Gene's 5E3 Build!

[The Ballzz]

Folks,
As promised, a few pics of this amazing little amp, not so different than others you've seen, but......... I couldn't be more pleased, other than possibly taming the bottom end just a tad, but I certainly don't want to lose any gain/drive in the process. I must say that if other builds of this design sound any better than this one one, I'd be pleasantly amazed!

First installment is pics of the fiber board to use as an insulator under the non-recommended turret board. I decided that one #8 keps nut provided just enough of a stand off to allow even a couple wires to cross each other under the board:

[The Ballzz]

More Pics<
It's all a little bit tight, but the way I laid out the turret board gives just enough comfortable clearance at the jacks. I swappedthe positions of the main reservoir cap and cathode bias resistor/cap to facilitate, IMHO, a better ground layout. I took the PT center tap direct to the negative side of the main cap and then it's own separate wire to the chassis ground lug which also gets the fused 6.3v center tap and one wire from all grounds for the rest of the power amp section, including the PI. All other grounds (preamp/inputs/pots/etc) are tied to a soldered to the chassis lug near the input jacks. No solder connections under the board and the only two wires that cross underneath the board are the lead from the volume pot to V2 and the B+ feed to V1. FWIW, this amp is extremely quiet and sounds amazing!

[xtian]

Awesome, Gene. I love the gen-u-ine tweed cab. Mojotone?

[The Ballzz]

I guess one "Mo' Betta" gut shot is in order:

[The Ballzz]

Thank You Sir,
Yep, MojoTone with 50/50 mix of amber/clear shellac through an HVLP sprayer. I was impressed that there was not a single knot in the pine and after pressing/burnishing the seam edges with a dowel they were wonderfully smooth. I know the tidyness could be a bit better, but I sure hate working with that current push-back wire! Not to mention, the next one will get a somewaht different order of procedure. This was my first "cramped for space" combo style build and I ran into a few issues that made me "NOT" a cappy hamper!

But as I said, It's quiet as a church mouse and sounds glorious! I now understand what all the "huh-bub" is about with these amps! Amazing variety of tones/sounds for such a simplistic setup. The tactile response to careful picking technique is nearly spiritual, as well as the unnatural amount of sustain generated even without distortion.

I will build more of these as folks ask for them, but will certainly not sell this one until I confirm that the next one is just as good. Considering the next to be the 6V6 - 5E4 Super, while retaining the cathode bias of this model. I'm thinking that the extra 12AX7 may add a little more complexity to the tone?


Thanks Again,
Gene

[sluckey]

...the fused 6.3v center tap...

Why did you do that?

[The Ballzz]

...the fused 6.3v center tap...

Why did you do that?

It was one of several suggestions here for filling/utilizing the hole from the standby (was actually labeled "ground" on this Mojo chassis) switch. After already having it done, there were other suggestions about fusing the PT center tap, HT and/or B+, etc, but, "oh well," I left most wires long enough to change it around if I get an annoying enough bug up my arse! What kinda bug are you today? Just teasin' as I really appreciate and value your thoughts and comments.

This amp fired up perfectly on first try and I will get a voltage survey up when I get a few minutes. I bucked a few suggestions, but am pleased as to where my own judgements took me. OT center tap is 384-vdc, using the 355v-0v-355v taps on a ClassicTone 40-18078 PT, with NOS 6V6's and 5Y3.

If I put this amp up for sale, I will likely swap the PT to a single tap ClassicTone 40-18021, to hang onto this multi-tap unit for more flexibility in future testing.

Thank You,
Gene

[sluckey]

Just wondering. The tube filament current does not flow through the center tap.

If you use a small enough fuse, say 1/4 or 1/8 amp, then if you have a short between pin 2 and pin 3 on a 6V6 tube or socket, then the fuse would blow and possibly save your OT or PT HT winding.

What size fuse are you using? Did you have some other purpose that I'm just not aware of?

[The Ballzz]

Nah,
It was simply one of the suggestions concerning the short you mentioned being fairly common and it made sense to me at the time that I was flipping the coin. Currently (pun intended) 1/2 amp slo-blo!

With that said, in my +40 years of cranking tube amps to and past their limits, I've never even blown a fuse, let alone a transformer, except for a truly horrendously modded Super Reverb done by a PROFESSIONAL!

Thanx Again,
Gene

[The Ballzz]

As earlier promised, here is a voltage survey. I will do another later with 1 volt/1K signal applied as per the Fender 57 reissue instructions, detailing AC voltages at grids, etc. I think I would like to see a few more volts on my B+, so I'm going try some other 5Y3's I have on hand.

Thanks Guys,
Gene

[The Ballzz]

Holy Shirt Batman!
I certainly won't be using the Sovtek 5Y3 that I have! It bumped the OT/CT to 411 VDC! I swapped an NOS Raytheon in place of the NOS Toshiba and it bumped all about 7 VDC. I'd like to see 385v-390v on the 6V6 plates, but oh well, currently at about 375 VDC. The amp does sound fantastic and quiet as a church mouse! The clarity, even of the distorted/overdriven sound is amazing!

I've never played through one of these amps before. I was shocked after about a half hour of playing "cranked" that by turning it down, a bit at a time, one by one, nearly every classic tone/sound I've ever heard on many classic hit recordings just jumped out and bit me. Truly one amazing little focker!
Just Sayin'
Gene

[martin manning]

It's well known that the Russian 5Y3 has much less voltage drop than the real thing. On the other hand JJ's 5Y3 performs very much like NOS examples.

[The Ballzz]

I hear ya, kind sir, but I did not expect a 40-ish volt bump! Turns out the Toshiba is the lowest of the small bunch I have and simply made the Sovtek seem even more exaggerated. I'll likely order in a JJ for poops & giggles!
Thank You,
Gene

[xtian]

nearly every classic tone/sound I've ever heard on many classic hit recordings just jumped out and bit me

My experience also. Very cool circuit. I opted for solid state rectifier, and VVR to hit the sweet spot(s).

Gene, if you want one of my MOSFET voltage droppers, let me know. You can swap out the Zener to adjust the voltage exactly where you want it.

[Firestorm]

Golly, that's pretty. Caps are 6PS I hope?

Did you contemplate the Dumble tweaks?