2 watt blues express variant-first build-demo video added

[T-diddy]

Hey Im a noob around these parts, but recently I embarked on a tube amp project, and as such I signed up here for advice, pointers, and to do the appropriate amount of research required for a successful build. I was going to build the 2 watt blues express amp posted on this site, but I ended up following the schematic for this amp:
http://diyguitarfreak.wordpress.com/201 ... niamp-2-0/
This amp is based on the Vox night train preamp with mods, featuring an EC99 power amp section in push-pull configuration. I wired this amp point to point as that is how the designer of the circuit did it. My amp features: TMB and gain controls, as well as an 8/16 ohm impedance selector, standby switch, and pilot lamp. The tube complement is as follows:
V1 12AT7
V2 12AU7
V3 ECC99
I have no tube oscillation issues, or excessive background noise (the tube complement helped with this)

[img:640:480]http://img849.imageshack.us/img849/2838/img1745g.jpg[/img]
[img:640:480]http://img24.imageshack.us/img24/4937/img1746fu.jpg[/img]
[img:640:480]http://img148.imageshack.us/img148/5595/img1741l.jpg[/img]
[img:640:480]http://img38.imageshack.us/img38/4282/img1742rd.jpg[/img]
[img:640:480]http://img834.imageshack.us/img834/5508/img1743q.jpg[/img]
[img:640:480]http://img148.imageshack.us/img148/9540/img1747ls.jpg[/img]

Thanks to all for sharing very important insight for a tube amp noob.

I just added a demo video:
http://www.youtube.com/watch?v=r0XVwXt0ZIQ

[T-diddy]

Also I was so worried about posting in an intelligible way, that I forgot to comment on the sound. Well there is plenty of clean headroom for recording. The cleans are very Vox like, and are chimey, but not sterile, or cold sounding. I get break up with my strat after 1/4 rotation on the vol control. And the overdrive at about 10 oclock is rich, warm with plenty of harmonic overtones. I can actually get away with diming the amp, and the distortion out of this puppy even with the tube complement that I have is full, rich, and yet again full of harmonic overtones. This is not a metal amp, but that is fine for me as Im more of a classic rock, blues, and country kinda guy.

[T Wilcox]

Very cool man.
Looks like that was a PITA to work on, being so small.

Todd

[T-diddy]

Very cool man.
Looks like that was a PITA to work on, being so small.

Todd

Yep PITA basically sums it up. The power section didnt fit, in the way that I had originally layed it out to fit. Actually if not for divine intervention of rotating the board 180 degrees, I would have had a serious road block. I did my drill layout on graph paper, and really tried to think ahead, but in the end I was blessed that it all worked out. I will NEVER build a tube amp in an enclosure this small again. I build guitar effect pedals, so I thought that it would be pretty easy to get everything in there. Well 3 months later, and 25-30hours total, I learned the hard way! Well worth it building for my own enjoyment and education though. Thanks for the feedback.

[T Wilcox]

Welcome to the addiction

Todd

[El_Martin]

Hi!

" I will NEVER build a tube amp in an enclosure this small again..."
Yep, me too. (Most of my builds w. ECC powerstage feature the crammed rats nest look.
Lil'Wreck (1 ECC83, 1 ECC82 w. single triode ECC82 output stage)
Blues Express combo

Wiring 5E3 is like a walk in the park in comparison.

Nice amp. OT looks familiar to me. 100V type?

Ciao
Martin

[T-diddy]

Hi!



Nice amp. OT looks familiar to me. 100V type?

Ciao
Martin

This is a Hammond 125C Universal OT. Its rated at 8 watts or so, so it was pefect for this amp. Im not sure about the voltage requirement.
Here is a link from Hammond:
http://www.hammondmfg.com/125a.htm

[T-diddy]

I just added a demo video link for the amp, if anybody wants to hear some of the tones out of it. This is not a high gain amp, and is really more for Blues, Country, Jazz, and some types of Rock.
http://www.youtube.com/watch?v=r0XVwXt0ZIQ