Buffer vs True Bypass ?

[rreiser]

I would appreciate your opinions.. Are there different designs for buffer circuits that help retain high end thru pedals and long cable?Is there a buffer design you prefer? What buffer circuit works well with pedals? Do the T-Rex pedals have a buffer circuit? Buffer before or after pedals? Thanks

[mbratch]

I can't speak to the T-Rex, or quote exactly how specific buffers are designed, but I can relate my own experience with certain pedals.

I have an old Cry Baby Wah pedal that was not true bypass and it very noticeably deadn't the tone of my guitar. I rewired it with a DPST button to make it true bypass, and things are much better. :)

My other pedals, which consist of DigiTech DigiVerb, DigiDelay, Ibanez CS-9, Ibanez TS-9, and DOD YJM308 are all buffered and they do not attenuate the highs noticably in the sound of my guitars. I've gone through them and plugged in direct and I don't feel that the "direct" sound is better and is only subtly different, if at all.

In the past (when I had different gear) I've used a Valvulator tube-based buffer which works very well. I believe the best place for the buffer is between the guitar and the effects, but that might depend upon which side you have the longest cable (?).

[hipfan]

Buffers! A constant source of confusion and bewilderment to me and apparently many others. You'll get a lot of different answers on these questions. I'm no expert at all, but here's what I've gleaned over the years and through my own experimentation.

Are there different designs for buffer circuits that help retain high end thru pedals and long cable?

Indeed! All buffers are not created equally. All properly functioning buffers will drive the signal through long cable runs and pedals (non-buffered ones, at least) by lowering the impedance of the signal. A low impedance signal travels more easily through cable. However, the buffers are little "amplifiers" in and of themselves, and their design (and resulting effect on tone, etc.) vary accordingly. I've used some buffers that seem to add something unpleasant to the tone, while I've used others (Axess BS-2, Radial PB-1) that are not unpleasant at all. I currently use the PB-1 on my board, and it's a great little box. The buffer causes the signal to make it through about 7-8 true bypass pedals and 20 feet of cable unscathed, and the tone is great.


Is there a buffer design you prefer?

One that does its job and sounds good! :) Honestly, I can't really answer this one with any specificity. I like whatever Radial has done for a buffer in its PB-1, fwiw.


What buffer circuit works well with pedals?

I think this question should be the other way around, i.e., "what pedals work well with buffers?" Most pedals I've used work well with a buffered signal hitting the input except for most, if not all, fuzz and wah pedals. For whatever reason beyond my expertise, fuzz and wah pedals prefer to see a high impedance signal at the input, not a the low impedance signal that results from buffering. In general, I've discovered what pedals play nice with my buffer by experimenting placing them before and after the buffer, and then noting the tonal difference, if any.

Do the T-Rex pedals have a buffer circuit?

No idea on this one. I think they claim that the Replica is true bypass...

Buffer before or after pedals?

See above. The only way to really know is to try it out. Ideally, it would be nice to run the buffer first in the chain so as to maximize the tone preservation you're seeking. However, some pedals sound better with a high impedance input signal than a low impedance one, so you have to experiment.

One thing to remember is that, in general, you're end tone will only be as good as what your worst buffer allows. In other words, if you have one really high quality buffer first in your signal chain and then a bad sounding buffer last in your signal chain, here's what will happen in laymen's terms. Your good buffer will do its work and drive your signal through all the cables and TB pedals in between it and the other buffer. Once the signal reaches the other buffer, that buffer essentially will "take over" the job and impart its own effect on the tone. :jo

Anyway, hope this helps or at least sparks some helpful discussion from others.

[rreiser]

Thanks for the data. Anyone else want to chime in? I will check out the Radial.

[kt77]

buffers in the form of non-inv followers w/ OPA134 w/ +/-18V lo-noise reg power supply (or any lo-noise, high speed FET opamp)