The "re-birth" of MF A1

Hey Nando,

Anything to say on this?

 

Hi,

You would also need this.


SCIDB

 

I wonder if it'll be more reliable than their previous efforts. Also at £999 I hope it has better heat sinks.

 

Class A is pointless in this day and age - most competent designers have banished crossover distortion to vanishingly low levels or eliminated it with higher efficiency circuits.

Waste of electricity and resources IMO.

 

the a1 was a great amp if a little unreliable but find it a bit confusing musical fidelity is producing yet another amp and the power figures of the a1 will if similar to the origanal in power output will totally go against what they have been advising in terms of power dynamics headroom and matching up with speakers correctly unless of course they will be advising potential customers to use with speakers of 92 db and above to get resonable results ??? mick

 

They are Mick. Take a look at their website and the link that Dean posted above. They recommend using sensitive speakers or their supercharger with the A1.

 

Blimey it's a bit FUGLY - much prefferd the look of the origonal, that LCD didplay looks really cheap.

 

will do dev , i like musical fidelity gear ive owned the A1 and the A100O in the past and found them to be very good , not sure why you would opt for the new a1 and add the superchargers i would probably opt to spend on a pre - power combo or big intergrated sure mf will have some marketing shpeal as to why this will not be the better option im becoming more sceptical about mf after every product release which is always far better than the previous models but they are slowly re releasing there origanal products its all a bit confusing for me !

 

I agree Mick, I would rather buy a pre/power or a better proper amp instead of an A1 and a "supercharger". TBH, I wouldn't buy any MF product now, given their marketing. I have owned and liked MF products in the past.

Come to think of it, if I was starting from scratch I'd probably look at a passive pre and active speakers but that's another thread.

 

I don't understand, why would you buy a low powered Class A amp and then put a high power Class B amp on the end of it?

I've seen it all now.

 

Absolutely.

Modern SS amplifiers sound so utterly convincing. Examples include Cambridge Audio......................................

 

Absolutely, with bells on.

 

It's nothing new. Quad did a very similar thing (albeit more cleverly in one box) with the 405 amplifier back in 1978. Revolutionary it was too.

I wouldn't buy the MF combo, but...

Class A is so obviously (subjectively to any listener) different/better than modern Class A/B that it isn't even funny. The minimisation of crossover distortion isn't really the point: With valves, single ended (Class A) operation allows much simpler and shorter circuits. With transistors, it can give rise to a circuit it requires no negative - corrective - feedback. We've had measurably close to perfect A/B amps since the 1970s (Jap crap) - most still sound horrid.

And Class A need not be low powered - See Krell KSA and MF A-270/A-370 and F series power amps (among others).

 

AFAIK, the Quad used a small class A stage as part of the corrective feedback (feed-forward?) loop to correct the class B power stage to specs similar to class A. Its rather different to using a class A amp and then simply boosting it through a completely separate class B stage. You would be better feeding the class B stage directly with a line level signal. I guess MF can get away with the new amp if they do strictly advise it for very high sensitivity speakers.

 

If you are satisfied with that Rob then I envy you - I truly do. Would these words of wisdom apply regardless of loudspeaker sensitivity?

 

hi, class a to my ear is very good in term of outright sound quality my last class a amp was a adyton opera intergrated stunning amp i had the pleasure of loaning a sugden a21se to compare and the adyton outclassed it in every way , valves are very good connected to the right speakers cables etc , my last set where a set of audion sterling monos , but at the end of the day all flawed no real bass grip lack of real dynamics very sensative to other kit , subjective volume levels unless using ultra sensitive speakers and run very hot which eventually leads to early component failure not to mention high running costs if like me you like to leave kit powered up , i took the plundge and went to the DARK SIDE ! and purchased a set of nuforce refrence 9 monoblocks though not perfect but bloody close in some areas they offer a very good balance sound which offers the best of both class a and a/b , huge power and headroom , class a like midrange , best bass ive heard from any amp and can partner with any speaker you care to mention think someone has already mentioned cambridge audios new amps which i believe use a mix of technolagys class d a/b ? as with anythink new it will take time to perfect i owned a tact 2150 intergrated one of the first digital amps and while good and expensive at the time it sounded digital with no real realness about it all very matter of fact the nuforce amps are in a different ball game , where will class d be in a couple of years ? ill get of my soap box now , ta mick

 

In the case of my amp, yes because the first 5 watts are in pure Class A. You've then got another 145w in XD @ 0.002% THD.
Cake and eating it, and all that. Of course you can use an amp with much lower output with a sensitive driver but exactly the same rules regarding quality apply as with high power amps.

I don't like amps with high distortion or ones that modify the frequency response through high output impedance. You might find a magic pairing for such an amp but they are far from universal.

Amps that stand out form the crowd as sounding different always turn out to have something wrong with the specs - always. Apply the same logic to amps as you do to cables and you won't g far wrong.

 

Rob,

amps don't need to be universal - they just need to be suited to the partnering loudspeaker.

Geez having switching distortion right at the power level used for typical listening sucks. Talk about having the worst of all worlds. ;-)

 

The designer would agree hence he built the 'XD' topology, which from what Rob told me has a sliding bias rather than a defined switching point. I really don't think there is much to dislike about the 840a.

 

Nice amp Rob. I don't think you have anything to worry about there.

People who think amps make large differences are strange or don't go about correctly pairing to the load and task at hand. I've tried a large number of amps now and can definitely say the there's differences between some of them but absolute improvements? That's a tougher question and quite a rarity in my experience.