Ntrain's UPA-7 review......... May 30, 2010 16:14:47 GMT -5
Post by ntrain42 on May 30, 2010 16:14:47 GMT -5
WHat your saying is really not the case. WHat Im doing is not stressing the amp out at all. THe UPA-7 is basically 7 indenpendant output boards drawing off a single large power supply. It is designed to run 7 different channels at once. WHen you play say a movie in 7.1, not all channels are being driven by the same load or output level. It varies CONSTANTLY. As long as the amp is being driven within/under its rated output ability and impedance loads it will be fine.
See, you didnt read what I stated earlier. If I just run zone 2 BY ITSELF(that means only 2 channels are running on the UPA-7, the other 5 are SHUT OFF)with at most modest levels of power(that means between 2-16 watts continuous at most), cross talk occurs and is audible in the other 5 channels, even though they aren't playing or getting any input signal. Running 2 channels of the UPA-7 is not going to stress that amp out in any way shape or form. THe UPA-7 is designed to run all channels continously with variable impedance loads within its rated output spec. Running just 2 channels at lower power levels is not going to stress out the amp. Running all 7 channels within spec also is not going to stress out the amp.
WIth my older Onkyo 906(Which also has a 7 channel internal amp), I can run 2 channels to zone 2, have the other 5 channels off and NOT hear any crosstalk whatsoever. THis is using the same speakers. The crosstalk spec. is significantly better with the Onkyo to the point where there is no audible crosstalk between any channels at any volume level.
Man...this is one of those situations where unless you see what your trying to do it's almost impossible to guage your disatisfaction. I think I understand where your coming from with the crosstalk, but does the crosstalk affect the sound when playing your source in two channels at normal volume? Does it bleed through so much that the audio just plain stinks and destroys the imaging, soundstage, and overall sound quality? Have you listened to the amp in surround sound with 5 channels playing and are disatisfied with the whole surround sound experience?
Your speaker wire could be acting like an antenna on the long runs. Are you using twisted pairs of reasonable guage (12)? Are you using any rfi shielding whatever? Unless we have an idea of your set-up its hard to tell. Does the crosstalk exist if the amps, source and speakers are closer together in the surround sound set-up? Are your cables somehow touching and causing leakage that way? Sometimes you have to subtract items from the set-up to minimalize all defective possibilities. Cause if the sound sucks with all the components close by and only running one source then you do have a problem and should return the amp as it doesn't meet your requirements.
Last but not least there could be a possible design flaw that allows pollution between the power source and each individual amp module? Maybe the five channel amp combined with a two channel amp could be an altogether better solution due to channel over crowding in one 7 channel amp chassis itself. Amps do give off magnetic fields and can do strange things when too close tegether. There might not be enough space between each module inside this chasis to meet your sound quality criteria.
The crosstalk between the left and right speakers, isnt what Im having an issue with. I dont use this amp for critical listening, just to power a pair of planars in my workout room, and the 5 channels in my bedroom HT system.
THe problem is, when I go downstairs in the morning to workout and turn zone 2 on to play tunes(with zone 1 HT system OFF), my wife gets awoken by the music bleeding through the speakers in our bedroom, all 5 of em. Its audible enough to wake her up.
Its not due to the rca cables or speaker cable itself(already checked out this scenario with cable swaps), its the amp itself. Swapping out the UPA amp for the 906's internal amp eliminates the problem 100%. This is just one spec where the UPA is IMO poor. So my solution is to eventually set the bedroom up for 7.1, and buy another amp for zone 2.