I am using a Sherbourn 5/1500A for my 4 height channels. It is a tank of an amp. However it behaves strangely. When I run Audyssey calibration (Marantz AV 7704) quite often one or more of the channels will sound like it is cutting in & out, almost a sputtering sound. I have played music through the channels both on the bench and just plugging a source in and playing through the ceiling speakers and everything sound clean. Other tests I have done;
In talking (email) with the tech folks at Emotiva, who bought Sherbourn, the technician said that cutting in and out was a common problem with these amps, and relays and caps needed to be replace on each amplifier board. The price would be $350-$400 plus ~$100 shipping. I would probably have done it but the shipping pushed it a little out of the budget. So I have waffled and done nothing for about a year.
One dilemma I have is "Does the amp cut out during normal playback?" I have played test Atmos tracks and can't detect any problem, and during normal Atmos & DTS-X video watching I haven't heard any problems, but I am not sure it would be noticeable.
I had an advertisement from Emotiva drop into my email today for their Bas-X 4 channel amplifier. It is only 100 watts per channel at 8 ohms, but this should be OK for height channels. It is $499.
The purpose of posting this is to get feedback about;
- I hooked a Crown K1 to the Sound Processor and tested 2 channels at a time using pink noise from the "Levels" menu on the sound processor. No problems.
- I continued testing the 5/1500A listening to music for 2 or 3 hours and occasionally switching channels. No problems.
- I used the outside 4 channels for the 4 height speakers. Ran the level test (pink noise), and got sputtering and cutouts on at least two of the channels. tried about 10 times and had the problem on at least 3 of the channels 2 or 3 times.
In talking (email) with the tech folks at Emotiva, who bought Sherbourn, the technician said that cutting in and out was a common problem with these amps, and relays and caps needed to be replace on each amplifier board. The price would be $350-$400 plus ~$100 shipping. I would probably have done it but the shipping pushed it a little out of the budget. So I have waffled and done nothing for about a year.
One dilemma I have is "Does the amp cut out during normal playback?" I have played test Atmos tracks and can't detect any problem, and during normal Atmos & DTS-X video watching I haven't heard any problems, but I am not sure it would be noticeable.
I had an advertisement from Emotiva drop into my email today for their Bas-X 4 channel amplifier. It is only 100 watts per channel at 8 ohms, but this should be OK for height channels. It is $499.
The purpose of posting this is to get feedback about;
- Has anyone ever seen this kind of issue?
- Does anyone have experience with Emotiva Bas-X amplifiers?
- What other alternatives might I consider?
4 channels of pink noise perhaps just might be more bass than the system usually handles, pink noise has a lot in the bottom octave. Suggests that either the power supply or filter caps aren't upto heavy load, which might be deterioration - replacing these caps might be indicated.
Alternatively it might just be that the pink noise test goes too far below 20Hz and the amp protection is kicking in as designed(*). Did you calibrate in the same way when the amp was new(er)?
(*) speaker DC protection works by sensing when the output has averaged too much DC offset on a timescale of tenths of a second, pink noise has more and more power the lower the frequency, and depending on the pink noise generator the subsonic power may be high enough to trick/trip a protection circuit.
Alternatively it might just be that the pink noise test goes too far below 20Hz and the amp protection is kicking in as designed(*). Did you calibrate in the same way when the amp was new(er)?
(*) speaker DC protection works by sensing when the output has averaged too much DC offset on a timescale of tenths of a second, pink noise has more and more power the lower the frequency, and depending on the pink noise generator the subsonic power may be high enough to trick/trip a protection circuit.
The pink noise is that supplied by Audyssey, So I do not know what makes it up. I can measure it however.
I can also use REW to supply the pink noise and try different frequency ranges. If it is a low frequency related I can, as a temporary solution, set the crossover in the sound processor high enough to avoid the problem.
Thanks for the tips.