Do Amps Have Pre-Amps?

[Rescon]

I had a new K&K Pure mini put in my new D42 and I've read a ton about weather or not a preamp is "needed" for this pick up. But my amp is confusing me. Its a Genz Benz Shenandoah 100W that has 2 channels and they BOTH have a volume knob that says "pre-amp". Is this a separate preamp circuit similar to other preamps (Fishman, Baggs, Fire-eye) offering a boost prior to speaker amplification?
I have a Acoustimax BBE preamp, so I thought I would take the forums general concensus and try it both ways (direct to amp & through BBE) and see what sounds best. I can barley tell the difference. I really thought there would be a dicernable difference. what gives??

Nick

[MrErikJ]

Originally Posted by Rescon

I had a new K&K Pure mini put in my new D42 and I've read a ton about weather or not a preamp is "needed" for this pick up. But my amp is confusing me. Its a Genz Benz Shenandoah 100W that has 2 channels and they BOTH have a volume knob that says "pre-amp". Is this a separate preamp circuit similar to other preamps (Fishman, Baggs, Fire-eye) offering a boost prior to speaker amplification?
I have a Acoustimax BBE preamp, so I thought I would take the forums general concensus and try it both ways (direct to amp & through BBE) and see what sounds best. I can barley tell the difference. I really thought there would be a dicernable difference. what gives??

Nick

Amplifiers have two power sections: a Preamp (gain/amplification of signal) and the power amp (output/volume). So, yes, amplifiers are pre-amplifiers that have a speaker section and "pre-amps" do the same thing as the first stage of a full-amplifier but are usually sent into another sound system and do not have their own speaker section.

The common tone between the two is "amp." They do the same thing: take your signal, which is low output and high-impedance, and turn it up to either go to a power amp or into a mixer.

[philjs]

Originally Posted by Rescon

I had a new K&K Pure mini put in my new D42 and I've read a ton about weather or not a preamp is "needed" for this pick up. But my amp is confusing me. Its a Genz Benz Shenandoah 100W that has 2 channels and they BOTH have a volume knob that says "pre-amp". Is this a separate preamp circuit similar to other preamps (Fishman, Baggs, Fire-eye) offering a boost prior to speaker amplification?

The preamp "volume" is actually an INPUT gain control used to get the strongest input signal without distortion. Because it's a two-channel amp those two "volume" controls are also your channel balance control (not always the best way to balance channels). The master volume control is the OUTPUT volume but it acts on both channels simultaneously. Note that all of the controls are on the preamp. There are no controls on the power amp.

Hope this helps,

Phil

[Rescon]

Ok, so thank you for that clarification. I thought that might be the :gain" volume but wasn't sure.
So, should I expect to hear a difference when running the signal through the BBE?

[lschwart]

Originally Posted by Rescon

Ok, so thank you for that clarification. I thought that might be the :gain" volume but wasn't sure.
So, should I expect to hear a difference when running the signal through the BBE?

It depends. In terms of the preamp itself and the EQ section, the BBE is redundant--the Shen has all of that covered. The Sonic Maximizer might make a difference, if you like what it does, and the feedback notch filter, phase switch, and mute switch might come in handy, and having controls at your feet might be more convenient than having them on the amp. Otherwise, the only thing that might make a difference is the input impedance. At 150 k ohms, the input impedance of the 1/4" inputs on the Shen are low for a passive K&K, so running into the BBE and from there to the amp by either the 1/4" or the XLR will solve that problem for you. That is, if it is a problem. You'll have to try it to see if it makes a noticeable difference. It might not.

Louis

[SalFromChatham]

I’d be curious if running your k&k through a Boss TU3w tuner (which has the impedance match) and then into your amp will make the sound as you like...

[sdelsolray]

Originally Posted by Rescon

I had a new K&K Pure mini put in my new D42 and I've read a ton about weather or not a preamp is "needed" for this pick up. But my amp is confusing me. Its a Genz Benz Shenandoah 100W that has 2 channels and they BOTH have a volume knob that says "pre-amp". Is this a separate preamp circuit similar to other preamps (Fishman, Baggs, Fire-eye) offering a boost prior to speaker amplification?
I have a Acoustimax BBE preamp, so I thought I would take the forums general concensus and try it both ways (direct to amp & through BBE) and see what sounds best. I can barley tell the difference. I really thought there would be a dicernable difference. what gives??

Nick

For playing live, amplification in done in two separate stages, the preamp stage and the power amp stage. Both of these functions can put into one box/place. Or they can be placed in separate boxes/places. The preamp stage increases the source's signal strength quite a bit, but not enough to drive speakers. The power amp stage increases that signal strength enough to drive speakers.

When recording, only the preamp stage is used and that resulting signal level is what is "recorded" to tape or computer disk. To listen to a recorded track, that signal is next routed to a power amp and then sent to speakers (or headphones).

Of course, there are many different boxes that perform these functions. Sometimes, two (or more) preamps will be chained together in series before the signal is sent to the power amp. This is where proper gain staging is required to make sure the signal does not get too strong while still in the preamp universe.

[Tommy_G]

On many amps there is a back panel jack called auxiliary input or power amp input that accepts line level signals... Compared to the much lower instrument level signal
.. For the purpose of facilitating use of an external preamp.