Hello, mid april I posted this problem : uniti atom screen blacks out without any trigger. Problem occurred twice in april, since then not anymore. I recently connected a parasound A23 pre-amp to the "pre-amp out" because the impedance of my loudspeakers was incompatible (4 ohm) with the Uniti. This solution works perfect. Beautiful sound and no volume problems on the atom anymore. The atom triggers the parasound to turn on with an outgoing signal on the pre-amp out, and when music stops, after 5 minutes the parasound switches itself of. That also works fine. But …. now my black screen re-appeared …
The uniti screen, out of the blue, goes black. The buttons are still lit, but no music is heard anymore. Havo to switch the uniti Off and On again to bring it back to life. Strange thing is that the Parasound also immediately switches off. In my opninion this should only happen after 5 minutes. Could this be some interaction between the pre-amp and the uniti ? Please help with analyzing this problem. Maybe anything with "auto stand-by" -turned OFF btw- ?
Posted on: 22 July 2018 by Sjoerdsr
Update on my post : further reading in this forum handed me a probable solution. The Atom seems to have a terribly low output signal. When this is lower than the lowest parasound setting (50 mV, 200 mV is highest) then the Parasound "thinks" it receives no signal and after a while switches off. I'm testing this right now by ng the Parasound to manual on/off instead of auto switching on/off. For now it has been playing some time without switching off …. I'll keep you posted. Hopeully this solves the problem. Well, nearly, because then I can't use the parasound's auto feature anymore and have to switch it manual because of the low output signal of the atom.
Posted on: 22 July 2018 by David Hendon
Did you try adjusting the input trim to give you a higher level out of the Atom? Also I don't know the Atom personally, but is there a maximum volume setting? If so, you could try adjusting that upwards.
best
David
Posted on: 22 July 2018 by Sjoerdsr
I tried to adjust the input level on the parasound but had to set this at its lowest value to even have the parasound switch on. The atom max volume is 100, I play mostly at 18. I could try this at > 50 and adjust the Parasound down at the same time. Now I use the parasound preferred MAX volume setting. I'll start experimenting on this.
Posted on: 22 July 2018 by TallGuy
What sort of volume are you getting from the set up with the Atom volume set to 18 ? That's very low and is more of a quiet background listening volume than anything using an Atom with it's own amplifier. What problems were you getting driving your speakers from the Atom directly ? I believe it's capable of driving 4 Ohm speakers and has been confirmed on these forums. How does it sound at 18 with your speakers connected to the Atom ?
If you're getting "good" listening levels it suggests that the output from the Atom is too high for your A23, or your A23 input sensitivity is set too high, which is the opposite of the results you report. Very confusing.
Are you going into the balanced or unbalanced input on the A23 ? I'm asuming the unbalanced.
Posted on: 22 July 2018 by Sjoerdsr
Sorry for the confusion, partly due to my lack of good english :-) I was Always playing music at level 18. I have a small room, and my phonar veritas P4 edma loudspeaker handled that level to my conveniece. Until my daughter started turning the volume louder and I noticed the music stuttering at about level 40-45. Together with my Naim & Phonar suppliers we concluded that it was the loudspeakers 4 ohm impedance the Naim couldn't handle. This is where the Parasound A23 power(!)amp came in. So now the setup is : naim > parasound > phonar. Great solution, volume levels up to the skies and me happy. Parasound is triggered from the Naim's pre-amp out with a setting between 50-200 mV. If the parasound don't sense anything with a certain setting it would switch off. Parasound also recommende a thx reference setting (whatever that may be) with gain on max volume on the parasound. This was ok with my naim's ~ 18 volume. But then the problem was that the very low mV of the Naim resulted in the Parasound sensing nothing and switching off. Solution came up with turning the gain of the parasound to about 40%, leaving room for turning the naim volume to ~ 40-45. This now seems to be the perfect balance. The parasound keeps sensing input due to the higher naim volume and doesn't switch off anymore. Problem solved ! 2nd conclusion so far I think is the black screen an incident, maybe triggered by the parasound switching off … Another conclusion : naim uniti atom can't handle 4 ohm loudspeakers on high volume. But then again on low volumes it is surprisingly clear. Thanks for the answer Tallguy and also David who triggered me on the volumes.
