The Amp Garage

donzoid wrote:Here is the corrected jack: in the picture the left side opens when the plug is inserted.

That looks OK now

Can't comment on the rest, but you might want to double check your jack wiring - it looks wrong to me. Shield should go to the sleeve connector (top in the photo) with a link across to ground out the tip with no plug inserted (where the 1M is now). The core of the shielded cable should go to the tip...

...all that's getting amplified is a very loud sine wave which I can adjust the frequency of via the tone (treble) pot. To my ears, it's adjustable between 800hz-2khz+ I'm guessing you've built in a couple of gain stages around an additional 12AX7 to the right of the PI (wiring looks like that, any...

Fix what Martin said first, then: You're biased heavily into cut-off for the EL84s - likely you will want to get down to about -10 to -12 V, but go gently, that's a lot of volts! I know that you said the PT is the same one as used in the organ - did the organ have tube or SS rectifier? Fixed or cath...

I see that the low voltage circuit (feeds the switching system) is still drawing WAY too much current (no tubes are installed). ... Welcome suggestions, if anyone already knows what to look for. Just a hunch, but check that the (bridge?) rectifier on the LV circuit for shorts - ohm meter will tell ...

LOL thats a dad joke if i ever heard one. i was thinking of using this ax84 6v6 poweramp as the base for my poweramp. except i will be using el84, as that is what i have on hand. i have read that 6v6 and el84 are very similar and can be a direct replacement with an adapter, but i have also heard th...

Cheers dudes!

(Sorry for the derail! )

What say ye on the jack? Should I just use a switchcraft or will this jack work being the isolated type? I think you can get both with extended bushings (and pots for that matter), but I used an isolated jack with a short jumper from the ground on the jack to the chassis next to the jack - you coul...

I counter-bored the back of the faceplate to fit over the pot nuts. The pots can then be bolted tightly to the chassis and the faceplate placed over the top - The input jack, indicator and switches fasten through the faceplate and hold it in place.

YMMV.

I would suggest putting the power transformer inside a metal box (doesn't have to be fancy) and making a good connection between the metal of the box and the main chassis. It's what I did with my little combo amp: [IMG:1024:680]http://i255.photobucket.com/albums/hh143/werdnayarg/DSC_0735_zps40c7ff81...

And then there's the effect of the negative feedback loop collapsing...

Steve Bench over on DIY Audio has a valve/tube library that I have found to be extraordinarily accurate for 12AX7, 12AU7, EF86, EL84 & 6V6 - it's done as a drop-down menu which makes it a breeze to use. There's also a selection of output transformers there, but I can't vouch for them. IIRC there's a...

Try tightening the clamp bolts on the transformer, too.

I wouldn't think it was a sign of imminent failure...

Edoardo wrote:I guessed an unplugged amp cannot electrocute you

Why yes it can!

Learn how to discharge capacitors safely...

Also: Where (exactly) did you connect the ground for the MV pot?