Stealth Mk3 Unipivot

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Hi Folks
My latest 12" unipivot. I now have a design which I'm really pleased with and it works equally well in 9"/10.5" and 12" versions.
Regards
Chris
 

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thought I'd better "weigh in" here...

Speakerdork, stop that ;)

Chris : I'm going to be taking a real long look at a couple of details, to see if you got them right. I can guarantee you that there will be no one else more critical than I (as in a connoisseur's critique, not as a snob). As you know (as does Cal methinks and most anybody who reads more than a single post of mine) I never intend to be hurtful. My criticism is because I've learned an awful lot of in a relatively short time (an intense period of a couple of years, about 10 years ago) regarding tonearms and their design.

There are a couple of "secrets" I've kept close to my vest over the years because some have taken advantage of information I had provided based on the knowledge I gleaned making my own arms. Now I just state "do this", with no reasoning explained. Just do it, as the NIKE ad says...I am very particular about a few details that if are not adhered to, will not pass my scrutiny.

This is not to suggest that my way is the only way, just that my way has always resulted in great sounding tonearms. I can't say that I particularly like the idea of clones. That is the easy way. The closest I've come to cloning an arm is stating emphatically that the basis for what has become the "219" came from Charles Altmann and his "joke" tonearm. I just wanted to use easily available everyday items that offered superior performance to many commercial offerings. As you full well know the "219" refers to CAD $2.19 (at the time about a single quid in Britian-speak) which was what I figured I had into the original example.

Give me a few days and I'll tear it apart visually to see what I can see.
 
Stealth Tone arm

Hi Stew
Thanks for the response. As I said, I've been a bit quiet of late due to job demands and travel but I'm now back on track,
A few things to mention:

  • The shaft is still the Eastton alu arrow shaft. I've found nothing else as good! It is of course in one piece-no joins anywhere.
  • Headshell is actually hardwood with the pivot point directly above the stylus tip- the slot has been tried but is very fiddly to do.
  • Bearing-I've stopped using the ball point tip and now use a 2mm ball bearing in the set screw 'cup.' It locates very well and performs equally as well as the ball point but wirthout all the mess cleaning the pen out. There is also no fore and aft play with this arrangement.
  • Different counterweights have been used- I can't tell any difference with those I use. This one just looks 'right'
  • The housing for the bearing plays no real part in the operation of the arm apart from preventing the bearing from jumping out when used by ham fisted users. I also think it looks a lot neater.
So there you have it-very simple, very purposeful and superb sound quality. What more could we want?


Regards
Chris



Regards
Chris
 
Hi Chris,
Beautiful work on your TT and arm. If you have the chance, could you post some pictures showing details of the ball bearing set screw pivot arrangement? Also what material is the bearing housing? Would more or less mass in the housing affect the arm performance?
Regards,
David
 
Stealth Tonearm

Hi David
Here is a pic of the bearing-I't's impossible to photograph the cup in situ as it is deep in the body ogf the housing. No secret though-it's an M6 set (grub) screw. Re the housing itself- I have tried different materials and found no difference in performance. As Stew knows, I've been working on this arm on and off for quite a few years now. I've owned (and sold-that might tell you something) some of the best arms available- Morch UP4, Ittok, OL (all sorts), Hadcocks, Mission, Kuzma Stogi, Clearaudio Tangent, Opera Consonance, Opus 3 Cantus and latterly the Transfi Terminator. Why do I prefer the arm I'm using at present? Because the performance of my arms satisfies!
Regards
Chris
 

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my thoughts....the Stealth MkIII

Hi Stew
Thanks for the response. As I said, I've been a bit quiet of late due to job demands and travel but I'm now back on track,
we all have lives...
A few things to mention:
  • The shaft is still the Eastton alu arrow shaft. I've found nothing else as good! It is of course in one piece-no joins anywhere.

Didn't and haven't I said that all along?

  • Headshell is actually hardwood with the pivot point directly above the stylus tip- the slot has been tried but is very fiddly to do.
This is the key (in my lowly opinion) to making pivoting tonearms of any length that require no anti-skating adjustment. The alignment is absolutely critical! I have never made a 9" or 10" arm to do direct comparisons of various lengths and their need for anti-skating. I suspect that the shorter the arm, the greater the need for anti-skating.

  • Bearing-I've stopped using the ball point tip and now use a 2mm ball bearing in the set screw 'cup.' It locates very well and performs equally as well as the ball point but wirthout all the mess cleaning the pen out. There is also no fore and aft play with this arrangement.

Chris, in my opinion, 2mm may be too large a diameter for the ball bearing. Something under 1mm is better. Of course a conical arrangement of 4 bearings could make sense as well, and most likely would give superior performance. I have looked into purchasing metal ball point refill tips that have never seen any ink, 100 at a time. So far, I can't get a response from any manufacturers.

  • Different counterweights have been used- I can't tell any difference with those I use. This one just looks 'right'

From a theoretical point of view, a counter-weight that is a "underhung" or an offset type does contribute to the stability of the tonearm. So you might not hear any possible improvements, but will see them.

  • The housing for the bearing plays no real part in the operation of the arm apart from preventing the bearing from jumping out when used by ham fisted users. I also think it looks a lot neater.

Yes, your bearing mount does look quite neat. I have to tell you though I still like the idea of using a complete (never filled) metal pen refill

So there you have it-very simple, very purposeful and superb sound quality. What more could we want?

How true. That was/is the point of the 219 and your variation. I'll still put my 10-ish year old 219 against almost any tonearm up to about CAD $2500 (roughly USD$1940, €1700, £1360). Recently mounted a friend's Clear Audio Virtuoso Wood (?) on his Kuzma Stabi-S/219. It kicked *ss and seemed a good match.

I figure if the 219 can support an expensive cartridge, all mounted on a pretty expensive turntable. that's good enough for me.

As always Chris, your workmanship is something to aspire to.

Oh, BTW, you answered any concerns design wise in your list...
 
rather than adding to my previous post as an edit ...

... I thought I'd comment on your tonearm board mount which is essentially what I thought should be the way to mount these on decks with existing mounting "holes" in their plinths.

What other arm is pictured with the Stealth? The tube above made it seem like a LT arm, but I see that I just wasn't looking close enough. Is the metal tube a light? Or part of a LT arm?

What about the turntable (it looks very good)? You build it from scratch? If so, I'd like details, of course.

As always a joy to see your work which appears to be done to a high standard.

And another afterthought: Isn't it funny how long it takes to work through seemingly small details. Unless you've done it for yourself, you may have no clue to how much of an ordeal something as simple as locating a screw can be. The devil is in the details...
 
Hi Stew
Thanks for the feedback.You know I rate your knowledge and views/comments very highly and it's good to hear what your thoughts are. I'll take on board your comments relating to the bearing.I'll go back to trying out the ball point nib- very easy to do an A/B with this design and report my findings. If it does turn out to be an improvement,I'll incorporate it.

The deck is a commercial design- an Analogue Alchemy- they were short lived and went into liquidation.A guy in darkest Lancashire bought up some of the stock and I bought this before Christmas-it really is superb- magnetic main bearing and dc motor and a huge amount of perspex! He didn't know what he'd got on his hands and sold some other gear for a song!
The other arm is an experimental one that I have from an engineer who builds them- it's carbon fibre (but very nice stuff I assure you Stew!) with a dual pivot similar to the Morch DP6 and the OL arms. I currently am trying out a slightly different design- 12"- which is proving very interesting. I'm getting to the point now where different arms are stopping sounding 'better'- they just sound 'different.' That's why I'm beginning to think I have a very good design indeed.
Take care and I'll come back soon- on my way to Vienna tomorrow! Holiday NOT work!!!!
Regards
Chris
 
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