Amp Mods and Soundclip

[Doug H]

Did a booster mod to my little 1.5W tube amp:

Schematic:

http://home.cfl.rr.com/dbhammond/FireFlyBoost_sch.gif


Soundclip:

http://home.cfl.rr.com/dbhammond/FireFlyBoost.mp3


Read more about it at my site:

http://home.cfl.rr.com/dbhammond/doug.htm


Doug

[aron]

I think it sounds fantastic!

[Ben N]

2204 at 1.5 watts--fantastic! Pretty nice playing, too.

Ben

[Phorhas]

Mean Tone and Sweet Playin' man!!!

Awsome work.



Dan.

[Prive]

Wow!!!!! i just can't follow you, i'm still waiting to have the time to try the first 12AU7 attempt, i have the OT since you called it Firefly but i can't start

Is there some layout to begin with??? Thinking i lost the most of the time jajajajajaja.

Great work Doug, like ever.

Saludos, Marcelo.

[Doug H]

Thanks for the nice comments, everyone.

No, I don't have a layout for it. I did it all point-to-point on terminal strips. I designed a point-to-point layout for it when I first built it a couple years ago. Unfortunatley, I realized after I wired everything up that I had oriented the tube sockets incorrectly. They were upside down on my layout.  Luckily I didn't blow anything up when I fired it up. So I had to rewire it on the fly, which is the way I did the booster mod too.

Doug

[Joep]

Hi Doug,

It sounds really cool!

Looking at the schem I was wondering why you used the cascode stage to get the extra boost and why not a SRPP or just a simple common cathode or something. Is it soundwise?

Thanks,

Joep

[Doug H]

Hi Doug,

It sounds really cool!

Looking at the schem I was wondering why you used the cascode stage to get the extra boost and why not a SRPP or just a simple common cathode or something. Is it soundwise?

Thanks,

Joep

It's more gainy than an SRPP (according to my Pspice model). I just wanted to try it to see how it works.

Thanks for the comments!

Doug

[aron]

It sounds amazingly cool and is just what I need for recording!

I like that "vintage" type sound at the start of the clip.

I need to find a cool enclosure for it.

[Warpfingers]

Very Very Nice :!:

How did you record that?

What kinda cab you running that little bug through?

I've built a Hi Octane from ax84.com, it's about 7 watts but it's still to loud for late nite recording, Ima wanting to build one of these now.

[Doug H]

Very Very Nice :!:

How did you record that?

What kinda cab you running that little bug through?

I've built a Hi Octane from ax84.com, it's about 7 watts but it's still to loud for late nite recording, Ima wanting to build one of these now.

I'm using the 1x12 in my yamaha transistor combo amp. I just stuck a mic in front of it and recorded it using Vision DSP on my mac.

It's not as loud as a High Octane but it is louder than "apartment volume" I would guess. It's perfect for my situation though.

Thanks for the comments!

Doug

[Steve C]

That is wicked!  Totally freakin' awesome.  

I'm however missing what type (maker, model) of tranformer you used for the power section.  Maybe I'm not looking at it close enough?

Steve

[Doug H]

That is wicked!  Totally freakin' awesome.  

Thanks! I replied to your request for the transformer info.

Doug

[Warpfingers]

Can i get some of that info too, please?

[Doug H]

Can i get some of that info too, please?

Sure.

I used a hammond 125a for the output transformer.  For power, I just used a 207VAC isolation transformer and a separate 6.3V/1.2A transformer for the filaments.

Doug

[Doug H]

I need to find a cool enclosure for it.

I just built it on a surplus modem chassis using terminal strips. I can't remember the dimensions, say around 15"-17" long, 7" wide, 1.5" deep, something in that range. Then I just used 3 pieces of wood for the ends and top. I got some of that flexible metal open grille stuff from Home Depot for the front and back. I put 1x2 trim around the interior of the wood, inside the top and ends,  to mount the grille to. It was pretty simple.

Doug

[Warpfingers]

I just built it on a surplus modem chassis using terminal strips. I can't remember the dimensions, say around 15"-17" long, 7" wide, 1.5" deep, something in that range. Then I just used 3 pieces of wood for the ends and top. I got some of that flexible metal open grille stuff from Home Depot for the front and back. I put 1x2 trim around the interior of the wood, inside the top and ends,  to mount the grille to. It was pretty simple.

Doug

Man that must be some old 200 baud modem, thats huge!

That enclosure sounds really cool, any pics?

Thanks for the Tranny info

WF

[Ansil]

i love it,   the next evolution of the firefly.   i have made a couple of the original amps for my friends.  you have no idea how many people i have gotten to diy from that little amp.  every time i get one done.  some one is bringin me parts to build another one, i always tell them to email you doug or atleast drop aline to the forum, you should really try to market these things there was a cat in chattanooga that asked me to build some but i turned him down and refered him to you, don't know if he emailed or not, but he was really loving your amp.  anyway man i have been trying to get the time to make a meteor, that just rocks too.  way to much fun.  if you get the time man you should check otu the drunk spider i think it would be right up your alley.

[Doug H]

you should really try to market these things there was a cat in chattanooga that asked me to build some but i turned him down and refered him to you, don't know if he emailed or not, but he was really loving your amp.   if you get the time man you should check otu the drunk spider i think it would be right up your alley.

Thanks for the comments!

I never heard from your friend in Chattanooga. I've been approached a few times with the idea of building them. I mull it over now and then.

Where is the drunk spider?

Doug

[Ansil]

:arrow:          http://www.geocities.com/cemaynard1134/schematic.htm

drunk spider is a little more than half the way down.