Preamp Question

New on here and have a question I couldn't find an answer for.

Since everyone seems to agree that AV receivers don't do the best job playing music I have a question for those in the know:

Most people seem to agree that the preamp is the most important factor in terms of the final sound quality of a setup. Most also recommend connecting an integrated amp to the preouts of an AV receiver for much better music playback. Now if you were to do that, you will be using two preamps AV receiver's preamp followed by the integrated amp.

Do you not think that having two preamps in succession will actually colour/confuse things further and have an adverse effect on the final sound quality as opposed to improving it even if it was a great integrated amp? Or is that just a theoretical way of looking at it but in practice the results are actually very good despite the two preamps working in tandem? Cheers

 

In my system, the AV receiver, actually, a pre-pro, isn't in the pure music chain and so two preamps are not cascaded.

I have a preamp and power amp set up purely for audio. My CD player and turntable connect directly to it. When I am playing either one, the AV pre-pro is not turned on and not in the loop. As my CD player is also my 4K blu-ray player, it connects to my audio-only preamp with two-channel analog connections and, at the same time, connected to the AV pre-pro by HDMI.

However, I have connected the front left and right outputs of the AV pre-pro to the video input of the preamp. When any multi-channel media is playing, streaming, etc., indeed two preamps are cascaded. Of course, any degradation and whether it is audible depends on the quality of the electronics in the chain.

By the way, when my son visited recently and I was attempting to persuade him to use an outboard phono preamp instead of the phono inputs on his aging AV receiver, I connected my turntable to my AV system and fired up "Kind of Blue." His reaction? "Holy %#$*! Where did the soundstage go? Stop it now so I can order a new preamp!" He bought and now swears by the awesome Lounge Audio LCR.

 

Thanks that's quite a setup you have there! But my question is more about the principle of the whole approach which I know lots of people use i.e. connect an integrated amp to the preouts of an AV receiver for better music playback. Surely if the A/V receiver's pre out is still in the chain then how can the sound be significantly improved? Sorry forgot to mention the MOST IMPORTANT point, my music sources are digital (PS3 slim for Spotify and Apple TV for airplay) and are connected to the AV receiver. That's why if I add an amp to drive my Mission 753 front speakers both preouts will be getting used and I want to know if that'll be worth doing?

 

Not an issue.............
Only when in Multi Channel mode.........but there are quite a few integrated stereo models with HT passthrough and unity gain which minimizes any degradation.

Simply put......When you want stereo you use your integrated.........Your AVR is NOT EVEN ON!!!!

When you want Multi Channel............You use your integrated in "HT pass through" mode and your AVR performs Multi Channel duties.

Your Mains will ALWAYS be run by your integrated's power section.

A LOT of people run this way as it maximises stereo SQ and also benefits Multi Channel SQ.

 

Are you asking about a POWER amp or an Integrated?
Adding either will improve everything.

If you want QUALITY stereo sound then you need an Integrated which you would plug ALL your 2 channel sources into.

100% worth doing..........adding an integrated is ideal if you really care about stereo.
Adding a power will still help too.

 

Thamks, yes I fully understand that and my apologies for not having made things absolutely clear. My issue is I have a limited budget of around £250. The amps available at this price point that have digital inputs are quite low in power (e.g. Marantz PM6005, Nad D3020) and probably won't be the best choice for my Mission 753s that sound best when given some good power. So my only option is to buy an old integrated amp with good power, connect it via the AV's preouts and use the AV receiver for the digital inputs. And that's the question, since the preamp from the AV receiver will still be in the chain would it really be worthwhile doing for SQ improvement?

 

You're talking about using one preamp to drive a second preamp? Yes. Makes no sense to add a preamp to drive a preamp unless for some kind of reason you need lots of extra gain, which I'm sure in the case of modern audio electronics, you don't.

More stuff-- more devices, more complex circuitry, more interconnects and input and output connections -- always gives you more chances for distortion and departures from linearity and voltage loss. Plus piling up unnecessary extra gain in a signal chain will narrow your headroom and/or will just be adding lots of gain up stream and attenuating it downstream.

I also think it's not true that "Most people seem to agree that the preamp is the most important factor in terms of the final sound quality of a setup." In fact, my guess is that most people would say speakers or source or setup/room/room treatments are areas where changes make the biggest difference. And, not knowing what your gear is or how it's set up, my suspicion is that the biggest step forward in sound quality for you would be to go away from lossy sources like Spotify and Aple

If you have a "great integrated amp" ...well, by definition it must have a great preamp circuitry, so there would be little advantage substituting a preamp for its preamp circuitry unless it was an even greater preamp.

 

The only benefit you will get is if the amplifier in the outboard amp is more powerful, and you require the power to drive your speakers, or of much higher quality. Otherwise, I'd stick with what you have.

 

Ahh.......... I get it now.

Either do nothing......... or look for a nice power amp (NOT integrated) that will drive your mains better than the AVR does.

Then just connect the power amp to your Main pre outs on your AVR and enjoy.

Chili555 pretty much nailed it!!!!

 

If the 2ch integrated doesn't have HT pass-thru and 2ch audio quality is the priority, then I would connect the tape out on the AV receiver to an input on the integrated for 2ch music listening (basically using the AV receiver as a DAC). You could also connect the pre-out from the AV receiver to a second input on the integrated for multi-channel listening, but the risks there are creating a ground loop noise problem and/or getting the volume levels right so the AV receiver preamp isn't over or under driving the preamp in the integrated and causing distortion or weak sound.

