Music First Audio Passive Magnetic pre amp

In my failing quest to find an Exposure 14 & 9 setup, I have been gay fully turned towards the item above.

I called 3 shops that stock this and each of them have "Best pre amp there is" no messing sort of answer, each and every time !

Not being a avid review reader or buyer of only 5 stars or more products, I wondered if anyone here had heard it or could comment on it.

Both shops have said it blows everything away, even the pre amps costing many many thousands !

Have a fallen in to the trap I try so hard to avoid by thinking "more expensive must be better" God I hate that !

http://www.mfaudio.co.uk/

 

Much along the same lines as michaelab's Bent Audio NOH.

 

?!?!?

 

I think the word intended was gainfully? Anyway, yes, the Music First Passive is, to all intents and purposes, identical to my Bent Audio NOH (were back to gay again ). Same Stevens & Billington TX102 transformers and same switches, just a different box really. I wouldn't disagree with "best preamp there is, bar none"

Michael.

 

Bugger, I have fallen in to that blasted "more expensive must be better" trap !

Ok then, so it could be demo time, I have another English pre amp set up to audition this weekend, but will make sure I try the MFA before I buy.

Thnx Guys

Oh by the way, sorry about the G word, that was my mistake !

 

Well, I'm about to buy one to upgrade my CJ Pv-10 .

Recently compared it with an Audion Premier Line Pre (£1000). The Audion was not as open, was more veiled and had a softer fuller midrange. The MF was sharper and revealed much more "inner detail" I suppose.

As I understand it, the transformers are pretty much the same as the Bent ones but do differ in specification I believe, so should sound pretty much on the same lines.

If your front end is up to it and you don't need the gain of an active or remote functions I think it's well worth a listen.

Thorsten (3dsonics) is yer man here tho.

 

Talk 3.1B, I have heard (not from press) it is superb !

As for the front part I am using Clearaudio for the black gold and for the silver Marantz CD63 MKII KI Sig DP Copper plated limited edition (if it ever comes back from Marantz !)

 

Hi,

Well, some warning notes first, I have been the driving force behind first getting Sowter and later S&B to make Volume control transformers. The S&B I got designed by JB after feeling the Sowter ones where good, but could be bettered. Since then quite a few finished products, DIY Kits and DIY'ers have used various incarnations of the S&B Volume control transformer. The current MK III is definitly the best of the lot yet.

MF-Audio was set up to provide a finished product for sale through traditional channels primarily in Europe. The current passive magnetic preamp (PMPA) has it's genesis in what was intended actually a "Pro" attenuator for studios. It was decided to actually merge the "Pro" & "High End" product which leads to simple and plain casework, but keeps the price somewhat on the ground (I know it is expensive, traditional distribution channels imply markups, sorry). :MILD:

I originally had on the drawing board a stunning postmodern steampunk style sculptur made of wood, acrylic and gleaming polished metal (this one MIGHT even come back at some time), but the costing on the casing suggested that at least for a startup company it was not fesible and arguably, it would not have sounded much different from the PMPA, but it probably would have cost 3 - 4 Times as much....

The whole thing was intended from the word go as close to the ultimate (but strictly in terms of sound quality) as the budget allowed. I have build a lot of Preamps and listened to many more, I prefer this particular passive (or indeed any other with the same transformers) by a good deal.

Some of this is actually a very direct result of the technical implementation (Transformer with multitapped secondary for adjusting level), the rest is in the specific transformer, switch and wire, plus connectors.

I think MF Audio can do EVEN BETTER, but only by consequent application of pure silver in all positions (switches, connectors, transformer windings) and the cost penalty for such an All Silver PMPA is not small (think around double, more with my favourite Type 72 silver switches).

I doubt you find something much better anywhere near the current retail price, but that's just me. I suggest you listen for yourself and carefully.

Ciao T

 

thought i'd seen this somewhere before

note also

http://www.noteworthyaudio.co.uk/New.html

 

Hi,

Just goes to show, I'm not enough in the food chain to even hear a silver PMPA, never mind owning one.....

Ciao T

 

I know someone who would re-wire it with high quality silver cable for about 300 if anyone needs it doing.

Cheers
Chris

 

Hi,

Another thing maybe of use....

http://www.stevens-billington.co.uk/page102.htm

I wrote a pretty detailed piece on why transformer attenuators do what they do (and how), incidentally this piece also contains any relevant compatibility warnings. Some of the noted features (eg transformer resonances) apply to the earlier revisions of the attenuator transformers, the current versions no longer have these problems.

A key spec to note is the transformers primary inductance. It is a measure of the number of turns on the transformer and in effect of the "virtual" impedance at low frequencies.

Making transformers is a bit of a black art, but in principle one might say that without special geometries of winding and all that serious black art a transformer will have the worse high frequencies the more turns are applied. Equally, it will have the worse low frequency performance the fewer turns are applied.

A simple way out of having to use complex winding structures is to use a small core and to use few turns. Such a transformer will measure fine on a generator with a 50 Ohm Source impedance, but in the real world where few sources are 50 Ohm internal impedance the lack of primary turns will cause problems at low frequecies with both actual freqency response and distortion.

The transformer applied to the MF-A PMPA has a primary inductance of 400H, which is between 5 to 10 times that of the attenuator transformers of other than S&B Manufacture (which are used by MF-A). At the same time the S&B Transformer used has exceptional high frequency perfomance as well, despite bing made on a large core and with many more turns than whatever else is out there.

Some measurements of the current Transformers are presented by Martin Colloms in HiFi News,

For what it is worth, he measured a frequency response of +/-0.05db from 12Hz - 40KHz (+/-0.5db is below 10Hz and above 60KHz FWIW) with significant capacitoive load. Distortion for 2V Input was measured as -115db (<0.00018%) at 1KHz while intermodulation for equal 19/20KHz at 5V was around -112db (or about 0.00024%). In other words, there are no AD or DA Converters yet that equal this performance and therefor no sources that actually manage to hit the limits. That as an aside for those people who keep harping on about how bad transformers are for the sound.... ;-)

Ciao T

 

Hi,

Does that include the transformers?

If not, there are literally hundreds of meters of copper wire in the transformer.... ;-)

Ciao T

 

errrr no!

I would bet the one at noteworthy just has the wiring done not the trannys...

Im going to have to borrow one of these one day. I dont normally like passive pre's, but Ive never tried one like this.

 

Hi,

The official MF-Audio Silver one has silver wired transformers, is internally silber wired and has Audio Note Silver Connectors plus the directly silverplated version of the switch (compared to gold over silver over nickel) all of which accounts for it costing nearly twice as much.

You should try one. Resistive Attenuation (be it in passive or active preamps) appears to rob the music of at least 10 - 15db subjective "Downward Dynamic Range" (Allen Wright coined that term). Also, most volume control potentiometers (ESPECIALLY however the often cited "audiophile quality" conductive plastic types and certain cheap carbon track types) suffer from very clearly audible and measurable distortion, plus all the impedance mismatch issues.

The first Volume controls in WE Cinema and Telephone Amplifiers where multitapped Transformers. Seems the guys had it right back then, except it cost too much. The accountant is always the enemy of the better technical solution....

Ciao T

 

Gee, thanx guys

3D - You either really know your stuff or you baffle the bull even better

I shall let you know how I get on with both the Talk and the MFA