built-in preamp in double bass amps

[myrick]

Between the mic and pick-up makers who make stuff for double bass sound enhancement and those few amp makers who also have products reasonably dedicated to this sort of application, I'm wondering why someone can't develop and market a pickup/amp combination with impedences matched so that we don't need to interpose an external preamp, in addition to the pre circuit that's already in the main amp.

Any thoughts, anyone?

I mean, for example, the AI seems to have various choices on input impedence and input gain, but it seems everyone still ends up using an external preamp as well for optimum sound with most dblbass pickups or mics. Perhaps someone more electronically aware (or market savvy) than I can offer a comment.

[Bob Gollihur]

Acoustic Image is one who does have an ultra-high impedance input (10 megohms) in their amps, and a few have 1 megohm inputs. However, I wonder if some other players also use a preamp because of its utility value as well as possible tone benefits??

I know that I will often take a preamp with a Contra or my Kern (10 megohm input) because of its utility value. If volume needs are anything beyond modest, I prefer to place the amp a few feet away, so I can better hear its output and to avoid any resonances or possible feedback. The preamp allows me to make volume and even slight tone changes without dragging the bass over to the amp.

Just curious.

[mje]

There's also a big advantage to having the high impedence buffer as close to your pickup as possible. Not only does it minimize high frequency losses, but it minimizes cable noise, too. A cable is one long capacitor whose value changes as it flexes. Hook that up to a high impedence source and you've got a nice voltage generator popping and crackling as the cable moves.

[myrick]

useful info

thanks to you both

[anonymous0726]

My personal experience is that a premap just gives you another bad sound. Crackling, popping, etc, I've never had a problem with. Then again, I've rarely used a guitar cord longer than 10', so maybe I've lucked out.

The reason that there isn't anything for The Bass that doesn't stink is that the market is infinitismally (sp?) small. Thus there is no financial reason for businessmen to involve themselves in the probably impossible task of amplifying the thing.

[Scotgun]

Originally posted by Bob Gollihur
... The preamp allows me to make volume and even slight tone changes without dragging the bass over to the amp.

Originally posted by mje
There's also a big advantage to having the high impedence buffer as close to your pickup as possible. ...

(I believe some of the Walter Woods amps have a built-in DB preamp too.)

If you ever have to share the stage with an (obnoxiously loud) electric guitar player, you will, of course, need to turn up louder than you would normally want to. The above mentioned advantages of an instrument- or nearby- mounted (mine's close to the endpin) preamp become even more apparent, as they did at a gig I did last night. Since I'm frequently playing an orchestra bass in a pop setting, these situations come up occasionally.

If you are also playing the bass guitar on the same performance (and through a single-channel amplifier), it is to your advantage to adjust the respective tone of your instruments so your amp controls can remain constant.