Firefly 1.5W Tube Amp Build

[duhvoodooman***]

Well, on to the next project! This is a cool one. Mentioned HERE back in Sept. by then-new-member Tunghaichuan, I was immediately smitten with the idea of building it. All the info you need is available on John Calhoun's website, where you can also purchase the PCB for the amp build for a very reasonable $19. If you want to hear what this little sucker is capable of, check out THIS CLIP. Sounds like a mini-Marshall stack, no lie!

Between some spare components that Tung was generous enough to send me at no charge, and the rest of the parts order from the sources given in Calhoun's amazingly complete instructions, I've started construction, and finished the PCB fab tonight. Below are some pics, tubes & all. It uses two 12AX7's for the main preamp and a switchable boost stage, and the power tube is a 12AU7!! Now comes the hard part--drilling the chassis and putting all the hardware together. I'll post back here as I make further progress.

[Algonquin]

That sound clip is Killer DVM!

Good luck with the rest of the build... Would absolutely love to hear the completed project! :

Way Cool!

[Robert****]

That looks cool! Imagine that thingy on top of a 4x12... what a sight, hehe...

At least you won't need rubber feet for it!

[Tone2TheBone]

Or wheels. Heard that little sucker today and yeah it rocks heavy. I think I want one.

[sunvalleylaw]

What was that clip played through? Wow!

[duhvoodooman***]

What was that clip played through? Wow!

A closed back 1x12 cabinet with a Celestion G12H30. Sounds bigger, doesn't it? :

[tot_Ou_tard]

Emminently cool Vood.

Was that your Goldtop straight in?

[duhvoodooman***]

Was that your Goldtop straight in?

Oh, sorry if I was misleading! No, the clip isn't me (I wish!!), it's a clip posted on the Firefly project page at AX84.com. Doesn't say who the player or the guitar is, though it certainly sounds like an LP or similar humbucker guitar.

[tot_Ou_tard]

Oh, sorry if I was misleading! No, the clip isn't me (I wish!!), it's a clip posted on the Firefly project page at AX84.com. Doesn't say who the player or the guitar is, though it certainly sounds like an LP or similar humbucker guitar.

My bad. I do see now that you haven't built the dang thing yet!:!

That would'a be some trick, playing through a pile of tubes & bits n' bobs!

[sunvalleylaw]

Hmm, what cab would you pick to run with it? Would one of those sale ones from a few months back do a good job?

[duhvoodooman***]

I expect I'll use it extensively with both the 1x12 I assembled myself and the 2x12 Drive cab I bought during that insane Music123 close-out sale. A 4x12 would probably sound great, but it's getting a bit ridiculous to be playing a 1.5W through a cab that size! Not that it would stop Tone....

[Tone2TheBone]

I wanna see what that circuit would like like in one of M29's amp head creations!

ps - you're right Bob nothing stops me moo ah ah ah

[abraxas]

Wow!!!

That sounds great!!! :

[SuperSwede]

ooohhhhh! (and everything warren said)

[duhvoodooman***]

Well, after spending a bit more time with this little dynamo, I must admit I'm pretty impressed. It can generate an unbelievable amount of volume considering it's power rating (I suspect that 1.5W is very conservative), and when you crank the boost gain, it has plenty of raunch on tap. And I haven't even really "opened it up" yet, because I haven't had the house to myself since I built it. But I will on Wed. night, and I'll try to record a demo clip then, too.

The only thing I don't particularly like is that it's a little dark sounding, at least at low volumes. The good news is that John Calhoun included an optional "brightness" capacitor spot on his PCB design, so I'm going to get two different value silver-mica caps and wire them to the board via an on-off-on DPDT switch. That'll give me three settings: normal, bright and brighter. That should cover it....

[oldguy]

Vood, that looks fantastic! You do nice work.
Thanks for the pics and updates, you are 'da MAN!!!

[Jimi75]

Why didn't GOD give the talent to assemble small amps and pedals on my own?

This amp looks gergeous and the sound in the clip is killer. I can only look up to people like you - respect!

[duhvoodooman***]

I can only look up to people like you - respect!

Funny, that's how I feel about you when I hear your guitar playing! Thanks for your generous comments, Jimi. Really--the building is easier than the playing!

[heatherd66]

Mesa Boogie Express 112 5:25 Tone demo Mic: http://play.kendincos.com/174562/Wrv...-demo-mic.html