Rolling P-Mounts...Again (another Hecksperiment)

Lazarus Short

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#1
With the bi-amping squared away, I decided to improve LP playback. I piled onto the top shelf of the Sanus rack, the usual slab of plex, and on that, three layers of MDF about the same size as the plex, and finished with black vinyl. Extra mass never hurts.

Then I tried the Arcam amp as a phono preamp, having used it that way before, but there was a ground loop, so I decided to try the Luxman instead. It did very well, showing off each cartridge in turn.

I started with what had been on the Sony for a long time, a Realistic RXT5, with a Shure N95E stylus of which I had picked up two at a pawn shop in Hobbs, New Mexico. I decided it sounded dull, so I went to my box of cartridges.

I tried an AT VS245LP with high hopes. It was just about as dull as the Realistic/Shure. Rats.

Next was the AT 6006, and that did sound better - almost, but just short of great.

Finally, I tried the Shure M110HE (with a Jico stylus) - the one the Sony came with. Now that sounded great! I started off with Mission Mountain Wood Band, and that was OK, but the LP is not quite pristine. Then, my demo copy of White Mansions, and that was just wonderful, maybe because the cart was limbered up by then, or the LP is in better shape than the MMWB LP. I think I'm going to be running this cart for a long time to come.


 

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stuwee

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#2
Hey Laz, I'm not familiar with your TT, do you adjust for the different carts on the arm? P-Mounts seem like plug and play, one reason I never cared for linear tracking tone arms, you can't dial them in. No offence meant buddy, sounds like you found the right match.

Can you upgrade the stylus when needed?
 

Lazarus Short

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Stuwee, it's just like rolling tubes, and you don't need to wait for them to cool, either. I can adjust the VTF, but the "dialing in" should be part of the design - you just have to know that not all P-Mounts are made to the exact T4P standard. I'm too old to be OCD-ing around with standard-mount carts... [Obsessive Compulsive Details]:angry5::angry5::angry5::angry5::angry5::angry5::angry5::angry5::angry5::angry5::angry5::angry5:

The best part - the LP sounds THE SAME all the way across - no inner groove distortion. BTW, there are several linear-trackers with standard-mount headshells, for dialing-in purposes.
 
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JustMike

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#5
Looking at the turntable from the front, the groove closer to the center is the inner groove.
That would be the left channel. The groove closer to the edge is the outer groove right channel.


Check my Edit, This might help as Confucius say "a picture is worth a thousand words"

http://www.vinylrecorder.com/stereo.html
 
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Lazarus Short

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Mike, are you pulling Lee's leg? I ALWAYS believed the groove (that's singular) carried both channels...
 

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The normal commercial disc is engraved with two sound-bearing concentric spiral grooves, one on each side, running from the outside edge towards the center. The last part of the spiral meets an earlier part to form a circle. The sound is encoded by fine variations in the edges of the groove that cause a stylus (needle) placed in it to vibrate at acoustic frequencies when the disc is rotated at the correct speed. Generally, the outer and inner parts of the groove bear no intended sound (an exception is Split Enz's Mental Notes).
 

JustMike

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Stuwee, it's just like rolling tubes, and you don't need to wait for them to cool, either. I can adjust the VTF, but the "dialing in" should be part of the design - you just have to know that not all P-Mounts are made to the exact T4P standard. I'm too old to be OCD-ing around with standard-mount carts... [Obsessive Compulsive Details]:angry5::angry5::angry5::angry5::angry5::angry5::angry5::angry5::angry5::angry5::angry5::angry5:

The best part - the LP sounds THE SAME all the way across - no inner groove distortion. BTW, there are several linear-trackers with standard-mount headshells, for dialing-in purposes.
I have always liked linear trackers. My first was a AR XA with a Rabco Sl-8E linear arm. The Rabco co. sold out to HK and they put out
a few with a cheaper Rabco design than the SL-8E. I think the market went nuts with Linears after that. A few great ones and a bunch
of mid fi ones.
I'm using a Phase Linear Linear now and it has every adjustment needed to dial it in. Awesome table but takes patience to get it right.

Glad to see Laz you are getting into Bi-amping. I would like to see your next move into Active crossovers. I think you are getting the
feel on how much dynamics and sound stage change for the better.
 
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Lazarus Short

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#10
I have always liked linear trackers. My first was a AR XA with a Rabco Sl-8E linear arm. The Rabco co. sold out to HK and they put out
a few with a cheeper Rabco design the the SL-8E. I think the market went nuts with Linears after that. A few great ones and a bunch
of mid fi ones.
I'm using a Phase Linear Linear now and it has every adjustment needed to dial it in. Awesome table but takes patience to get it right.

Glad to see Laz you are getting into Bi-amping. I would like to see your next move into Active crossovers. I think you are getting the
feel on how much dynamics and sound stage change for the better.
Some years ago I had one of those HK/Rabco units. It needed fiddling-with all the time, and I got rid of it. I don't see the turntable as being so important anymore, as it simply spins the LP and holds the all-important transducer - the phono cartridge.
 

Lazarus Short

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#11
I bought one of those cheap digital scales from Harbor Freight last night. It was too thick to fit between the top of the plinth and the arm/stylus, so I was set to return it. Barb suggested that I try taking the platter off, so I did that...almost...shaved the feet off the scale and removed the battery hatch for good measure...it barely fit. Reads at 1.4 grams, but I need to calibrate it to be sure.

Then, I looked at the bottom of the platter. It was diecast, and very light, but the fellow who sold it to me at Twangfest for $75 (and that was with a JICO stylus!) told me he had dampened it. Nicely done!
 

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laatsch55

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#12
Yes, it was, to not crease the foil anymore than he did , that took some doing...
 

orange

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#13
Mike, are you pulling Lee's leg? I ALWAYS believed the groove (that's singular) carried both channels...
It does...they are cut at about 45 degree angles and the cartridge receives the information at the left and right coils which are sent to the phono preamplifier along the way. There was a two groove system but the one we have now is basically a version of stuff Bell Laboratories was working on 80-85 years ago.

And it was Stokowski conducting IIRC, so it was really decent crap. I have an LP of some of those recordings I got sealed on eBay, it's from 1977?

A mono cartridge only sees one aspect (I think there are also hill and dale movements in a stereo groove that it can't sense, in effect a kind of matrix)...I don't think about it a lot, I just play the records.
 
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