Help required! Is it worth adding a power amp?

[Les Adams]

Hi, I am new to this forum and I am seeking advice (already)!

I have a Denon AVR3801 receiver which I use for home cinema and stereo listening. I must say I am very happy with the cinema side of things but I have read many comments that A/V amps do not perform well in stereo, although I believe this Denon is one of the better performers in this area.

My question for the group is:

Is "the problem" with these A/V receivers normally the preamp section, or the power amps? If it is the power amps, would I be better off using an external higher quality power amp? The Denon has a pre-out, so it would be simple to do, but is there any benefit? Power is not an issue as the Denon delivers around 140w into the 6ohm speakers, but quality may be!

Funds are a bit limited (my wife wants a new kitchen!) but I have been thinking of buying a s/h Quad 405-2 to drive the front speakers for stereo.

I ask because I have recently got back into listening to vinyl / CD / Stereo.

This is my current system and suggestions for improvement would be welcome!

Garrard 401 Turntable / SME3009S2imp (non-det) arm
Shure V15Vxmr cartridge
Denon AVR3801 receiver
Arcam Delta 70.3 CD player
Denon DVD-2500 DVD Player
Meridian A500 Loudspeakers (Front) (Silverlink Aero Cables - Bi-Wired)
JBL Control Speaker (Centre) (Supra Cable)
Gale Satellite Speakers (Rear) (Supra Cable)

Your thoughts please gentlemen?!

[Jimmy C]

Hi, I am new to this forum and I am seeking advice (already)!

I have a Denon AVR3801 receiver which I use for home cinema and stereo listening. I must say I am very happy with the cinema side of things but I have read many comments that A/V amps do not perform well in stereo, although I believe this Denon is one of the better performers in this area.

My question for the group is:

Is "the problem" with these A/V receivers normally the preamp section, or the power amps? If it is the power amps, would I be better off using an external higher quality power amp? The Denon has a pre-out, so it would be simple to do, but is there any benefit? Power is not an issue as the Denon delivers around 140w into the 6ohm speakers, but quality may be!

Funds are a bit limited (my wife wants a new kitchen!) but I have been thinking of buying a s/h Quad 405-2 to drive the front speakers for stereo.

I ask because I have recently got back into listening to vinyl / CD / Stereo.

This is my current system and suggestions for improvement would be welcome!

Garrard 401 Turntable / SME3009S2imp (non-det) arm
Shure V15Vxmr cartridge
Denon AVR3801 receiver
Arcam Delta 70.3 CD player
Denon DVD-2500 DVD Player
Meridian A500 Loudspeakers (Front) (Silverlink Aero Cables - Bi-Wired)
JBL Control Speaker (Centre) (Supra Cable)
Gale Satellite Speakers (Rear) (Supra Cable)

Your thoughts please gentlemen?!

...do up the kitchen! MuChO better investment, IMO... and just as fun ;^)

Honestly, I would borrow an amp from a dealer to see if you think it's worth it... the diffs may not be quite what you are hoping for. As you say, you are still at the mercy of the preamp section of the Denon... my most accounts, this makes a bigger difference in sound quality than the power itself.

But, hey - I don't know your rig, all I can say is try it. If you are already enjoying, what are you expecting to gain?

That Viking stainless fridge is lookin' good...

[Woochifer]

The benefit of adding an external amp will vary depending on how demanding the front speakers are, the size of your room, and your typical listening level. I know about Meridian's self-powered towers, but not their other passive models, so I have no idea what kind of a load they put on an amp. As Jimmy mentioned, you could try borrowing an external amp from a local dealer and see how much (if any) audible benefit that you can discern. Only then can you figure out whether such an investment is worthwhile.

[sam9]

Definately try borrowing an amp.

Where you are most likely to hear a difference is on peaks. It depends a lot on your speakers. It is very hard to say how a specific AVR interacts with a specific set of speakers without expirementing. The benefits are also bit complex to predict because you will be taking some of the load off the AVR so it is possible that the suuround quality my improve some (assuiming it was limited). And don't discount the affect on DVDs -- at least the ones with loud dramatic sound.

Be preparred to accept that you may not hear a benefit. That is a real possability too.

[Les Adams]

Ok, thank you all for your comments and suggestions so far. (Jimmy, has my wife been talking to you?) I would also appreciate some general comments about what you may think is "The weakest link" in the overall system.

I have tried a rather old Rotel RB850 50w dual mono block amp. There was an improvement in overall "musicality" and detail, the Rotel also sounded warmer and "fuller", but it was lacking the dynamics of the Denon. The Rotel is about 10 years old and it may be that the capacitors are drying out, so it is not performing as well as it used to. I particularly noticed this on timbale and snares (in particular the big toms at the begining of Paul Simon's "The Boy In The Bubble" on "Graceland" which lost some weight, body and attack.

I do play loud, very loud sometimes, so I think the extra power of the Denon helps in this area. The Meridian's do not seem hard to drive and even the Rotel managed some pretty impressive SPL with no evidence of amplifier clipping, it was just the dynamics that were lacking. This may of course just be a characteristic of the Rotel amp.

