Thursday, March 22, 2018

Linn Sondek LP12

Thanks to the very nice Mark of Austin Hifi, the Linn specialist (but no longer a Linn dealer) who originally sold it to me in the first place in 1998, my Linn Sondek LP12 Valhalla is now fully operational again with a brand new Dynavector 17D3 cartridge (my house standard) mounted and playing beautifully in my living room.  Mark himself repaired my Valhalla board, replacing capacitors, installed my new cartridge, and set the turntable up in my living room, all for a very reasonable charge.

Immediately I enjoyed it more than my Mitsubishi LT-30.

Thinking "the pitch is now more stable" I went back to the problem record, Dance of the Universe with Peter Sprague, which was the very first LP I played on the Mitsubishi and led me to worry about the speed constancy of that turntable.  (The Mitsubishi was greatly improved after that by damping and mass loading the tonearm, counteracting the arm-cartridge resonance which was the key issue causing the underwatery sound with this record, but perhaps not the only issue.)

On the Linn, the pitch of most of the band seemed perfect, with the exception of the greatly out-of-tune (to my ears) bass line, which is exactly the way I remembered the band in a live concert around 1981.  This contrasted greatly with my first playing on the Mitsubishi, in which the out-of-tuneness of the bass seemed to permeate the entire band, making it sound underwater.  The Mitsubishi has gotten better than that now, though from memory (I didn't do an A/B test) I think the Linn is still better.

I shouldn't be asking this question, but here I am.  What is the next thing to upgrade???

According to Linn, and many Linnies, the best thing to upgrade is the bearing, which should be upgraded to the Cirkus bearing (which requires a bunch of other parts in the Cirkus upgrade kit).

That rubs me a bit the wrong way, and did in the 1980's when this upgrade first came out.  The Linn was supposed to have this super superior "mirror polished" bearing in the first place.  IMO still the turntable design has many other faults, why upgrade the best part of it first???

IIRC, it was the bearing that was most bragged about in the mid 1970's.  For a considerably lower price than the Linn Sondek, one could buy the Ariston, which seemed pretty similar, but lacked the highly praised Linn bearing.

Apparently that exclusive bearing wasn't so fine after all.  In this Linn authorized blog, it is explained how the Cirkus bearing was required before the subchassis could be beefed up as most peopled claimed to want.  The original Sondek subchassis was deliberately designed to be lossy, a "mechanical filter" of sorts, to absorb the fault (very low frequency vibration?) of the original bearing.  It is claimed that when people beefed up the subchassis with the old bearing, the sound simply got worse.

(Maybe this was it.  It wasn't so much the Linn had a better bearing, as that the Linn had the deliberately lossy subchassis to absorb bearing noise.  In fact, I do remember that the Ariston subchassis was more substantial than the Linn subchassis, and at the time I wondered why the more expensive and highly touted table came with such a flimsy subchassis when the cheaper unit had a more substantial one.)

Nowadays the Cirkus upgrade kit does not include the required less-lossy subchassis because there are even better less-lossy subchassis models available (Kore and Keel) which the Linnie might choose to upgrade to, or they can get a traded-in subchassis from the Linn dealer (who has been collecting them from those who do upgrade to Kore and Keel).  I might also note that Cirkus-suitable subchassis are also available on eBay at prices less than the difference between the original Cirkus kit and the later one.

Personally, the thing that bugs me the most, is the ridiculous belt repositioning required to play 45 RPM records, many of which are my favorites.   I have always refused to do that.  But this problem is not so easily or inexpensively fixed, Especially if you already have the Valhalla board, and a 60 Hz motor.

Here's a discussion about the origins of the Linn Sondek LP12.

Linn disputes this sort of story, saying instead that the Ariston RD11 was an OEM turntable that Hamish Robertson "ordered."  They have tried to correct the story at Wikipedia, though it seems about the same now.

A friend of mine insists the design of the AR turntable, in 1960, was better.  But they were not made for universal arm mounting, and the arm of the AR turntable was far inferior to my Ittok LVII.

Here is the list of lists of Linn upgrades and serial numbers.

In my initial test of using clamp, it does change the sound to blacker and better imaging, which I think is good.  It may however sour the intonation slightly.  I think the felt mat performs both damping (on either side, platter and vinyl, separately) and also isolation, and compressing it with clamp reduces the beneficial isolation from platter ringing.

Because of the suspension, it is a big pain to clamp correctly.  The record must be turned when you are clamping to be sure that the clamping is good all around at the periphery.  At each spot you then must press the platter down to the top of the plinth.  I'm not sure if this is safe (though I think it is), but it is awful and time consuming.

Clearly, however, the Ittok arm speaks louder than the surface of vinyl.  I think in my system it is the arm which requires damping more than the vinyl.  The felt does a pretty good job at damping the vinyl without a clamp, and because of the difficulty of clamping, I'm inclined to leave that alone and focus on modifying the tonearm.

Is the name "Ittok" mean something like "I talk" meaning it's an undamped and therefore somewhat "loud" tonearm???

It seems excellent quality, but I think it NEEDS damping, contra Linn and Rega myths about damping being bad.

Here's a discussion of one company's modified Ittok, along with a discussion of the different Ittok versions.



Friday, March 16, 2018

Update on the Godar FM DXR 1000 antenna

Extended full length, the antenna has a high SWR at FM radio frequencies.  The manufacturer recommends extending full length for AM and TV frequencies, this has the effect of suppressing FM broadcast stations, which is useful because they are quite strong and can interfere with AM and TV.

The manufacturer suggests reducing length by 5 inches for FM if it needs it.  This creates excellent SWR at FM broadcast frequencies, so I'd suggest always doing this for FM.  I measured the precise length of the second section required for best FM performance: 3 inches.  All other sections are fully extended.

I couldn't see any effect of this change above 120 Mhz, so I left it that way--optimized for FM, though I "intend" to use this antenna for a 140 + 880 Mhz scanner, it might also serve as an extra FM antenna.