Hello to everyone. Sorry for not replying to posts - I've simply been swamped with electronics and cartridge work.
A reply to Cedric inquiry about the Connoisseur 5: Similarly to the Connoisseur 4, the 5 series preamps were originally designed as one big star ground. This is true of both the topology, and the physical construction.
The power transformers (one per channel) have completely dual secondaries, each with its own rectification bridge. The raw DC positive and negative supply rails are kept completely separate from each other, and the individual grounds do not combine until they are inside the preamp main unit.
If you look at the bottom of a 4-2 or 4-2SE, you will see a protruding lid in the center of the floorpan. This covers the bespoke grounding board, which combines all of the incoming and outgoing ground links into a single star.
The chassis and mechanical layout design places the star ground so that it is equidistant to every circuit board, and the input selector and attenuators (for the line preamp).
The input selector and attenuators were designed specifically so that everything could be ascloseaspossible to the central ground. This is why the Connoisseur 4 only has a single knob and uses a coaxial rotary switch for both the input selector and the dual attenuators.
If I would have used separate left and right attenuator switches, or one rotory switch for the input selector and one for the attenuators, that would have increased the loop area of the ground network, and would have pushed the amplification boards farther apart, which means longer signal wiring, longer power supply wiring, and of course longer ground wiring. I could have circumvented this by using an "over and under" arrangement for the input selector and the attenuators, so that the attenuator would come on top (for example), the input selector on the bottom, the left amplier module to the left, and the right amplifier module to the right, with the grounding board in the center of everything. But that would have made the grounding arrangement much harder to work on physically, and I would have needed to keep the grounding board super-flat (in reality a variety of components are installed on the grounding board which makes it easonably thick - not just wires).
When I designed the 5, I kept the star ground design philosophy and scaled everything up, so that the 5 continued to sport a single large(r) knob, with all of the key components carefully arranged around the central ground.
However, when the 5 was launched, our Japanese distributor was told by some of his dealers that, since the price was a good deal higher than the 4, they expected the main unit to show more glitz and eye candy. Perhaps because our thenJapanese distributor himself has a love for eye candy, he caved in and completely redesigned the 5 chassis structure into a dual-knob arrangement, which forced everything apart and cause the wiring networks to become much larger and sprawling. There were a handful of single knob 5s built, but he had all of these taken apart and rebuilt the boards into the new two-knob chasses.
I think that one single-knob 5 may still exist, but I am not aware of any other ones.
Essentially, our Japanese distributor broke the original design philosophy of the 5, and certainly he destroyed any interest or desire that I had in taking it further. At the request of one customer, I did work on one dual-knob 5 in an attempt to bring it closer to the 4-2, and the sound definitely improved. However, what I found was that I had to "fight" the mechanical layout and chassis design too much to accomplish what I wanted to - the design philosophies were simply not very compatible.
So the 4 kept on evolving and getting better, while the 5 took a step back in performance due to the shift to a dual knob chassis, and there is were it remained. This is a shame because the 5 was more sophisticated in the areas of circuit topology and board design, but such is life, I suppose.
I hope that this answers any questions about the 5 and what happened to it (including what didn't happen to it).
Well, that should be enough rambling on for today. More at another time, I hope.
BTW, I will be at the Munich High End audio show, at the Fast Audio booth. This will only be for the Lyra cartridges - no product from Connoisseur will be on display. If anyone happens to be in the area around that time (next week), please feel free to drop by and say "hello".
kind regards to all, jonathan