Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Analogue Source Turntables, Tonearms, Cartridges, Phono Stages, Tuners, Tape Recorders, etc.

The Incredible Technics SP-10 Thread
The Incredible Technics SP-10 Thread
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 20th October 2019, 05:02 AM   #1271
warrjon is offline warrjon  Australia
diyAudio Member
 
Join Date: Feb 2011
Location: Terang Vic
Looks great, and glad to hear it sounds good.


Can't wait to get mine running...............
  Reply With Quote
Old 20th October 2019, 08:22 PM   #1272
Pitrus is offline Pitrus  Italy
diyAudio Member
 
Pitrus's Avatar
 
Join Date: Jun 2019
Location: Italy
Quote:
Originally Posted by rhthatcher View Post
Now itís time to move the SME V over from my SOTA. As I suspected, it will not rest parallel to the SP-10. The geometry doesnít seem to work out. Does anyone have pics of their SME V (or similar) arm on their rig?


only the Sme 312 (not 310) or the IV and V at 12 "remain parallel, all the 9" tonearms arms it is necessary to accept that the tonearm is not perpendicular, several 10 "tonearms vintage remain parallel.

Epa 100 and Epa 500 are 10"

Last edited by Pitrus; 20th October 2019 at 08:30 PM.
  Reply With Quote
Old 21st October 2019, 10:04 PM   #1273
warrjon is offline warrjon  Australia
diyAudio Member
 
Join Date: Feb 2011
Location: Terang Vic
Quote:
Originally Posted by brianco View Post
Why not make a seal - similar to a speaker driver interface to the speaker cabinet? The practical use of this is that if you use paper of the type children draw on with crayons you will damp some of the motor vibrations from reaching the top-plate. Such paper has been used very successfully as interleaf layers in stacked sheet stacked + bronze plinths.

This is a common mod for an LP12 between the platter and sub-platter.


I am in the process of building a bentonite ISO resin plinth. I've already made the mold and hopefully will start poring resin today depending on weather. With the motor coupled to the TT frame this should in theory transmit the vibrations to the plinth, where they will damped.
  Reply With Quote
Old 23rd October 2019, 12:28 AM   #1274
brianco is offline brianco  Ireland
diyAudio Member
 
brianco's Avatar
 
Join Date: Aug 2005
Location: Scottish Borders - Kelso; on the famous Tweed River!
Quote:
Originally Posted by warrjon View Post
This is a common mod for an LP12 between the platter and sub-platter.


I am in the process of building a bentonite ISO resin plinth. I've already made the mold and hopefully will start poring resin today depending on weather. With the motor coupled to the TT frame this should in theory transmit the vibrations to the plinth, where they will damped.
It is good for most metal to metal interfaces. I am still looking out for some good alloy plate in the 'used' yards! I found one piece of the right dimensions by 5mm. I also have a bronze large circular plate - just right to use as a motor to plinth mount. [My SP10 has the boards off motor & connected by umbilical; no top-plate] But - having an itch to get it going I will probably have to use something different. Like to hear how your resin plinth sounds when finished. Ideally I would like to use fine grain carbon sheet with alloy and copper interfaces...but at the price of carbon I am more likely to use flying pig skin sandwiched in platinum sheet!!! I suspect I will use slate.
  Reply With Quote
Old 23rd October 2019, 04:32 AM   #1275
Bon is offline Bon  Australia
diyAudio Member
 
Join Date: Mar 2004
Location: Sydney, Australia
Quote:
Originally Posted by warrjon View Post
Finished sub platter.

I was thinking of a resin bentonite plinth, I've heard good things, any body have one?
I have been making plinths for SP10 mkII for 20 years. I have used mdf, Corian, engineered stone, resin-fibreglass and for the past 5 years, resin-bentonite. The final resin-bentonite composition took a bit of fine-tuning by trial and error, but the results are excellent IMO. The casting process needed a few wrinkles ironed out. Many samples were tested to destruction (sledge-hammer) to refine the mould/inserts construction, bentonite-resin-hardener mixing ratios, pouring strategy, curing regime, mould-insert extraction, surface prep and painting, etc. I invested in a SP10R a year ago but I won't post comments here since there is a companion SP10R thread to this one, where I may post if there is any interest.
Attached Images
File Type: jpg Mold+inserts.jpg (763.1 KB, 132 views)
File Type: jpeg Raw plinth.jpeg (932.5 KB, 126 views)
File Type: jpeg Plinth+SP10+SME.jpeg (724.9 KB, 119 views)
File Type: jpg Complete-lid.jpg (641.6 KB, 125 views)
File Type: jpg Complete+lid.jpg (507.7 KB, 118 views)
__________________
Bon
"Moderation is a fatal thing. Nothing succeeds like excess." Oscar Wilde.
  Reply With Quote
Old 23rd October 2019, 10:04 AM   #1276
warrjon is offline warrjon  Australia
diyAudio Member
 
Join Date: Feb 2011
Location: Terang Vic
*******It lives********


Finally got the thing working, almost. PLL locked and speed stable on all speeds, except for a slight glitch on the speed, you can see the strobe blink for a couple of mS, this maybe the 5V as my power supply is maxed out at 4.8V.



5 faults including 2 modifications repaired so far..




Bon.

I cast my bentonite/resin plinth yesterday. I used 2% catylist which was way too much for the 50mm think pour. I should have used 0.5% for that thickness. I used 50/50 ratio but could have used 40/60 resin/bentonite, I have about 5mm of clear resin at the top of the mold.



