|
Dear Mr. Pass,
My name is Kostas A. Vazakas from Egio, Greece and I 'm an
agricultural engineer. Two of my hobbies are listening music and diying (specially audio), for more
than twenty years ago.
I was a happy owner (I still have one in the living room) of many
versions of A-40 from 1981(more transistors, regulated PS etc.).
More than fifteen friends of mine, are listening music from my old
A-40s. In 1995 I built the BOZ with dual PS and after four years with dual PS of the BOSOZ (only the
positive branch). These preamplifiers took the place of my diy tube pre. All these years I built more
than fifty projects of pre and power amps and A-40 was still my main amp. Until Aleph came into my
life.
Last year I decided to build the ALEPH 5 (two monoblocks with IRFP
150) for my brother and later, for myself, two monoblocks (photos) of 3? or 30? [+/- 27V DC, eight
(4+4) IRFP250 per channel, balanced front stage like ALEPH 5, and adjustable bias (with 6 steps
switch) from 0,4 - 1 A per device]. Now during the winter I work them biased at 0,8 A per device. The
temp of the heat sinks is 51C with the room temperature at 22-23C and DC offset 8 & 11 mV. The PS
is a 300 VA toroid transformer with 2 X 47000 uF/63V caps. My next upgrade will be 2 X 300 VA
transformers per channel.
The sound is better than my brother's A 5 except the power.The
difference from my old A-40 was much more than I expected. The ALEPHs are made for music! I thought
that I had change my diy loudspeakers (ODIN with SEAS Excel units). The amps are working for more than
500 hours without problems.
Then I constructed an ALEPH L (photos) with relays at the inputs,
remote controlled motorized PANASONIC pot. and changeable line stages. I can change them on the
printed circuit with the other version of Aleph L or BOZ. The PS is dual regulated per channel, first
at 80 V and finally at 61 V DC. I think that it sounds better than BOZ (the only cause is the upgraded
ps?)
My next construction will be the ALEPH ONO , or PEARL PHONO. Anyone
who likes to have the schematics and the layout of the circuit boards of the ALEPH 5 (3 or 30 with
eight IRFPs), be free to e-mail me, so as to send him with (.cdr) or ( .jpg) format. (I drew the
circuit boards with Corel Draw ).
I would like to thank Mr. Pass for sharing his knowledge with us,
for so many years, first from the Audio Amateur, and now from diyaudio.com and his website.
I 'll appreciated if you publish my e-mail with the photos in your
website. Thanks and I wish you happy 2002.
|