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back to the Teres Dept.

Q: What is a Teres...?

A: look below.....!

It is sold as a kit, and some assembly is required.

Date: 5/01/02

 Here's the breakdown:

The Standard Kit:

Teres Model 135 Acrylic Kit minus tonearm, comes with motor pod, power supply and a two piece screw-down record clamp.

Options:

Expressimo Audio modified RB  250 tonearm  w/VTA adjuster

Black Diamond Racing resin cone feet 

For more info surf over to this link: http://www.teresaudio.com/product/index.html

'Ya-think they put enough acrylic in it...?

Assembly and polishing, how it went.

Even though this is termed as a "Do-it-yourself" kit, there isn't much for the purchaser to do except for polishing the acrylic and then some very simple assembly.  I did the whole thing in the kitchen of my apartment.  Actually I have a garage workshop, but I found working in the kitchen sink to be more convenient for the wet sanding process.  Running water.

The platter comes finished and ready for assembly, but the base and armboard are in 'as machined' condition.  The polishing process is similar to the color sanding operation used in custom show quality automotive painting.  The surface is sanded with a succession of finer grit papers followed by a fine polishing compound.  After the compound, the acrylic takes on the look of transparent cut crystal.  It's satisfying to do this work and see the material transform under your own hands and before your own eyes.  It's easy too.

Here is my approach to the sanding process:

6 inch sanding board. (pro-quality, purchased at an automotive paint supply store, years ago)

120 grit dry sandpaper

220 grit wet  

400 grit wet 

600 grit wet

1200 grit wet

3M heavy duty polishing compound (bought in an automotive paint supply store years ago)

McGuires #5 Mirror Glaze

The process goes like this:

Rough cut with the 120 dry on the sanding board to cut below all machining tool marks.  

Wet sand with the 220 thru 1200 grits in succession.  It's important not to skip or go lightly at any of these levels as the finer grit papers just wont cut below coarse sanding marks.  I used the kitchen sink for this wet sanding.  With the rubber base of the dish rack angled against one side of the sink and a heavy sponge for the platter base to rest on as I did my sanding.  This worked well and made very little mess.  All the dust went down the drain. By the time I was at the 1200 grit level, the acrylic was quite transparent when wet and a bit cloudy when dry.  The 3M compound polished the plastic clear and the McGuires #5 put a finish shine on it.

Assembly:

1) The bearing drop.  The spindle and bearing housing undergo an interesting process of assembly.  Due to a close tolerance of fit between spindle and bearing housing, a structured process of assembly is used.   The supplied instructions were adequately clear so there is no need to improve on them here.  

I'll just say the following: The spindle bearing is a nice bit of machined hardware.  The housing is solid bronze, the spindle is stainless steel.  There is a precision ball bearing that rides between the spindle bottom and a teflon coated thrust plate in the bearing housing.  The whole assembly is submerged in oil.   Installing the spindle into the housing took over 12 hours to accomplish due to the close tolerance fit between spindle and bearing in combination with the oil loaded into the housing sump prior to assembly.  The spindle drops easily down to the pool of oil in the sump. There the spindle stops solidly with no cushion.  Brick wall. Then the platter is installed over the spindle to add weight and push the spindle on it's way down to the housing bottom. Over time oil is displaced up past the microscopic gap between spindle and bearing and thus allows the spindle to make it's way down to the bottom allowing the ball bearing to ride solidly against the thrust plate. Once the spindle is fully home, there is visible oil clinging between spindle and housing at the top.  This can be seen through the acrylic platter.  It looks as though the spindle rides in an oil-bath vacuum.  Neat.

2) Arm board and tonearm.  Straight forward stuff here to anyone who has ever aligned a cartridge except that the pivot to spindle distance must also be set.  This is simple as the arm board is secured to the plinth by a single bolt.  Loosening that bolt allows the arm board to swing into position.  I took advantage of the Clearaudio protractor I have to set the spindle to pivot distance, stylus overhang and offset angle.  Piece of cake.

The Expressimo RB 250 'modified' tonearm:

The difference between this tonearm and the 'standard issue' Rega RB 250 is that Expressimo has exchanged the plastic counterweight stub-shaft at the end for a stainless steel one.  Expressimo has also manufactured an offset counterweight that locates the center of it's mass approximately at stylus level for improved tracking.  Another improvement on this arm is an upgrade Cardas wire set.  

1) The cartridge clips are springy and snap over the posts locking into final position.

Teres_7web.jpg (70535 bytes) (close-up view of Cardas clips)

2) The wire set is of a continuous piece from cartridge clip to RCA plugs.  That's an advantage over more standard tonearm wires that terminate to an rca junction with multiple solder joints. 

BTW, the buzz on the RB250 is that when modified as above, it becomes superior to it's more expensive siblings in the Rega product line.  The difference being that the more expensive Rega arms employ a Vertical Tracking Force adjustment mechanism.  This device has just enough 'ring' to it to add a resonance of it's own to the arm and subtract a tiny bit from the pick-up signal.  The '250 has no such VTF adjuster and therefore does not have this problem.   The cheap arm wins.  How nice for us, the teaming masses.  Power to the people. 

VTF (vertical tracking force) adjustment is accomplished by sliding the counterweight into position on the end stub and then tightening an Allen set screw.  Not elegant, but effective.  Of course, you'll need a scale to set tracking force with this rig.  Then again, a scale should be used with all arms so it's really a non-issue.

