The ADC P-Mount That Wanted to be Real

We could also title this thread "The Lost ADC P-Mount".


For a few years now we've been seeing NOS ADC styli with the XT prefix. Until recently, you could even get an XT version of the famous ZLM stylus for far less money than a 'real' ZLM stylus.

But where were the XT bodies? And what had ADC intended the XTs to be? In a casual conversation with one of our better-known online retailers, I was told the XTs were ADC's first p-mounts, and was shown a drawing of one taken from a 1980 Pfanstiehl catalog [center image above]. This immediately became a mystery, since I'd never seen such a thing.

Like many of you, I'd heard of and actually owned the ADC-branded Japanese-made p-mount cartridges, the PSXs and SERs...

...and they have been indisputably good cartridges, but they were not designed by ADC and thus not physically compatible with any previous ADC models. I couldn't, for example, use them to play my QLM 36 Mk III Improved stylus in any of my p-mount tables. And I so desperately wanted to! Because geekiness, don't you know.

On eBay, faked versions of this alleged p-mount showed up, making me think the XT cartridges were vaporware, or worse, rumorware. I'd begun to believe that ADC had intended to make this line, but, since time was running out, abandoned the idea at the last minute and went with the PSX/SER lines. But then..


This all changed when a bunch of XT-II cartridges in legit-looking packaging showed up on eBay. There was an additional shock: the packaging said Integra XT. We know the ADC Integras to be well-designed integrated headshell-cartridge combos with slightly eccentric electrical specs. There are even Integra pre-mounts. But what was "integrated" about a p-mount cartridge?

I still don't know the precise answer to that question, but I finally know that the Integra XTs are both indisputably real p-mounts (mine weigh 5.95g) and real Integras, at least electrically, namely wrt inductance and resistance-- 480mH and 760 ohms. Checking the US audio magazines, they emerged from the void in the fall of 1982 without fanfare and were gone only a year later, replaced by the PSX/SER line.

The XT Integra bodies and styli are close enough electrically and VTFwise to the final-generation XLM/VLM/ZLM/QLM36 (including the XLM Mk II Improved) for their styli to be interchangeable. They're also close enough to be interchangeable with the better previous-gen (Mk II, not-Improved) styli, not to mention the better regular Integra styli (RXM-II and III) and Series styli (RS-III and IV). The VLM Mk II is the only exception, and it's a near miss, so stick a ~0.25g weight to the top of the cartridge and you're good.

Now, finally, I can use any of those styli in my p-mount tables, where the lower-mass arms, especially in the close-n-plays, are friendly to high compliance.

Styli: XT-I is a bushed 0.7 mil conical; XT-II is a nude round-spike 3x7 elliptical on a straight canti; XT-III is a nude 2x7 'tombstone' on a tapered canti, and XT-IV is an "Aliptic" version of the XT-III. Since these are T4P styli, VTF is nominally 1.25g. Makes stylus-swapping a snap.

Found! The long lost ADC Pinocchio!

Cool! Another reason for me to keep looking fro a good P-mount table to play with.

John

wualta said:

For a few years now we've been seeing NOS ADC styli with the XT prefix. Until recently, you could even get an XT version of the famous ZLM stylus for far less money than a 'real' ZLM stylus.

But where were the XT bodies? In a casual ADC conversation with one of our better-known online retailers, I was told the XTs were ADC's first p-mounts, and was shown a drawing of one taken from a 1980 Pfanstiehl catalog. This immediately became a mystery, since I'd never even heard of them.

Like most of you, I'd heard of the ADC-rebranded Japanese-made p-mount cartridges, the PSXs and SERs , and I already had a few of those, and they were obviously good cartridges, but, equally obviously, they were not made by ADC and not physically compatible with any previous ADC models. I couldn't, for example, use my QLM 36 Mk III Improved stylus in any of my p-mount tables. And I so desperately wanted to!

On eBay, faked versions of this alleged p-mount showed up, making me think the XT cartridges were vaporware, or worse, rumorware. I'd begun to believe that ADC had intended to make this line, but since time was running out, abandoned the idea at the last minute and went with the PSX/SER lines.