One other point that concerns me is that the Denon does not have a switch to turn off the output to the speakers, so when using an external power amp, the Denon is seeing an open circuit at the speaker terminals. Is this likely to cause any harm?

I am also still a bit puzzled by why A/V amps are generally not rated for stereo use, so some more explanation of this would help me.

I agree that borrowing an amp is a good idea, but as I would prefer to buy something good, but older (to reduce the financial outlay) it might be difficult to borrow something like an older Naim or Quad 405-2.. Unless there is somebody in my area (Cheam, Surrey) who has a Quad and would like to pop round for a few beers one evening to experiment?... all in the name of research you understand!

Les.

[Woochifer]

Ok, thank you all for your comments and suggestions so far. (Jimmy, has my wife been talking to you?) I would also appreciate some general comments about what you may think is "The weakest link" in the overall system.

The weak link in your system is probably the nonmatching five-speaker setup. From what I know of Meridian speakers, a JBL center speaker could provide a significant enough contrast for you to notice the timbral mismatch. Generally, you're best served by going with as close a voice match all the way around as possible. If the multichannel performance is not your highest priority, then obviously the speaker mismatches will not matter as much as they would to someone else.

Also, your system setup might benefit from the addition of a subwoofer, if for no other reason than to allow you more placement flexibility since main speakers typically locate along the middle of the front wall -- the location in the room where low frequency reinforcement is weakest. And by equalizing the subwoofer to minimize the room-induced peaking and create a more accurate bass, you can extend the range considerably while creating an in-room bass performance that can rival most full-range speakers for considerably less money.

One other point that concerns me is that the Denon does not have a switch to turn off the output to the speakers, so when using an external power amp, the Denon is seeing an open circuit at the speaker terminals. Is this likely to cause any harm?

Doubt that this would cause any harm whatsoever. Can't complete a circuit if the signal path goes nowhere.

I am also still a bit puzzled by why A/V amps are generally not rated for stereo use, so some more explanation of this would help me.

Of course they're rated for stereo use. It just happens that most people who buy them use them more for the multichannel applications. AV amps with an analog bypass for two-channel sources are fine with stereo playback and the 3801 does an analog bypass directly to the amp with no digital conversion when playing two-channel sources with the digital processing switched off. Almost all of the reviewers that I've seen include at least some two-channel playback in the subjective evaluations of AV amps.

[Les Adams]

Thank you Woochifer, you make some very interesting points and clear up a myth or two for me. The comments on my system are much appreciated and taken on board.

The mismatch of speakers came about in a series of upgrades. Originally I had a pair of JBL Century L100 speakers at the front, so when I got my first "Pro Logic" receiver, the JBL centre made sense and matched well. The Meridian's were my most recent upgrade and were bought for their stereo performance, rather than trying to match them to the rest. The Gale rear speakers were some small speakers that used to live in the bedroom! So yes, I agree that for 5.1, it is not a match made in heaven!

However, as you may already have guessed, my main concern is stereo performance as I listen to music more seriously than I watch films. I enjoy the 5.1, but it is not my priority. My wife is the TV watcher!

By A/V receivers not being "rated", I meant that most of the hi-fi press seem to frown upon them in serious hi-fi stereo terms and are rather dissmissive of them. I have often read that they believe only a dedicated stereo amp, or a pair of mono blocks will give true stereo performance and that seemed rather odd to me. After all, an amp is an amp, regardless of what it is being asked to reproduce and why should the amps in an A/V receiver not be good for stereo. I suspect there is some snobbery going on here! I was asking if there is any technical reason why this should be so.

I have been into hi-fi and music for many years and used to earn my living as a record producer and remixer for the likes of Aretha Franklin. I still have a pair of very large Westlake studio monitors driven by a C-Audio SR606 amp in my home studio (now a radio production studio where I produce shows) and that system really kicks, but it is not a good environment to relax in and enjoy music, it is far too "clinical"!

My main problem with the system is that it does not give me the dynamics and absolute clarity I get in the studio and there is sometimes a "muddling" of the sound on complex pieces of music. I am trying to find out where that is coming from. I may try lifting (with the help of a friend!) the C-Audio amp into the lounge. That beast is 650w per channel and has a power supply that would run half the village! These amps are widely used in recording studios for the main monitors and are superb and accurate sounding amps, although you wouldn't want it in your hi-fi rack.. it would probably buckle under the weight! I guess that will at least tell me if it is the Denon power amps that I am not happy with and I can go from there.

If that doesn't help then I guess I could try an outboard phono preamp.

The 3801 does indeed have a "direct" mode and I use it for all stereo sources. My concern is the quality of the Denon phono preamp and the power amps. In general, I am happy with the system, but I keep wondering how much better it could sound if I made some changes. The Garrard 401 is a remarkable turntable and the SME / V15Vxmr are a perfect match so I think I have got the front end right. I think I am also happy with the Meridian speakers although I suspect I have yet to hear them at their best.

The subwoofer suggestion as also a good one, thank you.

My goodness me.. I really do have the hi-fi bug again! Is there a cure?