I think I've made up my mind


After having auditioned the following :

1. Avantgarde Uno G2 + Audio Note SET amp/Pathos Twin Towers integrated amp
2. Magico V2 + Soulution 720 pre + 710 power amps
3. Sonus Faber Elipsa/Wilson Sasha + ARC Ref 3 + Ref 110
4. Thiel CS3.7 + Parasound JC1 pre + JC2 power amps

...and after weighing all factors like room interaction, degree of difficulty of setting-up, value for money, magazine reviews, and comments posted here and AVguide.com....

...the winner is: Thiel CS3.7 + Parasound JC1/JC2!

Now for the cables. MF and JA of Stereophile noted that the specs of Parasound show ultra-wide bandwidth and high-current capability which reminds me of Spectral amps. Therefore, would MIT Magnum MA speaker cables and interconnects be a good match? Anyone has any other suggestion? Thanks.
jtein

Showing 7 responses by ack

Rrog said: > How many of you believed Spectral when they said their amps would go into oscillation if you didn't use MIT speaker cable?

I did and do, and it's easy to demo - they run considerably hotter w/o MIT cables. That's because - if you cared to look into it - the amps offer no input choke or output coil, leaving those functions to the cables, and therefore the MIT/Spectral cables are specifically and specially spec'd.

What's your point?
Rrog: > So, they tell you to use MIT or it will void your warranty.

Nonsense. I suggest you start by understanding SS amplifier designs, especially those with extremely wide bandwidth and no chokes, then you will perhaps understand that the MIT/Spectral cables limit that bandwidth to something manageable in the range of 800kHz, that keeps the transistors within acceptable operational thermal limits.

The amps will not die immediately without the MIT/Spectral cables, but long term they will cease to operate - has happened way too many times to those that think they know better.
Rrog: > My point is; what's at the end of the speaker cable?

The missing output inductor, with a value that compensates precisely the length of the cable purchased that carries its own RLC characteristic values. In the end, they limit the bandwidth of the amplifier to 800kHz (-3dB) and they optimize all electrical characteristics from the input cables to the tip of the speaker cables.
Rrog: > Spectral could have easily incorporated bandwidth limiting in their amplifiers and allowed the use of other cables.

NO. Per my previous response, the inductor in the cable box optimizes the electrical RLC characteristics of the LENGTH PURCHASED. No fixed inductor in the amplifier would ever achieve perfect matching with any but one cable of a one particular length.

They like to optimize the entire chain, it's as simple as that. Same goes for the interconnects. If you don't like, don't buy their products.

Rrog: > This is an example of where highend audio has gone wrong.

I think this is where your analysis falls flat.
Rrog: I and others care about an optimized set up. It's that simple. Lots of other people want to play with cables and tweak the sound to their liking and/or add or subtract "things" to the sound for better match in their systems - that's a valid approach AS WELL (but not necessarily optimal). They may even get "better" results. None of this implies that what Spectral is doing is wrong or not based on solid engineering principles - it's just not to some people's tastes and goals. I personally have no qualms about the performance of the top MIT/Spectral cables, and am glad I don't have to overspend on cables. In fact, I have compared them to higher-priced MIT cables and still find them superior (that could also mean that MIT is generally producing colored cables, and I am a strong believer of that).

Advantages over other amplifiers? I haven't analyzed other amplifier designs, other than to observe that other edge of the art SS gear, like the Soulution, are also wide bandwidth designs - wide bandwidth achieves (or aims to achieve) extremely fast circuits, which theoretically follow the signal more closely - the sound Spectrals and Soulution achieve is probably testament to that. I don't know if these other amplifiers filter the output inside the amplifier or not (and an output coil is very easy to spot but I have not seen close-up pictures of the units), but I have also observed they include ventilation fans, so there is a possibility they don't filter but achieve optimal thermal operation by blowing air in and out of the unit, which would let one play with cables - that's fine too.

Another edge of the art vendor, FM Acoustics, also believes in fine-tuned amplifier/speaker interfaces. You should read http://www.fmacoustics.com/pdf/audiophilpoweramp.pdf and take notice of a couple of claims:

1) "One of the most important characteristics that determines the quality of the entire system is the interface between amplifier and speaker."
2) "In amplifier-speaker interfacing a variety of criteria have to be observed, and the ideal cable has an optimal mix of these criteria."
3) "The criteria that has the most significant influence on the transmission quality of cable - the transfer characteristics - is often neglected for some other - often visual - aspect."
4) "As no wide-band width cable of this calibre is available as standard, engineers at FM ACOUSTICS in co-operation with the world's leading experts on cable technology have designed a unique cable that features a variety of proprietary characteristics. FOORCELINES guarantee optimal signal transfer, truly highest damping
and perfect control of the speakers."

So there you have it - another manufacturer that uses specific, optimized cables for their needs.

The bottom line is that what Spectral, FMA and others are doing is nothing but *optimal implementation of transmission line theory*. To everyone else, it's just a cable that can act as a tweak. Personally, I have been sold on wide bandwidth designs and transmission line theory decades ago.

You may still think Spectrals are not worth the trouble - and that's fine with everyone. I am surprised, though, that you brought up the cables as being the limiting factor and not the requirement for their preamps (and a lot of that has to do with stability into the MHz, proper output impedance and ample amperage to drive the amps), except for the inferior "S" versions of the amps...
Every manufacturer of electronics worth their salt should have optimally tuned their products with a single kind of cable (or a range of cables that are extremely similar to each other), and they should be able to tell you which one. I have no experience with tubes and extremely little with Transparent - I used to run a McCormack DNA-1 with some $800 Transparent speaker cable over 15 years ago, but honestly I did not like the construction inside that box (looked very sloppy). Basically, I can speak with confidence with products I have used since then.
Yes indeed you don't have to experiment with cables - it's done for you. What do you think we as consumers are doing by experimenting with cables? We try to find synergy. Well, synergy is also an electrical engineering science that can be calculated. It's that simple.