Reactive Load SS amps

[garybaldy]

Yes, Award Session was/is onto something imho. I find their amps sounding and reacting better than other SS-amps. The most striking is their volume: the 22 watts of the Bluesbaby are really the same 22 watts as that of a Deluxe Reverb for example, whille typically 22 watts in other SS-amps would by no means be enough to use that amp on stage. I can even use the Bluesbaby with a big band (mic-ed that is, but still).

I think their amps are worth checking out for jazz guitarists as well, especially the 45 watts models. And they are very reasonably priced.

Btw, Eric Clapton used the Rockette:30 model ;-)

Thanks for the EC info. I had a Rockette late 80s early 90s to amplify a Jacques Favino Oval hole with an Ashworth transducer. Never really worked but I think it was the transducer.

[orri]

Can't you just add a 1:1 transformer between a SS amp output and a speaker, if you want a load that behaves like a transformer and a speaker? (yes it is lossy, has some weight, and is not for free).
You could also just connect your speaker in series with an inductor if you just want a more inductive load,

[thpm]

Here is some info on that topic:

Amplified music : Solid-state valve amp

and

Amplifiers: Solid State amps verses Valve amps (esp the section on amplifier history)


The gist of the whole thing is that when solid-state became a thing, engineers loved the new technology for its superiority in technical terms: it finally allowed them to design amps with zero distortion and zero output impedance. That this was great in engineering- but not necessarily in musical terms fell off the wayside.

An interesting explanation the author offers is that the „flatter“ sound might also not have mattered so much to the white collar engineers and their music (vs the bass heavy music of the working class)

[aquin43]

From the point of view of guitar amplification, the net result of these schemes for current driving the speaker instead of voltage driving it is to produce a mid scooped response where the output power reflects the impedance of the speaker. With true current drive, the power delivered to the speaker could become very large at low frequencies - but where are the volts to deliver the current going to come from? At resonance, an 8 Ohm speaker might have an impedance of 30 Ohms or more, depending on its internal damping. This would require something like four times the mid range voltage to drive the same current. Valve amplifiers, particularly smaller output ones, tend to be very inefficient and have high internal resistive losses. They can provide a few dB more output voltage to the higher loudspeaker impedance at resonance.

In practical terms, I would expect that a suitable EQ would effectively emulate the response caused by a high amplifier output impedance. This is what Fender seem to do with their Tonemaster amps. The output stage is a bought in switchmode power amp with very low output impedance. The power module has a balanced speaker output connection, so it is unlikely that they are using any further feedback around it to raise its output impedance. It has a rated power larger than the rated power of the completed amplifier to give the necessary headroom to emulate the slightly increased voltage swing that the valve circuit can provide at low frequencies. With a switch mode amplifier you don't have to worry about loss of efficiency due to running an amplifier below its rated output. The EQ would be part of the digital emulator.

Award Session, on the other hand, obviously use current feedback to raise the amplifier output impedance and use an amplifier module with more than the rated power capacity to emulate the slightly greater headroom at the ends of the frequency spectrum. Clipping will be arranged to happen before the output module.

[icr]

With "Reactive Load" and this, it is nice to see there are still avenues for improvement in non-modeling amp design.

[jads57]

At the end of the day no matter how great an amp is, it almost a moot point.
Other than occasionally being able to gig or just for self enjoyment. With Covid best to just play acoustically or some other low volume solution.

I do enjoy my Quilter Aviator amps and TB202 quite a bit, when I do get a gig!

[thpm]

With "Reactive Load" and this, it is nice to see there are still avenues for improvement in non-modeling amp design.

It seems to me not that many manufacturers are pursuing these avenues (SS without DSP) though.

On the low end / entry level, DSP is the way to go (an amp which can sound like anything is an easier sell to the beginner).

Are there any recently introduced mainstream offerings? (Ignoring our Quilter-Henriksen-etc niche here) — I can only think of „power amp“ (or marketed as power amp) boxes like the Orange Pedal Baby, no?

(Nothing wrong per se with modellers, just wondering)

[patshep]

In the end, it's still modeling tube amps, 'sag' is from tubes... jazz guys using tube amps get rid of the rectifier tubes to reduce sag
i'd still rather have a tube amp, but if i were to play a jazz gig, i can still deal with solid state, i'm not sure who will spend money to develop technology that jazz guitarists will use, it's not much money to be made