Revox HELP!!
A linear tracking analogue saga...
So it is time for a new cartridge on the B795 Linatrack....
I spend over a year finding a cartridge mounting kit... finally get one last week
Then begins the search for a cartridge/needle.
1) I am told the tonearm has a mass of 4g (ultra low mass)
2) There are 2 optional counterweights to adjust for various cartridges - Brass - at what seems to be 7g for cartridges of less than 6g, or Lead at 14g for cartridges of more than 6g
So the tonearm has possible mass configurations of 4/11/18g
To make future cartridge changes and experimenting with cartridges easier, I have decided to try to go P-Mount (as revox did in their later models)
The Audio Technica P-Mounte adapter weighs in at 1.5g
This makes for a tonearm of 5.5/12.5/19.5g....
Given that cartridges of 7.5g (the T4P / P-Mount standard + 1.5g for the adapter) require the Lead counterweight - I am now looking at an effective arm mass of 19.5g
This is no longer a low mass tonearm - at this point it has become a medium mass tonearm...
Now I start doing calculations on Resonant frequencies with the cartridges that people have been recomending (high compliance)
Ortofon OMP10/20/30/40 Comp 25 - res Freq 6.4Hz - not good
Digitrac 300SE Comp 30 - res Freq 6 Hz - not good
Stanton L720EE Comp 16 - res freq 8Hz - useable but not ideal
AT 301/311/92 family comp 20 - res freq 7Hz - not good
This makes no sense - these are the cartridges that should match according to the online gossip.....
So I check the service manual for cartridges that were shipped with it originally:
Shure V15VP - Comp 30 - res freq 6.6Hz - STILL NOT A MATCH
How is this possible?
What am I missing?
Am I somehow miscalculating the resonant frequency?
I am using the calculator at
http://www.mh-audio.nl/MySystem/RF.asp - and have spent many hours online collating information on cartridge weights, compliances etc... (the Cartridge database being one of the principal sources!)
My end result is coming down to needing a mid compliance cartridge rather than a high compliance one. Ideal for a p-mount seems to be a comp of around 12.
Can I have input please from the Revox experienced out there... have I missed something?
I also remember some mention in one thread of a damper with sticky blue-tacky type stuff in it on the back of the tonearm - but I don't remember seeing anything of the sort on my B795 (or on the service manual diagrams!) - was this a feature of the later B291's? (does it even exist?)
Help much appreciated!
thanks