Grado Signature Laboratory Standard Tonearm

[MikeR]

Over the holidays I came across this Tonearm while window shopping and I could not resist the temptation after see the quality of the build.
It is all steel and well designed. The two issues are a very slow weeping O ring in the base of the hydraulic arm lift.

The other issue is the secondary base is missing but I found someone who has the Tonearm with a base, so when he has time to remove it from his turntable he will send me the measurements
and my son has offered to make up a set of proper electronic engineer drawings and I will get it manufactured as there are companies who will do one off parts
for a reasonable price.

The diffucult part will be figuring out the finish so the new base and the rest of the tonearm match.

 

[Lee]

That's pretty cool. I had heard about these but never saw one. Thanks for posting.

 

[Rook85]

One of the most unique and almost outlandish designs. Extremely well build. A fascinating and unusual construction.

Great choice!

 

[tony22]

I almost bought one during the 80s. I was sorry I didn’t as soon as I walked out of the store.

 

[MikeR]

One of the most unique and almost outlandish designs. Extremely well build. A fascinating and unusual construction.
View attachment 146006
Great choice!

The attention to detail in the design and the execution of the tonearm is quite staggering. Apparently Joe Grado lost money on every one of these tonearms that he sold, easy to see how.

​

 

[Lynnot]

Have a look at an Ortofon RSG-309 (Summit 12) tonearm ...

 

[MikeR]

Why, this tonearm does look familiar, a budgeted copy of the Grado / Jelco arm with a few major differences. Thanks for pointing that out.

 

[MikeR]

Here is Ortofon's 9" version

RS-212D 9"

RS-212D 9" tonearm Technical data Effective mass (without headshell) - 3.5 gEffective length (distance between the stylus and pivot point) - 231mmMounting distance between the pivot point and turntable center) - 216mmOffset angle - 22 degreesOverhang - 15mmInner null point - 58,5 mmOuter...

ortofon.com

 

[nitrodan9]

i just aquired a oricle delphi with the grado signature laboratory standard tonearm it is missing the tracking force weight the microbalance weight and the coarse balance weight i can machine bbronze ones but i need the weight of them does anybody know the weights? thanks nitrodan9

 

[MikeR]

i just aquired a oricle delphi with the grado signature laboratory standard tonearm it is missing the tracking force weight the microbalance weight and the coarse balance weight i can machine bbronze ones but i need the weight of them does anybody know the weights? thanks nitrodan9

According to the manual the coarse balance weight came with two diferent sized lock knob 's so you have another weight option. My tonearm is missing that lock knob so I do not know if thIs one is the heavy knob or the lighter lock knob. If you find that information please let me know the dimensions.

- The tracking force weight including the lock knob

26 grams

6/8 " body length
7/8 " full body diameter
5/8 " + 1/2 eighth remaining from the removed section
5/8 " total length of lock knob
4/8 " + 1/2 eighth length of lock knob
threaded shaft
1/8 " diameter of lock knob
threaded shaft

The microbalance weight including the lock knob

21 grams
6/8 " body length
6/8 " body diameter
4'8 " + 1/2 eighth total length of lock knob
3/8 " length of lock knob threaded shaft
1/8 " shaft diameter of lock knob


The coarse balance weight including the lock knob

94.02 grams.
1 2/8 " body length
1 " body diameter
4/8 " taper length
5/8 " drilled hole
6/8 " width of drilled hole
2/8 " lock knob threaded shaft diameter
3/8 " lock knob threaded shaft length
4/8 " thickness of cap
8/8 " diameter across of cap

 

[nitrodan9]

thank you so much you are awesome spending the time for the info nitrodan9

 

[MikeR]

thank you so much you are awesome spending the time for the info nitrodan9

I see that I didn't include two sets of measurments. Let me know if I left out any other details.

The microbalance weight lock knob cap.
1/8 " thickness of cap
3/8 " diameter across cap

The tracking force weight lock knob cap.
2/8 " thickness of cap
4/8 " diameter across cap


Michael

 

[nitrodan9]

ONE THING THAT I KNOTICE IS THAT TRACKING FORCE WEIGHT DIAMETER ID 7/8 DIAMETER AND COARSE WEIGHT SAYS 1 INCH DIAMETER BUT LOOKING AT YOUR PICTURES THE COARSE WEIGHT HAS TO BE 1 1/4 OR 1 3/8 JUDGING BY THE SIZE DIFFERENCE IN PICTURES ??? THANKS NITRODAN9