Guitar lead capacitance per metre.

[ian field]

Where's a good place to look for guitar lead tech spec's?

Thanks.

[RichL]

Post by ian field
Where's a good place to look for guitar lead tech spec's?
Thanks.

You want specs for a particular cable or just general figures?

Good cables usually run around 20-40 pF/foot (65-130 pf/m).

[ian field]

Post by RichL

Post by ian field
Where's a good place to look for guitar lead tech spec's?
Thanks.

You want specs for a particular cable or just general figures?
Good cables usually run around 20-40 pF/foot (65-130 pf/m).

Thanks - your answer is a "hole in one".

I was thinking about a SS MOSFET for a clean boost front end, but the gate
capacitance is about 10x that of a JFET - but compared to 2m of guitar lead
its not going to be a problem.

[jh]

Post by ian field

Post by RichL

Post by ian field
Where's a good place to look for guitar lead tech spec's?
Thanks.

You want specs for a particular cable or just general figures?
Good cables usually run around 20-40 pF/foot (65-130 pf/m).

Thanks - your answer is a "hole in one".
I was thinking about a SS MOSFET for a clean boost front end, but the gate
capacitance is about 10x that of a JFET - but compared to 2m of guitar lead
its not going to be a problem.

Ian,

is the booster to be implemented into the guitar, or an FX box?

if it is intended to be external, it would be like playing an 8m cable
instead of a 6m. The resonance peak of a passive pickup *will* be damped
down a bit, making them sound with less "lifely".

IMHO, not a good idea to "improve" sound.


regards

Jochen

[ian field]

Post by jh

Post by ian field

Post by RichL

Post by ian field
Where's a good place to look for guitar lead tech spec's?
Thanks.

You want specs for a particular cable or just general figures?
Good cables usually run around 20-40 pF/foot (65-130 pf/m).

Thanks - your answer is a "hole in one".
I was thinking about a SS MOSFET for a clean boost front end, but the gate
capacitance is about 10x that of a JFET - but compared to 2m of guitar lead
its not going to be a problem.

Ian,
is the booster to be implemented into the guitar, or an FX box?
if it is intended to be external, it would be like playing an 8m cable
instead of a 6m. The resonance peak of a passive pickup *will* be damped
down a bit, making them sound with less "lifely".

The gain is going to be way too much, so its going to have to have plenty of
nfb - I think there's a way to arrange this so it cancells some of the input
capacitance.

[RichL]

Post by jh
Ian,
is the booster to be implemented into the guitar, or an FX box?
if it is intended to be external, it would be like playing an 8m cable
instead of a 6m. The resonance peak of a passive pickup *will* be damped
down a bit, making them sound with less "lifely".
IMHO, not a good idea to "improve" sound.

Ah, but can you really tell the difference between an 8 m cable and a 6 m
cable?

I don't think I have any cables as long as 8 m, but I do have some that are
around 4 m and others around 6.

I can tell the difference with SOME guitars but not others.

[jh]

Post by RichL

Post by jh
Ian,
is the booster to be implemented into the guitar, or an FX box?
if it is intended to be external, it would be like playing an 8m cable
instead of a 6m. The resonance peak of a passive pickup *will* be
damped down a bit, making them sound with less "lifely".
IMHO, not a good idea to "improve" sound.

Ah, but can you really tell the difference between an 8 m cable and a 6
m cable?
I don't think I have any cables as long as 8 m, but I do have some that
are around 4 m and others around 6.
I can tell the difference with SOME guitars but not others.

that's the point - exactly.

Some pickups are more prone to the "damping" of the resonance peak, some
not so.

I assume Ian to develop a "product". Inherent sound degradation for
"some" customers is never a good marketing idea. IMHO a linear booster
should leave the signal intact under all circumstances. Some people have
good ears; rumours spread fast; reputation is killed instantly

regards

Jochen

[ian field]

Post by jh

Post by RichL

Post by jh
Ian,
is the booster to be implemented into the guitar, or an FX box?
if it is intended to be external, it would be like playing an 8m cable
instead of a 6m. The resonance peak of a passive pickup *will* be
damped down a bit, making them sound with less "lifely".
IMHO, not a good idea to "improve" sound.

Ah, but can you really tell the difference between an 8 m cable and a 6
m cable?
I don't think I have any cables as long as 8 m, but I do have some that
are around 4 m and others around 6.
I can tell the difference with SOME guitars but not others.

that's the point - exactly.
Some pickups are more prone to the "damping" of the resonance peak, some
not so.
I assume Ian to develop a "product". Inherent sound degradation for "some"
customers is never a good marketing idea. IMHO a linear booster should
leave the signal intact under all circumstances. Some people have good
ears; rumours spread fast; reputation is killed instantly
regards
Jochen

I was comparing the MOSFET gate capacitance to a JFET optimised for RF
amplifiers that is sometimes used in pedals by hobbyists, but that device
has a Vp of up to 8V and isn't ideal for running off a 6F22 battery (we call
them PP3). Manufactured pedals generally use a low frequency JFET, one of
the commonly found types has a Vp up to 3V - the MOSFET I've selected is
only twice the input capacitance of that as opposed to nearly 10x that of
the RF JFET.

[Jim]

Post by ian field
Where's a good place to look for guitar lead tech spec's?
Thanks.

You could always buy a capacitance meter, so you know what YOUR cable
measures at.

This one works for my needs (building, modifying, repairing tube amps
and occasional effects -- as a HOBBY):
http://www.allelectronics.com/make-a-store/item/CP-350/CAPACITANCE_METER/-/1.html

If you want to know cable specs before you buy, some manufactures can
provide values.

But a general comment about cable capacitance: It only matters with a
high impedance source. If you use effects, it only matters between the
guitar and the first pedal that is on, or the first pedal that does not
have "true bypass" (because there's a buffer amp in it). If you have an
active guitar, it doesn't matter at all.

[underwood]

Post by Jim

Post by ian field
Where's a good place to look for guitar lead tech spec's?
Thanks.

You could always buy a capacitance meter, so you know what YOUR cable
measures at.
This one works for my needs (building, modifying, repairing tube amps
and occasional effects -- as a HOBBY):http://www.allelectronics.com/make-a-store/item/CP-350/CAPACITANCE_ME...
If you want to know cable specs before you buy, some manufactures can
provide values.
But a general comment about cable capacitance:  It only matters with a
high impedance source.  If you use effects, it only matters between the
guitar and the first pedal that is on, or the first pedal that does not
have "true bypass" (because there's a buffer amp in it).  If you have an
active guitar, it doesn't matter at all.

You could also reduce the lost of high frequencys by using a buffer
with a high impedance soure before your amp/effect board.

In case your guitar is not very good sheelded, you could get some more
noise than with a low impedance input on amp/effects.

Normal pedals have 500k-1000k. I use a buffer with more than 100M.

greets
Jürgen