TD150 - RB300 mounting question

[Flyingorthopod]

Sorry for another TD150 related question. Grateful for advice.

Deck is with a very helpful local shop for service. Springs are sorted. However he has pointed out that the RB300 I had fitted 25 odd years ago isn't quite at the right position - the spindle to pivot distance is about 7mm out. This may have been deliberate to help the arm clear the lid. AFAICR the armboard was off the shelf at the time of changing.

It sounds pretty good to me but could probably be improved!

He's offered a free swap to Linn Basik or to change the board for correct mounting.

Or I could ignore it.

What would the forum wisdom do?

 

[SONDEKNZ]

Avoid the LINN BASIC. Your RB300 is way better!

Sort the arm-board with a new hole, correctly positioned.

 

[Lurch]

Get it sorted with a new armboard and correct S-P distance.
7mm is way out of spec. The std for Rega is 222mm with 17mm overhang. Having the S-P out by more than 2mm will mean that the correct Stevenson/Baerwald etc geometry and resultant distortion values can't be achieved.

 

[Flyingorthopod]

Thanks. Sorting the armband. Hopefully the lid will still fit!

 

[Flyingorthopod]

armboard. Hateful autocorrect.

 

[Hazelberry]

Here’s a thread from a year ago about Rega overhang:

Rega overhang

Hello, is it 14.5mm or 17.5mm, I have seen various measurements. Rega state 14.5 but I've seen 17.5 also, I for the life of me can't figure why they should differ and would it make that much difference. Thanks and a happy Easter.

pinkfishmedia.net

I use 14.5mm with my RB300 & Rega geometry. Around 17.5mm is recommended for Lofgren A/B (& presumably Baerwald) geometries.

Personally, I prefer Regas geometry to Baerwald.

 

[chartz]

I found that the RB300 with a TD160 was a boring combination. Do try it, use the Rega geometry, and tell us what you think. They just didn’t gel.
I went back to the original TP16 in the end.
The Rega went to an SL-1200 and there it sang.

 

[Mr Pig]

The 300 is a much better arm than a Basik. Partner in with a lively cartridge like an Audio Technica mm and it should be fine.

 

[Flyingorthopod]

I've had the td150 with rb300 running for quite a long time and have been pretty happy with it, albeit aware it wasn't perfect. I'm intrigued to.see how much difference correcting the tonearm mounting makes

 

[Mr Pig]

I've had the td150 with rb300 running for quite a long time and have been pretty happy with it, albeit aware it wasn't perfect. I'm intrigued to.see how much difference correcting the tonearm mounting makes

Will probably depend a lot on the cartridge. The better the stylus profile, the more of a difference.

 

[Locheeboy]

Free turntable cartridge alignment protractors | setup tools

Generate a custom phono cartridge alignment protractor! Perfect for any turntable ✓ Easy to use ✓ Print or PDF download ✓ All free ✓

alignmentprotractor.com

This place offers calculations for the turntable+tonearm . Put in make/model/ settings of (almost) any t'table+tonearm , hit calculate and a series of settings are offered.

PS...

Rega Tonearm Specifications​

Low effective mass 11 grams
Effective length 240 mm
Overhang 17.2 mm
Offset angle 23 degrees
Mounting distance: platter centre to arm hole centre 221.7 mm
Diameter of mounting hole 23 – 25mm but 24mm is preferable as it allows threaded VTA adjuster to be fitted
Size of base mounting nut 32mm A/F (across flats)
Maximum armboard thickness 27mm
Total Weight 436 grams
Capacitance 0.002uF
Resistance 0.002 ohms
The tip of the stylus should be 240mm from the pivot. In approximate terms, the armboard mounting hole should be such that the cartridge stylus will “overhang” the record centre (spindle) by a distance of around 17mm for an arm that is of 240mm Effective Length (distance from stylus to armboard mounting hole centre). Roughly check this by swinging the stylus over the record spindle.

Not just Origin Live specs, but several dealers offer these specs... Rega themselves offer 17.23 overhang...and Roy Gandy reckons ye only need one node point to be correct. I've tried it and he is correct (IMO)...

 

[Flyingorthopod]

Thanks, shall.experiment when it comes back with correctly mounted rb300

 

[Chops54]

To the best of my knowledge the mounting distance of the original Thorens arm is 216mm so maybe that’s why your Rega is 7mm out. As for the Rega I remember some years ago quite a few people were mounting the arm at 219mm or thereabouts and using Baerwald to set the cartridge as over the side of an LP the distortion was less than using Stevenson’s. The cartridge did need skewing in the headshell slightly to line up with the null points. Never appealed to me be honest and I stuck with Stevenson’s.