Thorens Ambiance rebuild

[Steph Dale]

I hope this is of interest...

A little while ago, I managed to get hold of a slightly poorly Thorens Ambiance, which I've just started rebuilding/repairing. Unfortunately the standard arm (a tweaked SME 309) had been removed, but it meant I got the basic chassis for a good price. Unfortunately not without the odd problem, sadly, but most issues are repairable.

Dragging it out of its box in the workshop, I was presented with this:
https://images2.imgbox.com/a0/1c/oycNITOn_o.jpg

Initially, it looks like it just needs a good clean and can then be mated to a new arm and off we go.

More later, if of interest...

Steph

[Pete The Cat]

Wow. Their top of the range around the turn of the millennium if I remember correctly.

Can't say I ever heard one but I have fond memories of earlier Thorens decks and refurbing a TD150 taught me a lot and gave me confidence to attempt more DIY on equipment. Seeing projects like yours is always interesting if not inspiring so I hope to hear more...

Aside from the arm, are you looking to restore the deck itself per original spec/only using OEM parts or are you making any modifications?

[Barry]

I've not heard of the Thorens 'Ambience'. I can't see from your photo what the drive mechanism is. Also does the record sit on the six raised discs on the platter?

Should make a nice project. Let us know how you get on. :)

[Steph Dale]

Barry,
As Pete says, it was Thorens' top model from about 1998 until they went 'pop' in 1999 - fewer than 200 were produced, so it's a pretty rare beast. It's a belt drive; you can see the pulley next to the sub platter, although it's not all that clear in the photo thanks to the Clearlight Audio 'Resonance Damping Compound' (RDC) that it's filled with. There's a lot of RDC in the Ambiance and although it's based on the TD 3001, the materials (and use of RDC) are different. The brass discs you can see on the platter are weights incorporated in the design to bring the inertia up; this is mostly acrylic and yet has higher inertia than the standard Thorens platter. It's also a big beast - a larger footprint than my TD 521, although the wood surround makes it much more domestically acceptable.

Pete,
The intent is to get it as close to original spec as I can. But there are a couple of changes I'm making to bring it together: with the loss of the original arm I'm going to fit an SME V, the arm cable will be a modern one (something from Chord or Furutech) and I'll fit a modern cartridge. I've also grabbed a decent mains cable for the PSU. The drive board in the turntable seems to be very similar to the one for the TD 2001/3001, although IIRC the components are a bit closer toleranced. It leaves the player open to being Phonosophie-ed with a DC power supply at some point in the future.

The postie has just delivered a new belt, so I'll leave it there for the mo. Hopefully more later, when I'll start reporting on the repairs.

Steph

[Steph Dale]

And so to my magnum opus, 'Still life with clamps'... :lol:
https://images2.imgbox.com/eb/3b/6OdoWIlQ_o.jpg

The previous owner had claimed the turntable had received a 'full service' (no receipt though, so...?) and out of idle curiosity I asked what had been done: 'Belt, bearing, speed check and new belt' was the response. The belt wasn't a genuine one, but that's a matter of personal opinion I guess; I use either Thorens or Phonosophie originals. But missing from the list were a. checking the earth wiring and b. checking for any structural stuff. Thorens tables of this vintage are predominantly wood and can, occasionally, suffer damp or similar damage. This one was missing the earth loom and the subchassis / armboard had a distinct sag. I'm guessing the turntable was tricky to use and probably sounded awful; perhaps the reason it was spilt up and sold?

After carefully disassembling the turntable, I bagged and labelled everything. This was not the turntable to lose parts or reassemble incorrectly. That done I grabbed some scrap timber from the workshop and played around with some clamps to work out how I could apply even pressure across the subchassis to close up the split that was causing the armboard to sag:
https://images2.imgbox.com/aa/c1/TKZSH4oM_o.jpg
https://images2.imgbox.com/2d/d5/oIznFuy5_o.jpg

It was then a case of mixing up some aliphatic resin (aka 'yellow wood glue' or 'carpenter's glue'), water, and couple of drops of detergent, which was then applied to the crack and squeezed into the join by hand. I then put all the clamps in place and that's where it's been since Sunday (it's now Thursday evening). I'll unclamp it and have a proper look at it over the weekend. At this stage I'm not expecting that the part will come back 100% flat, but it should be stable and I expect I can adjust from there with shims under the armboard.

