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Phono stage w/automatic Load-Impedanance.

Yes, automatic load impedance! The WLM PHONATA offers very high dynamics as a result of its very special design (see below)

A few years ago i purchased a slightly used demo unit from Australia. It was reasonable priced (mint- condition) WLM PHONATA reference MM/MC phono stage from respected WLM Acoustic brand (made in Europe). I use it since that day in my system.

a picture of the wlm phonata linked below:
http://audioaddiction.net.au/wp-content/uploads/2012/05/Phonata_3XL.jpg
http://audioaddiction.net.au/wp-content/uploads/2012/05/Phonata_4XL.jpg

When i bought mine demo it was newly released and totally different for previous WLM model (which was a smaller tube stage). The reference WLM Photana is not a tube stage. I'm not sure what's happened after, but probably it was not widely distributed, maybe they made first run and stop the production of this nice unit. They never updates their own website with info about this new unit. It's impossibe to find any reviews online and i assumed there are not so many users.

I wonder if anyone on AudioGon aware of this ice nproduct. I'm sure most of you familiar with amazing range of WLM speakers and different Tube Amps.

But do you know anything about WLM Photana Referense Phono Stage MM/MC ? It has some interesting features such as AUTOMATIC LOAD IMPEDANCE and 2 RIAA CURVES. It comprises pinnacle circuitry and design features that have never been realized before.

The PHONATA works with two-stage amplification:

• An inductive voltage amplification stage (for MC cartridges) using high
performance professional audio step-up transformers.

• A solid state current amplification stage, using specific MOS-FET transistors with tube-typical harmonic distortion characteristics.

The PHONATA offers utterly precise RIAA equalization:

• RIAA equalization is implemented across two amplification stages (within current amplification), providing a frequency expansion from 10Hz to 50kHz (Subsonic cut below 10Hz). Selected components (1% tolerance) are used.

• RIAA equalization can be selected from two positions with a switch at the back of the unit:

- Position “high” for records produced before 1965 or to improve the performance of somewhat “darker” sounding cartridges at higher frequencies. This position provides +3dB equalization as from 5kHz and +6dB as from 10kHz.

- Position “low” for all other records The PHONATA offers automatic adjustment of Load-Impedance:

• You don’t have to adjust the load-Impedance of your cartridge (plus the interconnect-cable between cartridge and Phono-Preamplifier). It goes automatically thanks to one ingenious piece of circuitry.

• You don’t have to adjust the source voltage of your cartridge as well.

• There are no micro-switches or any other mechanical contacts in the signal-path.

Technical Data:

MC-Input Impedance Range: < 100 Ohm to 50kOhm
MM-Input Capacity: 100pF
THD (Total Harmonic Distortion) @ 1kHz: 0.01%
SNR (Signal to Noise Ratio) MC: >72dB
SNR (Signal to Noise Ratio) MM: >85dB
Max. Input Voltage for MC-cartridges (theoretical value): 1200mV @ <1% THD
High Performance, Professional Type Step-Up Transformers.
chakster
chakster's avatar
chakster OP
6,144 posts
 
I definitely need to compare my Automatic Impedance Load phono tage to some other phono stages with Manual Load options if i can invite someone with such stage to my house to check this out (and drink some wine).

I have no idea how it works with Automatic Load Impedance, but i try to understand the process and need for manual load (when you don't have 10 cartridges).

What did the improvement in sound of very low coil impedance (4-6 Om) cartridges is my external cpp-1 headamp for such cartridges as ZYX or Ortofon SPU. Lewm, 4 Omega is very low coild impedance - right ? And the ouput of these cartridges also very low (about 0.24 mV).

At the same time my AT Art2000 MC cartridge impedance is 12 Omega and output voltage is 0.4 vM. Absolutely no problem with 47db gain of my WLP stage. Sounds good with auto load, but with connected external headamp cpp-1 (between cartridge and my MM input) the sound is more like on steroids.

With high output MC like 1.9 mV Argent (don't know the coil impedance) my auto-loading stage sounds simply amazing and no need to change anything.
swampwalker's avatar
swampwalker
5,138 posts
 
Where you at Chakster? I've used the Zyrtec headamp w Azusa and now I have a Doshi all active gain mc phono stage. If you're in the Northeast U.S. We could run them both sto compare. I'm in CT (but not this week).
chakster's avatar
chakster OP
6,144 posts
 
Swampwalker, thanks for your kind offer, that would be great, but we have a problem... I'm in Saint-Petersburg (not in Florida).
atmasphere's avatar
atmasphere
12,138 posts
 
Cartridge loading of low output moving coils is almost of no consequence unless the preamp is unstable or unhappy with ultrasonic or Radio Frequency bursts at its input.

If you find that loading is making a difference with your setup, its an indication that the preamp has stability problems. This is because the cartridge is entirely unaffected by load at audio frequencies. You hear a difference because the load resistance is detuning the resonant circuit created by the cartridge inductance and the cable capacitance. So if the preamp is unaffected by this the loading will have no effect.
chakster's avatar
chakster OP
6,144 posts
 
Atmasphere, seems like it's your answer to Lewm who prefer different load for different catridges?

I have no ability to change load, this is automatic option with my WLM MC 47db gain stage with build in suts. I just noticed the difference (positive) with some mc cartridges when i use additional device (active headamp with 26db gain by zyx which compete with top suts). Nakatsuka-san made it for his own cartridges and using Zyx Airy and Zyx 4D with or without his headamp i prefer to use them with his headamp (it was an improvement even with additional cable).

Zyx headamp + WLM mm stage is better for low output Zyx Cartridges than my WLM MC stage with build in suts and automatic load impedance option.
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