Wood Plinths: removable armboard or no armboard? [Archive]

nickbaba

25-09-2018, 14:02

I'm putting together a design for a wood plinth for my next TT. I have the option to include removable armboards, the kind that are held in by 2 screws and can be swapped out and cut for different tonearms, or mounting the tonearm directly to the plinth.

Been googling this subject but found surprisingly little opinion online about which way is considered superior. My consideration is SQ overall. Of course the removable boards are solely for convenience, but can they also affect SQ either positively or negatively e.g. are they less stable, or perhaps do they offer opportunity to further decouple the arm from the motor/plinth?

I'm not planning to swap tonearms on a regular basis, but did think that the option to swap the armboard might make the plinth more flexible should I decide to change arms in the future. On the other hand, the arm I've chosen will sit on an SME-style sliding base, which does also suit other tonearms, and would still give me a degree of flexibility if it was direct mounted to the plinth.

But chances are I'll stick with the arm I have - so leaving aside considerations of convenience, which is the way to go for best sound?

Wakefield Turntables

25-09-2018, 14:27

Your coupling the tonearm board directly to the plinth by using two screws, albeit to a minimum but these screws will act as a conduit for motor vibration into the cartridge. Either decouple the tonearm completely or decouple the motor completely to solve this problem.

Barry

25-09-2018, 14:45

What is the turntable?

nickbaba

25-09-2018, 15:51

TT is a Garrard 401

Yes, good point that screwed on armboard will couple the arm to the plinth - I was thinking perhaps it left scope for de-coupling using something like rubber grommets or washers around/under the screws...?

but, logically your point infers that whether there's an armboard screwed down, or direct mounting, the outcome is the same: armboard is coupled to plinth.

So what else is a potential variable - solidity of the removable armboard mount?

If there's no difference to the 2 methods I'd lean towards having removable armboards as its simply more flexible for future arm changes.

tlscapital

25-09-2018, 15:56

Armboard material can make a huge difference in SQ. Even more so if your phono chain is "clear" (neutral) and "detailed" (transparent). Then according to the build of your turntable all the same. On my Thorens TD14X 'Super' DIY tweaked by me where the suspended sub-chassis design allow some of the good resonance to shine through, likely more so than on an "over dampened" turntable like a SL-1200 where the arm board material will have less to little impact on SQ if any.

I kept the original less "desirable" acrylic tonearm board my Thorens and SME3009 came with. I have tried DIYed beechwood armboard but got a "bassy" and "muffled" sound so took it off. Then tried a vintage original cast alloy SME armboard but got "bright" sound. So I kept my humble but perfect for it's SQ job acrylic armboard. I guess it depends on your tonearm and turntable build combination, tweaks and configuration matches that makes it "work" or not. Then there's one earbuds as well...

Barry

25-09-2018, 16:05

If you are using an SME, then the sliding bedplate already adds one mechanical interface between the plinth and arm.

However, since I presume you are using the SME spacer to place the arm tube at the right level to the platter, you could well replace this spacer with a new removable armboard. I would have it made from metal (aluminium) or a dense hardwood and secured to the turntable board with four screws.

nickbaba

25-09-2018, 17:23

Sorry, didn't mention that the plinth is a Russ Collinson (Layers of Beauty) Garrard plinth.

The sliding SME mount is so I can use Ortofon SPUs, as well as standard headshells, and still adjust overhang correctly. But with a decent sized gap beneath I could have it fixed directly to the plinth surface instead of to an armboard, and continue to use it with other tonearms in future (at least those that fit the SME style mount).

Wakefield Turntables

25-09-2018, 17:40

Panzerholz, or ebony work really well for this sort of thing. I use Panzerholz spacers on my two arm Garrard 301, I have a SME 3009 and a 3012. Ideally you should bond the spacers to the plinth rather than rely on screwing them into place. This increases the coupling interface between the spacer and the plinth and in theory dumping more nasty vibration into the plinth. Just a tip, it's probably better housekeeping trying to stop vibration from the motor in the first place, less vibration from the motor = less dumped into the plinth.

Barry

25-09-2018, 17:48

Which tone arm are you using?

nickbaba

25-09-2018, 18:32

Audio Creative Groovemaster ii

Thanks for all the armboard advice everyone - any thoughts on whether its better to have an armboard at all, or simply fix the tonearm to the plinth?

YNWaN

25-09-2018, 18:47

I won’t bore you with detail but I’ve done a lot of turntable, plinth, armboard experimentation, theorising and building. In theory, perhaps, no seperated armboard is the best solution. However, I have found that a unified armboard and chassis combo works just as well and has many practical benefits. What I would also add is that the material and form/construction of said armboard can have a profound effect on the performance of the attached arm and I personally spend a great deal of time designing the armboards I use (I wouldn’t personally use just two screws to mount an armboard).

nickbaba

25-09-2018, 19:27

24260

I'm sure I won't be giving away any trade secrets if I illustrate how RC makes his standard armboard fixing (the image is on his website) - the board is supported on a narrow ledge and fixes with 2 screws.

