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After 2 year of developing
300B Single Ended amplifiers with DEEP bass,
we have come to the conclusion that
it is IMPOSSIBLE to build
a 845 Single Ended amplifier with DEEP bass,
WITHOUT resorting to negative feedback,
WITHOUT losing the treble.

There will be a few people,
who wrongly claim that
their 845 Single Ended amplifiers have DEEP bass,
but when you talk to them, you realize that
they are using SMALL 6 inch woofers !

When we say DEEP bass, we mean 12 inch woofers, in a MASSIVE transmission line.
( Try one of the USD 25,000 MONSTER SIZED transmission lines from PMC ! )

Try reproducing a "Church Organ" using 845 Single Ended Amplifiers
( WITHOUT "negative feedback" )
before you tell us that 845 Single Ended Amplifiers has DEEP bass !

Try reproducing a "Church Organ" using our EL34 Push Pull Valve amplifier
and 12 inch woofer, in a MASSIVE transmission line,
and you will be shocked by what we mean by DEEP bass !

Unfortunately, 90% of Hi-Fi enthusiast are DEEP bass virgins !

90% of Hi-Fi enthusiast have never heard DEEP bass from
from a MODERN 12 inch or even 15 inch HIGH FIDELITY woofer,
because the most Hi-Fi shops only sell 5 inch or 6 inch woofer !

Please note that 12 inch or 15 inch woofer for PA/Disco
are designed for UPPER bass,
and do NOT have any DEEP bass.

Designing PA/Disco speakers for DEEP bass,
will reduce their power handling dramatically.
  So PA/Disco speakers are designed NOT to have DEEP bass !  


The 845 valve has TWICE the output impedance of the 300B valves,
this means a MONSTER sized transformers (much much more than 15 pounds)
to get the twice as much inductance,
to get DEEP bass.

MONSTER sized transformers (much much more than 15 pounds)
has a lot of stray inductance and capacitance,
so you lose 1 dB or 2 dB at 20 kHz

You can use negative feedback to flatten the frequency response curve,
but you will lose the magical midrange of Single Ended amplifier !

Nothing in life is easy !


Any questions ?  You can  click  here  to  e-mail  us  at


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