Thorens TD 150 Mk2 with Rega 250 arm

[SonyThorens]

I'm thinking of trying an upgraded (stainless counterweight & rewired) Rega 250 arm on my Thorens TD150 mk 2 deck. Out of curiosity as much as anything. I originally believed that the Thorens arm left something to be desired but having scoured various forums etc. I'm not so sure now. The cartridge is an Ortofon M20FL super. My amp is a Sony TA 5650 and speakers Epos M12.2's. I'm a relative newcomer to hifi so any advice or comments would be much appreciated.

Many thanks in advance.

[Trackside]

While the arm itself is good it's fitment on the TD150 is not. The sprung suspension will have difficulty accommodating the extra weight and the top right spring may well be compressed to the limit. You could try replacing the stock springs with those from a Linn LP12 as they are stiffer but there still remains a mass offset with the center of suspension so the springs are still unevenly loaded which for various reasons makes for a non optimal sound. The Thorens arm is not that good by (modded) RB250 standards but it's much lighter and works with the decks suspension. If you want to upgrade there are plenty of choices out there which are compatible which others will no doubt be better experienced than me to advise on.

[SonyThorens]

Many thanks for that Trackside, time to think again.

[avole]

No, I have an RB300 fitted to a TD150. The top right spring isn't compressed to the limit, and there's plenty of nice bounce.

Well worth doing, it's a magic combination.

[raphaelmabo]

The suspension is a factor to consider, I believe the springs are tuned to the weight of the plattern and tonearm. If you change to different weights you get a different resonance damping than the designers intended.

[avole]

Springs are adjustable. The tonearmboard is designed to be changed. Therefore, the designers expected different tonearms and allowed for it. If they didn't, they'd not allow interchangeable armboards nor arms.

This doesn't seem a problem for Linn so why on earth should it be for Thorens? The only issue from my own conversion was the height, because the Thorens arm is taller than the RB300, nothing to do with the weight.

[Spinnr]

SonyThorens.

First of all, nice system. Deserves the extra effort you are puting into component matching.

Perhaps you could weight the Thorens arm, and post. And Avole could weigh the RB300 and post too. Wouldn't be too far from a 250 if it was designed for compliance on the Rega 2 and 3 tables. So far the opposing sides are just launching words from drone concepts, as good as they both are. That would solve the weight question. And I think this is a really important topic for others in the future doing a search on similar matching. Good post SonyT.

Vinyl forever.

[avole]

Spinnr, as the only one who has actually put a Rega arm on a Thorens deck of those who have responded to this thread, the last thing I'm going to do is take it off to weigh it. Let the others try to prove their point. If you google around you'll find plenty of people who have put Rega arms on Thorens turntables.

I'm only sorry the OP has been put off by some crank posts. Thorens TD150+Rega arm= magic!

[alternativeroute]

This old article muddied the Thorens TD150/Rega waters originally...

If you weigh the tonearm then this site should help you decide if its worth it....

I have had the good fortune to be able to experiment and try different arms on a TD150.

Between this one:


Thorens TD150 Mk1 + Rega RB300 + Shure M97xE by arclients, on Flickr

and this one:


Thorens TD150 Mk1 + SME3009 MKII Experimental plinth (material and construction) by arclients, on Flickr

The SME definitely sounded better to me.

There are a few caveats though. The cart I had on the Rega was not the best match for the arm, so my results were perhaps not the best reflection of the combinations possibilities...

What I can tell you though is that with both arms (Rega and SME) the cable dressing was massively important. I am not sure which Rega arm you have but if the cable is quite stiff then it is difficult to dress the cable so that it does not become a 'fourth' member of the suspension...

There are loads of happy people out there that find pleasure in the TD150/Rega 250/251/300/301 combo - so give it a go... Luckily the market for second hand Rega arms is quite buoyant so if it does not work for you the you shouldn't lose too much money (if any).

[Trackside]

Spinnr, as the only one who has actually put a Rega arm on a Thorens deck of those who have responded to this thread, the last thing I'm going to do is take it off to weigh it. Let the others try to prove their point. If you google around you'll find plenty of people who have put Rega arms on Thorens turntables.

I'm only sorry the OP has been put off by some crank posts. Thorens TD150+Rega arm= magic!

Actualy I have fitted an RB300 to a TD150 hence my 'crank post'

[SonyThorens]

Thank you everyone for your contributions. I think that the only thing to do now is to try it. Like so many things in hifi it seems to be, to a large extent personal and subjective. However, I've already purchased the Rega arm (thank you Ebay!)so I'll go ahead anyway. I think that the effect of the cabling on the suspension is a valid point, the signal wires are quite substantial and will have to be arranged very carefully. I'll use an after market armboard so I can easily restore the status quo, nothing venture etc....... As a matter of interest I will weigh both arms and feedback to this forum.

Very many thanks again.

[Trackside]

The correct functioning of the suspension is the key issue to address( from someone who has done this ). The unequal loading of the springs which is the major design flaw of this and the LP12 which copied it creates additional lateral instability in a design which is already lateraly unstable. By this I mean the arm pivot can rotate around the platter creating at worse obvious pitch variation heard on decaying piano notes and vocals and at best a certain insecurity and edginess to the sound (which some may like BTW). Any variation in the drive system (motor or belt) or unevenness in the main bearing (too thin an oil or wear) causing the spindle to move around in the journal and vary it's drag rather than rotate perfectly on its axis will cause this. Linn spent the entire development history of the LP12 trying to rectify it with better motor control and a very, very high spec bearing and they even started off with a heavier platter, better motor and better main bearing than the 150. They even used the tonearm cable to restrict lateral movement. Good luck with teh RB250 and if it doesn't work out do what I did and buy a deck better suited to it which in my case was a Systemdek which uses more stable tension springs ( the subchassis hangs) which are arranged symmetrical with the arm and platter axis and who's subchassis has a counterweight to balance the mass on the center of the springs geometry.

[Spinnr]

Trackside.

Many thanks for the description of the problems involved here. I have learnt a lot from your words, and now also understand much of what has been said about this with turntable design, but not explained as well.

Every day on these forums I learn something new which brings deeper understanding to our hobby.

A Thorens 150 is a gorgeous deck, and deserves all the applied skills you detail.

Vinyl forever.

[avole]

The correct functioning of the suspension is the key issue to address( from someone who has done this ). The unequal loading of the springs which is the major design flaw of this and the LP12 which copied it creates additional lateral instability in a design which is already lateraly unstable. By this I mean the arm pivot can rotate around the platter creating at worse obvious pitch variation heard on decaying piano notes and vocals and at best a certain insecurity and edginess to the sound (which some may like BTW). Any variation in the drive system (motor or belt) or unevenness in the main bearing (too thin an oil or wear) causing the spindle to move around in the journal and vary it's drag rather than rotate perfectly on its axis will cause this. Linn spent the entire development history of the LP12 trying to rectify it with better motor control and a very, very high spec bearing and they even started off with a heavier platter, better motor and better main bearing than the 150. They even used the tonearm cable to restrict lateral movement. Good luck with teh RB250 and if it doesn't work out do what I did and buy a deck better suited to it which in my case was a Systemdek which uses more stable tension springs ( the subchassis hangs) which are arranged symmetrical with the arm and platter axis and who's subchassis has a counterweight to balance the mass on the center of the springs geometry.

Absolute nonsense, from start to finish. I don't understand how anyone can, except for Dan Brown, create such fiction.

Anyway, each to his own. I'll be putting the Rb300 on the LinnI've just bought. It isn't a perfect match, but for none of the reasons mentioned in trackside's misleading post.