Hi Gents,
Today I went over to my friends with the new cables and installed them into his system. I was very methodical and triple checked each connection before powering anything up. Looking around the rear of the components I noticed some of the other cables are simple RCA types (with no Boxes), so I dutifully pointed them out.
During one of my triple checks (the last one) I pointed out his Maxx speakers were connected to the 8 ohm output of the Audio Research Reference 600 Amplifiers. (He had swapped out the MIT Speaker Cables for a "standard" pair without boxes.) I advised I thought based on the Stereophile Magazine review (see links above) that these should be on the 4 Ohm connectors. He said the Distributor (Sound Room) and the Wilson Techs all knew and approved of this connection when installed. He wanted to light them up. So as a compromise I said, let's keep the volume low until we get confirmation from Wilson and Audio Research.
We warmed up the Amps & Pre-Amps for over half an hour before trying to amplify a signal. While waiting I took a photo of the Specifications Page for the Wilson Maxx Speakers while reviewing his hard copies of the manuals.
Initially he played a record on the turntable but we got no sound when "Phono" was selected on the Audio Research Reference 1 Pre-Amplifier. So after checking a lot of connections, I put a CD into the Mark Levinson No.31 Reference CD transport, changed the selector (after ramping down the Gain, putting the system in mute) then ramping up and we got sound. (Tube systems require such a ritual every time you change sources.) So then I went looking in more depth at the Phono connections but still found nothing. Then my friend started rotating the selector knob on the Reference 1 Pre-Amp, and when he stopped on Aux 1 there was the sound from the turntable. So I checked where the Audio Research Reference Phono Preamplifier was connected to the Reference 1 Pre-Amp; and yes someone had the RCA inputs going there. Yes there is a large
separate Phono Preamplifier. There's separate boxes for almost everything. ( 3 separate components for the Mark Levinson CD equipment too!)
I was surprised at the Aux 1 connection, and it took me a while to come up with a theory. I suspected someone didn't want to input the output from the Phono Preamp into the Phono input of the Reference 1 Pre-Amp; as it would be injecting a "line" signal into an input expecting the unamplified low level signal from a phono cartridge. Well that sounded rational to me (at least at the time) as every preamp with a manufacture date since the late 60's I'd seen with a Phono input, had a built in RIAA preamplifier circuit to boost the signal enough before pushing it onto the preamp stage. This is an expensive Tube based system, and my experience is almost exclusively solid state, but I thought the basics should hold. So as we had success, I left it and researched it tonight.
I actually got all the manuals from
Audio Research Manuals whereas there were not there previously. They were actually the same as I had found years earlier by scouring the web, but they were far better resolution that those scanned copies. The Reference 1 Pre-Amp manual is very poorly written (especially for something from the USA) and only infers that there is no RIAA preamplifier circuit. On page 4 it mentions a Gain Increase for the outputs and explains it with "This allows greater reserve gain for low-gain phono preamplifiers with low-output moving-coil cartridges." So from that I assume you can (and probably should so folks who operate it aren't confused) move the connection to Phono on the Reference 1 Pre-Amp. (My friend had tape labels on the cables designating they go to Aux 1 but no memory as to why.)
So I'm looking for input. Does my logic sound reasonable? Do you see any downside?
Other than that glitch, everything went fine. The system sounded amazing. Even though my friend is a vinyl fan, I played CDs instead as he had some more to my tastes, and there is less ritual changing them versus records. My friend (and his wife) were very pleased and appreciated it working so much. They were saying it had not run in about 10 years! (I can't believe it's been that long since I heard it. But as they say -time flies. They could be right.) My friend did turn it up quite loud but it was only drawing about 5 watts average on the meters.
Just before I left he called the previous owner of the Sound Room while I was there, who gave him the name & cell number of the new local Wilson distributor. The old owner of the Sound Room insisted the 8 ohm connection was correct. The new Wilson Rep said the Wilson Speakers were 4 Ohm, “but we always connect them to the 8 ohm output on those ARs”.
I had left my Friend after discussing again my concerns about connecting his Maxx speakers to the 8 ohm outputs.
My biggest surprise was when I got home and after dinner was reviewing the photo of the Spec Sheet. I was surprised that there was no Nominal Impedance in the specifications. (Even really crappy speakers make up something.) Then I noticed right at the bottom of the sheet it said Wilson Audio- X-1 Grand Slamm (and
not Wilson Maxx).
OMG ! That’s a huge difference. Check out page 45 =>
Wilson X-1 Grand Slamm
Check out
Stereophiles Review Here
By the way, Stereophile Magazine in 1995 (the year of release - my friend bought his in 1999) had awarded the
Product of the Year to the Wilson Audio Specialties X-1/Grand SLAMM loudspeaker as well as their
Loudspeaker of the Year & Editor's Choice Awards.
They measure / define the Nominal Impedance as 5 ohms. I never found it in the manual. They go on to say:
“In the event, the Wilson presents a relatively easy load to an amplifier (fig.6). It's not quite classifiable as an "8 ohm" loudspeaker, which is defined as having a minimum magnitude of 6.4 ohms, though it comes close. For example, in music's main power band (120Hz-10kHz), the loading does not fall below 6 ohms, and averages 7.3 ohms. The magnitude does drop from 5 ohms at 15kHz to 3.2 ohms at 20kHz, which will give rise to some "dulling" of the treble balance both with SE-type amplifiers and with others featuring a higher-than-usual output impedance (1-3 ohms, say). Conversely, the X-1's commendably uniform mid-band impedance means that it will remain neutrally balanced with many tube power amplifiers.”
Needless to say, I'm a bit more comfortable with these connected to the 8 ohm outputs.
They look like these but have Spikes and not casters!