More in a few days, I think.

Steph

[Barry]

Am I right in believing the Ambience and 2001 and 3001 predecessors used leaf springs rather than coil springs for the suspension?

Is your Thorens TD521s (plural?) one that was made by EMT?

Following your "refurbishment/ repair" with interest - thanks for posting. :)

[Wakefield Turntables]

:popcorn:

[Steph Dale]

Barry,

You're correct - to the best of my knowledge all the sprung Thorens tables after the 320 had leaf springs, so that feature is shared across the 2001, 3001, Ambiance and my 521 (and the Phonosophie No.3 - a slightly different story). The implementations are slightly different; the 521 with the 's' suffix shares bearing and platter with the 3001 and I've put a Puresound Tenuto mat on mine. Thorens did make a bronze outer platter at one point (now unobtainium and worth more than the turntable) and the Tenuto brings the mass/inertia up to the same level, but needs the suspension springs beefing up, which is not 100% straightforward.

I think the Thorens/EMT 'tables were the 534 and 738, they are rarer than unicorn poo.

Steph

[Barry]

I mentioned the Thorens/EMT connection (when Thorens production moved from Switzerland to Lahr in Germany), as I notice you have a Tubaphon Tu-2 cartridge which is a 'nuded' and modified EMT generator. I have an interest in EMT equipment (having about 8 EMT cartridges as well as an EMT 930st turntable).

I also have three Thorens TD124/II turntables, so will also be interested in yours that is "in the works". :)

[Steph Dale]

I've had the Tu2 for a looong time - it's approaching its second rebuild I think. It's a good match with the ARC Ph5 which has relatively modest gain. I've got a couple of other EMT cartridges here so one of those may make an appearance on the Ambiance, at least as a trial. I note lots of original photos of the Ambiance fitted with the better Ortofons (Jubilee, Kontrapunkt series) and so I'm likely to start around there first.

We'll see what happens about the 124. That, too, has been here a few years with little progress beyond occasionally looking in the box and/or buying one of the odd handful of bits it needed. With an Ambiance here it's probably time to put on the big boy pants and have a good hard think about whether I should sell it.

Steph

[Pete The Cat]

After carefully disassembling the turntable, I bagged and labelled everything. This was not the turntable to lose parts or reassemble incorrectly.

I quickly learned that this and/or to photograph every stage of the process from every angle is essential. It's too easy to think that you'll remember how to reassemble components and then find that you can't.

Look forward to reading more.

[Steph Dale]

Earlier today the subchassis escaped its shackles and I'm now leaving it for a few hours for any clamping-related stresses to come out before I get too far into the set up:
https://images2.imgbox.com/2d/78/aTIp5Y3R_o.jpg

There were a lot of clamps. I don't want to jinx anything, but my quick curiosity-level check looked very promising. As I progress through the re-assembly I'll check for parallel with the platter top surface, after I've fitted the main bearing.

There may be more later, but I'm now into the laborious process of cleaning and checking everything. Most of it is fingermarks, but I'll want to have a quick look inside the power supply to see if there are any signs of corrosion/damp. I believe it's a version of the Thorens TPN2000 in a sexy case, rather than anything active or regenerative, but it'd be good to know and check it's in good order.

