overloading:p/u vs amp

[cstockdale]

Okay, a question here. I am finally getting to understand the guitar after 8 yrs of playing (8yrs on acoustic, 3 yrs on electric). I would finally say I am a decent guitarist, but some elements of pick-ups interacting with amps I am still sorting out.

Can someone describe to me what is happening in the following scenario:

I have two guitars:
A) Fender Tele Standard with two standard tele single coils
B) Epiphone Wildkat, semi hollowbody, two Alnico VP-90 pickups

two amps:
Fender Frontman 25R (solid state)
Vox Cambridge 30 (tube pre, rest is solid state).

When I play my Epiphone through the Fender amp with the volume knob on the guitar between 6-10, and the Fender amp as low as 2, I get incredible low end breakup rumble out of the amp, irregardless of the pickup I have chosen (although this is more pronounced on the neck pu) (I am not saying I don't like this sound), but if I turn the guitar down to 4 or so, and turn the amp up to 6 or so, it is clean.

Same guitar, same settings on teh guitar, and fiddle with settings on the amp, but plugged into the Vox amp: no low end breakup, just rich, thick and creamy.

Now, plug in the Telecaster, and do the same things with the Fender amp: no low end breakup until I turn the amp to 8 or so, and guitar at full.

Tele into Vox: clean, even at high volume.


So what is happening with the P90's and the Fender amp to produce this jet-engine rumble?

 

[Major Tom]

Guitar pickups vary lot in output, amps vary a lot in the amount of gain available, and what their intended use is. "Distortion" pickups don't produce distortion, they have a lot of output which will drive any amp into distortion. The design of an amp is also influenced by the market the mfr. is trying to sell to, the Frontman may be designed with extra gain in its first stage to work well with cheaper guitars, like the Fender Squire, which typically have low output pickups. Maybe the Frontman is targeted to the buyer who wants a lot of distortion. I also believe mfrs. build in extra gain in the preamp on some models so that when you try it in the store, with the knob on 2 and it blasts your ears, the potential buyer will think "wow, if its that loud on 2 it must really kick butt on 11, dude !!", not realizing that its already close to its maximum output. I'm guessing the Vox was designed for the classic Vox tone, which is not mondo distortion.
Most amps have 2 inputs for each channel: the A or #1 input being the higher gain, B or #2 is attenuated for either a cleaner tone, or a higher output guitar - this is pretty much the extent of the amp's ability to handle different signal strengths. Does the Fman have 2 inputs?