It's done!

The guided tour:

Back: 2 tubes are the Direct Heated Triodes - 2A3 or 45 plug and playable without any circuit changes.
Middle: left tube is the Super Mu 6AS7 and right is the 5U4 rectifier

The tube sockets are mounted in a subplate which is compliantly mounted to the chassis. Rapping on the chassis produces no audible feedback.

Front: the power transformer. From our 98db speakers we can hear just a little tube rush from the 2A3. No hum.

Front panel: Remote controlled selector then power switch left, 120 step volume control on the right. Selector has 5 inputs (also additional inputs for REC on back panel)

Answer:
The tubed output stage operates differently to the solid state logic one. The Tube stage operates as linear Class
Amplifier and does not "saturate". The normal logic IC based output buffer circuitry operates in "saturation" meaning
it is slower to react to signal changes. The Tube stage also has much less input capacitance than CMOS logic IC's, so
the rise-time of the signal is faster.

The technical result is a signal output that is cleaner and closer to the theoretically "ideal" SPDIF Signal.

As a result the DAC's SPDIF receiver can recover the signal and clock with less jitter, in technical terms. This in turn
generally produces a better, more natural and non-fatiguing sound.

We’ve been enjoying the coherence of the Feastrex field coils for some time. But the laws of physics eventually catch up with a 5” driver even though the Feastrex does push those limits to their…ah, limit, and we find ourselves wanting the less limited dynamics and greater sensitivity of horns.

Unfortunately horns with any bandwidth are the size of a refrigerator.
So…we have developed a horn ribbon based system which achieves our goals.(please keep in mind the picture shown is for testing and development only)

Cole Max

Some quick facts
phono stage:
Tubes are E180F and 2C51
LCR direct coupled
Silk Step up transformers 10x/20x
Mute and stereo/mono
All the best bits inside

power supply:
FCUPS film cap power supply
5AR4 tube rectifier
ULNFS (ultra low noise filament supply)
connected by umbilical

Next: more.

This is a completely subjective notion prompted by recent experiences with 24/192 computer music playback.

We've recently gone back and forth between CD transport, computer transport and vinyl.
The scales have tipped.
Even the best CD playback has always had a certain imperceptible grain, so that when we switched to vinyl there was an ever-not-so-subtle sense of relief, and a sensation of the aural apparatus relaxing.
However many of the HD recordings now have such fine textures that that is no longer the case.

Today I was impressed listening to Eiji Oue - Rachmaninoff Symphonic Dances. Reference Recordings seems to strike just the right balance of edge and silk, bass and presence. Dynamics surpass vinyl and of course bandwidth is linear, goes deep and is unconstrained.

Morello Max:

"Today i receive one of your new Morello Max units, as soon as i can, i connected to my main system:

MSI GX620 Laptop. 4 TB Droboshare NAS. JRiver Media Center ASIO->
Wireworld Ultraviolet USB 1 M Cable->
Morello Max->
Canare Toslink 75ohm 1M->
Audio GD DAC9Mk3->
Audio GD ACSS Cable->
Audio GD C39 Preamp->
Marchand Electronics Active Crossover->
MBL 8006 DIY Amp for Bass, Kingrex QS-01 Amp for Mid and Highs->
Monitor Audio RS8 Mains->
Monitor Audio SRW-12 Subwoofer.

After the Morello Max i was using an Original Musiland Monitor 01 USB and a Teralink X USB.

I know there are many of us out there, silent, wondering. We didn't want digital music because vinyl sounded better; eventually there was no choice. We succumbed. Now 30 years later we're sitting on a mountain of CDs.
Some have written to ask what Computer Music Playback is all about. Some have dropped by our shop to see and listen to the setup.

Computer Music Playback is where the computer replaces the CD transport, BUT does so much more.

A customer asked:
>Can you help me get into Computer Music Playback?
Answer: Yes, the best way to get into it is to
1. get your computer set up for music playback and
2a. get a device such as the Morello to connect between computer and existing DAC
OR if not having a DAC

Cleo: USB DAC (meaning usb input only): ASYNCHRONOUS USB DAC up to 192KHz with Tube Output.

In between it's like this:

Computer Music player>>>
>>>USB by ASIO (or other direct stream to USB), bypassing Windows playback>>>
>>>USB input of Cleo where asynchronous signal is reclocked>>>
>>>on board DAC>>>
>>>UTS (tube output stage)>>>
>>>RCA outputs

Of course the secret's in the sauce
From clockwise, upper left:
MuMetal wrapped power transformer
Ultimate Clock power supply
On board Linear power supply (LPS) (nothing powered from the computer)
Ultimate Clock module with 0.5ppm TCXO
UTS (tube output stage)

We have playing in house a monoblock version of the Lux91.

The original Lux was Thorsten Loesch's circuit and excelled in drive and dynamics, putting out 12w on musical peaks. The key feature was the reactive interstage - a 5687 with choke on the cathode and direct coupled to the grid of the 300b. The role of the reactive interstage is best understood by viewing the 5687, choke and direct coupling as a unit.

Thorsten has been at it again and we've been tweeking the implementation these few months. These are:
1. 310a used as driver tube: This tube just has such a luscious tone -- it's too good not to have.
2. Monoblock chassis: needed as the extra parts would be too much to fit into a single stereo chassis

Who would've thunk it?

Today we configured a Universal Tube Stage (UTS) for placement at the SPDIF output of the Morello computer-to-DAC enabler as discussed here :24/192
All the other bits and mods were left in place and the upgraded output transformer moved after the tube output stage.

The result?
The best square wave we've ever seen from an SPDIF. Even extreme high end CD players output square waves that look like a literal train wreck. The Morello Level 3 is already way ahead on that count but adding the tube output produces an even better looking square wave AND alomost doulble the voltage.