Why and when is a buffer needed in a system?

[BJF]

Hi,

Let's talk loading and signal sources.....

BJ

Gentlemen please:

[JKoeth]

Fill me in buddy!

Bjorn, I don't know if you got my email about building me a custom buffer. I'd love to know more about this topic.

[BJF]

Hi,

Let's start with pick ups.
Most guitar pick ups are of the passive kind, made from a coil of wire, and a magnetsystem and some mechanical parts to hold the contraption together
Due to the coil the pick up then gets an impedance that rises with frequency. It's an impedance as it contains several 'ghost' parts as in the wire resistans that is measured in Ohm's or more often KiloOhms
which makes the unit more managable and this is also what one easily can measure with a DVM or VOM, but then it becomes tricky as there is also an inductance, interwire capacitans, an possibly metalparts that add to the inductance and so a complex filter is formed: a lowpassfilter with resonans.

Now just keeping the last part in mind the peak of the resonans is affected by the loading it sees.
Loading here means anything that is connected across the poles of the pick up so that means potentiometers
tone capacitors, capacitans in the cable that connects the guitar to first amplification stage( really this can be a fuzz or a buffer or amplifier input or.......)

In a pedalboard system all capacitans in the cables add up as the appear in parallell with eachother, like this first cable 50pF, second cable 50 pF and if we stop here total capacitans is 100pF.

If all pedals in the system are truebypass, all cable capacitans adds on.
This then appears in parallell with the controls inside the guitar and the input network on the amplifier.

Often it is desired to tune the resonans of a pick up. There are examples of guitars with preamps to the pick ups in an effort to make as pure tone as possible, i.e Les Paul Recording, but musicians tend to want a voice from there instrument. There's another example of the Levin Horseshoe pick up that could reproduce signals up to 40KHz- well it was the time of treble guitar maybe this example was for the dogs, as normal human hearing only extends to about 20KHz if ears are in good condition.
I don't know about you, but I'd tend to define treble into useful treble that is just a bit lower than I actually can hear. There's just this point where intelligence is affected. Here's an experiment if you compare just the delay signal of a BOSS DD2 ( most any digital delay would do fine), with the straight tone, do you find that you have lost any treble? Let's for the sake of the discussion exclude the influence of the buffers and just toggle effect on and off.
If you'd do the same thing with an analog delay of standard type what do you find?
This effect should perhaps be more evident if you'd throw a tapeecho in there too.

All will affect high treble to some extent, but there may also be a level of nothing really important lost.

Back to loading in pedalboard systems, the most noticable effect of loading is just loss of treble.
Now if there is a level of tolerable or even wanted losses, the use of buffers in such a system may totally depend on user preference.

Let's assume system with a couple of pedals, that are all truebypass, medium lenght of cables and desired pick ups in guitar.
Worst case of losses would result when all pedals are bypassed.If there are no detected losses or let's say
nothing troublesome, then a buffer may be redundant.
Now if sound changes when going through the whole system like described, then a buffer may be needed.
There can be this scenario that introducing a buffer in a system nulls losses to such an extent that sound has more treble- sometimes this would be desirable.

Buffers are problem solvers, but if you don't have a loading problem a buffer is just a piece of electronics.

As I see it strings to speakercloth and what's in between is the instrument and you may tune all buildingblocks to your ear and vision, not by an exact rule.

To be continued

BJ

Oh, Jamie please resend message and take care

[JKoeth]

Thanks Bjorn,

I re-sent the email. Is this still your email address? bjfelectronics@mac.com

What do you think of the Radial Dragster? http://www.radialeng.com/re-dragster.htm

It sounds good in theory but does not look like a buffer.

[JofZ]

Thanks Bjorn,

I re-sent the email. Is this still your email address? bjfelectronics@mac.com

What do you think of the Radial Dragster? http://www.radialeng.com/re-dragster.htm

It sounds good in theory but does not look like a buffer.

Everyone should chime in on this topic as it is an interesting one. I recently went through this with a lot of help from Bj and Scotty!

Bjorn will correct me :D but I do believe some of his pedals are buffered!

I had an interesting problem, I had too many pedals being pushed by a PP2 that didn't have enough power to keep up to the task. My signal would just drop. It was a nightmare at first, but it made me think and at the end of it I really learned a ton of new information (buffers and all)

How many pedals are on your board now?

[JKoeth]

Hey J,

Bjorn just emailed me some cool info.

I've currently got a:

Strobostomp
Pro Analog Supa Quack Wah
5 Loooper (will be replaced soon I hope)
Digitech Jamman (will be removed from main board)
Toneczar Echoczar & Angel Baby
RRB
EGDM
PPF
HB
SBEQ

(all powered by a Juicebox 3.0)

I'm planning on adding a:

PGC
Pro Analog Boost Royale
Toneczar Halophaze
Toneczar Distortion
Toneczar Powerglide
Axess GRX4 (to replace the Loooper)
Axess MFC5
Pedal Power 2 Plus

So, the total number of pedals will be 13 (not including the GRX4). The GRX4 has a defeatable buffer. So far, I have tried the Lehle buffer and the Lovepedal buffer and didn't really care for either of them. I'm hoping that the Axess will work great but it may not be my thing either.

