Odd that you’d have issue with two separate units.Hi @Laserjock
1) The static does not happen when music is playing.
2) No, I don't have any dimmer switch circuits near the outlet.
They replaced the power brick too I assume?
Odd that you’d have issue with two separate units.Hi @Laserjock
1) The static does not happen when music is playing.
2) No, I don't have any dimmer switch circuits near the outlet.
Odd that you’d have issue with two separate units.
They replaced the power brick too I assume?
Hop you don't mind a suggestion ... Try a completely different amplifier... If you've still got the noise it is being fed to your amplifier by something upstream.
Yep, power brick was replaced as well.Odd that you’d have issue with two separate units.
They replaced the power brick too I assume?
I did swap out with my backup rig (Pi4+Hifiberry DAC+Hifiberry amp). No problems whatsoever with that combo. Static is only present when PA5 is in use.Hop you don't mind a suggestion ... Try a completely different amplifier... If you've still got the noise it is being fed to your amplifier by something upstream.
According to tests done (earlier in thread), that is not the case.Yes, but only at the input connector.... It's done in pro-audio quite a bit.
Basically the input is an opamp set up as a differential input with single ended output.
Like this....
View attachment 200347
Grounding the cold signal (Pin 2) just forces it to revert to single ended behaviour.
Or is this amp "fully balanced", input to output?
Awww .... I just knew it was too good to be true.According to tests done (earlier in thread), that is not the case. If you drive it unbalanced, you only drive one side of the BTL amp.
In that case I would be forced to conclude there is a problem with the PA5 ... @JeffGB may have it figured out. The TPA3251 spec sheet recommends 36 volts. Has anyone checked the voltage rating on the bulk capacitors?I did swap out with my backup rig (Pi4+Hifiberry DAC+Hifiberry amp). No problems whatsoever with that combo. Static is only present when PA5 is in use.
I read that, but don’t understand amplifier topology enough to understand the issue. I have been feeding my PA5 an SE signal for months now and have no issues with it. Given that, is there a reason to upgrade the DAC/Preamp?According to tests done (earlier in thread), that is not the case. If you drive it unbalanced, you only drive one side of the BTL amp.
The same question has been asked many times, but the PA5 cannot be used with an unbalanced connection.I read that, but don’t understand amplifier topology enough to understand the issue. I have been feeding my PA5 an SE signal for months now and have no issues with it. Given that, is there a reason to upgrade the DAC/Preamp?
The topology isn't that complex... basically they have 2 complete power amplifiers for each channel. If they drive them out of phase (one going negative while the other goes positive) they can at least double the output power. BUT if you shut one of the two in each BTL (Bridge Tied Load) down not only do you lose power you get terrible distortion because one side of the speaker is not being properly controlled.I read that, but don’t understand amplifier topology enough to understand the issue. I have been feeding my PA5 an SE signal for months now and have no issues with it. Given that, is there a reason to upgrade the DAC/Preamp?
That's what I'm wondering. In pro audio it's all done with cables. Surely they would have thought of that... But they're not talking about the small details in any of their documentation. That's why I asked here, myself...Ok. But are we sure that is the topology or the consequences? Because I am not getting terrible distortion. Or maybe I don't understand what that is. REW shows THD at <1% for everything except deep sub bass and around 150-250hz where it approaches 10%.
Subjectively, my speakers sound crisp and clean. Even my sound engineer friend said they sounded great to him. These are speakers I paid $300 for 30 years ago. This setup certainly sounds better (cleaner and fuller) than my APA150 feeding an Elac Debut 2.0. It is also not noticeably distorted compared to my headphones listening to the same signal but via the pre/headphone amp.
Anyway, any recommendations for the converter? I had been planning on getting a Schiit SYS and Magnius and selling of my L30, but the Magnius is out of stock for another 6 weeks or so.
Edited for spelling
Thanks! I'll check those out. I do plan to go fully balanced, but just wondered about it since I am not getting huge audible issues. I mean my distortion level at 96dB is under 1% for everything except the bass (which is close to 5% at the worst, I misread the scale). That seems pretty close to the distortion measurements for good speakers in the reviews. And while I can hear the distortion during the 96dB tone sweep (in the bass) it isn't terrible and I don't hear it during normal playback of music (which I listen closer to 86dB). I am using LA Audio RCA to TRS cables, but that wouldn't overcome the differential audio issue, since it is essentially just having the ground function as both the ground and one half the audio input. Probably the issue would show up pretty quick if I listened louder/had a bigger space to fill.That's what I'm wondering. In pro audio it's all done with cables. Surely they would have thought of that... But they're not talking about the small details in any of their documentation. That's why I asked here, myself...
You could try this converter.... the fidelity won't be perfect but for a short term it should be okay...
https://www.amazon.com/dp/B0027V760M (You will need two for stereo)
If you like the sound, is it an issue? I'm in the same boat and planned on upgrading to balanced feeds, but now I'm questioning it.Bummer. I like the sound with one of the sources I have connected single-ended with TRS adapters to the PA5.
If you like the sound, is it an issue? I'm in the same boat and planned on upgrading to balanced feeds, but now I'm questioning it.