Or, yes, just buy a dedicated power amp and connect it to the preamp out on the AV receiver.

 

What a top bunch of guys, answered all my questions in one thread! And yes Chili555 absolutely did nail it! Cheers all......

 

Actually... Despite their best efforts, no one has yet steered you in the proper direction. You hinted at what you were looking to do (get better 2 channel sound through the use of a better preamp) and commented on how you were confused by the advice of others to use the receivers pre-outs. All are correct in that it isn't a good idea or of much, if any, benfit to use the pre-out from the receiver into the preamp and amp end of a stereo integrated amplifier. That's basically a waste of money. If the integrated amp had a significantly better power amp section, and if it allowed for the bypass of its preamp, and if you needed that added power, then it might be of some benefit, but at quite a cost. If that integrated was an exceptional sounding integrated amp, all-through,then it might make sense for a good combined stereo and HT to connect the stereo sources to. But... the very best way to get the best sound is as you suggest and to get a really nice, and I mean exceptional sounding preamp that has a HT bypass function to connect your stereo sources to. That way, all stereo sources go through the preamp, but use the power section of your reciever as before, which is likely adequate. That will dramatically improve the sound by keeping the 2 channel source signal quality intact and going through a high end preamp, only to be final amplified through the receiver. It is pretty much the same as getting a super nice integrated, but has two advantages. One is that there are more choices of better quality preamps, which outperform most integrated amps, and the preamp can be used as a building block to later add a separate power amp to fully replace the receiver for 2 channel listening, should you want to continue to improve the system or to separate them into two independent systems. As mrvco indicates, if you must use an integrated amp as a stereo amp, then it is likely best to feed it the signal from the tape loop of the receiver, if it has one. That would avoid the double preamp gain stage that you were concerned about, but it might also have complications in various receiver designs in that the processing for the front channels might be bypassed when the tape loop is selected, which could open another bag of mulch.
-Bill

 

Yes, this. My setup runs like this. My system doubles up for home theater and gaming. When I am playing 2 ch vinyl, CD, digital, whatever the AVR is not even in the picture. It is only there to take in digital video sources. When watching a movie, playing a game, whatever then it is AVR pre-out to pre-amp running in HT bypass mode. In that case, I am really using the pre-amp in the AVR and the dedicated 2 ch pre-amp is just basically bridging the signal to the 2 ch amp to run the front speakers. All pre-amp functions are handled by AVR

 

Thanks Bill (KT88), you're a very knowledgeable man by the looks of it! A preamp with HT (though a great suggestion) might be a bit over budget for me at this stage. The other option of using the tape out to avoid doubling of preamps will supposedly rule out the AV's use for movies wouldn't it, since presumably, you will no longer be able to control the front speaker volume from the receiver?

 

Another question after reading Joey_Corleone's post: If an integrated amp has HT bypass and one controls the volume from the receiver - Is the preamp in the integrated amp then bypassed completely or is the volume control just linked to the AV's volume control but the preamp of the integrated amp still gets used?

 

Been thinking about the question I asked 2 posts above -

"The other option of using the tape out to avoid doubling of preamps will supposedly rule out the AV's use for movies wouldn't it, since presumably, you will no longer be able to control the front speaker volume from the receiver?"

Potential Solution:
What if I connect the tape out to one of the inputs on the integrated amp and then use my AV receiver as a DAC as has been rightly suggested above but also connect the receiver's pre out to another input on the integrated amp and then use that when I play 5.1 channel stuff for movies on the receiver?

 

Yes, that's the work-around that I was thinking of. It still has the disadvantage of the double preamp for one of the inputs. No free lunch it seems. The best bet is to get either a top quality preamp or integrated amp with HT pass-through features. That's going to be expensive for a real improvement. For anything uberbudget, you might as well just stick with the receiver for everything IMO.
-Bill

 

Not too bothered about the double preamp for movies as I don't really watch many nor am I too concerned about the sound quality of the front two speakers when it comes to watching a film.
I think there's a fair chance I can pick up a decent old amp fairly cheap (without the HT bypass) which should still be a lot better for stereo than my receiver?

 

Maybe. Or you could just do what I do and run only a 2 channel system for everything. Having two speakers vs 6 buys better speakers. You can also buy very nice stereo amps that will last many years and sound much better than an AVR. Basically money saved in one area is invested into another. Once set-up, all sources play through the same, nice sounding stereo system with the TV monitor between the speakers for video. Alternatively, you can use a projector to project an image on the wall between the speakers. It works for me anyway.

-Bill

 

In an ideal world that'll be the perfect solution mate. However, I do have a family who like to watch a movie from time to time and it's for them that I need to have some sort of a surround system in place as I've long had everything set up, wiring and all! Cheers......

 

By the way, did you see my other question about the HT bypass. I don't suppose it bypasses the integrated amp's preamp stage? I wouldn't have thought so.

 

I think that most all integrateds with this feature would bypass the internal preamp in its entirety and go right into its power amp section. Well, a great stereo sounds great for movies too. I watched "Pearl Harbor" last night with my wife and it was pretty decent, even at a low volume. I have seen that several times with a projection system and both a stereo and a surround system. A top notch stereo has it sounding at least as good as the surround version. The scene where the Spitfire / Messerschmitt dogfights occur is fantastic.
-Bill

 

Yes I'm sure it does and as I said if it was up to me that's the route l would have taken. But my kids won't have it any other way and in a true democratic household you have to respect & accommodate everyone!

 

I wouldn't worry about the double preamp for HT. I doubt if you will even notice any difference.

 

Agreed!