My REAL hope is that Bjorn can custom design me a tunable buffer when things settle down for him. I'd like to have a bit more control over the buffers effect and sound. I guess this would be like combining the concepts of the Dragster and a Buffer in a way.

Do you still have your crazy huge board?!

[JofZ]

Hey J,

Bjorn just emailed me some cool info.

I've currently got a:

Strobostomp
Pro Analog Supa Quack Wah
5 Loooper (will be replaced soon I hope)
Digitech Jamman (will be removed from main board)
Toneczar Echoczar & Angel Baby
RRB
EGDM
PPF
HB
SBEQ

(all powered by a Juicebox 3.0)

I'm planning on adding a:

PGC
Pro Analog Boost Royale
Toneczar Halophaze
Toneczar Distortion
Toneczar Powerglide
Axess GRX4 (to replace the Loooper)
Axess MFC5
Pedal Power 2 Plus

So, the total number of pedals will be 13 (not including the GRX4). The GRX4 has a defeatable buffer. So far, I have tried the Lehle buffer and the Lovepedal buffer and didn't really care for either of them. I'm hoping that the Axess will work great but it may not be my thing either.

My REAL hope is that Bjorn can custom design me a tunable buffer when things settle down for him. I'd like to have a bit more control over the buffers effect and sound. I guess this would be like combining the concepts of the Dragster and a Buffer in a way.

Do you still have your crazy huge board?!

You are catching up :D

Yep I still have the out of control board. PumaMan is making me a walnut board, should be done soon. Since I am pretty much there and will only be changing things on a limited basis I figured it was time to clean it up.

I need to shoot a before and after and Kevin will be sending me some progress photos which I will post.

[JKoeth]

I'll be getting a Pumaboard too!! Great boards, killer prices.
I'm planning on getting a tolex/formica board with 4 1/4" jacks and 1 or 2 IEC's. It was either get the extra features or get the Walnut. The GRX4s and Power Supplies will live underneath it. I've gotta get the pedal collection together first though.

Are you using a buffer in your chain?

How did you resolve your power problem?

Here's a current pic (before the additions):

http://i17.photobucket.com/albums/b78/jkoeth/150_5090.jpg

[JofZ]

I'll be getting a Pumaboard too!! Great boards, killer prices.
I'm planning on getting a tolex/formica board with 4 1/4" jacks and 1 or 2 IEC's. It was either get the extra features or get the Walnut. The GRX4s and Power Supplies will live underneath it. I've gotta get the pedal collection together first though.

Are you using a buffer in your chain?

How did you resolve your power problem?

Here's a current pic (before the additions):

http://i17.photobucket.com/albums/b78/jkoeth/150_5090.jpg

I went with a 46 x 15 walnut board, 3 PP2s installed underneath using Round nema style recessed sockets for power.
I have buffers built into some of my pedals. But the signal loss came from the PP2 being overworked, so I added another one LOL.
Kevin said this is the largest one he has made and I am out of control. I hope to have the board ready by Florida ToneFest!
I run the TTE last now with 18 pedals and all of it goes into the MP effects loop. I bump the powersuck up from bedroom to pub and all is very, very good!
I will shoot some photos!

[JKoeth]

WOW.

I thought my board was expensive.

Which pedals are buffered? What are Round nema style recessed sockets?

I'd love some current pics.

[JofZ]

WOW.

I thought my board was expensive.

Which pedals are buffered? What are Round nema style recessed sockets?

I'd love some current pics.

Here is the most current photo I have:
http://i21.photobucket.com/albums/b291/JofZ/IMG_0677.jpg

I will have to pull up my notes to find out which ones are buffered :D too many pedals to try and remember it all.
The nema sockets are used in place of the IEC, they are better for my application.

Here is a photo of a nema style plug:
http://www.elect-spec.com/nema_plgsokt.htm

Here is an IEC:
http://en.wikipedia.org/wiki/IEC_connector

[Teahead]

What makes a good buffer? For instance, will leaving a good comp, eq or mild boost/drive pedal permanently engaged act as an adequate buffer? Or should it be a dedicated unit?

Also, would it be correct to assume that no buffer, regardless of how good it may be, is going to give the same performance as guitar > amp? Is this a necessary evil that we must suffer for using pedals?

[BJF]

Hi,

Hm, in your setup JofZ, the Baby Blue Booster is buffered and the rest truebypass.

( the original tremolo circuit that SYT is based on was buffered, while SYT is truebypass)

Right, well Teahead, that is actually a good question wether a buffer needs to be a dedicated unit. Any pedal run always on becomes a buffer, though it also may do other things. For instance if you run a compressor always on, perhaps set mildly, then everything downstream from the compressor will be driven by the compressor, while your guitar sees the input of the compressor, so in that case a dedicated buffer would be redundant.( that's if the compressor does not need a buffer to work it's best, which would be highly unlikely).

