How much difference does a phono preamp really make?

Hi @audionoobie 
I have been a Phonostage Enthusiast and Obsessive for far too many years, where the over interest has encouraged myself to have spent more time experiencing them than any other Device in my system.
This is a undertaking that is still with me, and COVID Travel Restrictions Impacted on most noticeably, when it come to my particiapation with the social side of HiFi .

I can not put a figure on how many Phonostages I have auditioned over the years, and my interest has not wained.
Very recently, now there are new freedoms to be exploited, I was with a group of friends auditioning one of the groups selection of ancillary devices that they have, to be used in conjuction with Phonostages.
On this occasion there have been Two Phonostages, in use, along with SUT's, Head Amp's and a Deguassing Device, to attempt to keep all Demonstrations carried out with the fairest of play times for each comparison.   
On this occasion there was a Debut within the Group of a very respected and reasonably well known Brands High Level Solid State Phonostage Model, using the Built in MC Stage and the other ancillaries.

This Debut was carried out as a Comparison along side a Bespoke Built all Valve Phonostage, using a SP10R, Glanz 12" Arm and a Miyajima Cartridge.
Due to Lockdown, this was my long overdue and first encounter with the TT Set Up.
In the above case all the auditions left very indelible memories, where the impression is very positive, and is a reminder of the bar that can be set for a Vinyl Front End.
Each Phonostage shared traits that were similar, but there was an overall separation in the Presentation, where one was Fleet Footed and offered an air of precision and control.
The other took the music on and showed a Tremdous Presence with ethereal room filling Voluminous Sound.

Prior to this meeting, I was keen to get on the road and meet a fellow enthusiast.
To achieve this I carried out a 200 Mile round trip, to visit a good friends home, and was listening to their own Bespoke Built Phonostage Design.
This was not a comparison, it was a update on a Demonstration of a evolved design I was becoming familiar with prior to the Lockdown.
The TT in use was a completely Over Hauled SP10 MkII.
This updated demonstration was quite phenominal, and left me with goosebumps.
I was greatly impressed, and am very keen to hear this Phonostage on my home system.

'In a nutshell' a Phonostage can quite easily make or break a system,
in relation to how it can produce a performance that leaves a very positive impression.
The effect that the use of can have on a individual, will only be understood by being in the Company of one, preferably being used on the Home System .
Most importantly the Phonostage is a Device needing to be heard,
hearing the choices of others who have taken a long time to find their Holy Grail of a Phonostage, can be extremely rewarding and educational.

There might be foot work required to get the best experiences and gain in understanding where your preferences lean toward, but what a great way to grow in understanding, through meeting fellow enthusiasts and being given demonstrations of the choices that others have made .     

The Ypsilon phono stage costs $30,000 and provides only 39 db of gain with a fixed input impedance. It sounds fantastic but price and flexibility do not go hand in hand in the current market.

A good phono stage is a wonderful upgrade but with a great one the magic happens on any good recording and you do not have to spend a lot to get a great one.

Theoretical options are interesting and means a lot but practical experience is much more relevant and has more value. I used to have DL-110 about 3 years ago and paired it with Parasound JC3 Jr and Rogue Audio Ares. I didn’t really liked the cart, find it pretty average sounding with no dedicated personality. The compiration of two phono stages with DL-110 was definitely in favor of Ares. It was noticeable upgrade in SQ. The Ares has pretty firm place in my system due to its flexibility and exceptional sound signature.  

Many Phonostages share similar Topologies and when Demonstrations are carried out where a comparison is available, even if for a limititation of the time allocated for each Demonstration.

It can soon become quite evident that a selection of Phonostages sound very Similar, especially in SS to SS  and Valve/Hybrid to Valve Hybrid Comparisons.

At Bake Off's I have attended, a £300  - £600 SS DIY Build, where a large proportion of the costings is seen in the casing and casing attachments, and where a Builder will inform the audience that they had discarded a large selection of components for matching purposes, that has added to the cost,  have been witnessed to fit comfortably into the SS Category of up to £4000.

My own experience is that I have preferred the DIY Models over 
Branded Models Demonstrations costing upto £3000ish, as well as think that some are almost parity in their performances.

Branded Phonostages I have heard that are approaching the Higher £3000's can usually be seen to deliver a much improved performance and separate themselves from the Line Up.
I would think this has got quite a bit to do with the Designers 'Know How'.   
How these Perceptions would unraval, if extended listening was carried out in the Home System will also produce different assessments of the comparisons.

As said it is all about the ears as the tool to discover a preferential presentation.