So, with the repair hopefully done, the work order looks something like this:
Clean everything
Crack the case on the PSU
Retouch some marks to the paint (along the exposed edges of the plinth and subchassis)
Fix main bearing and sub platter into subchassis so I can tram out the armboard
Reassemble, working out the earth wiring as I go
Install arm, cartridge etc. and set up

So, cleaning. In general that means soap and water. Wooden parts means damp cloth. Brass weights means metal cleaner, soap and water and a finishing wax to seal. Bearing means isopropyl alcohol and cotton buds, followed by a small amount of turbine oil (don't do this to a 1xx-series - they have sintered bearings so flush/clean with oil).

Wish me luck!

Steph

[Wakefield Turntables]

So, cleaning. In general that means soap and water. Wooden parts means damp cloth. Brass weights means metal cleaner, soap and water and a finishing wax to seal. Bearing means isopropyl alcohol and cotton buds, followed by a small amount of turbine oil (don't do this to a 1xx-series - they have sintered bearings so flush/clean with oil).

Wish me luck!

Steph

These are ok options but you might want to try an ultrasonic cleaner, they are cheap enough. I'd be worried about leaving cleaning product residue on key components, especially the bearing which is supposed to be low friction. Oh, and food luck!

[Steph Dale]

Andrew,

You're correct, of course. I'm wary of immersing any of these parts in anything, so I won't even be using the ultrasonic cleaner I have. In most cases it's just a case of moistening an applicator with a cleaning substance or solution, wiping it on and then removing it almost immediately, with the occasional rinse. With a little care it's not a difficult job when you've the correct materials and cleaning substance/solution available - it just takes time.

My philosophy is not to try and return the turntable to 'mint' condition; I recognise that it's been used, so it's a case of trying to get it clean and tidy with a strong emphasis on the engineering/functional performance. Hopefully you'll see what I mean when I've got something to show for my time this afternoon!

Steph

[Wakefield Turntables]

Andrew,

You're correct, of course. I'm wary of immersing any of these parts in anything, so I won't even be using the ultrasonic cleaner I have. In most cases it's just a case of moistening an applicator with a cleaning substance or solution, wiping it on and then removing it almost immediately, with the occasional rinse. With a little care it's not a difficult job when you've the correct materials and cleaning substance/solution available - it just takes time.

My philosophy is not to try and return the turntable to 'mint' condition; I recognise that it's been used, so it's a case of trying to get it clean and tidy with a strong emphasis on the engineering/functional performance. Hopefully you'll see what I mean when I've got something to show for my time this afternoon!

Steph

Steph, all good sound logic! Need more pix!!!!

[Steph Dale]

More pictures you say! Okay, here's where I've got to having been working on this for most of the day...:

https://images2.imgbox.com/42/47/gqmz9PNc_o.jpg
https://images2.imgbox.com/77/9a/KLJ6coeY_o.jpg

So, from left to right (and top to bottom):
Suspension hardware
Mat (washed)
RDC-filled sub platter (cleaned, small burr removed from rim)
Outer platter with RDC fill (brass weights polished, one loose weight re-fixed, edge polished to remove finger and possible oil marks)
Power supply with cables (cleaned, and I can confirm it's a TPN 2000 in a sexy case)
Baseboard (note RDC swirl)
Plinth and new belt (cleaned and checked. It has the odd small dink and a watermark, which I'll worry about when the weather is a bit warmer and I can do something about it)
SME tonearm
Subchassis, with RDC bearing now re-fitted (glued and straightened, checked for square; it's pretty good but I'll see how it assembles and correct as necessary)
Chord tonearm cable
Ortofon cartridge
RDC armboard (washed, annealed and flattened)
Earth loom is not shown (I'll make this up as I go during assembly)
The RDC Stabilizer (platter weight) is missing, I'll keep my eyes peeled if one turns up, in the meantime I've got an Ortofon equivalent on order thanks to the Black Friday sales
Lid/Dustcover is also missing. After-market versions are available, so I've ordered one.

So, I'm ready to assemble, but it's getting a bit late in the day and I'm starting to feel hungry. It'll be a good thing to do when I'm fresher tomorrow morning, but I think it's been a successful day. I'm very pleased with the way the cleaning has worked out, particularly with the platter and armboard and I'm very relieved the couple of repairs I've needed to do have worked out well. I'm now convinced this turntable was not giving its best with previous owner(s) and hopefully I've found and sorted all the issues it had.