This all changed when a bunch of XT-II cartridges and their legit-looking packaging showed up on eBay. There was an additional shock: the packaging said Integra XT. We know the ADC Integras as being well-designed integrated headshell-cartridge combos with slightly eccentric electrical specs. There are even Integra pre-mounts. But what was Integrated about a p-mount cartridge? Nothing, as far as I could tell, so why call it Integra?

I still don't know the answer to that question, but I finally know that the Integra XTs are both indisputably real p-mounts (mine weighs 5.95g) and real Integras, at least electrically (ie, wrt inductance and resistance-- 480mH and 760 ohms).

The Integras and the last-gen (ie, Mk III) XLM/VLM/ZLM/QLM36 are close enough electrically for the styli to be interchangeable. They're also close enough to be interchangeable with the previous-gen (Mk II not-Improved) styli.

And now, finally, I can use any of those styli in my p-mount tables, as long as they can track safely at 1.25g VTF.

Styli: XT-I is a bushed conical that tracks a tad high at 1.5g; XT-II is a diasa-mount 3x7 on a straight canti; XT-III is a nude 'tombstone' on a tapered canti, and XT-IV is an "Aliptic" version of the XT-III. As of this writing, there's still an XT-II and a III on eBay, and for conical fans, the XT-I is still in stock at tVOM.

Click to expand...

Yep. You got my attention..... :yes:

Yes, it's The Velveteen (or Pinocchio) ADC P-Mount.

One AKer in particular was burned by one of the fakes but did manage to avenge himself by getting a genuine one. I hope he sees this thread and throws his story into the communal pile of ADC p-mount mythos.

wualta said:

Yes, it's The Velveteen ADC P-Mount.

One AKer in particular was burned by one of the fakes but did manage to avenge himself by getting a genuine one. I hope he sees this thread and throws his story into the communal pile of ADC p-mount mythos.

Click to expand...

I'm real, curious as to how this sounds. I have a PSX-40 (OK, a 30 with the 40 styli) which sounds beautiful except there isn't much bottom end to it. I'm really curious as to how this would stack up to it.

<been on a old stylus buying binge this week.... Shhhhhh..... Don't tell the wife!!!). I actually found a real Empire 875XLT stylus too! :yes:

Vinylmasters said:

I'm real, curious as to how this sounds.

Click to expand...

Like an Integra, I would imagine, with a similar stylus, of course.

In the case of Walt's XT-II, I'd think it sounds a lot like the original Integra with an RSX II (XLM-II) stylus.

This is not a bad way to sound.

John

VM: Don't worry, wives won't speak to us, so your secret is safe.

boreas said:

I'd think it sounds a lot like the original Integra with an RSX II (XLM-II) stylus.

Click to expand...

I agree. No different from the XLM Mk III in the proper body. If you like the final-gen XLMs, you'll like the XTs, preferably with an XT-III or IV stylus.

Interestingly, the user guide that came with the XT-II only has specs for the XT-I and XT-II. Does that mean the others were different? [UPDATE: Nope, just better specs.]

wualta said:

Wow! I think those are even harder to find than the Integra XT bodies. I'm very interested in how this sounds, or, rather, how well it tracks. The ellipticals can't track worth a darn, though they sound great.

And don't worry, wives won't speak to us, so your secret is safe.

Click to expand...

LOL! Good point on the wives!!

I am too. The only thing I could ever find for it was the generic 'blue' .03x.07 elliptical (and yes, it tracks horribly). The original was a 'red' line contact stylus and everything I ever read on it was that it was a top-shelf cartridge. The stylus wasn't cheap, so I REALLY hope it is anyway!

The specs on it:
http://www.vinylengine.com/cartridg...chi=&stid=&masslo=&masshi=&notes=&prlo=&prhi=

I've got two of these. One is a sloppy conversion of a standard mount ADC XT to p-mount, that came sealed in Rivertone packaging: http://www.audiokarma.org/forums/showthread.php?t=384624. IIRC, I cleaned up the ugly melted plastic where the cover meets the base, and then properly glued the cover on, but it has always been more than a gram under the T4P standard mass.

The other came to me used via Ebay, with a blue Radio Shack/ADC co-branded stylus that does not seem to be original. The cartridge seems to be authentic, but the provenance is quite murky, including the original model number.

