help Graham mod his Rega!

Mmmm - help you mod your Rega - OK
Identified issues :
VMS 20 sounds less than good on Rega but great on Technics.
Music Maker hums when used on Technics.
Never impressed with P3 anyway - bass not as good (resolved with better support).

Constraints :
Financial - minimum cost = best use of available resources.

First issue simply solved - use the VMS on the Technics, forget the Rega.
Second issue - hum issue with Grado (and Grado based) cartridges on Technics - possible resolution by modifying motor electronics/external PS - maybe talk to Leo on this one - not sure this will solve that particular problem though - more info needed - eg ask someone who has done that mod.
Otherwise use it on the Rega.
Reported by some users of the Music Maker that it is a good match with the Hadcock you already own.
Yes it is a "tweaky" arm and requires constant fettling, but can probably be mounted on the P3 without too much hassle. Does not provide easy cartridge changes.
Do you still have, have you tried, the MM with the Tabriz on the P3 ?
Cost so far, nil.

Now come the "spend money or trade gear" options,
my pick "best" arm for the P3 - Michell Tecnoarm (best VFM and execution).
a very good alternative that offers removeable headshell, Jelco 370H OEM may still be available NIB from ebay US, or Sumiko MMT (virtually the same arm) centre for centre drop-in replacement for Rega arms. slightly higher than medium mass and very good allround arms offering oil damping.
Another "drop-in" for the P3 is the Roksan Nima, another Unipivot which should work well with the MM.
Often available SH for not ridiculous money.
Either put a Funk Achromat on the glass platter or replace the platter with a Funk platter - this will give a more neutral presentation than the felt on glass while retaining liveliness.
A clamp or weight should be used with the Funk and check the amount of spindle exposed before obtaining one of these, they require either 3mm or 5mm - (I do not have the spindle extension problem as I use an aftermarket sub-platter with a longer spindle)
Some like the open weave sponge type mats on the glass platter - cheap to try - make your own.
Less "dead" sounding than rubber but still damp the glass ringing to some degree.
Regas tend to run fast, I suspect this is a design compensation to counter the inevitable slowing when transients are encountered (belt will momentarily stretch in reaction to increased drag from the stylus).
This, I think, will tend to emphasise the leading edges and requires impeccable tracking from the cartridge to balance that will a full decay. Good dissipation of spurious energies in the record will improve the tracking, as also will good dissipation of the extra energies the cartridge puts into the arm, the Tecnoarm is well thought out in that respect and the oil damping of the Jelco/Sumiko similarly. The quantity of spurious energy generated at the stylus/groove interface is dependent in large degree on the stiffness or lack thereof of the cartridge suspension - eg the compliance. - low compliance = more energy.
You could have a chat with John from Audio Origami in Glasgow (I think) - he is reputedly very good with many arms/mods and an excellent craftsman by all accounts - does not have a "golden pen" either.
There are many other mods for the P2/P3, I have done many of them and really like how mine sounds.
They did cost a considerable amount.
I personally would not attempt putting a 1200 arm on a Rega, the dynamics of the plinth are vastly different. Unlike many I was not that impressed with a Rega arm on the Technics, best results were with the locknut barely holding the arm and a decoupling "O" ring above the locknut - this would not be possible with one of the new 3 point mount arms - the arm put too much energy into the plinth otherwise - to my ears - the Rega composite plinth is better able to dissipate this energy - the directly coupled rubber "boots" no doubt contribute.
Apologies if any of this sounds like telling nan how to suck eggs.
T

PS - you replied while I was composing all this - I note your comment on the the Technics sounding "warmer" - my feeling there would be that it is more related to the glass platter and damping of the record than on the arm.
In that respect, SRM Tech (another Michell - don't know if they are related) make a "platter damping ring" that fits around the rim of the glass platter.

tg wrote: Apologies if any of this sounds like telling nan how to suck eggs. T

Welcome to the moderator group!

What an incredibly good guide you are!

tg wrote: Erm, thanks, I think   I'm no "born again" policeman so I hope the duties are largely ceremonial.

Shouldn't need them in this backwater of what is otherwise "hyped-up-virtual-space"

If I can alter the word "moderator" to something more fitting for 'quite knowledgeable/experienced people who are considerate in what they write and share it', I'll have a go. But as to the word to choose...???