After not using my strata for a little while - I encountered the FW issue that many dealt with a few weeks ago (in late June), and updated the FW.
I am not sure if my issue is related or not to the new FW update (probably not):
After the upgrade, my speakers do not work!
Headphones work just fine, but unplugging the headphones - still won’t get the speakers going!!
I am using the optical input to my Strata, and the input itself is verified to work (though headphones). It is only an issue outputting to the speakers.
Also, my speakers are tested to work using a different amp.
Any idea what could be the issue, or how to isolate root cause?
Good news / bas news:
Factory Reset made no difference.
My amps are not directly connected to the speakers, but rather go through a switch box:
My other amps work great going through the switcher, but Strata won’t work when connected through the switcher. Connecting the speakers directly - works!
Any ideas what makes Strata so picky? Other amps are totally happy with this switcher!!
Anyone from PS Ausio?? I have no heard from you guys despite couple emails on the matter…
Strata requires the speaker grounds to stsy separate and most switch boxes do not do that to save switch costs. It is protecting itself by muting. It states this in the manual.
Interesting, as my other 3 amps (all custom built tube amps) work flawlessly with the speaker switcher box. But I think I understand the reasoning behind this explanation.
I wonder if there is a way to disable this muting functionality, or is it hard-wired?
Also, why would this protection kick in when 1 speaker is connected directly to Strata and only 1 goes through the switcher box? How does Strata determine the grounds are common if only 1 channel is connected to the switcher?? This makes me wonder if that is indeed the root cause here
You never mentioned only one channel was connected. Quite frankly I don’t understand what you are doing with it, According to the switcher’s docs you need to have all of the outputs connected to speakers/dummy loads or the switch will not operate properly. Tube amps have output transformers that isolate the output circuits from the load. The Strata uses a bridged amp configuration which means that both positive and negative output connectors are driven directly and not referenced to signal ground, This is not defeatable as it is a design feature to provide higher power, Since it works without the switcher there must be an issue in how you have it connected. You would need to fully explain or provide a diagram of its complete connection schematic to assist further,
Why would you consider continuing to risk damaging a $3500 amplifier with an Amazon switch box? You have already determined that it doesn’t and won’t work so just stop there. The design of the Strata’s Class D amp module is not compatible with that type of device.
I connected 1 channel as part of my debug efforts… Initially, both channels were connected and it did not work!
At this point, I believe the switcher box may have some wiring issues… I will look for a different solution for connecting several amps to the same speakers (and switch between them).
Thanks for helping out!!
You cannot use this type of switch box with multiple amps to the same set of speakers at all as it’s designed to work the other way to keep a safe load. I would not recommend that you use any switchbox with a bridged amp such as the Strata in this fashion as you can very easily damage your amp.
