mass style tt

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Berndt

mass style tt
« on: 26 Jul 2009, 04:14 am »
First I want to welcome Herbies to AC, I use your halo dampers on my phono stage and linestage.
I've also used the dots under xo boxes with my magnestand maggies.
My question is in regards to high mass suspensionless turntables. I am building a high mass tt that has a 45lb platter with motor pod and armboard total coming in around 100lbs total.
I have a cantilever wall mount and an isolation box with catlitter. What are your thoughts on coupling or isolating the tt from the isolation box? I have been using spikes on my current replinthed empire but am thinking of going to a sorbothane style connection for the tt to iso box connection.
Thanks in advance for your time and welcome again to AC! :D
Regards, Bill

TheChairGuy

Re: mass style tt
« Reply #1 on: 26 Jul 2009, 04:39 am »
45 lb platter, Bill? :o

You're wonderfully insane :)

John

Herbie

Re: mass style tt
« Reply #2 on: 26 Jul 2009, 04:43 am »
Hi, Bill. I like playground sand myself; it's always worked very well for me, with baltic birch plywood embedded onto the sand. Great for leveling, you can just squoosh the birch around as needed.

Suspensionless turntables virtually always benefit with some compliance, if done right. With a heavy turntable like you describe, a set of four Herbie's Extra-Firm Big Tall Tenderfeet will give you the best decoupling and isolation that I know of.

With Extra-Firm Tenderfeet, you'll get the decoupling you need and absorption of the micro-vibrations that cause so much of the sonic anomalies you don't want. Your turntable will most likely achieve a linear and honest musical reproduction without sonic "trade-offs" that most Sorbothane-type materials introduce.

Best Regards,

Steve
Herbie's Audio Lab
« Last Edit: 23 Aug 2010, 01:51 am by Herbie »

Berndt

Re: mass style tt
« Reply #3 on: 26 Jul 2009, 02:38 pm »
My isolation platform uses 2 3/4" sheets of mdf glued/screwed together as its top.
Sould the feet be mounted to the platter base?
What would their loaded height be so I can create additional offset for the motor pod.
Yes, 45 lbs because I can and had the material laying about. I laminated 2" pvc, 1.5" aluminum and 1" bronze fwiw.
Hopefully the empire motor will turn it. Made a 1" tool steel spindle helb by a 4" bronze bushing into a cast iron baseplate.
First tt was an empire replinth, now I am just using the motor.

Herbie

Re: mass style tt
« Reply #4 on: 26 Jul 2009, 03:43 pm »
Big Tall Tenderfeet are 1.02" tall; with your turntable, loaded height would be about 1".

Tenderfeet can be adhered to the platter base. I recommend using them free-standing, though, because then you keep versatility of placement. Footers don't always work best placed arbitrarily, and some experimentation with placement sometimes finds "sweet spots" where they do best. Tenderfeet get a good grip on whatever materials they are in contact with; you're component stay firmly put and not slide on them or anything.

(Big Tall Tenderfeet work particularly well on MDF. Becuase so many shelves and platforms are made of MDF, we chose this material as the primary reference in developing the Tenderfoot material formulas.)

Steve
Herbie's Audio Lab
« Last Edit: 23 Aug 2010, 01:51 am by Herbie »

Berndt

Re: mass style tt
« Reply #5 on: 26 Jul 2009, 05:39 pm »
the platter bearing base is a 12" circle
the tonearm board is @3 o'clock with the motor pod @ 8.
Would you suggest 3 or 4 footers?
The build isn't going to be complete for another couple of weeks but I just want to have all the possible offsets worked out, thanks.
Regards, Bill

Herbie

Re: mass style tt
« Reply #6 on: 26 Jul 2009, 06:45 pm »
Three or four will do. With non-compliant footers like cones, you're often limited to three (in order to define a plane); you'll almost always end up with one "short" footer otherwise.

With compliant footers like Tenderfeet, four is usually better. This gives you more vibration-absorbing contact area and more vibration-blocking "beef." More even distribution of the weight load on the footers. Also, it provides more lateral stability and allows for more latitude with placement of the footers.

Steve
Herbie's Audio Lab
« Last Edit: 23 Aug 2010, 01:51 am by Herbie »