SPL Phonos Phono Preamp

I just listened to this amp at the Singapore AV show and thought it really kicks ass man. Managed to get the exhibitor to play a Metallica 12" single. Rockers will love this phono amp! 

audiofun, Back in January of this year, you responded to my question about the fuse upgrade by this statement: "If you can’t hear the difference a better circuit conduit makes while carrying the entire electrical signal then by all means keep the stock fuse."  First, while I am always a sceptic of any tweak that has no science behind it, only subjective impressions, I do concede that some such tweaks sometimes do leave me with a favorable opinion.  And I am a believer in power cords, although my thoughts there are that current-carrying capacity (should be in excess of the current demanded) and characteristic impedance (should be as low as possible and depends upon topology of the conductors in the cord) are what's needed, regardless of cost.  So, I am not dead set against or for anything. 


Second, the fuse does not by any means carry the "entire electrical signal".  A fuse must pass the voltage (120V in the US) and the current to the power transformer, so IT can do the job of delivering unrectified AC of a specified AC voltage to the rectifiers/inductors/capacitors that do produce DC from AC.  The DC thus produced provides the "ride" for the AC signal voltage output.  So a fuse is very far away from that vital pathway.  I went to the website and read the specs for the SPL.  It might be wonderful sounding, but there is nothing in its specifications that gives any hint as to why that would be so.  The description of the power supply suggests it's fairly pedestrian.  But by no means do I pass judgement on the quality of the end result; it may be as excellent as you say.

Lewm:

Hi, in retrospect and after rereading my response, I find that I was unduly curt in my response, for that I apologize.

Now to your points :) in fact the fuse in this case absolutely does carry the entire electrical signal as it is in “direct” series with the power line into the unit. This is not a case of a fuse somewhere upstream of the transformer/diodes/filters (pi filters, etc). Remove the fuse, and no power is delivered to any part of the device, i.e. open circuit.
Remeber that the audio signal is nothing more than modulated DC, which was derived from the rectification of the transformer AC output. This is why a fuse does actually have a sound. Everything matters in a highly resolving system.

Now as to why it sounds so good. I believe part of it comes from the 120v rail design used by SPL and the proprietary discreet opAmp technology. The other part is most likely due to the Douglas Self styled RIAA filtration. I am a big proponent of Douglas Self and regularly refer to his book The Design of Active Crossovers (ISBN-13: 978-1138733039).

I am not saying this is the best phono stage I’ve ever heard but it is among them. Does it bloom like my Luxman EQ500? No, but the dynamics! The timing and clarity are just simply top notch.

audiofun, It is I who owe you an apology for being a bit snotty in my initial post.  We can agree to disagree on whether or not AC from the wall socket carries the "entire electrical signal", but I do disagree with you.  You use the word "signal"; the AC from the wall has not one iota of audio signal on it.  It's just the raw material, if you will, from which the AC signal is derived.  I said why I disagree, also, in my earlier snotty post.  The AC goes through a power transformer, rectifier diodes, filtering in the form of capacitors, resistors, and/or inductors, just to produce DC, which STILL bears no audio signal.  The DC runs transistors or tubes to amplify or pass the audio signal coming from an upstream source to some downstream source.  Where in this process does the fuse pass the audio signal?  There's no need to respond, because we are just at odds on this. 

A fuse is a piece of wire designed to burn up when a certain amount of current passes through it for too long a time.  That's ALL it does and all it should ever do.  The only way that I see for a fuse to affect sonics would be if its inherent resistance is great enough to retard the current demands of the component in which it is installed. So, I could be made to imagine that a fuse that displays very low resistance when in operation at tolerable current levels would be preferred over one that exhibits higher resistance at that very same current draw.  Yet I have never seen any of the boutique fuse marketeers touting their products on this basis.  Most seem to prefer an allusion to Quantum Mechanics. Further, the conductivity of different metals is not a scientific mystery. I would have thought that the major manufacturers of fuses have known for a long time what metals exhibit properties (low resistance, high temperature coefficient, etc) that are favorable to optimize fuse performance. Likewise, directionality can only come into play if in the process of reversing the fuse in its holder, you do something to lower the resistance at the interfaces between fuse and holder, either deliberately or accidentally.  Finally, what is the rationale for expensive fuses that are only going to be used in the typical crappy fuseholder?  Shouldn't a fuseholder affect sound, as well?

As to why the SPL Phonos sounds so good, I have no dog in that fight.  As noted, I have never heard it.

Lewm:

We are cool :)
When I used the word signal, perhaps not the best choice, I was referring to the 60hz sinusoidal from the wall.

I understand your point to a degree. Think of it like an auto engines fuel line. All the processing is done in the engine but if I have an inferior fuel line it will directly affect my engines performance. The fuse is a DIRECT corollary to the fuel line. Just like inferior metals (elementally contaminated copper for example) in a power cord will affect the sound, the wire and in fact the material of the end caps of a fuse and its resonance properties will affect the sound. It is the same reason that different power cords absolutely have an effect on my PS Audio Power Regenerators.

The Quantum argument is marketing crap and we certainly are not dealing with quarter wavelength theory or the like.

The entire power source first must go through the fuse, the choke-point. Remove the fuse, no power...