Simplest flea-powered amp?

[gmilitano]

50EH5 Spud

I realize this is a little late, but here is the schematic for a little spud amp around the 50EH5. More details about this project are on my website.

Cheers,
Gio.

 

[planet10]

I would be cautious about using LEDS in the cathode.

SY really likes his "Red Light District" EL84 PP. Run with something like 48 Red LEDs in the cathodes of the PP pair.

Me i'm a bit leary of LEDs, but i figure its worth a try. Our mule is currently running triode strapped in Class A.

dave

 

[planet10]

Re: 50EH5 Spud

I realize this is a little late, but here is the schematic for a little spud amp around the 50EH5. More details about this project are on my website.

Strapped in triode probably about a 1/2 W, i did one of these too...

<http://www.t-linespeakers.org/tubes/SEP_50EH5.html> I've got a much beefier one planned.

The ELL80 amp we built is also quite sweet, but really needs a driver tube if used with just a CD player.

dave

 

[planet10]

,

 

[arnoldc]

gio, dave, when I find one of them 50EH5 i'll make one thanks

dave, i've seen your $5 amp before, with much more expensive tube damper

 

[gmilitano]

Re: Re: 50EH5 Spud

Strapped in triode probably about a 1/2 W, i did one of these too...

<http://www.t-linespeakers.org/tubes/SEP_50EH5.html> I've got a much beefier one planned.

I should have mentioned that my 50EH5 was based largely on Dave's 5 buck amp in the link above.

A CDP drives the 50EH5 in Pentode mode to less than a watt. So in triode mode, power will be very limited without a preamp.

Keep us posted on your beefier 50EH5.

The ELL80 amp we built is also quite sweet, but really needs a driver tube if used with just a CD player.

dave

Are there any advantages or disadvantages with using only one tube for both channels?

Where did you get those cages to go around the tubes? They look nice.

Regards,
Gio.

 

[planet10]

Re: Re: Re: 50EH5 Spud

Are there any advantages or disadvantages with using only one tube for both channels?

I'm sure there are... but it is cool to build a stereo amp with 2 tubes when one of them is a rectifier...

Where did you get those cages to go around the tubes? They look nice.

Gifted to us by Eddie Vaughn... i can check on sourcing. He'll be using them on his Carina i believe.

http://www.vaughnaudio.com/

dave

 

[gmilitano]

Tube Cages

Yeah, please do look into sourcing. I would be interested in 3 for use in a EL84 SET with EZ81.

Cheers,
Gio.

 

[arnoldc]

OT: I would like to post the specs of Carina for poobah and Sy

Some of the Carina's features include:

EL84/6BQ5/6N14N/7189 power tubes, 6DJ8/6922/7308 preamp tube
Uses any octal fullwave rectifier tube (comes with 5AR4), including 5V4, 5U4, 5R4, and 5Y3
Switchable Triode/Ultralinear operating modes
"Tone Mode" switch to shape the sonic signature
1.5 watts per channel in Triode Mode
3.5 watts per channel in Ultralinear Mode
Proprietary, high performance method of constant current preamp tube operation
Zero global negative feedback
Electra Print transformers used exclusively
Oil-filled polypropylene power supply capacitors (no electrolytics)
Mundorf and VH Audio coupling capacitors
Riken Ohm, Audio Note, Kiwame, and NOS carbon composition resistors
Solid silver RCA jacks with solid 99.995% pure solid silver signal wire
Gold plated copper CMC binding posts
PEC mil-spec volume pot
All switches are life-rated for a minimum of 10,000 switching cycles
Silver plated, Teflon insulated, mil-spec copper hookup wire
The finest Azuma brand ceramic/gold tube sockets
Floating star point ground scheme
Point-to-point hand wired.
No printed circuit boards, and no terminal strips in the signal path
3 sets of inputs and a Swiss-made ELMA selector switch are optional
Available in export version for any world voltage, at no extra charge
30 day trial period with full money back guarantee
Transferable limited lifetime warranty on all parts and workmanship

 

[planet10]

1.5 watts per channel in Triode Mode

I'd like to comment on the Triode Mode (Eddie actually calls it Virtual Triode Mode). This isn't just strapping the screen to the plate thru a resistor. The DC operation & the AC operation are dealt with separately using something conceptually similar to the PEARL trick.

dave