signal boost through long pedal chain

[powerplayj]

Is there any sonic differences between having a boost (MOSFET) at the beginning of a chain vs. a buffer (JFET, for instance)?  I was thinking of putting a buffer in my MOSFET boost for bypass mode but if it has the same tonal effect as the boost itself I wouldn't bother.  I just want to retain my highs without coloring the signal.  All pedals in the chain are true bypass.

[Seljer]

if you lower the gain on the mosfet boost so its the same volume as bypassed = you have a buffer

[Pushtone]

Is there any sonic differences between having a boost (MOSFET) at the beginning of a chain vs. a buffer (JFET, for instance)? 

I have done what your asking. I put a GGG IC buffer into a box with a boost.

I've done it with the MosFET and the Sparkle Boost.

The IC buffer and the MosFET do have a similar sounds as far as both accencentuate the high end.
The MosFET has more personality. The IC buffer has the framiliar cold and brittle sound.
I tried lowering the buffers input impedance and that seemed to help warm it up a little.
That led me to this Radial Dragster thing as an idea to give a variable impedance control
that allows one to add loading to dull the ice-pick high end. This is something I've been meaning to try.

I perfer the Sound of the MosFET over the IC buffer and it usualy just stays on all the time.
I'll use a second booster after the MosFET to add volume boost so I guess
I'm using the MosFET as a buffer with its level control at minimum (unity gain).

The IC buffer is just to clean sounding but it does it job of driving a TB pedal chain well.

With the Sparkle boost I'm finding the sound of the two circuits just to different. The Sparkle Boost has a throaty mid-range and full low-end sound. Going from it to the IC buffer is too much of a contrast for me.

Another "buffered bypass" pedal combination that has worked out well for me is the Fetzer Valve Booster with a Strat-o-blaster as a buffer. The Stratoblaster, like the Sparkle boost, has a full range thick sound. The fetzer is a little thinner on the bottom which makes it perfect for me. The bypassed sound (Stratoblaster) is fat-full-range and the boost (Fetzer) drops a little bass and adds highs for solos.

Heres a pic of the Sparkle Boost with GGG IC buffer inside.

[Barcode80]

point of correction: no buffer "emphasizes" the highs, they merely don't shunt them like cable runs do. just don't want any confused inexperienced pedal builders confusing the two.

[Pushtone]

OK

Let me re-phrase...

The MosFET booster is closer in tone to an IC buffer than a Sparkle boost or Strat-o-blaster at unity gain.

The MosFET and Strat-o-blaster both work well at unity gain and can be used in place of opamp buffers
by replacing the pot with a fixed resistor.

All sound different.

[Processaurus]

if you lower the gain on the mosfet boost so its the same volume as bypassed = you have a buffer

Absolutely.  Instead of truebypassing the AMZ Mosfet booster, use the footswitch to disconnect the 5K volume pot wiper from the pot's outer lug and you'll be at ~ unity gain.  It won't matter if its exactly unity.  Connect the wiper with the footswitch and you have boost.  The advantage is you have a nice ultra high impedance buffer on all the time without sacrificing the utilitiy of having a boost available.  Piece of cake.

[Barcode80]

which wires from the pot would you wire to the switch? this sounds like a great idea.

[Processaurus]

which wires from the pot would you wire to the switch? this sounds like a great idea.

The pots middle lug (the wiper) is connected to one of the outer lugs, either on the pot or back on the board, depending how you made it.  This makes the pot a variable resistor, going from 0 ohms to 5K.  Its loudest when its at 0.  Insert a pole on a stompswitch between the wiper/outer lug connection to make the circuit see the full 5K when the wiper is disconnected.  Connect it and the circuit sees whatever 0-5K setting you have set on the pot. 

You could actually do it another way with a SPDT stompswitch and have an LED be on when the boost is off (kinda bcakward, but whatever).  Disconnect the gain pot from ground.  Connect the common on the stompswitch to ground, one lug to the LED cathode (remember a current limiting resistor) and the other lug to the gain pot lug that used to be connected to ground.  You might need a high value resistor (~1M) to go between the ex-ground lug of the volume pot and ground, so DC doesn't leak through the cap and cause a pop when you switch.

If you had a 3pdt and wanted to you could use the other 2 poles as a true bypass FX loop or something.

[Barcode80]

i'm thinking a bicolor LED, each color indicating either buffer only or boost and buffer, possibly with one off/on stomp and one boost/buffer stomp, though i'm trying to decide if you would ever want if off.

so, i wire the wiper to one switch lug, then the outer lug connection that is bridged normally to the switch lug with the common pole, right?