Is solid-state power amp saturation recognizable? >With a speaker isolation cabinet and with
>MIDI processors placed before and after the amp-and-cabinet, it would be
>easy to set up the world's best test rig...


You might need to switch between two different guitar power amps -- both the input and output of the amps. It depends on what you're A/B'ing. There are probably MIDI switch boxes that can route high-level signals. I like this rig, using MIDI-controlled eq before and after the amp+spk+mic. But you can do this with studio separates too.


Here's a way to make a really good A/B test rig for comparing two guitar amps (or an amp and amp emulator), using traditional components.


You need dedicated eq before and after each amp, to normalize eq. We don't want to hear simple variations in frequency response; we want to home in on the guitar power amp, assuming we're doing an A/B of a tube and transistor guitar amp.


guitar -->


A/B switch box --> eq 1 --> amp 1 --> A/B switch box -->
--> eq 2 --> amp 2 -->


--> mic --> A/B sw.box --> eq 3 --> mixer (mixer eq flat)
--> eq 4 --> mixer (mixer eq flat)


Step on all 3 A/B boxes together, to switch pre eq, post eq, and amp while using a single cabinet and mic. Adjust the eq's and levels to get the same tonality and distortion level. Adjust the pre eq's so that the same amount of distortion happens across the frequency spectrum, for both amps.

It's best if you can bypass the amp preamp sections and go in through the effects return of the guitar amps.

I'm pretty interested in A/B comparison rigs. When imitating a tone, you have to be able to rapidly flip between the reference tone and your working tone. I was using my speaker isolation cabinet to imitate Stevie Ray's tone, but without an A/B switching capability between the record and my rig, I couldn't say how exactly close I was.

There are some specialty switch boxes controlled by MIDI. It's good to be able to handle both line-level and power-amp level signals.

>>The bigger-than-life guitar sounds on the first Led Zeppelin album are from a solid-state amp: >>A Supro 1x12 solid-state combo and a fuzz pedal.

>No, a friend of mine owns the same model of amp that Page used. It's all tubes.

>I have a 70s era solid-state Rickenbacker amp that is
>one of the nicer solid state amps I've ever heard. I also have an
>Ampeg tube amp and use an A/B box to play through both of them at the
>same time, which gives a remarkably neat sound, at least to these
>ears.

Harmonica sounds very round and fat through a cranked 15 watt tube amp.

The album Little Walter - Essentials is supposed to be good. This might have some of the best harmonica "amplified blues harp" tones.

I think some rock violinists play through tube amps as well.


Go into a music store. Put a Fender solid-state 15 watt amp next to a Fender 15-watt tube amp and play them at half and full volume.

Use an experienced guitarist to do a blind A/B test: which is the tube amp, and which is the solid state amp? It's easy to prove whether there is a distinct difference in tone between a standard tube and solid state guitar amp.

I personally do not have enough amp-cranking experience to say whether solid state is recognizable. However, with a speaker isolation cabinet and with my MIDI processors placed before and after the amp-and-cabinet, it would be easy to set up the world's best test rig. I would also need a MIDI-controlled switcher to route through the tube amp vs. solid state amp.

I would use the MIDI-controlled processors to experiment with equalization before the amps and after the cabinet, to see whether tube and solid state amps are simply equalized differently.

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