Quick question :D

[Rock_on]

Just a quick question,

Whats the difference between

Buffered boost and Boosted Buffer?

I mean Buffer --> Boost and Boost --> Buffer??

And their uses also... What happen if the buffer is first? Or if the buffer is last?

[GibsonGM]

I haven't gotten much into separating these elements into their 'constituent parts', Rock On, but I'll take a stab!  To me, a boost is a boost, a buffer is a buffer.

Yes, a buffered boost would seem to mean a booster with a buffered input, and perhaps also a buffered output.  Not necessarily a bad idea, from a casual thought about it (provided the boost itself didn't give you what you wanted re. input/output Z; most should).

A boosted buffer?  Maybe one that offers better than unity gain (boosts the signal a bit as it passes thru it).  But that is sort of against the definition of "buffer", whose job is solely to offer a high input impedance and low output impedance - for maintaining your signal level and to drive circuits that would load down 'conventional' circuits with output impedences.   Again, you could buffer, then boost, then buffer the output.  Why you'd need to, I don't know - the design should incorporate the proper in/out Z.

The 'use' of buffers & boosts is in 100's of posts on here....generally, you buffer the input to your effects chain if you are going to be driving long cable runs, or lots of effects.  It presents a 'proper' signal to the following circuitry...prevents what comes after from 'sucking the tone' out of your chain....impedance bridging.   Bad combinations of high output impedance and low input impedance can really screw up your tone!  Loss of highs, like turning your tone controls down.   You kind of know it when you hear it! 

Maybe this is a 'hybrid' idea?   To my way of thinking, there isn't too much that would be great about hitting a buffer with a booster, LOL.  That could result in some strange impedance CHANGES on the fly, I think.

[Rock_on]

I asked because i saw 2 circuits from google

The first one is a 2 jfet with a switch that would either turn on the buffer or not

The other circuit is a TL072 based. It has a switch that would either turn the boost or not.

So there comes the question in my mind and asked it here.


Correct me if im wrong. Input buffer is needed if long cable would be used and/or i have many true bypasses pedal and it should be close to the guitar.

Then booster is just a boost. It'll amplify.


And one more question. What's the use of an output buffer if i already have one in my input (assume i dont have wah and fuzz face)?

[GGBB]

I asked because i saw 2 circuits from google

The first one is a 2 jfet with a switch that would either turn on the buffer or not

The other circuit is a TL072 based. It has a switch that would either turn the boost or not.

So there comes the question in my mind and asked it here.


Correct me if im wrong. Input buffer is needed if long cable would be used and/or i have many true bypasses pedal and it should be close to the guitar.

Then booster is just a boost. It'll amplify.


And one more question. What's the use of an output buffer if i already have one in my input (assume i dont have wah and fuzz face)?

Buffers also prevent interaction between circuits themselves, so they are important not only when driving long cable runs or multiple true bypass pedals.  That's why many pedals have either a buffered input or output or both built in.  You could have a buffer going into a pedal that "unbuffers" the signal (has a high output impedance), so whenever that pedal is on, a long cable run after it or another pedal with a low input impedance turned on could be a problem despite the fact that you used a buffer at the start of your signal chain.

Also, buffers can boost - they do not have to have non-adjustable unity gain.  A booster may or may nor be buffered at input or output.