz has the tiny pre made jfet buffer module, smaler than a 9v battery, "close to unity gain 0DB" Power supply protection and filtering and RF blocking on the input, input impedance is 1m.

Not sure which route to go really. Again, i was planning to make a true bypass strip and have an input buffer and a buffer after the pedals in the return loop to handle any change in impedance from activating any effects.

Thanks

M

[deadastronaut]

ive breaded up this buffer before, (2nd from bottom) just out of curiosity
to see if there was much if any tonal differences

i added a 100r on both the in and out, and it was as near as i could tell to the same as bypassed..unless my ears are shot of course..

obviously add a 100uf across power...

use a dual opamp and you have 2 buffers. 

http://www.muzique.com/lab/buffers.htm

[slashandburn]

Again, i was planning to make a true bypass strip and have an input buffer and a buffer after the pedals in the return loop to handle any change in impedance from activating any effects.

I'm not sure I understand the necessity of having such an arrangement, unless for A/B testing? Maybe I'm misunderstanding you.

I default to the basic opamp buffer that deadastronaut linked. It's always been fine to my ears (which are admittedly, very probably shot) and I'm never short of opamps.

They all do they same thing though. Buff! 

[msurdin]

Pretty much I was saying I am building a true bypass looper strip of 10-15 send and returns. It would have an input buffer, and each effect return would be buffered. I've already had issues with some pedals and signal issues running together.
I would think with the buffers on the returns this would also eliminate the need to have an output buffer at the end of the looper to drive the signal.

[induction]

It will be easier for us to make intelligent recommendations if you tell us more specifically what problems you've had in the past that you're trying to avoid. We'd need to know which combinations of circuits you're having trouble with, what the symptoms are, and how do you know they were impedance-related. Without that info we can't really recommend one buffer over another for your specific use case. Nor can we predict which whether your buffering strategy would make the problems worse or better. It could actually go either way, depending on the pedals and the symptoms. Same goes for the choice of buffering each return vs buffering the looper output (or both, or neither, or whatever).

Minor vocabulary quibble: any looper with an input buffer and buffered returns is by definition not a true bypass looper. 

[PRR]

If you are stringing 10-15 buffers, use op-amp!

One FET buffer is nearly perfect. But not quite. Say it has gain of 0.95. String 15 of those, gain is down to 0.46! (not counting whatever you got between sends and returns)

A low-price TL074 will give gain of 0.999 to the top of the audio band. 15 of those is 0.985, or 1/8dB down, quite inaudible.

One FET at 0.5% THD, 15 stages, rough-computes to 107% THD! The reality is that each stage re-distorts all the distortion products so far, and you have a haze of IM distortion all over the audio band at non-musical frequencies.

This is also a problem with op-amps, of course. It limited early recording consoles. Op-amps got better and 10-15 op-amps in cascade was quite normal in large analog consoles. While the first and last op-amp would be specials, many mix split and EQ op-amps were TL072 even in fine German gear.

[msurdin]

Currently my situation of running the following
BOSS cs2, dynamic comp, eat, sovtek green big muff, colorsound power boost, Benz tube driver (2 of them), volume pedal, dlx electric mistresss, phase 90, boss ce2, boss dd6, h&know replex, memory man.

The standalone ggg ic buffer has helped a lot at the front of the chain. Still, using the tube drivers,  the power boost and muff/rat in combos makes the signal sound weak, or off.
This problem does not occur when using it singular into the amp or a 1-2 pedal setup.
I've been told a looper with buffered returns would greatly improve such issues