Tube preamps containing a tube power amp section and dummy load

[bongomania]

So, here's an esoteric category of gear that intrigues me, and may intrigue some of you--while others will groan, roll their eyes, and say "what's the point?". Tube preamps that contain a 1-watt to 5-watt tube power amp section, followed by a dummy load. The idea is to get the sound of a full tube amp, either feeding into a recording/PA desk, or driving a solid-state power amp or otherwise too-clean amp head. They have individually been discussed a bit in other threads, but not all of them in the same place, as a category of interest.

Here are the ones I know about:

SWR Interstellar Overdriver
Warwick Quadruplet
Hughes & Kettner Blues Master/ Crunch Master/ Bass Master/ BATT
Lexicon Signature 284
Garnet Herzog
Electrosonic Parallax
SAMAMP (not Sansamp)
Stephenson Stage Hog

I recall there being a couple of others, but I can't remember their names right now. Please post the ones you know about here!

I bought a Blues Master not so long ago, on the recommendation of TB'er jibreel, and I love it! The fully-clipped overdrive tones are not so great, too buzzy and grating; but the "mostly clean" (just at the edge of breakup) tones are terrific, super fat and warm and "3D" sounding. I am by no means a tube amp expert, in fact I've only owned one all-tube amp, a Univox U-1011 (which is FS now ); so I cannot say whether the Blues Master "really" sounds like the best an all-tube amp head has to offer. I can say that it sounds just as good as the Univox, for what that's worth. Again though, that's just in the "not really overdriven" gain range.

I'm interested to hear other peoples' experiences with the various different versions out there. Please contribute what you know!

[JGR]

Wow, I didn't realize there were that many. I had the SWR for a while and it was a nice unit but it didn't sound any more like an all tube rig than my own preamp or any others that I own/have owned. There are simpler ways to get this type of effect with normal preamp tubes; I think it is a cool idea that is better on paper but falls short in practice. I've never like liked the sound of tubes running into a dummy load - even the reactive ones I've had left a lot to be desired. The SWR did sound much better when I ran it's mini power section into a cab (which bypasses the load resistor) but it was impractical and I found it prone to instability.

[majortoby]

I've always thought an evj modded to contain a dummy load would be interesting for this purpose. Granted, it would have a rather limited "bag of tricks", so to speak.

[beans-on-toast]

I've used the Garnet Herzog. The amp is based on a Fender Champ. It has a resistor in place of a speaker as a dummy load. There is a voltage divider on the dummy load resistor that bleeds off signal that can be fed into the input of another amp.

I tend to think of these devices working with guitars where you want an output that is saturated in distortion. I've never tried them with bass.

A device that I have that is along the same vein is the Groove Tubes Speaker Emulator. You feed the output of your amp into this device instead of connecting it to a speaker. The SE feeds the signal through an encased speaker motor. The advantage of the speaker motor is that it is a speaker without the sound. It reacts like a real speaker in terms of how the impedance changes with frequency. There is an adjustable EQ circuit and the output is fed into the input of another amp. It is a great device but the amp that you connect it to is limited to something like 50W of power output.

Similar devices are the Palmer PDI-03, Marshall Power Break (just a resistive load), and the Weber MASS attenuators.

[brianrost]

I've owned the H&K Cream Machine and the Blues Master. None of the H&K boxes are 100% tube, there is a small solid state buffer right at the input for some reason. The Cream Machine has no tone controls which is probably why it was replaced by the other models. I've had fun hooking them up an EV 15" and thumping away.