However he is very open to customizing options. Assuming that I'm sticking to wood as a material, what could I do to improve this design? Add 2 more screws, to have 2 at each end of the armboard?

montesquieu

25-09-2018, 20:47

nickbaba

25-09-2018, 21:11

Thanks Tom sounds good

montesquieu

25-09-2018, 21:36

Thanks Tom sounds good

https://i.imgur.com/mEAYEhr.jpg

Not the best pic but shows my rear armboard with its four bolts. I swapped out my ply armboards for these funky stone-resin ones from Konnedesign on ebay. See top of the deck below. These work pretty well I think.

I have to say I was pretty impressed by the effect of Townshend Seismic Pods on the sound of the deck. Well worth the cash.

https://i.imgur.com/e3i2K9r.jpg

Barry

25-09-2018, 23:29

Ugh - they look awful (or rather - not to my taste). Are they really an improvement over solid hardwood, plywood or acrylic TD124 armboards?

WESTLOWER

25-09-2018, 23:39

Ugh - they look awful (or rather - not to my taste). Are they really an improvement over solid hardwood, plywood or acrylic TD124 armboards?

I reckon they look very good indeed. Very Individual Plinth combination :clap:
Sounds flipping incredible to boot!

Barry

25-09-2018, 23:45

Even if they do make an improvement in SQ over the usual TD124 armboards (and I will accept that they might), I would still want them sprayed semi-matt black for the sake of appearance.

WESTLOWER

26-09-2018, 07:16

Even if they do make an improvement in SQ over the usual TD124 armboards (and I will accept that they might), I would still want them sprayed semi-matt black for the sake of appearance.

That’s a bit ...dull! When you have an opportunity of creating something nice and different.

nickbaba

26-09-2018, 07:48

I think they look pretty 50's chic, quite appropriate really, and also match the green leather!

btw Tom, do you have the seismic pods attached or stuck to the plinth somehow, or does it simply sit balanced on top of them?

I see Townshend do a seismic platform too, with 4 pods fixed to a metal plate to rest the TT on... but its about £150 more than 4 single pods.

Barry

26-09-2018, 10:12

Ah well - just me then.

How about a slate armboard instead?

nickbaba

26-09-2018, 11:37

heh heh - is that directed at me (OP) or Tom?

mikmas

26-09-2018, 18:06

Ugh - they look awful (or rather - not to my taste). Are they really an improvement over solid hardwood, plywood or acrylic TD124 armboards?

Have to agree - absolutely not my cup of tea, even from a 'retro' perspective. Also very much at odds with the Thorens design ethos (if that really matters)

WESTLOWER

26-09-2018, 20:19

Have to agree - absolutely not my cup of tea, even from a 'retro' perspective. Also very much at odds with the Thorens design ethos (if that really matters)

That’s Ridiculous

mikmas

26-09-2018, 20:27

That’s Ridiculous

Opinions invariably vary .... ;)

Barry

26-09-2018, 20:32

heh heh - is that directed at me (OP) or Tom?

It was in response to others over my somewhat brusque comment of Tom's stone-resin composite armboard on his TD124. I then had the thought that perhaps slate might make a good material for an armboard.

I know you are thinking of using a separate armboard/armbase with your Garrard 401, so maybe my interjection has not been thread drift after all. :)

WESTLOWER

26-09-2018, 20:33

Opinions invariably vary .... ;)

Indeed, but the tosh about Thorens design ethos, ridiculous.

walpurgis

26-09-2018, 20:39

Not too keen on seeing the views of others described as "ridiculous" or "tosh".

mikmas

26-09-2018, 20:41

Indeed, but the tosh about Thorens design ethos, ridiculous.

In what way?
Can't recall anything from Thorens using such off-beat fablonesque design features - usually typical sober Swiss modernist design informed by Bauhaus 'form determined by functionality' rather than the frivolous.

Although it's true that some of their more recent efforts show more of a leaning towards bling and silliness for the sake of it :lol:

WESTLOWER

26-09-2018, 20:50

In what way?
Can't recall anything from Thorens using such off-beat fablonesque design features - usually typical sober Swiss modernist design informed by Bauhaus 'form determined by functionality' rather than the frivolous.

Although it's true that some of their more recent efforts show more of a leaning towards bling and silliness for the sake of it :lol:
Apologies, if ‘ridiculous’ and ‘tosh’ was not in order.

nickbaba

26-09-2018, 20:55

Barry

26-09-2018, 21:00

In what way?
Can't recall anything from Thorens using such off-beat fablonesque design features - usually typical sober Swiss modernist design informed by Bauhaus 'form determined by functionality' rather than the frivolous.