I'll post more later when i get back home, as both cartridges are there. I need to get them back out and compare the two.

Here are the two cartridges. On the left is the Rivertone converted cartridge. With the XT-I stylus that came with it, it weights 4.9 grams. There's more photos of it in the packaging at the link in my previous post. I ended up using some superglue to attach the cover onto the cartridge. Without adding some mass on the cartridge (such as blue tack) it us not usable on my Technics SL-M3.

On the right is the mystery p-mount cartridge, purchased on Ebay. It was sold with the Radio Shack branded stylus assembly sitting next to it, which I doubt is original. Along with the stylus that came with my Integra mk X (RXM-II?) I have been using on it, it weights 6.0 grams. As you can see, the fit and finish of this cartridge is much better than the Rivertone one.

[edit] I had always thought that the XT had been converted to p-mount by Rivertone, and not originally made by ADC as a p-mount cartridge, due to photos of 1/2 inch mount ADC XT cartridges like this one: http://www.vinylengine.com/cartridge_reviews.php?make=ADC&model=XT I. The text "Digital Series" across the top does make it look like one of ADC's later offerings.

Thanks for the writeup. It helps explain the dead ends and tortuous searching for clues that we sometimes go through to finally see what these manufacturers were up to 35 years ago and more.

You're right, the RK50E stylus is, best guess, a K5E stylus that was sold only with a standard-mount K body at Radio Shack. Same mishmash with the photo from the socalled Cartridge Database [Errorbase], which is why I don't trust its contents any farther than I can throw a cottonball. That's a "Mk III Improved" (ie, high inductance) body with an XT stylus stuck on it, probably because they couldn't find an XT body to put it in.

Add all this malarkey to the inaccurate drawing of the Integra XT cartridge-- not their fault-- in the Pfanstiehl catalog (Integra wasn't even mentioned), and there were plenty of design revisions, false leads, sheer WAGs and wrong assumptions. I still haven't seen a brochure or test report.

OK, so my assumption had been that Rivertone Stylus Co. had (poorly) converted an 1/2 inch mount XT cartridge into a p-mount cartridge. However, we now know that ADC themselves made p-mount cartridges with the XT model designation, and they were much better made than the my Rivertone cartridge.

Due to the differences between the genuine XT cartridges and this Rivertone cartridge, my new theory is that Rivertone took some other model of 1/2 inch ADC cartridge, sloppily converted it to p-mount, slapped an XT stylus on it, and then sold it as a "counterfeit" XT p-mount cartridge, packaged with a sticker that says "ORIGINAL". I cannot think of any other good explanation for how this cartridge came to be made and packaged as it came to me.

Anyone have any information on the history of the Rivertone Stylus Co.?

Unlikely though it may be, ADC could have accidentally shipped a pre-production prototype to Rivertone along with the actual production version.

But actually, I think it's somewhat less likely that Rivertone would go to the trouble of making up what was probably a small number of P-mount "plugs" and then disassembling some 1/2" mount ADCs, carefully unsoldering the coil wires and then attaching the P-mount parts.

John

Probably doesn't mean anything but Rivertone was located a little less than 100 miles from ADC.

John

Hmmm, prototype, now that's an idea I hadn't thought of. Really makes me wonder about the provenance of this ADC/Rivertone franken-p-mount.

Especially since it was the first XT cartridge I could find any mention of whatever! Threw me off the trail for quite awhile.

I set up a quickie comparison of the XT-II (NOS stylus) and the Japanese-built PSX-40 (NOS stylus), both at a VTF of 1.3g in the straight pivoted arm of a Hitachi HT-51 turntable using Yamaha HB4 p-mount headshells.

Both carts had slight trouble with the high-energy sibilants on side 1 of the Bangles album Different Light. No outright mistracking, just a few "sh" sounds that should have been "s" sounds, and not bad even then. How do I know they should have been "s" sounds? Because that's what they sound like when played by the Shure V15VMR, at 1g.

This is actually quite good performance. But this is also the best that the PSX/SER cartridge can do. ADC, however, made several styli more advanced than the XT-II. I pressed on a ZLM stylus and was actually surprised at the obviously better tracking and superior cleanliness of the treble. On a less-demanding disc, perhaps you could still hear the extra sweetness of the ZLM's top end, but the tracking differences would disappear.

