Finished another SE EL34 build

[panhead]

Just wrapped this one up over the weekend. The BOOST 2 control works better than I thought it would. Basically the 250k pot sweeps the cathode of V1-2 between the NFB loop and the cathode resistor bypass cap. The sucker is pretty loud driving a single 12" speaker.

[panhead]

Here are some pics. The "string piping" across the front face is actually #14 THHN neutral wire from Home Depot (it doesn't have printing on it like most wire).

[panhead]

back view. I'm looking around for some stainless steel mesh that doesn't cost a fortune. The jack on the left is for the first stage boost footswitch. The next jack is the speaker jack, and there's a 4/8 ohm impedance selector switch to the right of the speaker jack.

[panhead]

Gut shot...

[jhadhar65]

Very cool!  Do you have a better shot of the control panels?  And what method did you use for the lettering?

[panhead]

I did get one close up shot of the control panel, but it came out rather distorted (like a fish eye lens type distortion). All my control plates are made for me by Bruce Birling (bbirling on this forum). I send him a CAD file and he etches them.

[CraigB]

Dude, that is one sweet build!  I really like the cabinet and faceplate, and the wiring is very clean.  Great job, thanks for sharing that.

[panhead]

Thanks for the appreciative words.

[Boots Deville]

Looks good - I use hookup wire for my cabinet string too. Works great. I think I got mine at Ace.

For mesh in the rear, well... it ain't stainless, and would need to be rattle-canned, but I've been using that screen intended to be put in gutters over the downspout opening, to keep debris out.  I got a roll of the metal stuff, and last time I looked at Home Depot, they were carrying a plastic alternative which doesn't serve us amp builders as well.  But if you find some - painted black - black mesh back there wouldn't look bad - match the faceplate.  And it's cheap!

I'm still gigging with the EL34 Champ I built from your schematic, and loving it.  The V1b cathode bypass boost in that one is not quite enough of a boost for me for leads, so I usually end up using a boost pedal, but I'm running the volume pretty far up to start with.

-John

[panhead]

Switching in the bypass cap theoretically doubles the stage's gain, but the cap is never entirely switched out, since there's the 47k switch-pop eliminating resistor across the footswitch jack (I don't know if you used that). The boost won't be as dramatic as an active boost switching in another stage (gain is about 10-20 times more than using the bypass cap method). Anyway, I'm glad you like that amp. I've built about four variations since.

[bigdaddy]

Yeah I use the Allen stuff too. I bet that amp sounds great!!!

Just for the hell of it have you tried using the choke before the plate and a 1K 5 watt in it's place? That's what I do and to me it sounds a lot better.

[panhead]

Yeah I use the Allen stuff too. I bet that amp sounds great!!!

Just for the hell of it have you tried using the choke before the plate and a 1K 5 watt in it's place? That's what I do and to me it sounds a lot better.

Yes, I have used a choke before the plate - mostly to quiet things down. This one has DC elevated heaters and it's quiet as a mouse (in terms of hum), even with all controls dimed and single coil pickups plugged in.

[madison]

Super looking amp!
I love those EL34 SEs.
Like the switching feature on yours.

What speakers have you tested it with ?

[zendragon63]

Very nice, way cool panhead--uncomplicated. Heck, I am realizing that my best sounding amps have the least amount of parts. What's up with that....

The etching effort on the faceplate really makes it look pro-fessional. Regards

dennis

[panhead]

I've run it through a 12" Celestion (decent speaker, but not one of the mega-expensive ones).

As I said, contact bbirling for faceplates if interested. He's done great work for me and his prices and turnaround time are great.

[ppaappoo]

Hi, I would like build this amp, but I will not use the choke, I can change it with a resistor?


great job by teh way

[Fresh_Start]

Really nice work, inside & out.

That Boost pot is cool.  As it fades in the cathode bypass cap, it also reduces negative feedback.

Cheers,

Chip

[simonallaway]

Hmmm. This might be a cool mod for a P1eX, which is basically an SE EL34. One project I've been working on is an overdrive pedal with a boost switch (like the 'more' switch on the recent Vox OD pedals). The boost mod would be an alternate to that.

[rzenc]

Congrats!!!!! Super cool looking amp!!!!!! Sound demos?

Best Regards,
Rzenc