More tomorrow, hopefully.

Steph

[User211]

Nice and well worth saving.

That platter kinda reminds me of a black and gold Gyrodec, but with the platter weights pushed into the platter.

I might think weirdly but as the cartridge passes over the gold bits it is going to feel a different vibration feedback compared to the black part. Until it doesn't later in the playback. Audible? No idea ...

Overall it looks well worth the attention.

Respect and enjoy.

[Steph Dale]

Justin,
That's an interesting question, but not something I can say I've noticed with my 2001 RDC that has the same platter - but I never noticed it with my Gyrodec either when I had one of those.

In other news, assembly has restarted, with checking and shaping the cable exit for the tonearm cable. It's a bit of a fiddle to be honest, but a job I'm used to doing with Thorens RDC turntables:
https://images2.imgbox.com/a8/0c/mgowzElh_o.jpg

That done, I could install the suspension:
https://images2.imgbox.com/c4/8f/PnKUQIES_o.jpg

And check that the armboard was square and level to the subchassis, which it is (even if the angle on this photo means it doesn't look like it!):
https://images2.imgbox.com/f1/a6/S0fHVeWS_o.jpg

That done, I shall lubricate and fit the inner platter for the last time and then remove the armboard again to install the arm. I'm going to grab a coffee first, but I'm just making up my mind whether to install the cartridge before mounting the arm...

There have been a couple of little cleaning jobs done this morning too; the caps over the suspension levelling screws and the parts for the arm lift.

More later, I hope.

Steph

[Steph Dale]

I've now got the cartridge, arm and arm lift installed, although none of it is done up particularly tightly; it will remain that way until I've got the turntable on the stand and am doing the final set up. The arm cable is also installed, which was a bit of a fight, and it's marked where it needs to go, particularly for where it passes through the baseboard.
https://images2.imgbox.com/29/da/DDdb686v_o.jpg

Next job is to buzz out the earthing and see what I've got connected and what's not. I'll then make up wires to join the various bits together. The aim is to electrically ground everything when the turntable is in use, so this may take a little bit of working out and certainly a few bits of soldering.

So I've stopped briefly for a cuppa, to update here and to grab a meter, suitable earth wire, soldering iron and solder.

Steph

[Steph Dale]

Another hour and a half or so has passed and the earth loom is in. It did need a little bit of thinking about, and I've ended up shortening the ground wire on the arm cable to ground the bearing, and another wire runs from the bearing to the armlift - that should stop any 'pop' noises when the arm is raised or lowered. Well that's the theory - fingers crossed:
https://images2.imgbox.com/1f/cf/HcVlbBBt_o.jpg

So, I think/hope we're done here for now. Time to button it up, I've run out of parts:
https://images2.imgbox.com/4c/2c/3NhjZ7wr_o.jpg

Time for a cuppa with Iggy on Radio 6 and then I'll have a think about lifting down the Technics SL-110 from the stand and putting up the Ambiance, before doing the set up. My rough workorder will be:
Level off the plinth.
Check the earth wiring is doing what it should.
Unlock and level off the subchassis and check the belt/motor tracking is okay.
Set up the arm/cartridge to specs/manuals.
Listening tests to sort azimuth, anti-skate, vta, tracking weight, etc.

Some or all of this may not happen this evening, I'll see how I go for time, eyesight, food, patience, etc for the rest of the day.

Steph

[Barry]

Are there some covers for the armboard suspension points? Also your arm cables look quite stiff and unwieldy, but that might just be appearences.

Otherwise well done - that's a handsome looking deck you have there! :)

[Steph Dale]

Thanks Barry,

Yeah, the suspension covers are the three black discs shown to the right of the turntable. That's the new belt towards the front, all will be fitted at appropriate points in the set up.

