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Main System

April 22, 2014

The Monument Nov 2015
A wag dubbed this system “The Monument” which amuses me. This system is the result of about 15 years experimentation starting with KT88 parallel PP amps driving Energy C8s. At this point, I am satisfied so I maintain that I am thankfully ineligible for being accused of the apparently heinous sin of being being an audiophile! (Most EE’s would say that “I can’t hear the difference” meaning that if THEY cannot hear a difference, then we must be fooling ourselves. I say that clearly you cannot hear the difference and that explains the truly horrible sounding early solid state amps and most cheap commercial gear.)

This is my main system with the 845 amp which is described on this blog.
The alternative amp on the table above the 845 amp, is a 50 design that can also accept 300Bs the design principles of which are described in the “The Audio Signal Path” post on this site. The UPS looking thing is a line conditioner that uses the secondaries of the UPS transformer as a common mode choke. It also provides a common power switch for the amps e.t.c.

(The secondary system still uses the C8s with a variety of small amps and a Meridian 508 CD player.)

The heart of the system is the line stage. Many years ago, I decided that with SE amps, it is a good idea to take the low bass via a separate amp so I designed a line stage that has 70Hz high-pass filters in both main channels and two bass channels that feed the plate amp in the woofer. (It is the polished aluminum unit on top.) The most important part of a music reproduction system is the speakers. The C8s are actually quite good and I spent several years in speaker hell, trying to better them. Many years ago, on the advice of my friend John Dahlman, I bought a pair of re-coned Tannoy 3836 drivers. These are professional units that were used in the Met production of Phantom of The Opera, Tannoy re-coned them they were re-sold. Finally, I took his advice and tried them in open baffles. Err, why oh why didn’t I do this sooner? Suffice to say that I am done with experiments. The baffles are large enough to work superbly with the 70Hz crossover. To me the bass crossover is seamless and this is particularly tricky to accomplish so I either got lucky or I know what I am doing. I claim that it is a combination of both.

CD / SACD player is an unmodified Sony SCD-777ES
There is also a DV-563A DVD player that I have modified with a transformer coupled output stage. This is a good-sounding unit that can play some (few) discs that the Sony unit will not digest. Full details at:

The turntable which is hidden behind the left speaker is a Sota Star Sapphire with a Benz L2 cartridge and AudioQuest arm.
The phono stage on the shelf above the turntable is my MKII WE 416 planar triode based design, full details at:

The line stage is a 2A3 based design, full details on the line stage at: The switched attenuator now has motor-drive and a remote.

Here is the back of one of the Tannoys:
Richard Tannoy 3836 Open Baffle
The straps on the bottom secure 40lb bags of concrete mix (in plastic shopping bags to prevent leakage) to weigh the speakers down. Sand would be better since the concrete will set over time and lose it’s ability to dampen vibrations.
The dimensions are based on the golden ratio with respect to the vertical location of the driver and the ratio of the width of each of the wings taken from the edge of the driver.
The 1.3KHz crossover is a factory recommended design I believe, that consists of a first order 4 microfarad / 6.8 Ohm high pass and a first order 2mH / 30 microfarad low pass filter and a 30 microfarad / 10 Ohm Zobel across the main driver. Here is a closer view of the crossover (Zobel not yet fitted):
Tannoy 3836 and crossover


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