View Full Version : TT2 Levelling & Arm Board
Hi Folks,
I'm hoping that some of the resident Heybrook TT2 owners/experts can offer some guidance......
It's always proved to be impossible to level both the arm board AND the platter. When the platter is level the arm board is out and vice-versa. Mostly I've just gone for a "middle ground" so as to save my sanity, but I read somewhere recently (can't recall where) of someone who found they hard a warped arm board. Moreover, I recently changed the cartridge to an Ortofon Quintet, which has a very square, straight sided body and this highlighted that the cartridge was not aligned flat to the record surface (RB300 so fixed headshell). I solved the latter by packing out the cartridge, but it's not ideal and added to the niggling thought that something is not right.
Upshot is that I'm considering replacing the arm board. At the very worst it wouldn't do any harm and could even be a solution. However, as a bit of a DIY retard I will need to get someone to do it for me, which leads me to the main reason for the new thread......
How can I find out the dimensions and spec of the arm board (Rega RB300 single pillar format)?
Where can I go to get a new arm board made up?
I'd rather not remove the old one until I have a replacement so that I'm not without a turntable for any longer than necessary. If I can get a replacement made up then actual fitting could be done by my local dealer, who is usually pretty helpful. I just need someone to do the fabrication.
Would appreciate thoughts and suggestions....
Cheers all
I did one for a Linn mount arm and used my existing board for the template - the Linn mount is more difficult than a Rega mount where you just need to get the main hole in the right position and locate the holes for the bolts correctly.
I think the template was put up in the thread Jamie started -there is a thumbnail towards the end which I think is it. The problem is that most people uploaded using photobucket so many images are no longer available.
http://theartofsound.net/forum/showthread.php?45075-Heybrook-TT2-project
Steve -- hello again! Gee, if we lived closer to each other it'd be easier to chat over a pint for all the back and forth we're doing today :cool:
As I might have mentioned before, you could send Guy at Puresound a message to see if he has any blank armboards for the TT2. Then your local guy could drill the hole and mount the arm for you. Would save you a bit of work....
Sorry if these next questions seem obvious, and not trying to be condescending in any way.... Have you checked the existing board for flatness? Are you sure it's warped? Have you checked the mounting bolt underneath the board to see if it's secure? There is only one bolt with a nut holding it -- the second bolt is left loose and is only used to locate the board (I just learned that a couple of weeks ago from Shane himself, the TT2 designer, so as much as I may sound incredibly knowledgeable about this machine, I'm just a newbie to it :)).
BTW, I think it was Clive who mentioned in my Heybrook thread that he had a warped armboard too.
Hope you figure it out.
Svend
With mine I had something like a 2 to 3 mm slope from the front to the back if I levelled the platter. I measured the board and the thickness at one end was about 1mm difference so the rest was down to minor warping. The result was a right channel bias that varied across the record. I checked mine was properly tightened and even tried a bit of sanding to try to fix it.
I did not have any woodwork skills. A board requires two sheets of 9mm ply sandwiched together. Getting smaller sheets of plywood may require making a few enquiries. The DIY stores only tend to sell large sheets. A suitable saw is needed though I got by with a jig saw. The locating bolts require one of the 2 boards to be drilled and a little bit of work to create a small depression so the bolt heads don't prevent the boards being plush when pressed together. I used tacks rather than glue for pressing the boards together. The large hole for a Rega mount could probably be done once they are pressed together with a drill and the right bit. Care needs to be taken to stop splintering.
This intrigues me, as I've heard about it a couple of times now. I can't imagine any circumstance where either type of chassis could be anything but flat and the bearing perpendicular to it, so it must be the armboard. Shouldn't be too hard to remove it and check if it's true with a straight edge on a flat surface.
Construction is as above, with two layers of 9mm birch ply glued together with the mounting bolts through the bottom layer only and only the one nearest the platter having a nut fitted. The staples were just to hold the layers together during assembly. Dimensions are available here somewhere but could easily be taken from your existing board.
The Rega arms need a 23mm diameter hole 221.7mm from the center spindle. The location of the hole on the 221.7mm arc is determined by the clearance between the counterweight stub and the rear of the lid, but i'm sure Svend would be happy to measure his when he swaps his arms over!
Definitely the armboard on mine. It was a problem from when I bought the deck new in the 80s. I eventually tried to adjust for it but was never happy. When I tried my replacement board the improvement for me was huge. My replacement board is probably still not perfect and I may get round to doing another but I am now very happy with the deck.
