Axiom Home Page Forums General Discussion Technical Questions Receiver problem

Hi,

I have a Sony STR-DG910 Receiver that I use to power my M80 speakers. My problem is that I need more power from my receiver. I was considering using a separate amplifier that would use the pre amp from the Sony. The problem is that the Sony does not have pre amp out connectors. Can I use the speaker outputs and put RCA connectors on the end of the speaker wires for the inputs to the amplifier? Will the quality of sound be OK? What brand of amplifiers would you recommended for a requirement of 200 watts rms per channel into 4 ohms? The amplifier needs to be 7.1.

Unfortunately I think your best bet would be a more capable receiver. One of the recommended brands for the M80s like Denon, HK, Sherwood, Rotel.

Do not try to run an amplifier from the speaker outputs of your receiver; the power output is far too high and will most likely destroy the input stage of the amp. The input stage of the amp needs a signal with just a few volts, the output from the receiver probably exceeds that 10 fold or more.

There are speaker level too line level converters you might consider if replacing the receiver is not an option.
http://www.hometech.com/audio/spline.html

Regards

As Rick said, go for a more capable receiver or seperates. There was a link kicking around for an amp that was able to take high level inputs(speaker output from a receiver) and amplify it for more power...hmmmm, where is it?

Anyway the best idea would be to get a new 7.1 capable receiver from Onkyo, Denon, H/K, NAD, Axiom sells Sherwood Newcastle because they will drive the M80s as well.

Many of us on the forum have been able to find deals for Denon's 3808. If you are in the States, you can get the 3808 from 6ave.com for $1099. You have to call them and request the AVSforums member special price to purchase it for this amount.

If you want to go the seperates route, Outlaw Audio, Emotiva are a couple of ID companies that sell good products for a reasonable price.

I would seriously recommend not pushing your Sony too much with the 80’s. Sony receivers tend to get very over heated if not specifically designed to run a 4 Ohm load. Don’t kill your equipment!!

I have been running my 80's for over six months now and had not had any probs with overheating on the Sony. I have pushed the Sony very hard over this time and it seems fine.
I live in Australia and receivers are pretty expensive here and buying one from US would probably mean that I won't be able to use the tuner as the broadcast frequency range I assume is different. This means I wouldn't be able to pick up any radio stations with the inbuilt tuner.
Has anyone tried the speaker level to line level converters? Are they likely to produce a lower quality signal?
What if I used the heaphone jack as a pre amp out signal. The only thing is I don't know if plugging in a head phone plug may cut of all speaker outputs.

Has anyone heard of E&W Power amplifiers. I found one on ebay that is rated for 1000 watts per channel into 4 ohms.

http://cgi.ebay.com.au/E-W-PS2000-POWER-...%3A1|240%3A1318

Is this type of amp suitable for home theatre?

Grant,

You can't use your speaker connections on your Sony to the Line In on an amplifier. You would be better getting a different receiver. Never heard of E&W, sorry.

Why do you think you need more power? At 100watts per channel the Sony should play to very loud levels, the 80's require very little power to play very loud.

How loud do you listen and how big is your room?

The E&W here looks like like a pro amp. Something used on stage or in a recording studio. It would work in an HT setting, but it doesn't look like it has RCA connections, so you would have to stick with XLR connections. You would then have to make sure your pre/pro had XLR, this could get expensive. It also looks like it has 2 big fans for cooling, which would mean it proably is pretty noisey. If it were me, I'd stay away from it for HT applications.



paul

I’m not sure but the headphone output might be the sum of all 5/7 channels, not a good thing in considering what you want to try.
As for your question about the headphone jack turning the mains off, if you have headphones, plug them in and see what happens.

Regards

I need more power only for some input sources only. Some dvd's I have seem to have low recording levels and I need to turn my Sony up higher to compensate. My Samsung Tv also has a low level optical output that also requires me to turn the volume up much higher on the Sony. I do like to listen loud and my room is 5 metres wide by 10 metres long.

Sounds like you are in need of the dynamic volume features on one of the newer receivers, I know Denon or Onkyo has this feature more than a more powerfull amp/receiver.

Are the other manufacturers offering such eq's these days?

DVD's having different recording levels is normal, we all have this issue, and we all find ourselves turning the volume up/down depending on the movie we are watching. Even if you find a receiver that puts out 200 watts per channel, your only gaining 3dB's of volume over a receiver that puts out 100 watts, very insignificant.

Maybe not. You would in essence be doubling your headroom and quite possibly lowering the distortion making dialog quit a bit clearer. More power is never a bad thing imo.

Grant, from your latest description, power has nothing to do with the situation. If some source material happens to have a lower voltage output than others, obviously the volume control on the receiver has to be set higher(cutting off less of the incoming voltage)to get the same power output(not more)from the receiver. There's absolutely nothing wrong with turning the volume control up, that's the way it's designed to be used with lower output sources. You don't actually have a power output question.

Apparently your DG910 isn't aware that it's connected to speakers rated at 4ohms while it's only officially rated for 8ohms, so it's been doing a fine job.

