ISO REGEN Listening Impressions (kicked off with some measurements)

[bds3151]

When the IsoRegen is in the chain with Libreelec Kodi 17.6 in and Intel NUC, sound stops when I switch between Exodus and PSVue. It doesn't happen every time but very often. I can restore audio by dropping power, disconnecting and reconnecting the usb cable, or reinstalling my RUR in place of the Uptone. I have tried the ground switch and grounding the usb output to no avail. The Recovery is rock solid in place of the IsoRegen. Any ideas?

[bds3151]

Just so I this is clear, I'm switching between add ons in Kodi and not physically changing inputs. So this is a Linux issue that the OS is not usb 3 compatible ? Not much of a "solution" to reboot every time or power off devices. 

[bds3151]

I tried it with two, Modi multibit and a Mojo, both drop out. I also have a usb/spdif converter in the mix (DXIO Pro 3x).  I also tried another NUC with Win10 that is rock solid with the same configuration so it looks like you are correct with the problem being the OS (Libreelec). I wonder though if it may be hardware related with the Libreelec NUC as it only has 3.0 usb ports. The Win 10 has a combination of 2.0/3.0 with the DAC being plugged into a 2.0 port. 

[bds3151]

I tried it with two, Modi multibit and a Mojo, both drop out. I also have a usb/spdif converter in the mix (DXIO Pro 3x).  I also tried another NUC with Win10 that is rock solid with the same configuration so it looks like you are correct with the problem being the OS (Libreelec). I wonder though if it may be hardware related with the Libreelec NUC as it only has 3.0 usb ports. The Win 10 has a combination of 2.0/3.0 with the DAC being plugged into a 2.0 port. 

[bds3151]

The dropouts continued with Win10. Well, the solution to this issue was simple, drop the input voltage to 5.5v. I was feeding it 8v and apparently the heat was causing the TPS7A4700 in the Iso to protection mode.

[bds3151]

Alex, a few more things are in the chain and the Mojo has a separate power connection. There is a small DXIO PRO3Z DDC,  iDefender  and iFi iPurifier drawing some current but it still should be ok with a 1amp regulator, or so I thought. Regardless, it was getting hot to the touch at 8v (I believe it's thermal protection not overcurrent that's being triggered) and the dropouts were occurring only after warm up. I measured the current draw at 250 ma. Looking at the specs of the TPS, it's 1 amp with some restrictions. It needs a fairly large heat sink (a 6" square plate I think was specified). I don't think there is any attachment to the case on the Iso so I believe it's correct to say there is minimal or no sink. The ability to deliver current and stay within the operating range drops off quickly without a sink per a graph I found.  I assume it's possible I just have a defective unit that can't deliver the power without tripping the protection. Alex, I am curious about how other Iso's would react to a 250 ma draw and dropping 3vdc. It takes a while to heat up, so mine takes maybe 30-40 min or more before it trips. 

[bds3151]

Ok thanks Alex. I thought the regulator was pc board mounted? The spec sheet says the sink has to be in contact with the plate on the back of the regulator? Anyway, mine is now working fine and sounding great for several days now. Thanks again for a great product.

[bds3151]

John, thanks for explaining this. The case does seem to heat quite a bit, even at lower voltages. After two days of operating fine, the sound dropouts have returned. I think there might be another issue with compatibility between something in the NUC/Iso/iDefender/iFi Purifier/DXIO Pro3z/Mojo chain and the Iso. When I remove the Iso and replace it with RUR, the dropouts go away. If I take the Iso to my office system which uses a NUC/Iso/iFi iPurifier2/Schiit EITR/Schiit Dac, the dropouts go away. I assumed it was a heat problem because the Iso was hot and the dropouts got further apart when I lowered the input voltage. Tough figuring this one out. I may just keep it in the office system.