Have fun
BJ

[Teahead]

Thanks BJ, would that mean that although a compressor driving the chain is acting as a sort of buffer, having a buffer driving the comp would be better?

Should the buffer be as close as possible to the front of the chain for best reults?

[BJF]

Hi,

Most compressors have high enough inputimpedance to make negliable load on pick ups, this would be all pedal compressors I can think of, though there are rack mount compressors that actually may require a buffer to be used with guitar.
In most cases though a buffer will not be needed ahead of a compressor and if a buffer is used in such a position it needs to have really low noise as the compressor cannot distinguish noise from useful signals.

Placement of buffer depends on where the undesirable loading takes place.

An example:
You'd like to use a Maestro Phaser. This is an older unit with rather low input impedance and it will degrade your sound if left hanging as well as when on.
Placing a buffer just a head of the Maestro reduces the loading and makes it negliable. Hm, so then the rest of the systenm has short cable runs and no other losses are present. The buffer may then make sound a little brighter if left in chain......one solution can then be to place a buffer inside the Maestro
or place the Maestro driven by an external buffer in a truebypass loop.

Again if a compressor or other pedal like an eq is on at all times there should be little chance of loading as either would also act as buffer when on.

BJ

[Teahead]

Thanks for taking the time to explain that, BJ. Much appreciated!

[Cotton]

Few others have explained this topic as well or as breifly as you.

For many years now, I've used an OD layout that has always given me the most flexible pedal drive to use with changing amps, guitars, moods, or rooms. The simple view is Guitar into Compressor into OD into Parametric EQ into Amp.

Years ago, when I only had three pedals, the layout was:

TC Sustain/Punch into vintage TS9 into Carl Martin Parametric EQ....

Today, I'm running in this order:

Retroman Sybil Fuzz
Budda Wah Plus
Keeley Comp
Hoochee Mama (Rangemaster plus od)
Proanalog Dual Drive
Lovepedal Eternity
Monster Effects El Dorado
Carl Martin Parametric EQ
Fulltone TTE

At times, there could be a Diaz Trem, Script 90 style phase, or Aqua Puss AD after the Carl Martin Para EQ....

It sounds like without the TTE, Fuzz, and Wah, as long as the Carl Martin Para EQ is at the back end and the Keeley Comp is up front, I'm okay.... Correct?

But with the Wah and Fuzz up front, I may have a buffering issue.... However, the only problem that exists is one that bothers me.... If I don't hear it, there is no problem.... correct?

Does a BBE Sonic Maximizer 482i clean up the tail end from all.... sins? One might still need a buffer up front though... for the loading on the guitar pups?

Thanks! Cotton

[Cody McLain]

Old thread, but I'm curious about the questions Cotton asked. I run my pedals similarly, with COT50, Pic Wah and then comp into drive pedals, etc. Just curious how this impacts the issue with buffers.

[BJF]

Originally Posted by Cotton

"It sounds like without the TTE, Fuzz, and Wah, as long as the Carl Martin Para EQ is at the back end and the Keeley Comp is up front, I'm okay.... Correct?

But with the Wah and Fuzz up front, I may have a buffering issue.... However, the only problem that exists is one that bothers me.... If I don't hear it, there is no problem.... correct?

Does a BBE Sonic Maximizer 482i clean up the tail end from all.... sins? One might still need a buffer up front though... for the loading on the guitar pups?"

Thanks! Cotton

Hi Cotton,

Thank you for the good words

Well firstly if nothing bothers you in your system you perhaps don't need further buffering than the Carl Martin gives to the cable leading to your amp.

It appears you have no problem.

Hm, you might want to be cautious with using a buffer at the beginning of this system as at least two of your effects capatilize on loading the pick ups for best effect...........again if you hear no losses you can't stand then all would be fine.

Hm, well you can't clean up all 'sins' at the end of chain. Losses happen along the way and sometimes you really want them too: if you'd play Hendrix system with George L's you'd have one shrill tone ;)

The loading your guitar sees would be the first cable and if all effects are bypassed also the cables between the pedals and finally the input of the Carl Martin. You can select your cables so there is minimum loss and in fact 'hifi' is rarely wanted in guitar systems ;)

Now most likely the longest cable in your system is the one that leads from board to amplifier and any loading that gives would be isolated by the Carl Martin.

I think you would know if you need a buffer and most notably by missing treble as in a dull sound- then your guitar may need less loading.

Note that some drives and fuzzes et.c that has a lot of gain also have a low inputimpedance to minimize stray noise and maybe also as a filter effect and such pedals may be quite bright if driven from a buffered output.

I hope this is of some aid


At your service
BJ

[Cody McLain]

Thanks for the info Bjorn. Good thread..

[Cotton]

Thanks, man... Thanks a whole lot... Actually, the topic is now clear to me and much of what I suspected was confirmed. I owe ya and look forward to placing some of your gear all around my tone! That day is a coming!

Cotton