Some questions regarding my new HT system

[eisforelectronic]

My opinion is that if there is a substantial drop in volume when switching from 2 chnl to 5.1 chnl, then it is possible the receiver is using a single amplifier and splitting power off to each chnl. Most of the manufacturers of higher quality receivers typically provide separate (discreet) amplification for each channel.

[NickWH]

My opinion is that if there is a substantial drop in volume when switching from 2 chnl to 5.1 chnl, then it is possible the receiver is using a single amplifier and splitting power off to each chnl. Most of the manufacturers of higher quality receivers typically provide separate (discreet) amplification for each channel.

Most low-end receivers only have a single power supply for all channels of amplification. This is another cause for the drop in volume when going into surround mode. Better receivers have a power supply for the main channels and a seperate power supply(s) for the surround channels.

[ausastronomer]

My opinion is that if there is a substantial drop in volume when switching from 2 chnl to 5.1 chnl, then it is possible the receiver is using a single amplifier and splitting power off to each chnl. Most of the manufacturers of higher quality receivers typically provide separate (discreet) amplification for each channel.

Nick,

The receiver definately has discreet amplification. It also has a pretty large torroidal transformer feeding the power supply for a receiver at this level. The unit weighs 27kg which compares to similar recievers in this class like the Denon 3805, Marantz SR-7400, Pioneer VSX-55TXi, Harmon Kardon AVR-630 and the Yamaha RXV 2400 which all weigh some 5 to 10kg less than the Sherwood Receiver. So if the weight is not in the power supply they have made the chasis out of very thick steel.

Regards
John

[NickWH]

The receiver definately has discreet amplification. It also has a pretty large torroidal transformer feeding the power supply for a receiver at this level.

While this may well be true, the power specifications for this receiver are quite wimpy:

AMPLIFIER SECTION
Power output, stereo mode, 8 ohms, THD 0.05%, 20Hz-20kHz | 2 x 100W
Surround Mode, only one channel driven
Front power output, 8 ohms, 1kHz, 0.7% THD | 110W + 110W
Center power output, 8 ohms, 1kHz, 0.7% THD | 110W
Surround power output, 8 ohms, 1kHz, 0.7% THD | 110W + 110W
Surround back / ROOM2 power output, 8 ohms, 1kHz, 0.7% THD, 110W + 110W

When this receiver goes into surround mode, the power level must drop because Sherwood only rates the power for a single channel, at a single frequency, and the distortion level jumps considerably. This is not the case with the Denon, HK, Yamaha and Marantz receivers. The receiver is indeed heavy, however there is no mention of just how large that "huge torroidal transformer" is in the literature.

[anamorphic96]

I would not worry to much about those output specs. In surround mode the unit is probably about 75 watts per channel. When you look at a rated 1khz spec you should take 15 to 25% off the wattage number and you will be in the ball park of what the full bandwidth number would be. The other thing to keep in mind is that companpies like Yamaha, Denon, Marantz,Onkyo, Sony all rate there receivers into two cahnnels as well. The only companies who do the all channels driven specs are Rotel, Nad, and Harman Kardon. But if you notice, there ouput specs are much lower. There might be some other companies that do the all channels driven rating as well. But off the top of my head these three came to mind. This does not mean that the receivers cant output the power specified into the channels listed. They just cant do it with all channels driven.

The volume change you are talking about is not drastic either. Most receivers need some volume boost when switching to surround modes. All the receivers I have owned needed some. If you had to bring the volume to 0 or a positive number I might worry.

Sounds like your unit is running fine.

Cheers.

[anamorphic96]

http://www.audioholics.com/techtips/...eiverpower.php

Copy and paste this link. Its a very honest look at receiver ratings and power diffrences between models and how receivers are rated. The article is well written and comes from a former Yamaha product manager.

Cheers