[Gerry E.]

Hi Morten:

Any thoughts about the new "Coffee" LDR passive?  The paragraphs below are from a review of the new unit.  It includes some indirect references to your units.  Even at it's Kickstarter prices, it doesn't appear to be price competitive given that it lacks a volume level display and balance control.

I'm not trying to stir anything up here (pun intended).  I'm just curious to hear your thoughts on their design approaches - as best as you can tell.  I like the aesthetic design of the Java but wonder if it's more of a "lifestyle" product.  Thanks!

Gerry           

"For example, in dealing with the problem of channel matching, the usual approach is to painstakingly and time-consumingly select components that match within a close tolerance, and even that doesn't effectively deal with inevitable drift in component performance characteristics over time. The JAVA design approach is different and superior. 

The self-regulating circuit detects differences between and changes in electrical characteristics of the LDRs of each channel and corrects. This is a complex problem because the current resistance relationship is nonlinear, varies between devices, and variously drifts with ageing of the device.  The Java HiFi approach to channel matching of LDRs is unique and differs to other LDR-based devices currently available.

The JAVA uses high-quality NSL32SR3 LDRs, manufactured by Advanced Photonix Canada. Extensive testing and trial and error has shown these to be the best quality LDRs available for audio applications, the electrical characteristics and reliability of these LDRs being very consistent compared to alternatives.

The JAVA circuit then uses current trimming to further balance each channel, resulting in outstanding channel matching between L/R channels (typically less than a 1% variation). This "current trimming" implementation is unique to the design of the JAVA, with the anode and cathode of the LED of the LDR employed in a closed high impedance circuit, separate from earth.

In comparison, other LDR products have a resistor and capacitor in parallel to earth, resulting in those components always competing with each other. Another approach uses sampling to adjust L/R channel balance on the fly. It's a valid but quite complex approach by comparison the JAVA's all-analogue, closed-circuit approach is inherently simpler."

[tortugaranger]

Hi Morten:

Any thoughts about the new "Coffee" LDR passive?  The paragraphs below are from a review of the new unit.  It includes some indirect references to your units.  Even at it's Kickstarter prices, it doesn't appear to be price competitive given that it lacks a volume level display and balance control.

I'm not trying to stir anything up here (pun intended).  I'm just curious to hear your thoughts on their design approaches - as best as you can tell.  I like the aesthetic design of the Java but wonder if it's more of a "lifestyle" product.  Thanks!

Gerry 


       

"For example, in dealing with the problem of channel matching, the usual approach is to painstakingly and time-consumingly select components that match within a close tolerance, and even that doesn't effectively deal with inevitable drift in component performance characteristics over time. The JAVA design approach is different and superior. 

The self-regulating circuit detects differences between and changes in electrical characteristics of the LDRs of each channel and corrects. This is a complex problem because the current resistance relationship is nonlinear, varies between devices, and variously drifts with ageing of the device.  The Java HiFi approach to channel matching of LDRs is unique and differs to other LDR-based devices currently available.

The JAVA uses high-quality NSL32SR3 LDRs, manufactured by Advanced Photonix Canada. Extensive testing and trial and error has shown these to be the best quality LDRs available for audio applications, the electrical characteristics and reliability of these LDRs being very consistent compared to alternatives.

The JAVA circuit then uses current trimming to further balance each channel, resulting in outstanding channel matching between L/R channels (typically less than a 1% variation). This "current trimming" implementation is unique to the design of the JAVA, with the anode and cathode of the LED of the LDR employed in a closed high impedance circuit, separate from earth.

In comparison, other LDR products have a resistor and capacitor in parallel to earth, resulting in those components always competing with each other. Another approach uses sampling to adjust L/R channel balance on the fly. It's a valid but quite complex approach by comparison the JAVA's all-analogue, closed-circuit approach is inherently simpler."

Hi Gerry,

Yes, I briefly discussed this with Chris back when he was contemplating this move. He's a good man and I wish them good success (kind of.... ).

If that last paragraph is referring to the Tortuga design it's not accurate.  Our design recalibrates the LDR attenuation table if and when it's needed but this is certainly not done "on the fly".  We do use a digitally controlled analog system to regulate the LDRs as well as for handling the remote control and visual displays. Our channel balance criteria during autocalibration is currently 0.2%. All of that is arguably more complex  and challenging to engineer but then again it does more and it works great!