JohnK,I think you are right that power is not the root cause of the problem but I do have to run my receiver at maximum volume and it still is not quite load enough for my liking. I am considering buying the Denon 3808 but they are $3000 AUD here which is about $1900 USD. I guess I will just have to save up some money.

If you're running at max power and it is still not loud enough for your liking then I must respectfully disagree. Not enough power is the problem.

He just needs to turn the volume knob a little harder.

It sure sounds like you could do with a little more power. Too bad your current receiver does not have pre-outs.

Grant, you may want to check Aussie pricing on one of the less expensive HKs, Denons, Onkyos ect making sure it has preouts so that IF you feel it necessary, you can add an amp afterwards. You'd have to do the math to see if this works for you.

He should just tape an e-le-ven onto the volume dial.

I just took a second look at that line. Your currency has been hammered harder than the C$.

If you have a receiver that is rated at 100watts per channel, and you have to crank the volume to maximum, there is something else wrong, and another beefier receiver and/or amp is not going to help. You have an input source level problem. Your telling us that for DVD movies, you have to crank your volume to maximum?

Something is not adding up.

Grant, you(and some others)may not have fully grasped the situation. You could get a 1000 watt amplifier and still not get a single watt more power if the input voltage to the amplifier isn't high enough to bring some of that power capacity into play. This depends not on the maximum power capability of the amplifier, but rather on the gain that the pre-amplifier and then the amplifier section itself apply to the voltage coming in from the source material. It's possible that a 90 watt receiver would have higher gain than your 100 watt and be louder with the volume at max, and it's also possible that a 200 watt receiver might have lower gain and wouldn't even be as loud.

The point is that you simply can't buy a unit with a higher maximum power output rating(neither the 3808 which you mention or any other)and be guaranteed the ability to play the lower output level sources which you mention at a higher listening level. You either have to have the gain specs of your present unit to compare with the gain specs of a possible replacement, or you'd have to actually try another unit to see if it would play your source materials more loudly. I know that you're looking for a relatively simple answer, but none is available, since maximum power capacity obviously isn't the problem.

Let's not forget he is working with a Sony amp and they are notorious for ratings that are well under actual real world requirements. It may have the 100watts on one channel with 1/8th watt on the others as required, but if it needs to use 50% on both fronts it most likely is only giving him 50W/ch or less if other speaker requirements are high as well, so it could very well still be an under power issue; not to say that a weak input signal couldn't be the problem or help alot as well. I noticed a huge increase in over all sound quality/loudness going from a Sony dvd player(middle of the line at the time) to my current Samsung(top of the line at the time). I am sure the output levels on that Sony were about half of what the Samsung puts out.

I think that the Sony is overrated in terms of the power output. I found a bench test result saying this:

http://www.soundandvisionmag.com/receivers/2354/test-bench-sony-str-dg910-av-receiver.html

I have no problems with the power output when playing dvd movies or cd's however I watch a lot of music dvds that many have very low output levels and I need to crank the volume to max and still lacking. I have taken one of these low level music dvds to a friends place and tested it on his system. He has a marantz receiver 80 watts per channel at 0.03%THD and speakers that are 91 db/w/m, where my system is the Sony receiver 100 watts per channel at 1%THD, 8 ohms, (4 ohms ????wpc) M80's with sensitivity of 95 db/w/m. His system is much louder than mine when playing this low level music dvd. I can only think that the Sony output is overrated.

you don't happen to have a voltage switch on your Sony that you've turned from 8ohm to 6ohm have you? If yes, put it back on 8 ohms as you would be limiting the current.

If no, then you probably need a different unit, as you didn't mention earlier that you've tested other receivers.

Hello

Here’s the problem, according to a Sound & Vision review and lab tests the receiver just does not have the power output into 7 channels.

DOLBY DIGITAL PERFORMANCE
All data were obtained using various test DVDs with 16-bit dithered test signals, which set limits on measured distortion and noise performance. Reference input level is -20 dBFS, and reference output is 1 watt into 8 ohms. Volume setting for reference level was 60. All level trims at zero, and except for subwoofer-related tests, all speakers were set to "large," subwoofer on. All are worst-case figures where applicable.

Output at clipping (1 kHz into 8/4 ohms)
1 channel driven: 84/138 watts (19.2/21.4 dBW)
5 channels driven (8 ohms): 30 watts (14.8 dBW)*
Distortion at 1 watt (THD+N, 1 kHz, 8 or 4 ohms): 0.02%
Noise level (A-weighted): -75.1 dB
Excess noise (with sine tone)
16-bit (EN16): 1.2 dB
Frequency response: 20 Hz to 20 kHz +0, -0.1 dB

*Multichannel tests, regardless of source signal (digital or analog, stereo or multichannel) or decoding modes, caused the STR-DG910 to limit output to about 30 watts or less per channel; see accompanying lab notes. Since the receiver lacks analog multichannel or preamp inputs, direct testing of power-amp channels was not possible.

http://www.soundandvisionmag.com/receivers/2354/test-bench-sony-str-dg910-av-receiver.html


Channel Power Rating : 7.1 Channel Power Rating: 100W x 7 Amp Power (700W) (8 ohms, THD 1.0%)
This last specification is from the Sony website and the power rating is not up to FTC snuff.