Although it's true that some of their more recent efforts show more of a leaning towards bling and silliness for the sake of it :lol:

I have seen photos of TD124s where the chassis has been variously re-sprayed mauve, red or green! :eek: :doh:

Sorry for the thread drift. ;)

WESTLOWER

26-09-2018, 21:15

Well... ahem, to get the thread back on topic, if I may... it's true that one other advantage of using removable armboards that I hadn't even considered is the freedom to try different armboard materials...
tho' I have the sneaking feeling that way madness lies... :mental:

Well the removable arm board does give you flexibility to try different materials, but personally, I have the Solid Russ Collinson plinth with a 401 and 2 armboard cut outs...I’d be amazed if there was a substantial difference in music presentation using different arm board materials on such a plinth.
But it’s intriguing to say the least. Even more variables in the chain to worry about!

Just be sure to consult the style guidelines before you embark on the journey!

montesquieu

26-09-2018, 21:30

Having lived in the Mendips for more than a decade (surrounded by slate in all its various forms) I have always considered it a totally inappropriate material for anything to do with sound. Too harsh, too resonant at high frequencies, too cold altogether. Might as well use metal!

Personally I think my armboards are rather fetching, I have the same made in solid sapele to match the outer surround of the plinth as well as my speakers, and think the stone-resin combination not only looks better but sounds better.

Overall the plinth weighs about 60kg when loaded up with the TD124 and two tonearms, and it certainly benefited from the Seismic Pods. I have heard my TT in lightweight, minimalist, 60s-Ortofon-style plinths and the sound was not nearly as good as it is now (it fact I don't think those lightweight TD124 plinths sound good in the least).

As for aesthetics of my current plinth, I have very little patience for most of the tin-can-driven-with-string turntables out there (the Verider excepted) and the TD124 dates from the early to mid sixties, when funky leather and psychadelic accoutrements would have been far from out of style.

The Schopper platter and bearing are a must, in my opinion though. There's a lot of bollocks talked about tweaks (I'm not, generally speaking, a cable believer, above a certain level of competence) but the Schopper kit's benefits were instant and irrefutable.

nickbaba

26-09-2018, 21:34

2427324274

I don't think Schopper got the memo... (about the style guidelines, that is!)

montesquieu

26-09-2018, 21:36

2427324274

I don't think Schopper got the memo...

Precisely. Would you rather it looked good, our sounded good?

nickbaba

26-09-2018, 21:42

I'm not a fan of the 'hot-rodded' TD124 look, myself. But diff'rent strokes for diff'rent folks, I guess...

back on topic (again) I don't doubt that Russ's plinth will be excellent with his own armboards - I'm not about to embark on a quest for the ultimate armboard material. As I say, that way madness lies... (and I don't mean the 80s ska band).

montesquieu

26-09-2018, 21:45

I've owned my RC plinth for about four years now it's only in the last six months I've bothered to try other materials. and I have the old ones should I want to go back.

Barry

26-09-2018, 21:52

So what about the slate plinths used by some (including 401 owners)?

montesquieu

26-09-2018, 22:00

So what about the slate plinths used by some (including 401 owners)?

They hold no appeal whatsoever, despite their high(ish) mass. Proper layered cherry wood construction is the way to go IMO.

mikmas

26-09-2018, 23:14

Apologies, if ‘ridiculous’ and ‘tosh’ was not in order.

Thanks - but not too bothered really; it's only a turntable :)

speedracer

27-09-2018, 10:26

They hold no appeal whatsoever, despite their high(ish) mass. Proper layered cherry wood construction is the way to go IMO.

Is that your view for all turntables Tom or just the TD124? I am researching this subject as I have just bought a 401 with a two layer plinth, looks like granite but is in fact MDF with a textured paint finish; I like the look & was considering making a similar one out of granite, Corian or slate, mainly because I have read that large deep wood plinths act as a sound board for vibration, which has made me look at which method is best for sound quality.

montesquieu

27-09-2018, 11:00

There’s a fantastic 30 page thread on slate and other plinth materials on Lenco
Heaven https://www.lencoheaven.net/forum/index.php?topic=1471.0

Lots of physics and materials info in there and a bit of acoustics. No real consensus though. (It’s a forum after all!)

Not entirely sure there’s a single approach to be declared overall winner - a Td124, standard Lenco, PTP Lenco, Garrard, SP10 all have different characteristics in certain ways

Anyway I know I’m not that keen on slate. Wood is good, my plinth is cherry with sapele surround, and (lately) arm boards that are similar to corian. In my view, for a TD124 and probably also for 301/401, the best approach is high mass solid wood. But other approaches - lightweight, skeletal, metal, even concrete (!) are certainly viable and have their advocates.

WESTLOWER

27-09-2018, 12:03

Is that your view for all turntables Tom or just the TD124? I am researching this subject as I have just bought a 401 with a two layer plinth, looks like granite but is in fact MDF with a textured paint finish; I like the look & was considering making a similar one out of granite, Corian or slate, mainly because I have read that large deep wood plinths act as a sound board for vibration, which has made me look at which method is best for sound quality.

heres some more reading too..
http://www.enjoythemusic.com/magazine/equipment/0107/slatedeck.htm