AXPONA 2025 Video Coverage Part 3

even more to come!

The beautiful J. Sikora turntable shown in the thumbnail below is not included in this video (it was featured in Video 1) but it's too beautiful to not feature so here it is.

Video 3 isn't the final Tracking Angle video shot at AXPONA 2025. There's at least one more, perhaps 2. This video begins with the "exploded" version of Mo-Fi Electronics MasterDeck turntable. Designer Allen Perkins is on hand to explain what's been revealed in "the explosion". Conceptually, the "blow up" demonstrates why this turntable's design goes so far beyond your average turntable at any price and how Perkins has managed to incorporate at a far lower price point many of the design features of his for more costly turntables designed under the Spiral Groove name.

In the same room you'll see the new Mo-Fi Electronics Peter Madnick designed circa $3000 phono preamp based on the about double the price original, a $70,000 Acoustic Signature tonearm and the company's new Apex phono preamp, Vertere's new VGX turntable that features almost instantaneous arm swap capabilities with all set-up particulars retained, PS Audio's PMG Signature Phono preamp, the Yukiseimitsu Audio Analog Record Player without arm, here shown with a pair of Glanz arms, Nagaoka's new "flagship" MP-700H moving iron cartridge ($1300), a new Air-Tight MM only vacuum tube based phono preamplifier, SME's new machined polymer tonearm fitted on a refurbished Garrard 301 mounted on a polymer plinth, and more!

There's much more, I mean MUCH more coming up on video 4. I'm keeping these show videos down to 1/2 hour each. Enjoy! Would you please click the "subscribe" button? There are videos in this channel with 100,000+ views so why not subscribe?

Comments

2025-04-18 05:19:03 PM

Come on wrote:

It seemed you know what a transimpedance input (PMG phono) means Michael. Seems to be a kind of unloaded input, but different. Are you able to explain? Sounds like it’s more direct coupled to the amp, but with no chance to match a cartridge specifically. How compatible is something like this to a variety of carts?
- 2025-04-19 01:18:18 PM
  
  Come on wrote:
  
  In the meantime I asked ChatGPT and got a good overview. It seems carts with higher internal impedance (>25 Ohm) are not well suited for this kind of transimpedance input and may lose highs unfortunately. They seem to need the normal input of this phono pre.
- 2025-04-20 11:05:40 AM
  
  bwb wrote:
  
  Cartridges produce voltage and current. Conventional phono stages are designed to amplify the voltage. Conventional wisdom is the input resistance of the stage should be at least 10X the cartridge resistance, so in this case 100Ω or higher.
  
  Transimpedance stages are designed to amplify the current. In that case you want the input resistance of the stage to be very low, ideally zero so you get the maximum current the cartridge can produce.
  
  Since most stages are voltage amplifiers, cartridge specifications usually specifications tell us the maximum voltage it can produce and the internal resistance, such as .5 mV, 10Ω. From this you can calculate the maximum current it can produce (I = V/R). In this case .5mV divided by 10Ω = .05mA. If it was 25Ω then it could only produce .02mA. As you can see, as the internal resistance of the cartridge goes up, the amount of current it can deliver goes down. If the resistance is too high then the current is too low and the transimpedance stage doesn't have enough to work with.
  
  There are various reasons why one is preferred over the other. In favor of transimpedance is the simple fact that you don't have to worry about selecting the ideal input resistance since it is always very low by design. Beyond that it gets a bit more complicated.
  - 2025-04-20 11:08:46 AM
    
    bwb wrote:
    
    MF... please add an edit function to this forum. Pretty sure this the only forum on the internet that does not allow editing.
    
    My first statement assumes the 10Ω cartridge I describe later.
    - 2025-04-20 01:00:32 PM
      
      Come on wrote:
      
      Thanks for your explanation and I agree, this is the worst comments software on the internet and this since years including analogplanet. The worst of the whole thing is that one doesn’t get noticed of answers to own posts. No one cares it seems.
      - 2025-04-22 04:58:28 AM
        
        Malachi Lui wrote:
        
        improvements are being made to the website interface as we speak, though i'm not aware of all the particular details as to what's being worked on. since we launched, those with back end access have been able to edit their comments through there but i support the idea of having such functionality on the user side too.
        
        2025-04-22 05:48:53 AM
        
        Come on wrote:
        
        Good to know! If you have any influence, please try to care for answer-update-notifications, too.