New LFD Zero LE mkIV

Perspex fabricated case tweak? No thanks. The following article is interesting, but doesn't mention this - Perspex has a low melting point. The LFD unit(s) under discussion generally run cool, but IMO, Perspex is not one of the better materials for a amplifier case:

Perspex is a thermoplastic widely used for making unbreakable watch glass.It was first produced in 1930. Its common use is in the form of contact lenses for those people who want to get rid of glasses.It is the most common and reliable alternative to glass. Perspex is too hard and too tough to shatter. But there are other uses of Perspex also beside personal uses. It is also used for making dentures and artificial eyes. Because of having a good degree of compatibility with human tissues it is used for manufacturing lenses and artificial eyes. Being hard and transparent, Perspex has many industrial uses also such as safety goggles, machine safety guards etc.

Perspex is widely used because of its unique property that it can be molded into any shape. Unlike other plastics, Perspex is made directly into sheets during manufacturing. Its specific name of PMMA plastic is used in making plastic bags, squeeze detergent bottles, washing up bounds, etc.

It is also used in film form for packing because it is cheap, transparent, tough, and flexible. It is also manufactured under different names in different places like Rhoplex in USA and Oroglas in Europe.

The cosmetic design isn’t to everyone’s tastes. This matters not one iota to him. his entire motivation is the sound. Aesthetics are in the main an irrelevance to him.

Are you quoting him or making an assumption that this is Mr. Bews stance? If this is true, it's a pretty arrogant stance. It's evident aesthetics are not important to LFD "except" in their top of the line models - and even here it's still too "simple" to be beautiful (lacking elegant details).

As for me it's "very important" and every bit as important as the sound. Having both makes for an exceptional piece. Who wants to display ugly gear?

The LFD LE III front plate and case look DIY. At the MSRP of above 3K I expect a better fit and finish.

given that so few of his 1000s of units rarely appear on eBay or Audiogon, one might conclude that the end-users are pretty much in line that form follows function.

Another meaningless stat. A search of aGon Virtual Systems finds 3 systems. 2 of which are dealers. So out of all recorded aGon virtual systems only one owner list one. To put it in context.

Dear Notec, why arrogant? I would think "sound" or " music" aspect most important. I think he should be applauded. If he had a fancy faceplate the price would go up accordingly. Perhaps you need to consider another piece of gear altogether.

And dear Airegin, thanks for the nice tutorial, but British maker DNM also uses some type of hard plastic, can't remember exactly what, for their cases, for he wants no metal in his design. And their products are superb.

I still cant convey a lot more detail on the Mk4. It's impressing me sound-wise, and I am very comfortable with the looks. The top plate is now a channeled affair, not a flat piece of metal, and overall the changes with the front panel groove and top cover at least to me look good. As much for me as the aesthetics matter but i agree i'd not want to put an ugly unit on display, but this is far from being ugly. I've seen plenty of gaudy high end amps i'd not want to have openly displayed but i would expect many people try to create a nice look for their gear where its a feature or another family member is focused on that (my move from my audiospace was exactly for that reason).
Bass is certainly an interesting topic. I may have wanted the tighter tauter bass described in the Mk3, as my speakers are ending up needing to be relocated to account for what appears to be "more" bass now with the Mk4. But back to back changes are making me question exactly what there is more of and my environment is difficult to really test correctly in - needless to say there is some subtle difference i can hear, but whether the proac's are now showing up a flaw in their bass handling or there's just a lack of synergy I need to find out.
Thanks for the additional discussion on this, it's helpful to get more information and i am looking forward to others who get the amp to provide real world experience i can learn from. The agent here also noted that this unit has pretty much the same "signature" changes I've seen announced for the North America model. I cant confirm that, and have no plan to open up and its probably far beyond anything I can detect or would notice a difference from anyway.

Perspex was a suggestion that occurred to a number of end-users simultaneously. It isn’t dogma. It was a suggestion. Nothing more than that.

If glass could be bent into the appropriate shape at a reasonable price then no doubt the end-users would have gone for that. You don’t like Perspex? Well fine. The point is though that microphony is not an imagined event. However it is certainly true that not everyone can hear the effect. It’s a question of choice as to what to do about it.

Mind you, to ability to hear the effect is somewhat dependent on the process involved. If for example you take a unit (not necessarily LFD) and play it in the system with its resonant top case attached, and then at the identical volume without the case attached, a slight difference may be perceived. Fair enough.

However in my experience, listeners are more likely to hear the effect when the process is reversed. By this I mean the system is played without the case and then with the case. The latter is more time consuming though.

In each instance, for the effect to be heard, the case must be screwed tight to the chassis. No easy matter with LFD as the deliberately soft-head Allen screws used are not happy about being removed and replaced frequently. Frankly, I do not advise it.

For those that can hear it, and don’t like it, a solution to microphony is desirable. Battleship-type construction is one approach, applying semi-inert sticky panels is another and safety issues not withstanding, removing a top cover (most certainly not endorsed by me as a retailer nor LFD as the maker) is another. That’s the reality. The end-user has a choice. Unlike a number of other UK audiophile makers, LFD recognise that their end-users are adults and, in the main, readily able to think for themselves. Over here in the UK, that’s an approach which is as refreshing as it is rare.

Thank you

HP
Stereonow Ltd