This thread is making me drool.
@John: I've always wondered about tangential arms. Saw a 4002 on Craigslist the other day. Thanks for your impressions!
Audioquest PT-6 recordscratcherholderstick with Grado Reference Platinum recordscratcherneedlebox. the Technics EPA-500 arm totally pwns this arm, but considering the disparity in price this should come as no surprise. the arm is only on the deck because the Grado screws dont fit in the slots on the EPA-500 headshell. grumbles.
The amplification of the signal from this cartridge is handled by an older Radio Shack DJ mixer which I have found to have a very good compliance to the RIAA equalization standard and generally good sound
In this photo the recordscratcherholderstick looks about 2ft long despite being slightly less than 12" (for what these things cost they should give you the full 12"! The audioquest is also less than 9"! Id expect this sort of "ooh we measure it our own special way that makes it look like 9" on a ruler that makes nikongod look like hes got a tice in his trousers" from a cable salesman, but never a reputable company) Most tonearms are an inch too short.
A closeup of the Grado recordscratcherneedle
Denon DL103 (the version that doesn't need improving, and hasnt been improved in its 40something years of production) mounted on the SME3012s2. There really is no other way to use this cartridge.
The amplification of the signal from this cartridge is done by a phono stage of my own design. Other days I use a cinemag SUT with the previously mentioned radio-shack mixer.
Its got a big rectangular button to start & stop.
it also goes at 33,45,78rpm, with +/-10% adjustment at all speeds.
The thought behind the tangential arm is: When a master record is (literally) cut from the original (2" tape of course!) master, it is cut literally on a lathe. While it is a mathematical fact that a true tangential relationship between stylus and groove is achieved only at two points (where the arc bisects the tangent), tracking angle errors occur at every other location.
Basically you need a high mass to keep the stylus in the groove, but the increased mass causes greater sluggishness in the movement of the arm (tangential inertia). In well designed tonearms, the total deviation is about 2-degrees, but even that will distort high frequencies. The main problem is the tonearm assembly mass causing the stylus to want to skate towards the center. This also has the added effect (when talking about anti-skating forces) of the stylus being pressed against the inner groove wall and producing unequal signal.
When B&O set out to design their new tone arm they had a number of criteria they wanted to meet. But, basically, they designed an optically triggered DC servo, a super lightweight tone arm, super lightweight stylus, and when finished had a tracking error skew that never exceeded 0.04-degrees (thats FAR less than the 2-degree error allowed by high-end radial arms).
The entire turntable is suspended inside the frame, and the tonearm is sprung and pendulum suspended, and physically coupled to the platter assembly. Move the platter, the tonearm moves too. All that means that a super warped record SHOULD play fine, but I'm not willing to find out just yet. It also has the benefit of being able to rap the side of the unit with a good sized hammer, and transmitting NO vibration.
One last note about the BeoGram 4002 (Gram because B&O state this is not a turntable, but rather a Gramophone): The Beogram 4002 was designed to be obsolescence-proof. The MMC 6000 pickup cartridge can play CD-4 (Quadraphonic), all matrix, stereo and mono discs. There is also space in the cabinet for a built in demodulator, but I don't think my unit has that. It can also be used with an external demodulator (which I found just the other day for $80, but I don't have any Quad discs)...
Hope that helps!
One last note about the BeoGram 4002 (Gram because B&O state this is not a turntable, but rather a Gramophone): The Beogram 4002 was designed to be obsolescence-proof. The MMC 6000 pickup cartridge can play CD-4 (Quadraphonic), all matrix, stereo and mono discs. There is also space in the cabinet for a built in demodulator, but I don't think my unit has that. It can also be used with an external demodulator (which I found just the other day for $80, but I don't have any Quad discs)... Wow I will have to check that out!
Pro-Ject RPM 1.3 Genie
- Zyx RS10-02 Cartridge
- Boston Audio Design Mat 1
Tom Evans Microgroove Phono Stage
Milky Zero Stat
Nagaoka Rolling 152
SOTA Record Cleaning Machine
Various Mobile Fidelity Cleaning Products
Is that an Onzow Zerodust I spy? How do you like it? I was thinking of picking one up. Cheapest I've seen it for is $50 on eBay.