WOW!!!  That's all I can say after hearing this beast.  I now understand what everybody was talking about
with the 300B.  This is a very powerful tube, capable of stunning bass reproduction as well as those
well-known velvety smooth highs and midrange.  I feed the amp directly from a CD player and run
Klipsch Cornwalls.  No tone controls to get in the way.   Like my other creations, this amplifier uses
Hammond transformers and metalwork.  I'm very pleased with the quality of the Hammond transformers.
I think they are good performers at their price level.  I have yet to try some of the more expensive transformer
brands, Magnequest, Tango, Tamura, Bartolucci, etc. in part because I get such good sound from these.  The
outputs are the 11 pound 1627SE, the power transformer is the Hammond 378CX which is rated at 400-0-400
at 465mA with a 6.3 volt filament winding.  I used separate Hammond filament transformers for the rectifier
and the 300B filaments.  I take the B+ from the center tap of the rectifier filament transformer fed to a small
Solen cap before the chokes to tune the B+ supply voltage to 435VDC.

Tube line up is:  5Z3, 300B, 6SN7, 300B, 6SN7.  The 5Z3 is a NOS National Union that I got from
Antique Electronic Supply, as are the RCA 6SN7s.  The 300Bs are Russian, made in the Reflector factory
which makes Sovtek tubes.  I think they are several years old, but unused.  I got five of them from a
friend at a really good price and that's what prompted me to tackle this amp.  I've shied away from the
Western Electric tubes due to their high cost.  The big oil caps in the center of the chassis are from Angela
Instruments.  They appear to be very high quality, rated 50uF and 30uF at 370VAC or about 520VDC.
I was surprised when I opened the box from Angela and the caps made a sloshing sound from the oil inside.
Steve advised me that the sloshing sound was normal and that the caps are filled with canola oil.
I normally use oval cased motor run caps which are filled with a gel material, so they don't slosh.

I had a bit of a problem with the volume control for this amp.  I purchased an Alps "Black Box" 100K log
taper stereo version which proved to be defective.  It caused a lot of noise from both channels and eventually
the right channel died until the volume pot passed the halfway mark, at which point it was too loud to appreciate.
I temporarily replaced the Black Box with a cheapo Alps pot from Radio Shack until I can get a proper
volume control.  The amp plays with more than ample volume without audible distortion.  I don't have proper
instruments or technical knowledge to do distortion measurements, but my ears don't lie to me.  I have
auditioned the amp on everything from Ry Cooder to Metallica and it sounds really good.

Also, like my other amplifiers, the chassis, bottom cover and transformer end bells are powder coated.  It's so
much easier than trying to get a good paint finish.  A company here in Tyler, TX does it for at a reasonable cost.

I welcome any questions or comments from other tube hobbyists.

Click here for a schematic, rough as it is.  Please let me know if you see any obvious errors.

If you'd like to see some close-up details, click here.

Comments?  rkoonce@dsityler.comt