|
e-mail to:
Roscoe Primrose
Roscoe's
web page
|
I've been tinkering
with electronics since I was about seven, when my step-grandfather (who
is an amateur radio operator and was an electronics instructor during WWII)
gave me a 100-in-1 electronic projects kit. My first serious stereo
was centered around an old Eico ST-40 tube integrated amp that my father
(an electrical engineer) built as a kit when I was in diapers. I
built my first serious piece of tube audio equipment (a low output MC phono
amplifier) in 1985. Due mostly to lack of time and inspiration, my
system was based around a Harmon Kardon Citation II power amp into a pair
of Acoustat 2+2 speakers from 1985 until 1997. Then, in March 1997,
I was inspired to build my current system after hearing my first SE triodes
and horns system, which consisted of a tri-amped system with huge double-Onken
enclosures with 2 Altec 515Bs per side, Altec 803Bs with Altec 288Cs for
midrange, and Altec 811Bs with TAD 2001s for highs. Amplifiers consisted
of custom made OTL amps (pentodes, actually), Wavelength Cardinal 300B
monoblocks for mids and, I think, Fi 2A3 monoblocks for the highs. Sources
included a Verdier turntable and an Audiolab (?) CD transport/DAC. I was
hooked right on the spot!
My current system is a constantly evolving
creature, I build and try a new piece of equipment about once a month.
I tried bi-amping briefly, and while I think bi-amping may be the way to
go, the $210 pro-audio electronic crossover I tried just didn't have the
sound quality to measure up to the rest of the system.
I'm a Member of DC Area DIYers Club: http://www.netaxs.com/~vkalia/dc-diy.html
System's Components
| Turntable: |
Homebuilt turntable based on a Rek-o-Kut K-33 platter/bearing (from
about 1960), with a Kenwood DD turntable used as a motor with thread as
a drive belt, a Magnaplanar Unipivot tonearm, Denon DL-301 low output MC
cartridge. |
| CD Transport: |
Theta Digital Data Basic, upgraded to Data Basic II |
| D/A Converter: |
Homebuilt digital filterless, non-oversampling I2S bus input DAC,
Audio Alchemy DTI 1.0 to convert coaxial digital from the Theta into I2S
for the DAC. |
| Preamp: |
Homebuilt interstage transformer coupled tube phono stage, with
a built-in 5 input passive line-stage. Denon AU-320 MC step-up transformer. |
| Power Amps: |
Homebuilt direct coupled 2A3 (or 45 with the flip of a
switch) SE monoblocks, about 1-1.5W/channel. |
| Speakers: |
Two-way fully horn-loaded system with Altec
515B woofers in JBL 4560 bass cabinets, Altec 288B HF drivers on Altec
803B HF horns. Crossed over first order at 780Hz with copper foil
inductors and paper and oil capacitors. |
| Cables: |
XLO type 1 interconnects, homemade interconnects,
Goerz, XLO and homemade speaker cables (three pairs necessary due to xover
being external to the speakers). |
| Accessories: |
Ceramic cones under the speakers, wall hanging behind the listening
position. |
Roscoe's comments
about his System:
AA: "Roscoe, how would you describe
your system's sound?"
RP: "The system has a huge, incredibly
dynamic sound, transients are much closer to realistic than most home stereos,
even with only 1.5W. Even for as big as they are, the speakers do
a pretty good job of just disappearing and letting the music out.
The system seems to convey the emotion of the music very well."
AA: "Do you think there is room
for improvement?"
RP: "Always! Until it's perfect
(which, of course, it will never be) I'll always be trying to make it better.
I could use a little more in the lowest and highest octave, and their is
a bit of a frequency rise in the high midrange which is a function of the
Altec 288Bs. Also, the tonearm cartridge could use some serious help,
I've had/used both since 1983/4."
AA: "Have you got plans for upgrading?"
RP: "Well, I've got one JBL 4550
bass cabinet, when I find another, I plan to use those, which should fix
the bottom octave quite nicely. I want to get a digital crossover,
which will not only allow me to bi/tri-amp, but will allow me to do time
alignment and frequency response correction (for both room and speaker
anomalies) in the digital domain. If I could find an SME 3012 tonearm
cheap, I'd jump on that in a heartbeat. I'm going to wait until after
the SACD/DVD-Audio wars are over to do anything on the digital side." |
