Running LOMC with MM (47K) loading

Pindac,

I find it interesting that you experimented with lower gain tubes and use of a SUT and like that combination.  I think that there are many ways to achieve the sound one personally favors, and it is your own taste and matching to your particular system that matters (I tend to like SUT in phono setups myself).  I also agree that one can have quite different sound from two arrangements and one is not necessarily inferior to the other.  

I am curious as to why the ECC83 in the input stage did not work out sonically for you.  I've tried a few different ECC83/12AX7 tubes in my phono stage and they can sound dramatically different, so, perhaps it was the particular brand/vintage that did not work out for you.  I was lucky to have a friend who had a wide array of these tubes so I got to hear a number of vintage tubes.  I ended up getting Telefunken ECC 803S tubes (real vintage tubes, not fakes).  These tubes are certainly not for everyone's taste as they are leaner and brighter than many other vintage alternatives.

@larryi 
             I have a long experience with Valve Equipment.
For a person like myself, with sesitivities to certain perceived sounds that are catergorised as detractors as a result of a Sonic Trait.
I am very careful not to produce a Sound that draws my attention to a Sonic Trait that is noticeably present and not an attractor to the Sound Quality.
The Phonostage I was having produced was a ECC83 Input/Output as a Prototype.
It had a lot to offer and I heard it evolve with a couple of design changes to the Power Supply and exchanges of the Internal Components to Matched Boutique Parts.
I heard the model,that in the words of the designer / builder was a finished model, without much more to be done.

I informed the designer that it was possibly one of the best all Valve Phonostages I had heard.
I made it known that the ECC83 was causing me a concern.
There was something overbearing as a Sonic Trait and the Perceived Weight Underpinning the Music and Vocals are too much for my liking.
The Weight was quite noticeable, and the projection of the Mid's and Highs were subdued as a result.

There was a friction between myself and the designer, that had a very constructive conclusion.
Shortly after the last audition, I was offered a audition of the same Device with ECC81 Valves at the input stage.
I accepted this offer and the rest is history, with a couple of twweaks to the components and the ECC81's the Phonostage was now where I wished for it to be.

As a follow up to my receiving the Phonostage, another friend kindly offered to extend the fledgling experience, by making available a very attractive collection of Vintage Matched ECC81/ECC83 Configurations.

It was agreed the Phonostage would receive approx' 200 Hours of use, which was done through a Reverse RIAA and CDP on repeat.
 
The Designer /  Builder,  myself and a selection of members of my local HiFi Group were present on the day, to take part in the Vintage Tube Rolling experience on the Phonostage. 

The Tubes in use today by myself were unaminously agreed by the attendees, that from the permutations produced, the combination of the Valves I have in use were a stand out over the other arrangements.
The options on permutations on this day were quite vast, so not all were achievable. 
One thing that is recollected quite strongly, is that particular valves that were thought to be quite capable, did not Pop into the Limelight with a
 X Factor during this Tube Rolling session. 

As said I can use ECC83's at the Input without any concern for the Phonostage.
I have not felt the need to return to a configuration I struggled with at an earlier date.    

we don't affect what the cartridge does at all (unless the value of the load approaches or drops below the internal impedance of the cartridge). What adding resistive loading at the phono stage input accomplishes is to dampen the resonant energy of the ultrasonic spike, and give the phono stage an operating environment that isn't so likely to trigger any latent non-linearity tendencies that the phono stage circuitry may have.  

For the reasons given, the phrase "cartridge load" is misleading. "Phono stage input terminator" is a better description of what really happens."

I am wondering what aspects of his comments you agree with or disagree with. I regard you both as experts in this field.

I agree with Jonathan. He commented to me when we met at Munich a few years ago about how loading can affect the compliance of the cartridge and I have to admit I'd given it no thought until he brought it up. My main concern since the early 1990s about using loading as a solution is that its a bandaid for a phono section that has problems with RFI injected at its input. He is probably correct that the loading won't affect the cartridge very much until the load is near that of the impedance of the cartridge itself (at that point the output of the cartridge falls off). The winding in a cartridge

But it *does* affect the mechanical resonance of the cartridge in the tonearm and this in turn can affect how the cartridge tracks, as you want that resonance to be between 7 and 12Hz.  But for the most part you can certainly get the cartridge to track in many arms while driving a lower resistance load. Its simple physics that the cantilever will be stiffer. How that affects things will vary depending on the cartridge, arm and load resistance used. 

Pindac,  I apologize if my earlier post seemed overbearing.  I do respect that each of us has a slightly different "taste" in SQ, for want of a better phrase.  What I assumed is that your phono stage was designed to provide what we commonly think of as MM levels of gain (anywhere from 39db to less than 50db), when using an ECC83, i.e., your phono stage was designed around the ECC83 input.  I assumed or guessed that into that ECC83 input tube socket, you are now using an ECC81.  This substitution would "work", but it would not be optimal for operation of the ECC81 (too little current, mainly), and as you know, there would be a significant penalty to overall gain of the phono stage.  With such a phono stage using the ECC81, it is not at all surprising that you found it worked best with a SUT.  In fact, if my conception of your phono is correct, I am surprised it works at all with an ECC81, when you use any typical LOMC cartridge, unless there is a second gain stage following the RIAA filter section.  (I guess I also misunderstood you to say originally that you far preferred the ECC81/SUT configuration to no SUT; I now understand you to say that you like the sound both ways but that the character is different, not surprisingly.)  Anyway, unless you are using a linestage with inordinate amounts of gain, into an amplifier with very high input sensitivity for full output, driving very efficent speakers, or some combination of these, it is no wonder you need to twist the VC fully over to achieve satisfactory sound pressure levels.  So, first question, was your phono stage designed FOR the ECC81 as input tube, once you inter-acted with the designer, or for the ECC83?  For slightly less gain in an MM stage, compared to the ECC83, many people use the 5751, which pops right in to an ECC83 design and is in between the ECC83 and ECC81 in terms of gain.

I am not a EE minded person.
My Trust was with the Engineer for the design / prototype builds.
As is, with all my other Amplification.

My contribution to the prototypes was to supply a quantity of Boutique Components from Brands the designer did not usually use, as well as supply ears to help with assessments as the design was developed.
This was done more under the guise of further learning, rather than believing a improvement could be achieved through exchanging components.
The designer had Two Identical schematics for 83Input / 83 Output Prototypes.
The Models only differed, as one model was a Single Input, and the other Model has Three Switchable Inputs. 
A Brand of Copper Cap's I chose are exchanged from the designers selected ones in my Phonostage,  these are allowing a Lighter Airier Presentation more aligned to my preference.
A lesson learned one can say.

As for the Phonostage as a development, I heard it with 83's Input Output, 81 Input/ 83 Output and a ECC82 Version .
The Power Supply has been produced in a couple of versions,
the second version is a very noticable improvement over the first edition.
I have the second version Power Supply.
I also know there was a surprise moment about the measurements, and in Layman Terms, the quietness of the Phonostage was extremely impressive.

Recently I have learned there is now another version Three of the Power Supply.
A friend who has been in the company of this Phonostgae on a few occassions has been impressed by this design, which has resulted in them now purchasing one with the Version Three Power Supply.
I am yet to learn whether it will be the same as mine or a 83/83.
This will be determined when the COVID restrictions are altered to allow non family members into anothers home, and the evaluations can start.

The restrictions with COVID over the past year has prevented the HiFi related 'get together' experiences I enjoy.
Hopefully I can get out and meet very soon and hear some of the
Lock Down developments that took place.