LDRx/LDRxB Passive Preamp Tour - 2014/2015

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Re: LDRx/LDRxB Passive Preamp Tour - 2014/2015
« Reply #80 on: 8 Sep 2015, 11:08 pm »
What is happing with the tour?  :scratch:
Seriously?!!?  I was going to ask if I could get back on at the end.   :D


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Re: LDRx/LDRxB Passive Preamp Tour - 2014/2015
« Reply #81 on: 9 Sep 2015, 03:02 pm »
What is happing with the tour?  :scratch:

Here's the full skinny on why the long hold up on the tour. 

Soon after the LDRxB tour started I discovered a minor bug that I wanted to correct before continuing. So I brought the tour unit back. Resolved the bug but meanwhile noted that a couple of customers were having problems with hum. This started a long frustrating process of diagnosis which ultimately culminated in my buying same amps as one of my customers to get to the bottom of the problem. The issue was eventually traced down to how pin 1 (the XLR cable shield) was terminated or not terminated to chassis ground. This proved to be a hugely distracting issue and all the more so because the only reason pin 1 can cause hum is if the amp designer uses it inappropriately as a conventional ground line. A true differential balanced audio signal doesn't require a ground reference and pin 1 was never intended to be used as a ground reference. The worst offender here turned out to be the Job 250 monoblock amps which even a 6moons review had flagged as being susceptible to hum. In the end we did arrive at a simple solution but meanwhile months went buy with the tour on hold.

Meanwhile we have come up with some design mods unrelated to the earlier hum problem that I wanted to incorporate into the tour unit before re-launching  the tour. But as these things go, it's taken way longer than planned to work out the details on the design mods which now also include a battery based power supply which are are pushing hard to complete in the next two weeks before RMAF in Denver.

So, yes the tour will resume as soon the mods and battery PS are good to go. Probably after RMAF sometime in October. Apologies to all for the long wait.



Re: LDRx/LDRxB Passive Preamp Tour - 2014/2015
« Reply #82 on: 9 Sep 2015, 03:06 pm »
Thanks for the update!   :thumb:   That's quite the story about Job.   :duh:
Please add me to the end if you don't mind...I'd like to try the mods out if at all possible.  See you at RMAF!


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Re: LDRx/LDRxB Passive Preamp Tour - 2014/2015
« Reply #83 on: 2 Mar 2016, 07:14 pm »
Could this tour be relaunched for 2016?