KRATOS active hi-fi SYSTEM
This system is the result
of 2 years of experimentation, tweaking, DIYing, and ultimately listening.
It is by no means complete. The tweaking continues, the tubes keep rolling,
the permutations are endless...
It would not have been attainable
without numerous correspondence over the internet and the help of many
individuals worldwide.
Many thanks to Michael Barnes
of Norh , Dan Wiggins at Adire
Audio, Joseph Lau of Antique Sound
Labs, Lance Dixon of Sounds Natural in Cape Town, articles from TNT-Audio
, DanG and others at Harmonic
Discord Forum , Mr Valve in Johannesburg, Schalk Havenga of Valve
Audio in Pretoria, Phil Marchand of Marchand
electronics.
CD Player-
Naim CDX or Norh CD1\QDS Valve CD player [12AX7]
Pre-amp- Valve
Audio Black widow now much improved with EI 6DJ8 elite gold tubes
Active Crossover-
3-way Marchand unit crossed at 3KHz and 150Hz
Amplification:
-Norh LeAmps monoblocks to the subs
-Audio Research D125 [Svet6550s or Sovtek KT88s] to mids
-Antique Sound Labs Wave 8s with 6BM8s, high frequency output transformer
version with MIT capacitor
upgrades to drive the tweeters
Speakers : Norh marble
9.0
Subs: KRATOS
S. P. 111 12" sealed passive units downfiring
Cabling: mostly DIY
with Siltech, VDH and Kimber
Acoustic ceiling and panels
Dedicated AC wiring to mains
panel with sepatate circuit breaker
The KRATOS subs.
This is my personal DIY
project in conjunction with Lance Dixon of Sounds Natural which is now
turning into a business venture.
We have launched a full
range of KRATOS subs here in South Africa and
hope to fulfill the needs of local audiophiles looking for musical and
detailed subwoofers.
Subwoofers in general get
a bad rap for being overbearing, intrusive and generally not very musical.
My experience has so far been otherwise and I believe that a good sub can
substantially enhance quite a few audio systems. The important thing remains
the integration of the lower frequencies into the complete sound picture.
The passive units will obviously need to be driven by external amplification and require a separate crossover. They are the most musical solution and not really suited for high impact Home Theatre. These are for pure audiophile uses only.
The active vented units for high end Home Theatre include a 250W class A\B amplifier with high pass outputs crossed at 125Hz [on the speaker level outputs only]. They have variable phase from 0 to 180degress, 30 dB gain control and a special rumble filter circuitry designed to be used in vented enclosures.
We use Adire Audio Shiva 12" drivers in sealed 88L enclosures.
The panels are 22mm MDF with
extensive internal bracing, filled with 450grams of polyfill stuffing .
The drivers have dual voice
coils and can be wired in parallel or wired to drive one coil and loading
the other coil with a 250Ohm pot in order to vary the Q range. This changes
the impedance from 8 ohms to 4 ohms to suit different amplification.
Prices will range
from R12500 for the active units to R9000 for passive ones.
The subs pictured below
are the KRATOS SP111s [88L sealed passive] which I use in my system.
I can also put together complete
hi-fi systems to suit any budget.
I am absolutely convinced
that a R50000 system put together correctly after careful research , using
partly DIY components and sourcing other components carefully, will outperform
most complete systems costing up to 3 times the price .
Please feel free to contact
me for further details at +27 083 6753341 guidodg@iafrica.com
Our subs are finished in a natural looking porcelain finish. Other finishes can be applied on request