Yep it cracked on the thick part where the tonearm would be. I am going to mill that away and just re-cast the repair.
  Reply With Quote
Old 23rd October 2019, 11:17 AM   #1277
Bon is offline Bon  Australia
diyAudio Member
 
Join Date: Mar 2004
Location: Sydney, Australia
Quote:
Originally Posted by warrjon View Post
*******It lives********


Bon.

I used 2% catylist which was way too much for the 50mm think pour. I should have used 0.5% for that thickness. I used 50/50 ratio but could have used 40/60 resin/bentonite, I have about 5mm of clear resin at the top of the mold.



Yep it cracked on the thick part where the tonearm would be. I am going to mill that away and just re-cast the repair.
Some info that you may find helpful. Firstly, it is a learning process, don't expect to get it right the first time (or even the second ... ). I use a 45/55 % ratio of resin/bentonite by volume, but my mold is 90mm in height. Catalyst/hardener is 1% of the resin by volume. One frustration is that the total mixed volume is always about 20% less than the measured un-mixed volume. This is because the bentonite contains considerable volume of air, which bubbles out during the mixing. In fact, the mixing must be done very slow and steady to minimise introducing air which gets trapped as the mixture cures, giving rise to an aero/malteser effect. (I found out the hard way using a drill mounted tile cement mixer.) The mix should be left for about 15 minutes before pouring to allow air bubbles escape. Too much hardener leads to rapid curing and heat generation that can crack the plinth. On a hot day, I have even had to fan cool the mold. Best to avoid hot days. The bentonite will settle. I aim for less than 5mm of resin in a 90mm plinth. The pour is crucial to promote a slow steady flow into the tight areas that could trap air bubbles. I leave the plinth in the mold for at least 7 days. I have bolts imbedded in the mold inserts to allow extraction by a bolt extractor style frame. Even though I remove the plinth from the mold after 1 week, it is usually best to leave it alone for up to 4 weeks before it is ready to be handled. 1% hardener takes a while for it to becomes non-sticky and be warned, it can distort if not kept face down on a flat surface, under pressure. I am not sure if your mold is base up or top up. Mine is base up which means the top in flat at the bottom of the pour. If yours is top up, the top (resin layer) will not be perfectly flat and will need dressing.
You will need to putty it up and prep it properly if you want a nice painted finish.
Hope some of this helps.
__________________
Bon
"Moderation is a fatal thing. Nothing succeeds like excess." Oscar Wilde.

Last edited by Bon; 23rd October 2019 at 11:43 AM. Reason: Autocorrect strikes again!!
  Reply With Quote
Old 24th October 2019, 12:22 AM   #1278
BrianL is offline BrianL  United States
diyAudio Member
 
Join Date: Mar 2002
Location: USA
The Incredible Technics SP-10 Thread
Interesting. do you have make / p/n for the resin and hardener? Is bentonite the cat litter used by some folks or something else? Also, what is your definition of 'hot day' as my desert cold days could possibly be what you consider a hot day.
__________________
bel
  Reply With Quote
Old 24th October 2019, 01:04 AM   #1279
Bon is offline Bon  Australia
diyAudio Member
 
Join Date: Mar 2004
Location: Sydney, Australia
Quote:
Originally Posted by BrianL View Post
Interesting. do you have make / p/n for the resin and hardener? Is bentonite the cat litter used by some folks or something else? Also, what is your definition of 'hot day' as my desert cold days could possibly be what you consider a hot day.
The resin is commonly labelled casting resin and is a isopthalic polyester resin with associated hardener/catalyst. It should be available from a normal fibreglass fabrication supplier. The bentonite is granular (not powder!) and is often sold as Fines or Cattle Feed Supplement. I am not sure if this is the same as kitty litter.
For suitable pour conditions, I prefer temperatures below 25 centigrade (77 fahrenheit). Today in Sydney, it will reach 29 C (84 F), possible but hotter than I like. Of course if you are in a controlled temperature, you can pour at any time. The fumes are unpleasant though, so I always set up in the workshop without air-con. Unfortunately, temps are climbing here and there will be relatively few days below 25 C for the next 4-5 months (2 in the next 10 days by forecast)
__________________
Bon
"Moderation is a fatal thing. Nothing succeeds like excess." Oscar Wilde.

Last edited by Bon; 24th October 2019 at 01:12 AM. Reason: Omission
  Reply With Quote
Old 24th October 2019, 02:49 AM   #1280
BrianL is offline BrianL  United States
diyAudio Member
 
Join Date: Mar 2002
Location: USA
The Incredible Technics SP-10 Thread
Thanks, Bon. That is very useful info.
__________________
bel
  Reply With Quote

Reply


The Incredible Technics SP-10 ThreadHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Technics SP 10 Speed Problems rollinr Analogue Source 29 27th October 2017 10:05 AM
Technics SP-10 Doesn't Spin breadhead Analogue Source 6 27th October 2014 12:09 AM
Cheap oscilloscope for setting up a Technics SP-10 johnm Analogue Source 22 28th June 2011 08:47 PM
Technics SP-10 speed problems Stefanoo Analogue Source 3 17th August 2008 11:05 PM
Technics SP-10 MKII pitch control peterb Analogue Source 6 28th March 2004 02:29 PM


New To Site? Need Help?

All times are GMT. The time now is 04:17 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki