I think in most cases you would benefit.If the PreAmp Output Voltage levels are good.Even if you only did the front 3 channels that would still be a benefit.Not sure on that Denon but,even without Speaker Outs hooked up there is a chance[if you are really cranking it up] of Bleed Through Distortion into the PreAmp Outs on most A/V Receivers under a certain price level.Someone else here probably has more info/facts on that.
Adding 5-channel amps to AV Receivers
I'm currently shopping for a used 5-channel amp to use with my Denon x3400h receiver with a 5.1.2 Atmos setup, speakers are the older SVS SCS1/SB1 which still do great. This setup is 100% movies/video games, music is for the 2-channel setup upstairs (Levinson, Revel, PS Audio). The home theater is never going to get the budget that the music system gets, but its still a lot of fun and Dolby Atmos is really cool with down-firing ceiling mounted speakers.
My question - It seems like adding a separate 5-channel amp to pretty much any AVR would be a very standard setup for anything above a low-end home theater setup, but I rarely see it discussed. IMO its asking a lot of a sub-$1k receiver to handle all the processing and 7 channels of amplification with its single power supply. When you can buy a used Rotel, Parasound, etc 5-channel amp for less than $500 and let the AVR be the processor, this should be a no-brainer right? Pulling out at least 5 channels to a real amp should have all kinds of obvious benefits. Even if the speakers are not full-size, reasonably efficient, and there's no clear need for more power, this should still produce much better sound.
It seems like an obvious move but its hard to find any discussion of it, usually the conversation goes from budget AVR to high-end AVR to separates. Am I missing something here?
My question - It seems like adding a separate 5-channel amp to pretty much any AVR would be a very standard setup for anything above a low-end home theater setup, but I rarely see it discussed. IMO its asking a lot of a sub-$1k receiver to handle all the processing and 7 channels of amplification with its single power supply. When you can buy a used Rotel, Parasound, etc 5-channel amp for less than $500 and let the AVR be the processor, this should be a no-brainer right? Pulling out at least 5 channels to a real amp should have all kinds of obvious benefits. Even if the speakers are not full-size, reasonably efficient, and there's no clear need for more power, this should still produce much better sound.
It seems like an obvious move but its hard to find any discussion of it, usually the conversation goes from budget AVR to high-end AVR to separates. Am I missing something here?
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Most receivers that are spec'd for say 120 watts per channel, will only actually do that with one or two channels driven. Usually the specs for multi-channel amps are for all channels driven. Adding an external amp should give you more headroom if nothing else and if it's a decent amp, it should sound better than whatever they were able to stuff into the AVR box. |
Personally I wouldn’t do a 5-channel amp unless I was big into high-quality surround music. Short of that, I’d rather do a better 3-channel amp for the L/R/C and let the receiver power the rears. There’s a McCormack DNA HT3 available now for $800 (List $2300) that I’d jump on if you want a big upgrade to your HT amplification. That said, if it were me I’d upgrade to something like a used Anthem MRX 520. Why? Well, as audiophiles we know the preamp is as or even more important to the ultimate sound quality of a system as the amp. So bu upgrading the amp you’ll likely get some improvement, but you’re still stuck with the preamp section of the Denon. By going to an MRX 520 you’d not only get better quality amplification but also a much better preamp and arguably better surround processing as a further bonus. Put all those together and the resulting increase in overall sound quality will likely far eclipse just inserting an amp in with the Denon. Used MRX 520s do pop up in the $800 range from time to time, which is only a little more than you were planning on spending on just an amp. Anyway, two other options to ponder. Best of luck. |
Good replies fellas I appreciate it! Soix - Great point on the Anthem (and spot on with pre-amp importance), that one was not on my radar, but you're right, for $800 or so used that's really compelling. I had not given much thought to higher end receivers, but if I see one come up for sale I'm going to buy it. Also good points on the 3-channel amp instead of the 5-channel. For whatever reason, quality 3-channel amps seem to be either more expensive or less available than 5-channels, and I thought I could run the five SVS speakers with the same amp, and run the other 2 with the receiver. I did snag a B&K AV5000 5-channel amp on ebay today for only $200, that's supposedly a pretty decent amp, so I'll do the experiment with the Denon and post back. I can sell both the B&K and Denon if the Anthem beats my budget separates combo, which it probably will after reading about it for a few minutes. Happy Holidays! |
This is interesting from Audioholics. You get what you pay for. Interesting watch. Seems like high end Denon's are the only ones the shut off internal amps when you add an external amp. https://www.youtube.com/watch?v=4sq2dyzJYvA |
It’s a huge benefit sonically to add a separate amp, but often it comes down to what needs to be passed over HDMI as that is generally the biggest impediment to AV Receivers and why it often requires upgrading or changing the receiver out before purchasing a multi channel amp. Also, after getting a new multi channel amp, that will easily lead to replacing the old receiver with a dedicated preamp/processor because though you are bypassing the amplifier section, there are still inherent advantages to having a good pre/pro. The difference you’ll hear adding the amp will be just as big or bigger when ultimately switching out the receiver to a good pre/pro. |
This is interesting from Audioholics. You get what you pay for. Interesting watch. That's such a great video, thanks for sharing! For the most part it reinforces my thesis here, that on most sub-$1500 receivers, the amps and power supplies get seriously compromised. On the other hand, its absolutely crazy to me that it takes a $3,000 AVR before the amps actually turn-off when using the pre-outs, that seems like the most basic function of even having the pre-outs. However, the amps simply being turned on but not actually driving any loads should be far less of a strain on the power supply than having 7 channels going. So it still seems like it would be far superior to run a separate amp. |
