Curious Why Benz Micro Slid Into Obscurity
I remember there was a time when Benz Micro was one of the more prominent cartridge manufacturers out there. The Ace and Glider sure were popular cartridges. Then there was a hiatus in production. The company recognition seems to have never recovered. There are still new cartridges for sale on the various sites. But none of ther upper tier cartridges seem to gather the same recognition or praise that the earlier cartridges did.
Is perception of them changed that much, or is it the fact that the brand has aged out? Are the designs that dated to where people no longer believe quality and value are there?
@mulveling You had mentioned above "...For Ruby, Gullwing, and LP/S models you have a ruby plate. Magnetically, this is not nearly as efficient. These models do NOT work well with a SUT..." I was hoping that you could help me better understand why you feel that because the higher end Benz cartridges that use the ruby square plate do NOT work well with an SUT? Thanks much and best wishes, Don |
The ruby plate is non-magnetic so it requires more coil windings / turns to effect the same output voltage. With the iron cross armature, the iron core basically makes coils more efficient at generating AC signal. So for example, let’s look at specs. First the ruby plate models: LPS, Gullwing L, Ruby L: 40 ohms (DC) coils for 0.38mV output Pay attention to the ratio of ohms to output mV. Now look at the much higher ratio effected with the iron cross models: (note some of the specs on the outdated Benz Micro North America site are clearly miscopied) So the ruby plate "Low" models are using larger coil windings, comparable to somewhere between a "Medium" and "High output" coil configuration in the iron cross line, but with an output strictly in the "Low" category! This poor ratio is at root of why they don’t match well to a SUT. A SUT basically converts cartridge current into voltage gain. MC carts with a high ohms-to-output ratio have plenty of current to spare for this. But cartridges with a weak ratio run out of current, and then experience voltage divider losses (losing gain) before they achieve the necessary voltage gain. The more you push it, the more the losses start exceeding the intended gains. On paper, an LPS (or Gullwing L or Ruby L) should still be OK with a 10x SUT. This boosts its signal to around 3.8mV into a 47Kohm MM stage. However, that’s still a little on the low side (I shoot for at least 5mV) and there’s about 0.7dB of losses from the net ~470 ohm load (47,000 / 10 / 10) reflected to 40 ohm coils (voltage divider - Ohm’s law). And then we have practice - in practice, I did not like the LPS paired to any 8x or 10x SUT I tried. It was OK, but not great. Just anemic and bland. JFET MC stages were much better (Hagerman, Herron, ARC Reference). Conversely on "normal" MC cartridges, including iron cross Benz, I easily prefer a good SUT to any active MC gain stage. Note that SUT limitation goes out the window if you have an MM stage which can load much higher than 47K, but so very few do. MM loading at say 100Kohm or higher solves the voltage divider issue. The Rogue Ares allows this! That blew my mind when I realized that. My Sonic Lab is an interesting manufacturer with cartridges that have insanely high output ratios. Like 1 ohm coils for 0.5mV output. I think they do this by using larger gauge (thicker) coil wire than usual. Which probably makes the coils just as massive as typical High output coil configurations anyways, lol. Still, I want to hear them. |
You’re welcome! I think about this stuff way too much lol. One correction: when I was saying "ohms to output" ratio I really meant the reverse "output to ohms". For an "ideal" transducer (and SUT match) you want as much output voltage as possible from as little coils (lower ohms) as possible. So looking at output voltages in microVolts (uV) might help get a nicer ratio number for comparisons: So why do they use a rube plate in the upper Benz models? The theory is that a piece of moving iron (iron cross) dynamically disrupts the magnetic field (it should remain static in an "ideal" transducer), which causes distortion. They can also use a much larger & stronger neodymium magnet in these models - it’s so powerful it would be impossible to accurately position the iron cross in there. The ruby plate has no problem there. "Air coils" achieves the same thing, but without the structure (and mass) provided by the plate - but these are rare. An alternative technique: Dynavector has that big copper coil wound around its front pole piece to "damp" magnetic flux disturbances from the moving iron armature. It's not in the signal path, it's just there to bleed off magnetic flux disturbances. |
