amp or pre-amp impedance

[Oreomeister365]

Hi, I'm having some custom pickups constructed and there's a few technical terms I'm not sure of.

Well, not true I know what impedance is I just don't know where to apply it in this situation.

The builder asked the impedance in put of the amp I want to use. Now, I assume he's asking about my pre amp and not my make large noises amp?

Thanks

[niftydog]

Yup, sounds like he wants to know what impedance the pickups will be "seeing." So whatever it is that comes first in your signal chain right after the bass itself, that's what you need the impedance spec for.

[Oreomeister365]

er, as in after the on board preamp? you mean like, the impedance of say, my gallien krueger 700RB right?

Thanks.

[niftydog]

Ah, well then, no... he'll want the input impedance of the device immediately following the pickups - so yeah, the preamp.

[DavidRavenMoon]

Most preamps have a very high impedance input... probably around 1M. Same is true for high z inputs on amplifiers. At the very least they are 100K.

So he really doesn't need to know that because pickups are never that high. Even if he was winding low impedance pickups, it still doesn't matter. Even though you wouldn't need as high an input impedance for a low Z pickup, it's very common to have high Z inputs on the buffer amps.

I'd have to question how much this guy knows about pickups. All commercial preamps will work with any high Z pickup.

[RyreInc]

Yeah, I wouldn't want pups that were custom designed to work with a particular input impedance, since I would want to be able to switch pre-amps, etc.