Overall frequency response: almost the same. Bass was nearly the same as well, though my Hafler M5s are not designed to judge really low bass. Obviously, you'd want the XT over the PSX if you could find an XT. But the PSX-40 is, for the vast majority of records, Good Enough. My experience is the PSX-30, still available as NOS as of this writing, is not far behind.

Here's a photo of an XT with a top shelf stylus:

http://blog.goo.ne.jp/technics_sl10/e/02c163caebf63f56e22935145267bd61

I thought that stylus was an astrion. I have a nice astrion body as well as the original stylus assembly but it's missing the cantilever. I just wish those styluses weren't so expensive and hard to find. I've never heard mine with the correct stylus.

testing the 'XLM Mk JIII' against the XT-IV and a surprise contenda

You know how it is when you get a new toy. You play with it, then you think, "Say, I could try it with that thing over there. I wonder what that would sound like?"

So tonight, wanting to try more of my ADC styli using the XT body and a Yamaha T4P headshell in my Pioneer PL-7, I dug around in my Drawer O' Styli and found, to my surprise, a NOS Japanese-made XLM Mk III. I had never noticed it was made in Japan, and at the time I bought it, I wouldn't have known what that meant.

As far as I know, these were made toward the end of ADC's phonographic life, after manufacturing ADC styli and bodies in the US had become economically impractical. I hope one of our ADC historians drops by to fill in the picture.

The XLM Mk JIII (my nickname; I don't know if ADC ever differentiated or felt the need to) was a de-contented XLM Mk III Improved; certain Improvedments were removed. The flip-up stylus guard went away, so did the fiber-reinforced plastic grip, and so did the Omni-Pivot machined permalloy sleeve. Because of this, I'd been avoiding buying any Japanese-made XLM-style styli, because who knew what other corners had been cut?

But I looked at the cantilever, the part I was most worried about, and noticed it was very slim and nicely tapered, and wasn't shiny and cheap-looking. It looked very much like the cantilever of the stylus I was going to compare it to, the Integra XT-IV.

And if the JIII I have is any indication, my opinion is we have nothing to fear from the high-end Japanese-made styli (I don't know how the lesser models compare UPDATE: the base models were made very cheaply). Yes, the Aliptic stylus on the XT-IV acquitted itself very well, and gave a small but noticeable bonus of high-treble detail and smoothness, but the JIII wasn't far behind. They're obviously siblings. The overall sound was nearly identical. For this test, I was using the '80s Don Henley recording Building the Perfect Beast.

Just for fun, I pulled out the ADCs and plugged in a standard-mount headshell with my Piezo YM-308 II and its little yellow $15 aftermarket stylus. Why? Well, like the ADC, it's an induced magnet cartridge, but the Piezo's fixed magnet is huge, plus the geometry of the permalloy armature is different to the point of eccentricity. The main reason, though, is this stylus-cartridge combo produces one of the liveliest, rockenrolliest sounds in my collection. It's tons of fun per square inch [indentation factor joke]. The 4x7-diamond-equipped moving system tracks, by my tests, very well at 1.5g VTF.

As I expected, the sound was vivid, forceful, with good channel separation, but I could almost immediately hear why the ADC styli cost so much more-- though the Piezo with its aftermarket stylus was certainly clean-sounding and very "musical", and the soundstage was so nicely presented that Henley seemed to be wheezing (he doesn't actually sing) just beyond the wall behind the turntable and smack in the center, you could tell the cartridge was doing a lot of extra talking in between the notes, as if the cantilever was still vibrating after the note had passed.

Nothing unpleasant, but more unfocused, confused, unclear. No sign of mistracking, always "musical", great bass, just lacking something by comparison. I imagine this is the same difference people who've spent thousands of dollars for their cartridges might hear when those carts are compared to the much-cheaper MM cartridges they used to own.

The soundstage thrown by the ADC styli was, to my ears, just as wide and 3D as the Piezo's. The Piezo is still lots of fun, and when you consider the cost of the styli, and that they're still available at retail... but I'm not giving up my ADCs. Nice to know I can now use them in my MCS 6730 or my Technics SL-QL1.