Typical guitar output?

[pinkmouse]

Post a pic.

[sreten]

Hi,

as far as I'm aware the nominal output of an electric guitar
and the nominal input sensitivity of guitar amplifiers is 10mV.

Though for amplifiers 5mV and 20mV is also common.

/sreten.

[Wynand]

I'm unfortunately at work now

I'll try to get one for tomorrow.

I'll do a search on the internet for humbuckers also.

10mV sounds more like I would have expected...We'll see.

[runebivrin]

Originally posted by Wynand
I'm not sure what pickups i've got on my guitar?!?

Do you know the output of other types of pickups?

How do I see if it's a humbucker?

Most of the time you can judge that by the width of the pickup. Single coils are rarely wider than 20mm / 1". Humbuckers are usually twice as wide, since they contain two coils side-by-side.

Another way to tell is through the position of the magnetic poles. If they're centered in the pickup case it's a single coil. If there's two rows of poles or a single row way off-center, it's a humbucker.

And guitar pre-amps need headroom. A lot of it, unless you want distortion. The initial "pluck" transient can be quite insane.

Rune

[Wynand]

I've got two pickups. Both look the same.

Black plastic cover. 4cm x 8cm . 1 row of screws in the centre of each.


P.S. I just saw the first sonar of my first-born-to-be.

[teemuk]

Originally posted by Wynand
Would anyboy be able to tell me what the typical output is from a guitar.

I want to make a guitar preamp with op-amps but I don't know what gain to use.

What is the input sensitivity of your power amplifier? You have to reach this figure at the output of the preamp with volume at ten. Later on you will attenuate the amplitude dramatically with a volume potentiometer. A good design value is to assume that the guitar signal is 50mVpp. However, this is only a mean value and the signal will occasionally exceed it: Some pickups may put out peak amplitudes exceeding one volt. Bearing this in mind, you should use low gain (less than 7) to retain headroom. You only need as much gain as attenuated by the passive stages (tone controls etc.) and what's left to catch up with the input sensitivity.

[runebivrin]

Originally posted by Wynand
I've got two pickups. Both look the same.

Black plastic cover. 4cm x 8cm . 1 row of screws in the centre of each.


P.S. I just saw the first sonar of my first-born-to-be.

That sounds like a P-90 type single coil pickup.

Originally posted by teemuk


What is the input sensitivity of your power amplifier? You have to reach this figure at the output of the preamp with volume at ten. Later on you will attenuate the amplitude dramatically with a volume potentiometer. A good design value is to assume that the guitar signal is 50mVpp. However, this is only a mean value and the signal will occasionally exceed it: Some pickups may put out peak amplitudes exceeding one volt. Bearing this in mind, you should use low gain (less than 7) to retain headroom. You only need as much gain as attenuated by the passive stages (tone controls etc.) and what's left to catch up with the input sensitivity.

I'd say this is one of those rare cases where you'd actually want a potentiometer to set the gain, or at least make it switchable. A range from 1 to 20 is probably all that's useful, unless you want heavy distortion, in which case the sky's the limit for the heavy metal freaks.

A lot of guitar amps have two inputs with different sensitivity to cover the single coil/humbucker issue.

Rune

[Optical]

My reasonably high output Seymour Duncan pickups put out a 200mV signal peak.
Picking a high pitched note is more like 10mV

the voltage decays very quickly though

[DoctorJ]

Dimarzio has their pickups rated as high, medium and vintage output. The X2N output is 510mV.

[Doc Blues]

If we take the first peak of the guitar signal into consideration, the signal can be much higher than 100 - 400 mV. If you play a chord with a strong attack, the intitial transient signal peak can be up to 1,5 volts - than the level drops down to 100 - 200 mV. Of course - this is only a short peak lasting a few milliseconds, but this peak is, what makes much of the sound. If you have only a headroom of - let us say 0,5 V in the input stage of your amp, you will not hear any distortion, but you will hear, that the sound is affected.
The way, the peak is handled by the amp is one of the main reasons, why tupe-amps sound different than most solid-state circuits. Tubes have a different way to handle transient peaks. FETs are similar - some OP-amps will also do fine. The effect of peak modulation is intensively used in dynamic compressors - in particular in opto-compressors and tube compressors.

As a rule, you should have enough headroom to accomodate at least 1 V - better is 1,5 volts if you are using strong output PUs, if you want the whole peak, dynamic and sparkle in the sound.

If you are using an OP-Amp input-stage in your guitar amp with typically +/- 15V supply, you should not exceed an amplification factor of maximum 15 - better is 10.