Pipe dream?

[msclford]

What do you guys think about this? Is it feasible? Is it already done? I know that there are pedals with preamp tubes in them, but how about this?

http://www.amptone.com/powertubedist...edaldesign.htm

[Satamax]

Msclford, i was onto a lead like this one. My idea was to take this a bit further, and make an amp, small disto machine, like a 5E3, and couple this with an iso cab. Feed the signal of the iso cab to my main clean amp, which is far too loud for using it's distortion. I was talking with some of teh guys here which were saying no to the RLC network because it's not a reactive load and might lack the natural feel of the normal amp. I've ended up using a speaker as a microphone, and got some pretty funky results Like a pedal steel or reso sound without any steel parts Thought i need to redo an iso cab of smaller size (i used 12 inchers! ) and make a proper filter cos teh bass are getting far too loud.

Best regards.

Max.

[msclford]

By "lack the feel of a natural amp" do you mean slightly or not sound like an overdriven power section at all? If it got closer than other pedals available, I think that would be a good start.

[Steve Conner]

I experimented a while back with a SE EL84 amp that used a regular output transformer and substituted the speaker for a dummy load. I tried A/B tests, comparing between the tube amp driving a speaker cab directly, and it driving a dummy load with a line-out into a solid-state power amp driving the same cabinet. There really wasn't much difference. So yes, I think the original poster's plan would work.

I don't believe in the concept of cranked tone at low volume, though. Once you take into account Fletcher-Munson curves and suchlike, it takes a completely different amp voicing to sound good at low volume than it does at high volume. An attenuator that just throws away power without changing the voicing will always sound dull. I believe the THD Hotplate does have this function (it's basically the same as what the Loudness button on those old Japanese stereos did) but I found that the EQ on my Toaster amp is good enough that I can make it sound good at any volume without using a power soak.

Having said that, I'm still working on the re-amping concept. I'm trying to build a hybrid power amp where the tube section can be used on its own for quiet playing, or helped out by a big-ass bank of transistors for loud playing, while still keeping the output impedance and sag characteristics of the tube section. So it would be like a regular tube power amp with a "Half power" switch, except the switch would choose between 3w and 150w

[dai h.]

seems to be a number of different things that have been done in the past and in recent years of this sort from Jose Arredondo apparently supplying EVH and others with resistor-only-loaded transformer-coupled output for his clients' Marshalls to the Guytron (small amp inside driving another main amp inside one amp), WeberVST MASS (pseudo-speaker physically moving motor unit as load), "Ultimate Attenator" (some sort of solid state interface between a tube amp output and speakers), the "Variplex" amp is which is apparently just independent control of the B+ (and bias) winding(s) using a Variac, ZVex nanoamp (super low power tube amp with an actual OT coupled output), or some DIY'ed stuff--one example being where someone shorted out the LC pair that creates the low frequency peak in a Marshall Power Brake (which doesn't have the best rep as far as attenuators go), added some series R, ran somewhat mismatched impedance and got (IMO) a very very good recorded result, etc. Someone drew out a layout for a Trainwreck Air Brake attenuator on the amp garage site recently also, and that was interesting since it is apparently almost completely resistive (yet has favorable reviews). There are various things you apparently have to watch out for like oscillations with a reactive load or taxing an old or new OT that isn't up to the job of being run hard into clipping for long periods.