Quote:
Originally Posted by Tim Armstrong
As I've mentioned many times in the past, as an experiment I once played a wedding gig through a Champ powering a closed-back 2x12 cab, and it was more than loud enough to keep up with another guitarist, keyboards, bass and drums.
In a crowded, busy barroom, I'd definitely want a mic on it, but I'd gig that rig anywhere (if I hadn't foolishly sold it!).
Tim
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I remember you mentioning that years ago - I tried it and was floored. Depending on the speaker, mileage will vary, but for most folks it wont cut it. I'm lucky, I'm in a 3 piece, so I could probably get away with it at many rehearsal spaces - maybe even a few gigs - though I need a big crunchy tone that Champs can't deliver :)
Quote:
Originally Posted by muchxs
Consider that we'd end up with a 10 watt "Champ". It's going to be clean at the "5 watt" level. That's how to build a "5 watt" amp with respectable cleans although no "respectable" manufacturer would call it a "5 watt amp", not when they could sell it as a 10 watt amp! It's primarily a matter of upgrading the power supply to support the superior (ratings wise compared to a 6V6) tube.
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I've simply put in 10w iron as well as 15w iron on "5 watt" builds and the improvement was huge. Afterwhich I then tweaked the circuit to keep a tight bass and avoid ratty overdrive. Flipping loud.
One of my favorite Bass amps for practicing is a modified 5F1 tweed Champ circuit with a 10w OT. Most Champs fart out and get blown out bass - this thing stays clean with a guitar even when almost dimed and with bass has tight, big bottom.
Quote:
Originally Posted by muchxs
Why not swap to an EL34? Vintage amps used 6V6s, 6AQ5s, 6BQ5s and the like because that's what was most commonly used in the output stages of radios and phonographs. Thumbing through the data sheet: 265 volts plate, 250 volts screen grid, 2000 ohm load, 11 watts output. Oh, my. See how low the voltages are in relation to the output? And the max ratings are 800 volts plate, 450 volts screen. We won't go anywhere near 800 volts on the supply because it makes our lives difficult when we shop for capacitors. We need to pay attention to the fact that an EL34 is greedy when it comes to power consumption, we'll allow 100ma with a 20% safety margin (120 ma) on the high voltage and we must consider the 1.5 amp filament requirement. It's not a straight plug and play in a vintage Champ. However, if we started with a bare chassis and some adequate iron we could easily end up with a little amp that would give a tweed Deluxe a thrashing. Is it a "5 watt" amp? Nope. Would it play cleaner than a stock Champ at the "5 watt" level?
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I've done this. I built a 5F1 tweed Champ circuit head with the power section with 6V6's, 6L6's, and EL34's in mind - everything switchable on the back panel. I used a 15w OT and tailored the preamp and gain. With 6L6's the bass is tight, the sound clear and clean (almost "hi fi" in the midrange), and the volume is huge. With EL34's the mids are smooth and warm. Right now I'm running that one with a 6V6 though.
Of course, voltage and biasing considered, I don't consider them "5 watt" amps HAHA :)