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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.
128x128chakster
atmasphere's avatar
atmasphere
11,633 posts
 
Apparently you think this is the only reason to load down a cartridge. If so, you're wrong. I've already explained that wide open is not always better. Maybe it is in your preamp, I wouldn't know, but we're not talking about your preamp.

I am not talking about MM, where achieving the critical damping value is important for best performance.

I am talking about the fact that if you hear tonality change with a LOMC seemingly due to loading, its on account of the behaviour of the preamp and not the signal from the cartridge.

I had a conversation with Jonathan Carr at the recent Munich show. He mentioned the same phenomena that I did in a prior post- that when you load a cartridge with a lower impedance, you are asking it to do more work. Since the cartridge is a magnetic transducer, the lower the impedance of the load the more work is being asked of the cartridge. For this reason he was very interested in developing a phono stage that had a high impedance input so as to minimize the work that the cartridge is doing. This would leave it more free to follow the modulations in the groove.

Re. current gain inputs: due to their inherently low input impedance, the mechanical loading issue as pertains to the above paragraph is likely not optimal, however you certainly would not have to worry about what the load impedance actually is since the electricalresonance would be well-damped.
fleib
1,124 posts
 
**I am talking about the fact that if you hear tonality change with a LOMC seemingly due to loading, its on account of the behaviour of the preamp and not the signal from the cartridge.**

I know that's what you're talking about. I made it clear that tonality change is NOT what I was talking about. What don't you understand?
george_a
34 posts
 
*the lower the impedance of the load the more work is being asked of the cartridge.*

What do you mean by "more work"? Are you talking about the cantilever/rubber suspension interface being stressed more?

I enjoy you posts.
atmasphere's avatar
atmasphere
11,633 posts
 
Many cartridges that make 0.2mV into 100 ohms can do so into 50 ohms as well. Its a small amount of wattage, but you can see in this example that in the latter case it would be making twice as much power as the former. This has to come from somewhere (the groove walls) and as such means that the stylus has become slightly harder to move.

I know that's what you're talking about. I made it clear that tonality change is NOT what I was talking about. What don't you understand?

Fleib, maybe you could outline what you *are* talking about as it is not clear from your posts so far.
fleib
1,124 posts
 
Atmasphere, From this thread:
*In the absence of noise one might prefer to load down a MC because of preference. Damping a cantilever/generator might improve focus and detail, while wide open might increase stage and size.*

*A phono cart is an electro mechanical transducer on the source end, but no electrical damping isn't necessarily better. Mechanical performance is the overwhelming determinant of cart performance, something that many EE's don't get. Loading, electrical damping can be a way to balance factors other than amplitude response and noise.*

Why does Jonathan Carr recommend for Kleos: *Recommended load directly into MC phono input: 95.3ohm ~ 816ohm* ?
http://www.lyraconnoisseur.com/Products/Products_Analog/kleos/kleos3.html

If you say that's because of inferior phono preamps, I say it doesn't matter or it's an inappropriate response. It doesn't matter because this isn't about you, it's about the Phonata. It's an inappropriate response because your examples and consequences are misleading at best.
Do you really think Kleos will start tearing up grooves if loaded at 100 ohms rather than 47K ? That's what you imply. Is every cantilever optimally damped? A MC cantilever is usually damped just enough to suppress mechanical high frequency resonance to between +3 to +7dB @ 20KHz. Of course usual isn't always and there are exceptions, like no cantilever or short ones. This is way outside the scope of this thread, but no-load always being better is a wrong assumption IMO. It's not right for any preamp all the time, and certainly not all MC's.
Regards,
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