$120 battery powered tube amp on eBay??

[ChopperCharles]

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=310014259042
and
http://www.jarl.or.jp/Japanese/2_Joho/gakken-tube-amp/making-tube-amp.htm

Err.... what what whaaa????

Charles.

 

[Colt45]

Never heard of battery tubes?

output is probably ~0 though.

 

[poynton]

It's really only a tube headphone amp for the Ipod !

Very low output from 2P3 and 1B2 tubes.

I think the batteries would last about 15mins.

I like the DIY horns !!



Andy

 

[diegot]

Just 3V! What is the output power?
It`s a very interesting kit with a good price.

 

[kstagger]

very neat... would make a good closet apartment stereo system

 

[ChopperCharles]

Possible to up the power?

Wiring a wall transformer to this amp would be dirt simple... but... how much voltage? Would more input voltage make the amp more useful? (readowerful)

It looks like it'd be a fun little project to take a cheap low power amp like this and build it into an iPod amp. Replace the faux center transformer cover / battery case with a dock, and paint the whole thing gloss black to match my nano. Not exactly high end audio, but it'd look sweet.

Hell... if this thing could be built into a decent phono preamp it would actually be quite useful.

But really, I get ahead of myself. I'd love to buy it and tinker, but I'm a total Toob Noob... I know enough about electronics not to fry myself, and while adding a wall transformer plug, input selector switch, and an iPod docking station is well within my capabilities, actually modifying the amplifier circuit (or even trouble shooting) is not.

Charles.

 

[Sal Brisindi]

I have a schematic that uses 1S4 output tubes and 2 1.5volt batteries. It has an simple inverter to create the B+.

Sal Brisindi

 

[poynton]

I have a schematic that uses 1S4 output tubes and 2 1.5volt batteries. It has an simple inverter to create the B+.

Sal Brisindi

Please post the circuit.

 

[dhaen]

Interesting...

Just 3V! What is the output power?
It`s a very interesting kit with a good price.

My estimation: About 150mW per channel.
But through those speakers, it may sound loud......

 

[Wavebourn]

Re: Interesting...

My estimation: About 150mW per channel.
But through those speakers, it may sound loud......

For such power it should have an anode battery, or at least a voltage converter.

 

[Sherman]

Please post the circuit.

This might be it. Don't remember where I found this schematic but it fits the bill.

 

[Sal Brisindi]

That is the schematic I mentioned on my post above.

Sal

 

[diegot]

I think this is not the right schematic. It uses only one tube per channel.

 

[djQUAN]

I think that amplifier has a SMPS in it in the box behind the volume pot.

 

[woodturner-fran]

No, in the pics you can see thats where the batteries go.

Intriguing that, would love to have a listen!

Fran

 

[poynton]

I think that amplifier has a SMPS in it in the box behind the volume pot.

I think you may be correct - the silver box. The battery positions are behind that.

Andy

 

[djQUAN]

No, in the pics you can see thats where the batteries go.

Intriguing that, would love to have a listen!

Fran

I meant the pic of the bare PCB.

the little rectangular box between the volume pot and batt area.

 

[Cal Weldon]

Quote:

Caution!:Vacuum tube in this kit are made in China more than 30 years ago.It is not acceptable to return the tubes because of scratches or something.

 

[poynton]

Quote:

Caution!:Vacuum tube in this kit are made in China more than 30 years ago.It is not acceptable to return the tubes because of scratches or something.

Isn't NOS meant to be a selling point ?

Or are they used, hence the straightener included ?


What are the tubes anyway?
I cannot find a reference. (maybe I did not try hard enough!)

 

[Fuling]

Cute thing!
I bet those speaker goes straight down to 18Hz +-1dB...