VTA (vertical tracking angle) adjustment is accomplished with another Expressimo manufactured device.  It is a simple threaded collar that screws on to the threaded barrel of the tonearm.  Fitting between the tone arm and the arm board, VTA is adjusted by turning the collar.  It seems easy, and is, however this can't be accomplished without removing the tonearm from the arm board.  Fortunately, this is not difficult to do with the Teres as the arm board is pretty much hanging out in the breeze, allowing full  access underneath to the tonearm retaining nut.  It is recommended that the retaining nut be torqued to just beyond 'finger tight'.  A light touch is required.  

Pivot to spindle, effective length, overhang and offset angle were set with a Clearaudio alignment protractor.

Teres_3web.jpg (46910 bytes) (view of VTA adjuster and off-center"heavy weight")

Cartridge:

I chose to use the Shure V15VxMR I've been using on my Thorens.  This cartridge has 6 mos. use on it and as such is just nicely broken in.  It also makes it convenient to make a comparison in sound between the new Teres and the old Thorens.  More about that later.  The Shure mounted easily to the RB 250 arm and aligned with no fuss.  This may not be the ultimate cartridge to use on the RB250, but it tracks well and offers great sound for it's price point.  It has a stylus guard too...!

Motor and Drive 'String':

Teres_5web.jpg (45244 bytes) (drive motor pod with silk string)

Motor arrangement.  An infrared optical sensor installed to the acrylic base reads a strobe grid on the platter bottom.  The signal is regulated by microprocessor with some circuitry designed by Manfred Huber and built by the team at Teres.  Nice work on this one I'd say.  Operation is straightforward.  There is a pushbutton to start the motor.  Push it for a short moment and up comes 33-1/3 rpm.  Hold the button down longer and you get 45rpm.   A red L.E.D. tells us the motor is still spooling up.  A flashing green L.E.D. let's us know it's getting close.  When fully up to speed, the red goes out and the green is constant. Should the rpm waver for any reason, the red comes back on.  I see this when I use the carbon fiber brush at the start of play each time.  

Another, very pleasant way to operate this table is by simply giving the platter a gentle push in the correct direction.  The motor will start this way.  You can stop the platter simply by stopping it with your hands.   I get a certain satisfaction using the table this way.

Then there is the drive string.   Extended use suggests that drive pulley needs to be closely parallel with the platter.  If close parallelism is not maintained, the silk string begins to ride against a corner of it's pulley and the resulting increased drag is enough for the string to slip on the pulley.  This slippage  will start a chain of events involving the speed calibration circuitry in the controller that will lead to an audible pitch variation (music slows down).  I found this to be very disturbing at first.  Now that I understand it, I simply maintain good parallel alignment between pulley and platter, and I hear no more of this.

Test Record Time:

I use the HFNRR test record for making final arm/cartridge adjustments.  Here is the final test report from that session:

Tonearm = Expressimo RB250

Cartridge = Shure V15VxMR

Vertical Tracking Force. 1-1/8 gram set with Shure SFG-2 scale.

Side 1

Track 1) Channel orientation...............pass

Track 2) Phasing..................................pass

Track 3) Balance..................................pass

Track 4) Balance, left...........................pass

Track 5) Balance, right.........................pass

Track 6) Anti Skate...............................pass

Track 7) Anti Skate, higher..................pass

Track 8) Anti Skate, higher still............Fail

(note, I used Track 8 to fine tune anti skate resulting in a mild buzz right channel when Anti Skate was set at 15/16 g.  The best result I could get for Track 8.  This is my final Anti Skate setting.  It's also worth noting that my Thorens never got to this level.  It would simply fail at track 6.  The Expressimo RB250 is obviously a better tracker than the TP16 MK I of the Thorens. This, using the same cartridge in both arms.

Track 9) Anti Skate, even higher.........Fail,  jumps out of track.

Side 2

Track 1) Tracking...................................pass

Track 2) Lateral arm resonance...........9hz, big wobble

Track 3) vertical arm resonance...........12hz, little wobble

Track 4) Tracking....................................pass

Track 5) Cartridge align - azimuth.........pass

Track 6) Residual background noise....quiet well beyond any listening level

Track 7) Tracking.....................................pass

Operation: see Review of Teres 135

The Teres Record Clamp:

The record clamp is a stainless/delrin 2-piece assembly and secures itself over the record by engaging threads on the spindle center pin.  Function is very good.  There is also a delrin spacer that fits under the record to assist in giving clamping direction to the vinyl.  In many cases clamping is so good that the record shows visible evidence of a slight vacuum when taking the record off the platter.  I'm truly impressed with this.

Clamp_puck.jpg (57178 bytes)  Clamp_puck2.jpg (61964 bytes)  threads.jpg (14509 bytes)

The Teres Platter Mat:

Guess what...?  There is no platter mat with the Teres...!

RB 250 operation:

It looks a little precarious having the cartridge 'hanging' out in space the way it seems to.  I find the cue device to function adequately for safe operation of the arm.  By leaving the cue lever in the 'up' position, there is no worry about the stylus dropping below record level.  The arm drop is nicely damped by the cueing device and is accurate enough to place the stylus anywhere one likes at will.  This arm will be easy to live with.  

Date: 5/13/02,  

New addition of a "Shelter model 501 type 2" cartridge.

Date: 10/02, Signature Motor Controller Upgrade (see Teres 135 review)

Date: 11/02, Wright WPP100C Phono Preamp with MC Step-Up Transformer (See review)

 

For a review of the Teres' sound link here. Teres 135 Review

 

 

comments to: user510@earthlink.net