|How it began ...
A music loving buddy called upon me to give his Thorens TD-126 a suspension tuneup, install an arm and to test drive a new cartridge.
I readily agreed as it also
gave me a chance to try out my diy protractor !
Most of the photos are kept small for faster page loading but there're some pics, with borders, that are linked to bigger images.
This 2nd 'pictography' (which is also my
own reference) is divided into 2 segments; the first part deals with the
suspension and the second pertains to cartridge alignment. For those
who can't wait, click here to go direct to the alignment
bit. Click here to laugh at my 1st
'pictography' on cartridge alignment.
|None of my decks has spring-loaded mechanism
for the dust cover and I was also curious how it works.
With the snap-on cover removed, the spring & thumb-screw can be seen. The thumb-screw is for adjusting the tension of the spring.
To make work easier, the entire attachment was dismantled.
|Sub-platter, belt drive & pulley.|
|Front panel ;
On/Off , 33 , 45 , 78 , Strobe window & Speed +/- adjustment.
|The underside of the sub-platter.|
|Closeup of the cone bearing.... there was
just a smear of lubricant left and fortunately, not bone-dry !!!
That said, the bearing is in very good condition... no corrosion or abnormal abrasion.
|Underside of the TD-126.|
|Two huge 'whatchamacallit'... trannies?? and the pressed-fit bottom of the spindle well.|
|Closeup of the spindle well. I've good reasons to believe that there are 2 more 'discs' inside.|
|The black knobby thingie is the suspension
'cup'. If you look at the picture above, there're supposed to be
3 of these.
On my TD-125LB, the suspension cups are white in color.
|While on it's side, I felt something amiss...
the entire thing was wobbly, and if you look at the mounting screws, they're
actually dangling around!! (no wonder my friend said it didn't "feel right").
These screws fasten the pressed-sheet metal panel to the plinth and on this panel, the cast aluminum chassis and other components are mounted.
|On the plasticky bottom cover, there's a slide-in strain relief thingie for the power cable. The red/black wire is the grounding Earth.|
|This is my 'jig' (better than nothing...
The bottom wooden frames in the plinth wasn't level and here, I have the deck balancing on it's side panels .... thank God I have a level granite slab flooring.
|but... the chairs aren't perfectly
leveled and shims (pencils, coins, whatever...) were added beneath the
Double check leveling again!
|With the outer platter on, i'm testing the
initial suspension... way too stiff...
The suspension cups were very very tight!! Danged !!
|I lubed the threads with some Mobil One
(SAE OW-40) that was in the storeroom, and let it 'soak' for a bit.
It helped ALOT! and now turning the cups were much easier.
Here, you can see the suspension springs, the inner foam and the washer.
|The SME 3009 Series 2 Improved was placed
into the armboard's slot (not secured).
IMHO, suspension should be tuned with arm, mat... well... the whole works!
|Reverifying the balance again.
I use more than one level ... in case one of them cheats on me.
It will take a while to get that vertical
bounce... nice & springy.
I also cleaned & lubed the spindle well with Mobil One... great stuff also for my Honda SuperFour!!
|Oh... you should check for a grounding point
before closing the bottom. In some cases (like this one), once the
bottom cover is installed, there's nowhere on the chassis where I can affix
the tonearm's grounding.
To solve this, I customized a short earth cable with crimped connectors at each end.
|Some SME interconnects comes with TWO earth
connectors at one end and a SINGLE connector at the other.
According to SME's manual, the Double Earth
goes to the StepUp or HeadAmp (for MC carts) OR to the Amp's phonostage.
It is my preference to have the TWO Earth connectors nearer to the tonearm's end; one goes to the chassis while the other connects to the tonearm's earthing 'shell' (yeah right.. that black 'can'!)
The original SME armbase screws were too loose fitting on this particular armboard and I decided to bypass the rubber grommets, thus giving the arm a more coupled mounting.