There's still the high level to low level converter option.

Now I know why I never liked Sony receivers. They do make decent CD/DVD players...

Sony Tv's are pretty good,too.

Am I reading that correct that at 5 chan driven at once, it only has 30 watts to offer? So you can't just say that "you don't have a power problem" because an AVR says it has 100w/c. This is a relatively new amp from a solid company. I guess this is what gets me when so many say "they are all the same, watts are watts, and you only need about 50 of them". Clearly there is more to it than that, as pointed out above, but there has to be a way to compare amps more effectively.

I don't think you can call Sony a solid company when it comes to receivers. A well known company, certainly. But wattage ratings are only required to be done for a single channel. When you see something like "100WPC, all channels driven" then it should be accurate.

Sounds like Alan pretty much summed up what the rest of us have been trying to tell Grant in the Alan section. Does looke like Russound offers a converter for his receiver to RCA for an amp, but it sounds like a new receiver would be the best option.

Looks like my guess of 50W/ch was too high. I think Sony makes a workable receiver for most applications, but for those that want more, like most of us, they just don't cut it. I know my old Sony actually works pretty good with the M80s in 2 channel but that is all it can do.

I agree, I hate Sony AVRs. but frankly I was beginning to wonder if I should reconsider given all the talk of all amps being the same regardless of price, as long as the w/c were close. Not trying to be pain in the arse, as i am quickly approaching, but i am looking to upgrade my AVR and the search has gone hay wire with all the talk about a $3000 AVR is the exact same as a $700 AVR, except for whatever video section is there. It conflicts with my most basic understanding of economics, but, then again, I have Transparent Audio speaker cable, so I have been sucked in before. Just looking for the Rosetta Stone of Amp specs. Is it Watts/ch at a given current level, power when all channels are driven, THX certification, ad budget...after all these years of AV and HT I find myself shockingly lost in this search were value is the goal.

I feel better know.

Pick a price and features then look at the usual suspects we talk about, Denon, yamaha, onkyo, H/K, Outlaw, nad, etc. and go with the one you feel is the best bet. They all work extremely well and it is highly unlikely anyone would be able to tell the difference amongst anyof them at the same volume levels with in each amps limits(this is the key part). If you put a 100w/ch amp in a huge room and then put a 400W/ch amp in the same room and play each at 100db the 400w amp is going to come through with better dynamics/less distortion etc.

What would you consider a "huge room"?

Between January and October 2006 Sony ranked #1 in retail audio sales in the U.S., so they must be doing something right. Actually, the ES line of receivers are probably decent units.
By the way, guess what company ranked # 2,


you guessed it - - - - - - BOSE!!


The Sony STR-DG910 is actually a entry level product.

That, my friends, is why companies spend so much money on marketing.

My guess would be around 4-5000 cu ft or more.

Like I said.

I hear you, but it is not my makeup to pick a price I can stan to spend and then go look for what fits the price. I want to spend as little as possible on what is needed to obtain flawless performance. That balance - $ v. performance - forces the list of options, etc. Why buy a BMW simply b/c I can, if the Honda would meet all my desires. If a $800 amp will do all I can hope to acheive in my stystem, why spend $2500. Chichen...egg...chicken. I guess that is why I'll spend over $1000 just to make sure i'm safe. Then again, that's how I got the Transparent wire - there must be a better way.
Oh well, I gather there is no tell-all spec and will just trust Denon and spend more than is likely needed to be safe. At least I know I have beat this horse all I can. But the first person to say "why did you get the 4308, the 1708 is all you could ever need" will get a ton of really mean looking smiley faces.

Rotel?

Charles, when I first started looking at AVRs, I was looking primarily at the HK 354. I was on the verge of buying it until I started reading several complaints/problems re firmware. I got to know one of the salesman at one of our local HK dealers and asked him about this and also asked him what AVR he uses....answer..."Denon". (I know! an honest salesman!) Anyway, I wouldn't overthink your purchase too much, it'll make it harder and you'll probably buy what you started looking at in the first place. I've been told to look for an AVR with high current capability which Denon, HK and a few others are known for. At $1000 US, I don't think you could be disappointed with too many of the receivers on the market, there maybe one or two that stand out though. For me, Denon seemed like a safe bet.

Grant, your comparison with the 80 watt Marantz receiver gives additional confirmation(and would have been helpful if mentioned earlier)to the point already established: that you already have ample power since some sources play at an adequately loud level. The similarly-powered Marantz played "much louder" with your low level sources because it applied a higher gain(most likely at the pre-amplifier stage)so that its full capacity could be brought into play.

Your DG910 might have an unusually low gain pre-amplification section, either by design or possibly because of a defect in your particular unit. If the latter, of course repair should be considered as a warranty matter. If the problem is inherent in the design you should consider a unit with similar maximum power capability but with higher gain for low-level source material. You know at least one that fits that description!

Yes, I agree. I started thinking I would replace my Denon 3300 with a Denon 3808. Then I considered all the tech knowledge here and thought better of it. Now, I'm back to where i started, Denon 3000 series. Funny thing is, I got the 3300 based on the magazine reviews.