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Registered Member #30
Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706
Wow nice job hazmatt, I like the Crate crate M.D.K is cool too, "Maximum Decibel Killage"
I totally agree with your tips too, except maybe one: I used a 12AT7 in the phase splitter on my Toaster amp. I used a different phase splitter circuit to the usual guitar amp design, too. The Toaster always tends to sound muddy and sludgy when it's cranked up, whereas my other amp (that has the usual long-tailed pair splitter with a 12AX7) sounds quite mean and snarly. So maybe I should change it.
I tried KT88s in the Toaster but they draw too much current at high volume. The power supply just sags to nothing. I put a protection circuit i was messing around with in this amp, that was intended to save the tubes if the amp were cranked with no speaker. But what happens is that if the power supply sags too much, it triggers this circuit and turns the amp completely off. I don't know what I was thinking when I put that in. An amp that turns itself off before it gets to "11" isn't very rock and roll.
I went to the Marshall Amps roadshow this week. They had a rock band demonstrating their amps. The guitarist had a huge wall of different Marshalls that he plugged into in turn to show them off. They all sounded great, although the handwired tube ones pwned the solid-state models IMO. The climax of the evening was when they plugged in the new Jimi Hendrix signature stack. It sounded awesome for 10 seconds and then broke.
Registered Member #30
Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706
Joe: Tube circuits can be very sensitive to small amounts of stray capacitance between wires and components. Especially in high gain guitar amp circuits. In the Toaster I had to cover the first preamp tube with a metal shield, or capacitive coupling between its anode and the anode of the nearby power tube made the amp oscillate when the volume was cranked on the high gain settings.
One tip I often saw on the Ampage forums was to poke the wiring around with an insulating stick of some kind and look for places that change the frequency or amplitude of the oscillations. The places that change it most are probably what's causing the trouble. If you get stuck, I bet you'll find someone with experience modding the Cream Machine over on Ampage.
The Toaster went on tour this weekend! The band I play bass in was playing at a music festival. There was no bass amp... damn folk musicians... so I brought the Toaster along with a 2x12" guitar cabinet. (There was no room in the car for the 2x15" that appears in my avatar.) It actually worked great! The other cool thing was that the stage was a truck trailer parked in the middle of a field.
Registered Member #75
Joined: Thu Feb 09 2006, 09:30AM
Location: Montana, USA
Posts: 711
Doh, I accidentially disconnected the ground on the µAmp, that's why it was buzzing like crazy But with a tidy layout like this:
it can take a while to figure that out.
Now I really want to get going on that Soldano SLO Clone, but all that talk about converting old tube PAs into guitar amps has made me curious: Maybe I can save around 200€ in parts by not buying the power- and output-transformer and other bits and pieces from my favorite online store (), but looking for an old tube PA on eBay instead?
I spotted this one which might be interesting, it has 2x EL34 and 4 x ECC83 and looks old and shitty, so nobody would buy it except for parts. On the other hand, these things seem to be quite expensive, here a similar one sold for more than 100€.
Registered Member #30
Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706
That Dynacord PA looks nice! It looks like a nice case too, you could keep it and just change the front and back panels. Great that it has 4, 8 and 16 ohm taps too, my Toaster PA only had 16. I think you could have it snarling like a SLO in no time.
If you do win it, for goodness' sake tell the seller to remove the large tubes and pack them separately. Or wrap them in bubble wrap and put them back inside the chassis. Otherwise they're bound to come loose in transit and get smashed. :(
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Show off your tube amp!
M.D.K is cool too, "Maximum Decibel Killage" 
The climax of the evening was when they plugged in the new Jimi Hendrix signature stack. It sounded awesome for 10 seconds and then broke. 
