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Post by MartinT on Sept 12, 2014 17:17:41 GMT
I had to scratch an itch recently as I have been having so much success with RDC Cones of late. They do a lot more than isolate, they seem to improve the sound of everything they sit under. So I decided to try them out under my Technics turntable to see if they would have a similar impact on the sound to that with the Ayre SACD player. I'm also suffering from a deep throbbing feedback issue with the volume turned up since I converted my system rack to spiked from sprung, but more of that later.
The components are: RDC 1 Cones with M6 stud x 4; RDC Cone Cups x 4; RDC Combi Bases x 4. The three together look like this at each corner: the cone point sits in the cup recess, which itself sits on a ring of sorbothane in the combi base. The deck can be levelled by dint of screwing the cones out a little, and you can feel the pressure on each combi by spinning them until the resistance at all four sides feels equal.
So to the sound: in a nutshell, they do the same things as with the other components in my system: a greater sense of detail, more air and space in the soundstage and tighter bass. Definitely good and better than the combination of Isonoes and Techniboots for just a touch more money. In terms of isolation, they are about the same which means I still have the bass feedback issue due to my concrete floor appearing to have a void underneath it which resonates at a low frequency.
I've put together an 'emergency fix' consisting of an old Russ Andrews Torlyte shelf and four SuperPods (the ones I used to used under the Ayre). It's not ideal, I know, and it needs more weight to allow the RDCs themselves to feel grounded, so I think I may need to find a piece of granite at some point. Another potential solution, which I know John favours, is to use a wall shelf. I don't want to reverse the system rack spiking as overall sound quality has risen rather nicely. The temporary solution looks like this:
In conclusion then, the RDC footer solution makes my turntable sound better than ever. Now to fix the bass feedback problem... |
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Post by John on Sept 12, 2014 17:47:21 GMT
Glad the upgrade helping I tried those cones a good few years ago had mixed results with them but like everything with HIFI accessories so system dependent.
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Post by MikeMusic on Sept 13, 2014 9:02:54 GMT
Wow !
The Isonoe feet and Techniboots are so good too
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Post by jandl100 on Sept 14, 2014 6:36:53 GMT
.... In conclusion then, the RDC footer solution makes my turntable sound better than ever. I thought it would. 
Squishy supports very seldom work for me. I almost always lose out on definition and rez, ime.
Have you tried your RDC stacks without the squishy combi base, Martin? I realise that may exacerbate the Evil Feedback problem - but my bet is that the sound will be better at lower levels. 
Would you like to try my magnetic levitator bases? - they support between 20-35Kg -ish. They are a sort of squishy anti-feedback support that can work well with some kit.
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Post by MartinT on Sept 14, 2014 8:58:27 GMT
Thanks, Jerry. Hold off until mid-week when I put RDC1s on the system rack. If that doesn't work, I'll take you up on your kind offer.
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Post by MikeMusic on Sept 14, 2014 10:28:32 GMT
Martin
What is the total clearance height between the Tech chassis and 'floor'
My FR arm needs quite a bit
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Post by Pinch on Sept 14, 2014 10:41:32 GMT
Interesting stuff Martin! I have Isonoes on each of my 1210s, with Technoboots on one and the Isonoe boots on the other. I think this is may be the best arrangement for me currently, as I live directly above a tube line, and there's a lot of incoming vibration to deal with, but if I ever make it onto firmer ground I might have to get some RDC cones for one of them and compare.
One thing worth noting about the Isonoes is that (IMO) there's a small design flaw, in that the 'bushes' which sit between the underside of the deck and feet aren't sufficient to take the weight the of the deck, all of which is then placed on threads of the M6 screws that secure the feet to the deck, and there's a not insignificant amount of wiggle room here - not secure at all - so hardly ideal from an isolation perspective. I fixed this by replacing the bushes with four appropriately sized nylon spacers, taking the weight off the screws and holding the feet firmly in place, and it made for a notable improvement.
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Post by MartinT on Sept 14, 2014 10:49:02 GMT
That's good to know, Tom. The accepted wisdom is that the Isonoes should only be lightly tightened but then, as you say, the threads are taking the total load.
I am doing the same with the RDCs in the Technics and will use nylon shims to perform the final levelling.
Mike: no problem with clearance under the Dynavector post.
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Post by MartinT on Sept 14, 2014 10:56:07 GMT
These shims:
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Post by MikeMusic on Sept 14, 2014 11:51:04 GMT
Shirly the shims get in the way of the RDC effect ?
Recently discovered bolts are 'M'.
Measured the Technics foot bolt and that is 5mm outer diameter, inc thread
Mana seem to use 7m and Isobarik stands 9mm
I'm measuring very carefully and I'm puzzled that 5,7 and 9 are what I have
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Post by MartinT on Sept 14, 2014 15:49:20 GMT
No, Technics is M6 thread (thought I covered that in the first post). 'M' is for metric.
The shims have got to be better than unscrewing the RDCs to get the level right, thus placing all the load on the thread?
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Post by MikeMusic on Sept 14, 2014 20:05:45 GMT
Got that
I measured my Technics Sorbothane foot bolt and it is 5mm - which tells me something is not right.
Checked it, got a 2nd opinion, still 5mm diameter
Add to that 7 for the Mana and 9 for Isobarik and it seems downright odd
Thought 6 and 8 were very common
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