A decade ago I rescued a couple of Garrard 301s heading towards a skip. I didn't think the SME 3009 arms on them competed with my Ekos 2, and the decks sat fallow for many years. When lockdown came I decided to solve this problem.
It was my intention to try to make an arm better than my Ekos 2, and I targeted the bearing as the weakest part of that arm's design (as I suspect it may be in all gimble/ball-bearing arms), and also the most difficult to diy, so I designed an arm with a very low tech but nearly ideal new kind of bearing.
Prototype 1 sounded so much better than my Ekos that I spent many months refining the design and I applied for a patent on the novel bearing.
It has been a steady learning curve going from this...
...to this...
...and this:
Serial number 2 is now in use by an audio blogger in Canada, and this is what he has said about it:
Please ask if you have any questions about this project.
Web site: supatrac
It was my intention to try to make an arm better than my Ekos 2, and I targeted the bearing as the weakest part of that arm's design (as I suspect it may be in all gimble/ball-bearing arms), and also the most difficult to diy, so I designed an arm with a very low tech but nearly ideal new kind of bearing.
Prototype 1 sounded so much better than my Ekos that I spent many months refining the design and I applied for a patent on the novel bearing.
It has been a steady learning curve going from this...
...to this...
...and this:
Serial number 2 is now in use by an audio blogger in Canada, and this is what he has said about it:
His deck is a Sondek and he normally uses a Tiger Paw Javelin.
Please ask if you have any questions about this project.
Web site: supatrac
Last edited:
Hi Caruthers: Some of Trio-Kenwood's direct-drive turntables from the 1980s featured a tonearm with bearings designed specifically to resist the forward pull of the modulated LP groove.
These DS (Dynamic Stability) arms were introduced (AFAICT) in 1983 on the KP-880D, subsequently reappearing in the KP-1100 (1985), and KP-9010 (1988).
??-???? (KP-880D 1983)
KP-880D ナイフエッジ トーンアーム (取外,破損ジャンク品) トリオ ケンウッド TRIO KENWOOD KP 880 D KP880D KP-880DII KP-880DⅡ
- (KP-1100 1985)
KP-1100/9010DS
Trio-Kenwood's tonearms used a side-ways pointing knife-edge rather than a side-ways unipivot as you have done, showing that there are different roads to the same goal.
These DS (Dynamic Stability) arms were introduced (AFAICT) in 1983 on the KP-880D, subsequently reappearing in the KP-1100 (1985), and KP-9010 (1988).
??-???? (KP-880D 1983)
KP-880D ナイフエッジ トーンアーム (取外,破損ジャンク品) トリオ ケンウッド TRIO KENWOOD KP 880 D KP880D KP-880DII KP-880DⅡ
- (KP-1100 1985)
KP-1100/9010DS
Trio-Kenwood's tonearms used a side-ways pointing knife-edge rather than a side-ways unipivot as you have done, showing that there are different roads to the same goal.
Thanks Jonathan - that's very interesting - researching now. I've found one other attempt at a sideways bearing but again it was only one axis and isn't what I've come up with. I'm aware that you have been responsible for some of the best cartridges ever made so I'm honoured to get a response from you. One day I hope to be able to afford one of your magical devices!
Hmm. I just hit the link you quoted and it worked. Mysterious. I'm going to look into this. I've noticed the server host messing around a bit, perhaps because I declined to pay extra for an SSL certificate. That's what we've come to.
It is a sideways uni-pivot arm (SUPA) achieved using suspension from a point. I have been using the design for a year and I think that it is a game-changer. The crucial developments over traditional uni-pivots are constraint of roll on the arm's axis and a pivot point which more directly opposes the principal direction of excitations from varying stylus drag, and so rubs less.
My previous arm was a Linn Ekos 2 which is not a bad arm. This new design is another level, in my opinion of course. I have compared them side-by-side on the same deck with identical cartridges and one stylus swapped between them.
It is a sideways uni-pivot arm (SUPA) achieved using suspension from a point. I have been using the design for a year and I think that it is a game-changer. The crucial developments over traditional uni-pivots are constraint of roll on the arm's axis and a pivot point which more directly opposes the principal direction of excitations from varying stylus drag, and so rubs less.
My previous arm was a Linn Ekos 2 which is not a bad arm. This new design is another level, in my opinion of course. I have compared them side-by-side on the same deck with identical cartridges and one stylus swapped between them.
Hi Carruthers, sorry I meant the link in your first post. The one I found and posted was from digging through your interesting posts on other forums...so posted the right one.
I love the aesthetic, sounds very clever. Would love to hear it sometime, once my DIY TT is made....which may be a while.
I'm with the others though, finger lift over string.
I love the aesthetic, sounds very clever. Would love to hear it sometime, once my DIY TT is made....which may be a while.
I'm with the others though, finger lift over string.
Thanks for the alert about the link. Supatrac.com is supposed to forward to supasound.com but sometimes it does and sometimes it doesn't. They are breaking the web by destandardising requirements for https. Stallman warned us.
The rigid finger lift may look better for some, but the string is a delight in use. I allow my small children to hand cue expensive cartridges without any worry.
Still, both are supplied with the arm.
The rigid finger lift may look better for some, but the string is a delight in use. I allow my small children to hand cue expensive cartridges without any worry.
Still, both are supplied with the arm.
Cheers Tom. The string arm lift is the default. I know that some are put off by it, but it does work better than a rigid one IMO. It's just a lot more comfortable, unlikely to jump away at a clumsy moment, and it may even have audible advantages.
I accept what you say about the rigid lift, but I am loath to start making new holes in the arm for an accessory which may not be used. I am, however, looking into new designs of finger lift which don't require further holes.
After using the string for a year, I find that I am happy for my children (10, 8, 5) to cue and turn over records for me, which I have never allowed before. I think it will catch on in the end, after some controversy, because it increases the pleasure of using vinyl and takes away a little bit of the handling neurosis.
VTA is set in the same way as on a Linn arm: loosen the pillar lock nut at the side of the base and slide the pillar up or down by the desired amount. There is no provision for VTA-on-the-fly. I would suggest that a few different thicknesses of platter mat are a better way of gaining fine adjustment to VTA record by record than another mechanism built into the arm base. I know that this is done very well by, for example, Kuzma, but I personally am not convinced that this level of fine tuning for each record is worth it, which is why there is no provision for this in the Blackbird.
Correct azimuth is well worth achieving for many reasons, including fine-tuned sound and stylus/record wear. There are two spools for adjusting the length of the hoists which support the arm. Using them you can adjust the azimuth very accurately. However, their primary purpose is to hold the arm at the right height with respect to the pivot, so once the correct height is achieved, azimuth is adjusted by raising and lowering the two hoists in equal and opposite measure so tha the pivot height does not change. In reality it is quite easy to do this - turn one spool clockwise a few degrees and the other anti-clockwise by the same amount.
I get that. I'm just pointing out that the rigid arm comes across as a last-minute add-on, which is a break with your nice design language overall. If you're going to offer the rigid arm, integrate it into the design so it looks like it was always there. But it sounds like you're working in that direction, so I won't belabour the point.
You may also have to begrudgingly accept that the market wants a rigid arm. Maybe you can drive a change, but I suspect many consumers are stuck in their ways. Deliver what the market wants. I've had several such "but it's not what I prefer" moments when taking products to market.
Tom
I expect Tom means a rigid lift.
I haven't used it in a while but my only arm -- an original Mission 774 -- had a very minimal headshell block (perhaps like the one on this arm... not that it's much in evidence... Pics?) I could cue the outside track readily enough but not any subsequent inner tracks. For those I had to use the arm base lift device which always seemed to incorporate an element of drift (sigh).
If I don't choose to replace the Mission, the string idea is actually pretty attractive as a mod. I assume it presents a combination of stiffness (to stand upright) and pliancy (to forgive hamfistedness).
I do hamfistedness quite well.
I haven't used it in a while but my only arm -- an original Mission 774 -- had a very minimal headshell block (perhaps like the one on this arm... not that it's much in evidence... Pics?) I could cue the outside track readily enough but not any subsequent inner tracks. For those I had to use the arm base lift device which always seemed to incorporate an element of drift (sigh).
If I don't choose to replace the Mission, the string idea is actually pretty attractive as a mod. I assume it presents a combination of stiffness (to stand upright) and pliancy (to forgive hamfistedness).
I do hamfistedness quite well.
100% agree. I have a plan for a 3D design to hide the rigid lifter bolt and block the possible loosening effect of rotational moments. I also intend, as far as possible, to make improvements easily retro-fittable. The design of the arm is amenable to this. For example I have deliberately dispensed with glue between arm tube and thrust-cage so that end users can upgrade if either part develops further. This is also convenient for anybody who wants to introduce their preferred internal arm wiring. I like the idea of users modifying according to their own tastes.
100% agree. The rigid lifter may become the default, pre-attached, if the string seems to be an obstacle to sales. That said, I'm hoping that positive reviews about the usability of the string may encourage this advance. I've no doubt that, by however small a margin, the string will be more silent from the cartridge's perspective. That's why I came up with it: I've never thought it makes sense to attach a springy tuning fork one centimetre from the buzzing cartridge.
Thanks for your input, much appreciated.
Absolutely - I fully recommend trying this on your existing arm. I use 2mm braided cord like this:
2MM THIN POLYPROPYLENE ROPE BRAIDED POLY CORD STRONG STRING IN BLACK & WHITE | eBay
Tie it around the neck of the arm. A simple noose should work, with about an inch of surplus pointing upwards. It is very light, just stiff enough to stand up, but not so stiff as to allow the application of significant downward pressure. If you are worried about downward pressure, use a slightly thinner gauge.
It's unlikely you don't have a few inches of suitable string lying around the house somewhere.
At first it seems odd because it feels so different, but soon you will notice that you are not having to use awkward hand movements to hand cue or pick-up anywhere on the record.
You will find that you can grip the string firmly between thumb and index finger while the record continues to play because so little sideways force is applied to the headshell by the string. Once firmly gripped, a confident vertical pluck will give you a nice clean exit.
For me it was the end of a hand-cuing neurosis which has lingered for 35 years, and as I say, I now ask my young children to turn over records for me: winning from the sofa!