[Theodore]

Does anybody here read or subscribe to Make Magazine (makezine.com)?
It's sort of an all-around DIY publication. I just checked it out for
the first time with issue #9.

Anyway, one of the featured projects is a $5 Cracker Box guitar
amplifier made from Radio Shack components. It's based around an
LM386 op amp and has about 0.5W output.

I was thinking about trying a similar thing with a tube amp. It
probably couldn't be $5 unless you scavenge tube(s) and power
transformer. It probably couldn't be powered by a 9V battery and
still be cheap except in the eyes of an aerospace defense contractor.

[Theodore]

Also, this particular article is available for free:
http://downloads.oreilly.com/make/09...er_box_amp.pdf

[Jon Yaeger]

in article , Theodore at
wrote on 5/3/07 11:36 AM:

Also, this particular article is available for free:
http://downloads.oreilly.com/make/09...er_box_amp.pdf



Fred Nachbaur, a late member of this group, specialized in inexpensive
projects:

http://www.dogstar.dantimax.dk/tubestuf/

He has a nice little guitar amp project listed, called the 4X4:

http://www.dogstar.dantimax.dk/tubestuf/4x4index.htm

[Theodore]

On May 3, 11:25 am, Jon Yaeger wrote:

He has a nice little guitar amp project listed, called the 4X4:

Looks nice, but it's not exactly analogous to the project in Make--
too complex and too hi-fi(!). I perused his site briefly, and it
looks like his "Real McTube" overdrive would be a more appropriate
starting point-- The Cracker Box Amp circuit could pass for a cheap
distortion box if it weren't for the speaker!

I especially like that his power supply came from two 12V "wall wart"
adapters-- who doesn't have a few of those to spare?

[Jon Yaeger]

in article , Theodore
at wrote on 5/3/07 1:15 PM:

On May 3, 11:25 am, Jon Yaeger wrote:

He has a nice little guitar amp project listed, called the 4X4:

Looks nice, but it's not exactly analogous to the project in Make--
too complex and too hi-fi(!). I perused his site briefly, and it
looks like his "Real McTube" overdrive would be a more appropriate
starting point-- The Cracker Box Amp circuit could pass for a cheap
distortion box if it weren't for the speaker!

I especially like that his power supply came from two 12V "wall wart"
adapters-- who doesn't have a few of those to spare?




Well, one can't know what your "reference" is when you haven't bothered to
provide a working link . . . .

Build 1/2 of this 6T9 project. It ought to fit the bill:

http://www.sparetimegizmos.com/Hardware/Stereo_6t9.htm

You can download a schematic for free.

If that doesn't get it, you can post to or send an e-mail to Andre Jute at
this site.

Andre is an accomplished tube designer, recognized world-wide, as evidenced
by his recognition in Wikipedia:

http://en.wikipedia.org/wiki/Bandon%2C_County_Cork

I'm sure if you ask Andre nicely he can whip up an amp that will sound
pretty crappy like your LM386; he's got years of practice.

Jon

[Theodore]

On May 3, 12:56 pm, Jon Yaeger wrote:
Well, one can't know what your "reference" is when you haven't bothered to
provide a working link . . . .

I did provide a link. You quoted it in your first reply. If you
don't want to go to the full PDF of the article, try he
http://makezine.com/09/crackerboxamp/

I'm sure if you ask Andre nicely he can whip up an amp that will sound
pretty crappy like your LM386; he's got years of practice.

It's not so much that I *want* it to sound crappy; I just don't expect
it to sound better than crappy. I'm also not looking to just build
from someone else's schematic (and definitely not a $200 kit!); I was
looking for examples and ideas on economizing the design. As simple
as possible, but no simpler...

PS I hope someday I'm famous enough to be the subject of Wikipedia
vandalism!

[Jon Yaeger]

in article , Theodore at
wrote on 5/3/07 3:25 PM:

On May 3, 12:56 pm, Jon Yaeger wrote:
Well, one can't know what your "reference" is when you haven't bothered to
provide a working link . . . .

I did provide a link. You quoted it in your first reply. If you
don't want to go to the full PDF of the article, try he
http://makezine.com/09/crackerboxamp/

I'm sure if you ask Andre nicely he can whip up an amp that will sound
pretty crappy like your LM386; he's got years of practice.

It's not so much that I *want* it to sound crappy; I just don't expect
it to sound better than crappy. I'm also not looking to just build
from someone else's schematic (and definitely not a $200 kit!); I was
looking for examples and ideas on economizing the design. As simple
as possible, but no simpler...

PS I hope someday I'm famous enough to be the subject of Wikipedia
vandalism!



I went to makezine.com and didn't find it. Sorry.

You don't need to buy the $200 kit to build one channel of the amplifier.
Can you make your own design from scratch? If so, there are lots of
possibilities. You can copy or butcher a cheap radio or other consumer amp
using a 50C5 output - the main thing is to get a cheap output transformer.
But you have so many limits as to what you are willing and not willing to do
.. . . It's a little hard to try to help you, so I'll stop.

Jon

[Theodore]

On May 3, 2:47 pm, Jon Yaeger wrote:
. . . It's a little hard to try to help you, so I'll stop.

The link to Fred Nachbaur's site was quite helpful. His MiniBlok is
an even better starting point for what I'm trying to do.

[Sal Brisindi]

Theodore,
You can easily make a tube based amplifier for $5.00. All you have to do
is purchase a junker tube radio, you will get a better deal if the
cabinet is crappy/broken. You will have your power transformer, audio
transformer, audio tube and even the tube to drive the audio tube. You
don't want a AA5 (All American 5) radio as the tubes are wired in series
and since there is no power transformer, you will not have isolation.

I am sure if you go to rec.antiques.radio+phono group and ask you can
get one for free.

Regards,
Sal Brisindi

Theodore wrote:
Does anybody here read or subscribe to Make Magazine (makezine.com)?
It's sort of an all-around DIY publication. I just checked it out for
the first time with issue #9.

Anyway, one of the featured projects is a $5 Cracker Box guitar
amplifier made from Radio Shack components. It's based around an
LM386 op amp and has about 0.5W output.

I was thinking about trying a similar thing with a tube amp. It
probably couldn't be $5 unless you scavenge tube(s) and power
transformer. It probably couldn't be powered by a 9V battery and
still be cheap except in the eyes of an aerospace defense contractor.

[west[_3_]]

"Theodore" wrote in message
ps.com...
Does anybody here read or subscribe to Make Magazine (makezine.com)?
It's sort of an all-around DIY publication. I just checked it out for
the first time with issue #9.

Anyway, one of the featured projects is a $5 Cracker Box guitar
amplifier made from Radio Shack components. It's based around an
LM386 op amp and has about 0.5W output.

I was thinking about trying a similar thing with a tube amp. It
probably couldn't be $5 unless you scavenge tube(s) and power
transformer. It probably couldn't be powered by a 9V battery and
still be cheap except in the eyes of an aerospace defense contractor.

That's a coll site, Theodore. Thanks for sharing it.

west