That's awesome, thanks for sharing! |
It’s a huge benefit sonically to add a separate amp, but often it comes down to what needs to be passed over HDMI as that is generally the biggest impediment to AV Receivers and why it often requires upgrading or changing the receiver out before purchasing a multi channel amp. Also, after getting a new multi channel amp, that will easily lead to replacing the old receiver with a dedicated preamp/processor because though you are bypassing the amplifier section, there are still inherent advantages to having a good pre/pro. Great perspective here. This is still an audio rabbit hole after all, so there is zero doubt in my mind I'll eventually get a separate processor. But for right now my home theater priority is getting Dolby Atmos with decent enough sound without spending $3,000. What baffles me on the current crop of separate processors (and I could be wrong here), is that there doesn't seem to be one that even has Atmos for less than $1,500 or $2,000. How do the $300 cheap AVRs have Atmos, but it takes $2,000 to get a processor that has it? It seems like the move is to let the processors come down to earth on price and use the Denon in the meantime. I actually have another amp on the way, a Krell Showcase 5 which is total overkill but the price was just too good to pass on it, but hey at least there will be zero chance the amp will be the weak link. |
That’s such a great video, thanks for sharing! For the most part it reinforces my thesis here, that on most sub-$1500 receivers, the amps and power supplies get seriously compromised.Keep in mind that according to Gene DellaSalla that even if the internal amps of AVR are not being used, and still turned on, they introduce distortion into the preamp section as volume is increased, so the internal amps must be shut off like in the high-end Denons. So adding an external multi-channel amp to an AVR is more of transition to having a separate pre/pro and power amp, so factor this long term transition into your budget. Since I’m not a serious videophile owning a somewhat newer high end AVR is a better choice for me. My 10 yr old Yamaha RXV2700 140 wpc 7.1 avr is a good compromise for me. Stepping up to something a bit newer with high power may be a good alternative to separates. |
Keep in mind that according to Gene DellaSalla that even if the internal amps of AVR are not being used, and still turned on, they introduce distortion into the preamp section as volume is increased, so the internal amps must be shut off like in the high-end Denons. So adding an external multi-channel amp to an AVR is more of transition to having a separate pre/pro and power amp, so factor this long term transition into your budget.For sure, without question its really disappointing that the pre-outs on pretty much all receivers apparently are not well implemented. That's a convincing explanation and it does reinforce that adding the external amp is not the final answer, even if its a good upgrade in the meantime. It also provides a good explanation for my original question of why this isn't more common, I'm very appreciative for the info here. |
I purchased an Emotiva UMC-200 pre/processor when it came out and paired it with an Anthem 5 channel amp. That combo definitely out performed an older but higher end Denon receiver that I was using as a 5 channel processor (i.e. it supported preamp out). I just got my first source (4K Amazon Fire Stick) that wouldn't work with the 6+ year old processor. I didn't feel like spending a lot on a new processor so I just purchased a refurbished Yamaha TSR-7810 receiver that has a preamp out. I cabled it up to the Anthem and after running its auto speaker setup listened to a movie soundtrack and I think it sounds at least as good if not better than the much older processor. I'm definitely happy with its audio quality (as I was with the Emotiva); the Yamaha can be had for $300ish refurbished. |
Finally have an update on the results. Had a couple issues with both amps I bought, but long story short I'm using now using a Krell Showcase 5 amp into the Denon 3400. I'm only using 3 channels on the Krell for the front 3, and the Denon is handling the rest. One of the channels on the Krell outputs some static (needs a re-cap maybe?), but I got a great deal on it so I'm fine with this. Overall, its a big upgrade. Way bigger soundstage, more transparency and clarity, just significantly better sound. This is my HT setup and its mostly movies with the occasional concert Blu Ray, so I used Metallica's "Quebec Magnetic" and Mad Max: Fury Road as the test subjects. Obviously, the Krell/Denon pairing is probably not a very popular combo. But for about a thousand bucks between the two, its hard to imagine doing better for the money for 7-channel 5.1.2 Atmos. I'd highly recommend going this route, especially if you have speakers that could be considered at all power hungry. Want to thank everyone here for their insight on the nuances and mechanics on some of the details I hadn't considered (especially the sub-par implementation of the pre-outs on most receivers). |
I am glad the OP has a solution to the question but I wanted to add something he and everyone could still use and that is a power conditioner with reserve power. I have a Furman Elite-20 PF I that I bought open box from Audio Advisor. It has in excess of 4.5 amps of continuous current reserve (over 55 amps peak charge). My system is 7.2.2 with a Denon x6300 AVR(11.2 channels) $1500 from Crutchfield, bi-amped B&W 803 Nautilus tower L&R, B&W HTM2, B&W LM1 surround, B&W DB4 subs and Polk in ceiling speakers and I have never heard or felt like there was any fatigue coming from the speakers. In fact I would characterize the sound quality as "riveting" when listening to a movie like Blade Runner 2049. I used Audioquest Rocket 44 speaker cables, Pangea sub interconnects and Pangea Power Cords on every component. A problem with using a separate multi-channel amp is all the extra interconnects and the extra expense and related sound degradation (EMI, RFI, or poor quality cables) they bring. Hope this helps future readers of this thread. |