The cables are, indeed, fairly stiff - I've got something similar on my 521 and I'm comfortable to carefully 'dress' them into shape/place. The tricky thing is to route them in such a way that they don't touch anything between the cable clip on the sub-chassis and the exit point.

It's also worth noting that the suspension design is more stable than coil springs used in Thorens 1xx series, Linn, etc, so stiffish cables are less of a problem than they could be.

I've left the set up for later in the week, but I'm looking forward to it...

Steph

[Wakefield Turntables]

A decent turntable based thread, something I've missed recently on AOS. Well done that man! :)

[Steph Dale]

It lives!!!

It's been a slightly painful evening:
1. The new belt had a knick out of it, straight out of the packet. I don't know what made me run it through my fingers before installing, but I'm glad I did.
2. Earth strategy wasn't right, so I had a lot of hum, and;
3. The white tonearm cable has a dodgy screen on the right hand channel, so it's going for repair. I've now got a black cable on it instead - and the earth is now looped up inside the turntable and no hum.
4. Realisation that the original rubber/aluminium feet had started to perish. A bit worse than I can sensibly restore with rubber restorer, so they've been replaced with RDC cones and cups.

So, we've got there. I've got the cartridge set up fairly conservatively at the mo; horizontal tonearm, middle of the downforce range, a touch of anti-skate. And it sounds magnificent. In the next few days/weeks I'll check the suspension levelling periodically, fit a new belt, and install the white tonearm cable when it arrives back with me. I'll also fine-tune the set up using the Hi-Fi News test disc to get the best out of the cartridge. At the moment I've got a modern RDC-X disc stabilizer on it, so I'll keep my eyes open for an original. I'll also want to do a comparison with the Phonosophie No.3 which is, to date, the best turntable I've had - I just need to work out how to do that.

Oh, and the lid arrived today, so i can keep it dust-free.

Steph

[Steph Dale]

https://images2.imgbox.com/8e/17/oLsSq46f_o.jpg

[Pete The Cat]

It has a reassuringly solid, classy look and the lid finishes it nicely. With no science behind this statement at all, I always feel that turntable build became more 'muscular' towards the end of C20th.

You're now at that stage where you probably want the day to last 48 hours so that you can play every record you've got on it!

[Barry]

Are the brass weights flush with with the platter, or proud and the record sits on them? Or is there a platter mat that is not shown in your photograph?

[Steph Dale]

Hi Pete

I agree with you on all points. I think it looks great, and wears it's age well. There's a few things I can do restore it further, like re-finishing the wood, but that's it for now. It's as impressive to listen to, bearing in mind I've not finessed the cartridge set-up yet. I'm hoping I'll have time for that soon. I think it's a keeper for me and in recent days there's been a bit of thinking around what to do with/about the other 'tables here.

Hi Barry,

The platter is clear acrylic and has machining for a wavy channel of RDC, and the six brass weights. Mounted on the sub platter, and without a mat, it looks like this:
https://images2.imgbox.com/5f/fc/vVXoCLBI_o.jpg

The weights are bonded into shallow pockets, and stick up about 3mm from the surface of platter:
https://images2.imgbox.com/a3/04/lLVqaPML_o.jpg

The mat is thick rubber, about 4-5mm thick and ribbed underneath (for added pleasure, obviously). It's actually a standard late Thorens platter mat, but with 6 holes cut into it for the brass weights to stick through. They're therefore about a mm shy of the record's playing surface and looks like this:
https://images2.imgbox.com/0b/ac/sHjV5vHf_o.jpg

I am pondering whether to do some mat experimentation; my first choice would be the Funk Firm Achromat which works so well on Thorens 'tables with die cast platters. But, Funk no longer do the 5mm thick version, so that's not something I can easily try now. One observation is that the rubber/acrylic/RDC combination seems to works well, it's only out of idle experimentation I'd try something else, and I'm wary about destroying a perfectly good platter mat by cutting six flippin' great holes in it!

Steph