The Article
Luxman EQ-500 phono stage: from solid state to valves
2nd November 2016
Luxman’s last top of the line phono stage, the solid state E-1 was released in 2001 and was only recently discontinued. Now they’re back with a valve-based model
Featured within are two step-up transformers per channel—one each for low- and high-output moving-coil cartridges. There are also three dual-triode valves per channel, for gain and buffering. Additional gain comes from the Perma-alloy-cored, step-up transformers.
There is a valve rectifier to the power supply circuit for supplying a stable voltage to the amplifier circuit, employing a choke-coil.
Valves include two ECC83/12AX7 dual-triode tubes (shunt-regulated push-pull) plus an ECC82/12AU7 dual-triode valve cathode-follower.
Around the back are balanced and single-ended outputs including three separate, single ended inputs.
Apart from Mundorf capacitors, the box also includes, JJ valves and Takamisawa capacitors.
Also available are filter switches for ‘low cut’ (20Hz/3dB) and ‘high cut’ (8kHz/3dB) plus a mono/stereo switch, an articulator switch (cartridge demagnetizer) and a phase invert (for balanced output). Price is £4,495.
To read more click www.luxman.com or call 01480 447700
Hi Paul.
love your writings in HiFi World – not only tech stuff but wisdom too!
One question about the Luxman EQ 500, which I am trying out at the moment. The literature for my Cadenza Blue and Black cartridges recommends a loading impedence ‘above 10 ohms’ for the Black and 50-100 ohm for the Blue. But the dial on the EQ 500 starts at ’30K’, way above the ’50-200 ohm’ specified for the Blue. Do Ortofon mean ‘above 10K’ for the Black and ’50K-200K ohm for the Blue?
I’m worried that presenting a carttidge with the wrong impedence will distort my assessment of this lovely phono preamp!
Help!
Roger
Thanks for your kind words, Roger. Onto your query – I don’t have the advantage of having a unit here or access to the manual so I’m shooting in the dark a little bit but, from what I recall, the impedance knob is for MM carts only. Activated when you switch the Cartridge knob to MM. If you select MC Low the impedance is 2.5 Ohms and if you select MC High the impedance is 40 Ohms. Both are automatic settings…I think. Not perfect for your Ortofons but near as dammit 🙂 Like I say, I’m partly guessing here so my words are not exactly gospel. Please check the manual again on this and seek out confirmation but I’m *fairly* sure that is the case.
Ortofon mean what they write. It’s above 10 Ohms and between 50 to 100 Ohms, not kOhms. A good rule of thumb is to multiply the internal impedance of the cartridge and load it there.
The values for MC given by the Luxman are the impedances of the transformers, not what the cartridge is going to ‘see’. To cut a long story short, your cartridge should ‘see’ 580 Ohms in the MC high setting and 75 Ohms in the MC low setting. At least with MM set at 47 kOhms. If you change that setting it should indirectly affect also the setting that the cartridge ‘sees’. For instance if you increase the MM setting to 100 kOhms it should change the load that the cartridge ‘sees’ to 160 Ohms.
You can calculate this yourself if you know the increase in gain that the transformer provides (or rather the increase in voltage). There are calculators on the web.
The really short version: MC low will be just fine for your Ortofons.
P.S. Luxman should have explained this in their manual.
*multiply the internal impedance of the cartridge by 10