The Rega arms need a 23mm diameter hole 221.7mm from the center spindle. The location of the hole on the 221.7mm arc is determined by the clearance between the counterweight stub and the rear of the lid, but i'm sure Svend would be happy to measure his when he swaps his arms over!
I'm happy to help in any way I can. I don't have a dust cover though. But locating the hole in a new armboard should be as simple as using the old board as your template...no? Just clamp them together and run a hole saw through the old opening. Alternatively one could use a Rega template - they can be downloaded off the web and printed on card stock.
Good luck Steve. Does Guy have an armboard for you?
BTW, I checked mine last night, as this thread made me curious. All's well - dead level with the platter, to my relief.
Cheers,
Svend
Thanks guys. I've not taken the arm board off to check, but as Shane said, there seems nothing else that could cause the issue. It was all quite perplexing, and it was only when I read of other people's experiences that I had a eureka moment, or so it seemed. Still quite odd though, since you'd think that sandwiching two layers of board together would help prevent any warping. Maybe it was just like that from day one - who knows?!
Looking at my own board it seems to dip slightly from the outside long edge towards the platter. Could it be a mounting issue? I guess the only way is to dismantle everything and check.
In terms of replacements. What are people's thoughts on a suitable material - would trying something other than ply, maybe MDF or such, be worthwhile?
Thanks also for all the measurements provided so far - are there any working drawings in circulation I wonder? It's just that selfishly I don't tend to have too much free time (mostly due to being a "dad taxi service"!), so was hoping to try and get something done without being without the turntable for an extended period. Still, nothing ventured, nothing gained, heh?
Good news Svend - one less problem for you to worry about! :)
My suspicion is that this would have happens in the finishing process. Birch ply as supplied is pretty flat, but once the board was assembled it would have been put through a belt sander before being sprayed. I'm guessing that if it doesn't go in straight it won't come out flat!
We tried all the commonly available materials like MDF and so on, ply definitely sounded best, I think because its less lossy than composite materials. Might be fun to experiment with a acrylics or carbon fire, but not exactly cheap or straightforward.
Steve, just a thought: you might consider getting some nice hardwood veneered plywood from a specialty lumber supplier to get a new armboard made up. Something like curly or birdseye maple, or a walnut burl, or yew, could look really beautiful on the Heybrook. For a small fee they would even custom cut it to your dimensions, so all you'd have to do is insert the recessed mounting bolts between the layers, glue together, and finish the top surface with, say, a clear spray lacquer (you can buy this in aerosol cans).
Food for thought.... :)
Svend
Just read this thread so i thought i would add my experience. I have a TT2 with alloy sub chassis. Also was unable to set cartridge azimuth relative to the platter. So scratched head! :scratch: In my case the culprit was the subchassis which is curved slightly to the right after checking with straight edge. This deck is in really good condition supposedly having been set up by the previous owners dealer. How they missed this is a mystery.
Short of having the sub-chassis milled flat the only answer is to shim the right side of armboard, not ideal.
This could only have happened during manufacture as the sub-chassis to strong for it to be bent after.
Jim
Unlevel sub-chassis - incredible!
Thanks for adding to the growing TT2 information Jim. Please expand.. how much was it out by? I'm guessing you must have totally stripped the deck to the bare components to check it with any degree of certainty? What did you decide to do in the end - shim the board or something else? My temporary fix was a shim between headshell and cartridge
As you may have gathered, I'm having a new armboard made up in the hope that that will fix or at least improve matters. Certainly there are others here on the forum who have experienced warped armboards. Did you check your armboard (guess you did??) - was it okay?
This is all very fascinating and it's excellent that people are sharing their experiences.
Here's a thought...... maybe if the ones who have experienced this issue shared the deck serial number we could identify some kind of pattern? It won't necessarily help the situation but could maybe explain things if there was a defined period when these QC type issues occurred?
Yes, out by a fair margin,enough to bother me. Initially i thought the arm was at fault (Linn Basic) so it took a while to find the curved subchassis. I would need to shim the right edge of armboard by about 1 1/2 mm or so. I took the subchassis right out and checked with a straight edge. It is noticeably curved even by eye. There was an article on the webb about the same problem. The owner had his subchassis milled flat.
Regards Jim
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