Two nylon washers, which fitted nicely into the screw recess, were added to protect the armbase from scratches.
|SME connectors come in 2 variant;
a 4 pin block and RCA.
|When installing the armboard, verify that the RCA connectors are not interfering with the seating. Work around it, were necessary, and please.... refer to your tonearm's manual !!|
|Satisfied with the bounce I achieved with
my 'chair jig', the deck is placed on a less precarious platform (in my
case, it's the dining table which I've already checked for leveling).
Verify again the level of the platter.
|ALL bubbles should be centered !!|
|Install headshell. PROTECT
THAT STYLUS !!
Deactivate the antiskating.
Bring the arm into a neutral balance with your counterweight.
|Place a expendable LP on the platter (something
you can afford to throw away).
Ball-park the VTF.... I went for an approximate 15mN on the Ortofon gauge, which converts to 1.5gram
|Lift stylus guard off, land on LP &
Adjust arm pillar till armtube is almost parallel to LP (with the stylus ON the LP!)
The following pics are somewhat underexposed
as my Canon A200 digital camera
tend to overexpose the white paper when in auto mode, losing the details.
Instead I went manual on ASA50 in ambient mode
... so bear with me for the darker pics.
My friend did this CAD drawn protractor specified
for an effective length
(LEFF) of 229mm and according to the Baerwald's alignment calculations.
|Stop the platter from moving by using either
mini 'door-stoppers' supplied with the V15VxMR or with BlueTac. The
protractor's top edge should also be 'tac-ed'
Ball park the pivot pointer line, that's drawn thru the spindle, to the tonearm's pivot or middle of the armbase.
|The arc seen on the protractor is the stylus
path as it transverse inward towards the LP label.
It's very obvious that the 'overhang' (distance of stylus from the middle of the spindle) is wwwaaaaayyyy off!
|Shift the arm (or the cartridge in a slot-mount headshell) backwards until it lands on 'the arc' (at 13mm mark).|
|Great... stylus follows the arc at the 89mm mark, which was I was told "that the maximum tracking error in-between the null-points occurs at 89mm".|
|... and on the outermost mark of the LP at 146mm.|
|Now I need to align the cantilever, seen here at the outer null point at 121mm.|
|A closeup (please note I'm following the
arc and not the crosspoint just in front of the arc).
There's also some parallax error... from
the position I'm taking the pic....
|Aligning to the 2nd, but the more important, inner null point at 66mm.|
|Danged.... I can't see very well... get
that torch light and magnifying lens... it helps!!
Re-check both points and the stylus arc again after tightening the arm's base clamping nuts.
Passed HFNRR test LP with flying colors and spinning nicely.
Resonates at about 11Hz ( which is appropriate, I think! ).
|... but what a mess one more deck can do
to my living room...
The TD-126 is now seated on my 'test trolley box' with nylon castor wheels. This 'trolley box' is very heavy... filled with extra aquarium gravel... it is leveled and very very stable !!
The Ortofon MC10 matches quite nicely .... now to spin...
... but the very next morning... I had the itch again...
|I hold MOFI's "Geo-Disc" in high regards and just have to compare it to my own protractor....|
|Same thing.... ballpark guide rail to tonearm's pivot and land the smacker on the grid!|
|Now I'm happy!|
I'm learning and sharing as I walk along Vinyl Road,
putting new lessons into practice
to be a wiser person.
If for any reason, someone feels that my
understand of cartridge alignment
is wrong or my terminology of things is incorrect,
Please let me know... I'm willing to learn.
drum roll please .... here comes the credits ....
Le NightFly ... for having enuff trust in
me to mess around with his deck
Casey ... for putting up with my nagging & the CAD designed protractor
and of course, not forgetting the guys who need their meds regularly
Without them, my "borrowed-idea-of-a-protractor"
... nor would I understand it all.
A BIG thankyou guys! Luv' ya!
Must visit links...
Steve Clark's "The Analog Dept" - Lotsa Thorens stuff
Wally's Analog Corner - handmade "WallyTractor"
and this is the 'EchoLoft' where I hang out
The Vinyl Engine - lotsa manuals there !!
My Vinyl Page
back to the top
Feel free to download the photos
for your personal reference and if you need them at your site,
please ask ... just don't claim them as your own.
'Pictography' created May 12th
All rights reserved. Ronnie aka RonWill