Ortofon SPU Classic GMII E & SUT

[Moko]

Hi I have an Ortofon Classic GM E MKII and a set of Beyer dynamics TR/BV 370 215 006 SUT's which have two settings 50 Ohms or 200 Ohms does anyone have an idea of which setting would be best for my SPU. Amplifier is a Fisher 500c if that's important.

At present they are wired for 50 Ohms but with a bit of soldering I could change this to 200 Ohms but before I get out the iron I thought I would see if anyone here has any knowledge / experience with this sort of thing

Here's the offical specs for the cartridge

Ortofon SPU Classic GM E MKII Technical Data

Output voltage at 1000 Hz, 5cm/sec. 200 µV

Channel balance at 1 kHz < 1 dB

Channel separation at 1 kHz > 20 dB

Channel separation at 15 kHz > 10 dB

Frequency range at - 3dB 20-25.000 Hz

Frequency response FIM distortion at recommended 20-20.000 Hz + 3 / - 2 dB

Tracking ability at 315Hz at recommended tracking force *) 65 µm

Compliance, dynamic, lateral 8 µm/mN

Stylus type Nude elliptical

Stylus tip radius r/R 8/18 µm

Tracking force range 3,0-5,0 g (30-50 mN)

Tracking force, recommended 4,0 g (40 mN)

Tracking angle 20°

Internal impedance, DC resistance 6 Ohm

Recommended load impedance > 10 Ohm

Cartridge body material Grinded wood

Coilwire material High Purity Copper (OFC)

Cartridge colour Black

Cartridge weight 30 g

Thanks for any advice / opinions

David

 

[pure sound]

50 Ohms would be better than 200. A little lower might be better still. Try putting 82K resistors across the output (or even 100K).

82K in parallel with the 47K of your phono stage would present a reflected load through the transformer of about 33 Ohms.

(set for 50 Ohms the transformer appears to have a 1:30 ratio)

 

[Moko]

Thanks for that it does sound very nice at 50 Ohms but as ever I suppose in HiFi I was wondering if it could sound even better, but I will follow your advice and see what happens.