[Chasefooo]

Hello, I was wondering if it was possible to use the parts out of this and the cool looking chassis to build a DIY vacuum tube amp, I figure it wouldn't be that great of quality but I don't have any amps right now so I would be ok with that.it has a 12au7 vacuum tube a transformer and a potentiometer. If anyone has a guide or anything that would be awesome!

http://i1175.photobucket.com/albums/r634/chasefooo/0d14a779.jpg

http://i1175.photobucket.com/albums/r634/chasefooo/eaf08afb.jpg



Also I have a bit of random electronic prices laying around as well.

 

[wakibaki]

Even though it doesn't look that hot, that's a little piece of living history. In my opinion it would be better to sell it on ebay and buy some parts with the money (or just keep it).
 
If you must have a tube amp, you could try this one using readily available cheap Russian tubes:- http://gilmore2.chem.northwestern.edu/projects/showfile.php?file=bender_prj.htm
 
There's no output transformer and you can make the HT power supply with a couple of back-to-back wallwart transformers.
 
w

 

[Chasefooo]

Even though it doesn't look that hot, that's a little piece of living history. In my opinion it would be better to sell it on ebay and buy some parts with the money (or just keep it).
 
If you must have a tube amp, you could try this one using readily available cheap Russian tubes:- http://gilmore2.chem.northwestern.edu/projects/showfile.php?file=bender_prj.htm
 
There's no output transformer and you can make the HT power supply with a couple of back-to-back wallwart transformers.

Oh sorry I forgot to say that it's not that old its just made to look old, it's like a project kit that I got for my birthday about 5-7 years ago. I did see that a coupple sold on eBay for about 80$ though.
I'll see if I can find the rest of the parts and get it to work and put it up on eBay if you still think it would be worth it. I have about 200 bucks in my computer building fund that I could spend too if there's anything good I could get.

Thanks - chase



Edit: yes it has to be a vacuum, I have had the biggest craving for a tube since I first took an interest In audio.

 

[tomb]

Yep - they still sell those "new:" http://www.thamesandkosmos.com/products/ra/ra2.html
They've also reviewed over on a HAM site: http://www.eham.net/reviews/detail/6392
 
Problem is, I doubt seriously that there was any consideration for an extended frequency response.  The tube is there to amplify microvolts of radio waves coming through the antenna.  I think you'd have better luck - and less expense - trying your hand at a CMoy.
 
 

 

[Chasefooo]

Yep - they still sell those "new:" http://www.thamesandkosmos.com/products/ra/ra2.html
They've also reviewed over on a HAM site: http://www.eham.net/reviews/detail/6392
 
Problem is, I doubt seriously that there was any consideration for an extended frequency response.  The tube is there to amplify microvolts of radio waves coming through the antenna.  I think you'd have better luck - and less expense - trying your hand at a CMoy.
 
 

Actually I think I might have all the parts for that Cmoy amp. I think I might build one of those too, I still reallyy want a vacuum amp though as well.

 

[wakibaki]

Well, it fooled me.
 
An alternate tube (hybrid) design which is cheap to build is the Millet 'Starving Student' http://www.pmillett.com/starving.htm
 
Don't miss out on the cmoy tho', everybody should have one.
 
w

 

[Chasefooo]

Ooo I really like that starving student design, it would look good on my chassis.
But where exactly would I find those tubes I can only find them on eBay for like 30$ a pair?
Is there any similar circuits that use different tubes, or are the 19j6s worth it?

 

[Forte]

You can build th Starving Student with other tubes, read here http://diyforums.org/SSMH/SSMHvariants.php as well as searching the Starving Student Thread.

 

[Chasefooo]

ok thank you very much for the help, one last question though.
is the 19j6 better sounding than the substitutes, enough to justify the price? or would they be the same

 

[Chasefooo]

Also how would one of th starving students compare to something like a Hi-fi man ef2a disregarding the dac

 

[Chasefooo]

Anyone have ideas

 

[tomb]

Quote:

ok thank you very much for the help, one last question though.
is the 19j6 better sounding than the substitutes, enough to justify the price? or would they be the same

Someone who's built both would need to answer this.  The circuit is definitely tailored to the 19J6 and those tubes probably perform closer to their plate voltage than one of the substitutes.  On the other hand, the substitute (at least in the case of the 12AU7) is probably a much better tube all the way around.  My guess is that it might be a wash, or a slight edge toward the 19J6's.

 
Quote:

Also how would one of th starving students compare to something like a Hi-fi man ef2a disregarding the dac

At least with the 19J6's, the MOSFETs are biased to 150ma.  So long story short - very few amps - commercial or otherwise - will exceed the current capability of the Starving Student.  Many of the original orthodynamic guys built the Starving Student for the simple reason that it was able to power the most inefficient of classic orthos (pretty much the toughest loads short of speakers).
 
There are some downsides: the 19J6 tube availability is one, another is that the Cisco power supply is known to fry certain DACs.  Finally, you will have to build one instead of buy one.  (Most of us around here would consider that last one a plus, but it depends on where you're coming from.)
 
I can't comment specifically on the Hi-Fi man product.

 
 

 

[Chasefooo]

Thank you very much .
I believe I will build one now, I am in the middle of a research report so it will take a while to finish but I will post on the starving student thread when complete.
Im thinking that I will build the 12au7 version unless I can find 19j6 for a little better price.