I've got an amp that needs killing and wondering if putting a Dumble preamp onto it's SE output is worth trying. Thought of adding a fake PI to mix signal and NFB to linearize the PA. I'd use the D'lite layout and subtract what's not needed.
Is this a dumb idea?
Other choice is a mini-wreak but I'm not sure wreaks are my cup of tea.
Thanks!
BTW it's NOT a VJ !!
Last edited by nickt on Tue Oct 16, 2007 11:37 pm, edited 1 time in total.
I'd love to hear some clips of it. Purely speculation, but it seems a Dumble might adapt better to SE than a Trainwreck. My attempts so far of a single ended TW were nice, but not nice enough to keep.
tele_player wrote:
Anyway, I wouldn't say a Dumble into a SE amp is a dumb idea, but I'd ask you why you'd want it.
No big plans here - just have an amp (Ceriatone HO) that I hate and want to turn into something useful - either to put on ebay or use as a practice amp. I've got a trannie coming from JimiB for a D'lite build but it'll take a while to put all the other bits together.
LeftyStrat wrote:
Something to take to a gig where I am not famous enough to have roadies and I don't want to break my back.
Hey I'm in the Australian dictionary of rock and have exactly the same number of entries as Angus Young - does that make me famous? - wait a minute they misspelt my name - you get no respect...
Weight.
Weight.
Weight.
Trouble is my favourite speaker is an old EV which I think is 30lb / 15kg by itself.
nickt wrote:
Hey I'm in the Australian dictionary of rock and have exactly the same number of entries as Angus Young - does that make me famous? - wait a minute they misspelt my name - you get no respect...
Well, if you know any of those guys from the original Icehouse (Flowers), tell them it was one of the best live shows I have ever seen. Saw them in ATL around 86 or 7. It wasn't good, it was devastating.
tele_player wrote:That HRM Champ isn't single ended, but it sure is tiny.
Anyway, I wouldn't say a Dumble into a SE amp is a dumb idea, but I'd ask you why you'd want it.
For the living room, or the jam session where the drummer didn't think he was Bonham Incarnate.
Something to take to a gig where I am not famous enough to have roadies and I don't want to break my back.
Weight.
Weight.
Weight.
Those aren't arguments specifically for SE, though SE amps are typically pretty low powered and light. At a given power level, PP probably adds about half a pound compared to SE, and you can certainly make low power push-pull amps.
I tried one years ago. Honestly I[ve learned a lot about these amps since then so the jury's still out. I can say that it didn't have that classic Dumble tone. My 2x6V6 in a Princeton Chassis is as small and light and is very close to a true Dumble. I swapped out the 6L6's and it's great, even at the lower B+ voltage.
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tele_player wrote:
Those aren't arguments specifically for SE, though SE amps are typically pretty low powered and light. At a given power level, PP probably adds about half a pound compared to SE, and you can certainly make low power push-pull amps.
The other way round, surely? SE output tx is heavier per watt due to dealing with a DC current, and most PP amps will be biased class AB, which will need a smaller power tx than class A SE. Seems to add up to a lighter PP for a given power.
My current ~15W SE project has about 8lbs of iron (not counting the choke), compared to ~5lbs for my last PP 15W amp (which didn't need a choke!).
I have a way to find out for myself at least how a D-style pre through a SE combo amp's instrument input will sound. Can rob the out from a 50w HRM's C-lator and stick it into the front end of my Frank-en-Champ, muting the host amp and run one of my 16 ohm 2/12/s or 2/15's with the Frank-en-Champ. Could also use the unused right channel out of my fx processor and run both amps simultaneously. Can't post clips but i can offer some descriptions at least.
Have a theoretical idea about what will happen with SE output topology, that the singing harmonics I get in a volume pedal swell will be having more content expressed as octaves above the fundamentals as well as the commonly heard octave plus fifth above the fundamentals, even to the point of faintly at least hearing entire "ghost" chords two and more octaves up from their fundamental roots within the speaker's output from the SE amp. Hopefully those octave chord harmonics will predominate at least fragmentally in long sustain/feedback episodes, but that is probably asking too much from my ummm... nice parts but first time, kludgy, poor lead dress build, even though that amp sounds much better than it has a right to. It is a harmonic generating machine in it's own right that can take the input from a clean amp and dirty it up all by its mischevous little girthy self.
Will be interesting to see if the ears hear out the same thing as the characters my keyboard has clicked out to describe beforehand... Will get back.
