XPA-1 Meter LED's

[gambino]

Hello everyone I recently purchase two XPA-1's to join my XPA-5. They were delivered today, after adding the XPA-1's to my setup and making the necessary connections I turned on the power to the XPA-1's. They went through the power cycle (all red LED's followed by a single blue LED). Afterwards here is where things seemed strange to me. With no music playing, on one of the XPA-1 the LED meter was displaying at least 6-7 blue LED lights and the lights would frequently increase and decrease. On the other XPA-1 there was only one blue LED showing (and yes both status and meter LED selectors are turned on for both XPA-1's). I then turned off all the equipment except the amps and then checked to see if I could hear anything coming from the speakers.

I could not hear anything coming from the speaker connected to the amp that displayed the single blue LED. However, when I listened to the other speaker connected to the amp with the increasing and decreasing blue LED's I could hear some noise (can't really describe it) increasing and decreasing as the LED meter increased and decreased.

I then disconnected both amps and connected them to another dedicated AC line. With nothing connected (RCA cable, speaker wire, trigger cable) to amps after turning them on, the same XPA-1 displayed the single blue LED while the other XPA-1 would have at least 6-7 blue LED lights and the lights would frequently increase and decrease. I then took the XPA-1's to one of my friends home and to simplify the story the amps did the same thing on his dedicated AC line.

I have been reading the threads here quite often however I have not read about anyone experiencing this before. I will be calling Emotiva tomorrow and see what they recommend. However if anyone has any ideas please feel free to comment. Besides this I have been using my XPA-5 for a little over a year and it has been a wonderful amp. Thanks.

[Legis]

Try to describe the noise coming from the speaker of the amp that's meter oscillaltes?

That the other meter oscillates and the other one stays constant, would indicate a clear (?) malfunction either at the led meters or at the output section of the amp(s). For example (I'm not saying that this is the case) the amp might leak a radio frequencies or something else (direct current) to the speaker outputs and the led meter responds that noise?


As a side note, these led meters of the XPA-1 are for a decoration purposes only:

1) I measured the power consumption of one of my XPA-1 with Tehnoline's "cost control" meter, which average error is 2,7% to either resistive, capacitive or inductive load. The result: the meters do not represent the reality what comes to measuring the output power of the amplifier. Driving a 8 ohm load, the power consumption of the XPA-1 is approx 140W when the led meter is maxed with 3 red dots, lol. As we know, the XPA-1 is capable of delivering 600+ watts to 8 ohms, what trasnslates to 1000+ watts of power consumption (due to ~60% efficiency of the AB-topology). When playing loud, do not watch the led meters as a reference to the amp's limits .

2) If a sine tone is fed to the amp, the meter oscillates while it should stay constant. At 20Hz sine tone the meter actually stays pretty constant, which would likely to indicate that the sample frequency of the meter is approx 20Hz (or more likely, 10Hz because is't so inaccurate).

So, never mind the led meters. Fantastic amps otherwise.

[paintedklown]

Congrats on the new XPA-1s.

As stated, the LEDs are more for "decoration" than anything, but I certainly do understand the frustration of having a noise issue. Contact Emo, see what they have to say, and please report back to us the results of your efforts. I am curious as to what would be causing this myself.

I am assuming form your description of the problem that only one of your amps is having this problem. Does the problem amp still make the noise if you turn on the status LEDs?

Also, Welcome to the lounge.

[gambino]

Legis:

The best way I can describe the noise coming from the amp that oscillates is it sounds similar to TV static white noise. The noise increases and decreases as the LED meter oscillate. Hope that helps, yes I have read that the LED meters are just for decoration purposes. However it just seemed strange that with nothing connected to the amp, the LED meter would behave like this.

Paintedklown:

Yes only one amp is having this LED / noise problem. I can hear noise from the speaker connected to the problem amp with the status LED’s turned on or off. I contacted Emotiva and explained this issue to the technical support guy. He apologized for the inconvenience and another XPA-1 will be sent out. He did not ask me to do anything to the amp, so I do not know what could be the problem. I did ask for someone to check the new amp before it is shipped. Excellent customer service (no hassling); I will keep Emotiva in mind for my future purchases.

Thank you guys for your response.