Preamp only? Bypass Necessary?


Forgive what may be some repetition as this subject has been discussed before.

 

Earlier threads discussed the limitations of an AVR’s preamp section to reproduce 2-channel music, specifically the sound quality. The discussions focused on use of the AVR pre-outs to connect an external preamp or integrated amp with an HT Bypass. As one respected forum contributor put it”

 

“The whole idea of the HT bypass is to do just that — have your higher-end sources completely bypass the AVR. Once they enter the AVR in any fashion, the higher-quality audio signal is effectively ruined. Specifically, the front L/R preouts from the AVR get routed into the stereo preamp’s (or integrated’s) HT Bypass input along with all other critical 2-channel sources connected to other line inputs thus “bypassing” the AVR while the stereo pre allows the AVR’s front channels to pass through it unaffected by and independent of the preamp’s volume control.”

 

From this I understand 3 things: 1) Because the AVR is still providing power to the front L/R speakers an integrated amp is not required (but could be used); 2) the preamp must have an HT bypass; and, 3) other components, such as a streamer, DAC or turntable, are connected directly to the preamp. However, elsewhere the author quoted above states:

 

“… all you’d need to do is connect the front L/R preouts from the [AVR] to an input of your choice (or HT Bypass if it has one) on the stereo preamp and that’s pretty much it. Choose that input on the stereo pre when you’re doing HT and another input when listening to streamer, CD player, etc. That’s really all there is to it, and the AVR will be completely out of the signal path when listening in 2-channel."

 

Other threads on this and other sites say or imply that an external integrated amp with HT bypass is required, so that the front L/R speakers derive power from the integrated and not the AVR.

 

I have an AVR with pre-outs and hope to clarify whether only a preamp, and not an integrated, is sufficient and in either event whether the external component must have discreet HT Bypass inputs.  

sadbird
Post removed 
Post removed 

Use your ’better’ 2 channel pre/amp for 2 Channel Music, AND Home Theater Front Speakers.

It’s about having the AVR control the FRONT VOLUME (along with the other speakers it is amplifying)

AVR must have front pre-out, many do not.

The HT Bypass on the preamp or integrated is simply an input (a pass thru), to be passed to the 2 channel amp for the front speakers, the AVR controlling the volume.

Note: I often change my AVR from surround sound to 2 Channel Stereo or Direct (and most often find direct is 2 channel, some pseudo surround got in there).

Thus, the AVR is controlling the source, and volume of it’s front pre-outs so your ’better’ amp is driving the front.

.................................

to suggest the signal is seriously compromised by a modern AVR is didactic crap.

Thanks Jerry. I get that and perhaps phrased my question poorly. Based on earlier posts, I understood one would need and integrated amp with and HT Bypass. The AVR pre-outs connected to the integrated's HT Bypass inputs, the L&R front speaker wires removed from the AVR and into the integrated's speaker output terminals and the music source components (e.g., streamer & DAC) into the integrated, not the AVR. 

The posts I included in my post appeared to suggest one may use either a preamp or integrated AND that an HT bypass may not be necessary in either of these. Thus my confusion and desire to clarify before adding components to my system. 

 

I have an AVR with pre-outs and hope to clarify whether only a preamp, and not an integrated, is sufficient and in either event whether the external component must have discreet HT Bypass inputs.

Let’s be clear here — you don’t want any part of the AVR in the stereo signal path, so you want only the stereo pre and amp (or integrated amp) in the 2-channel signal path when playing 2-channel sources. To specifically answer your question, you need either an integrated stereo amp or separate pre and amp to make this work. Since you very fortunately have front L/R pre outs on your AVR you connect that into either a stereo preamp (that then feeds a dedicated stereo amp) or integrated stereo amp, and all your 2-channel sources also get plugged into the stereo pre or integrated. If the stereo pre or integrated has a HT bypass you’re pretty much done with the speakers now hooked to the stereo amp or integrated instead of the AVR. Choose the HT bypass input on the stereo pre/integrated for movies and the other appropriate inputs for your stereo sources and it’s totally seamless.

If you don’t have a HT bypass on the stereo pre or integrated amp this still works by just choosing any unused input on the stereo pre/integrated, but since the stereo pre/integrated volume control will still be active (unlike with an HT bypass input) you need to set a reference volume level on the pre/integrated when you set the individual speaker volume levels for movies with the AVR. I used the 9 o’clock position on the volume knob on my stereo pre because it was easily repeatable and so when I switched the input between stereo sources and HT the volume wouldn’t blast if I forgot to adjust the volume beforehand. So when you’re doing HT the volume on the stereo unit needs to be at the 9 o’clock position for the channels to be in proper balance as you set them with the AVR.  Hope this is clear — it’s really very simple but just seems more complicated when put into words. Lemme know if something still not clear.

Hi Elliot

Thanks for your reply. As mentioned in the post, my AVR has pre-outs for all speakers. Perhaps my post was too long-winded and should have limited to the last paragraph where I stated "I have an AVR with pre-outs and hope to clarify whether only a preamp, and not an integrated, is sufficient and in either event whether the external component must have discreet HT Bypass inputs.   

Soix--perfectly clear and specifically responsive to my original post.  Having read some of your previous responses, I didn't fully appreciate the solo reference to a preamp also necessarily included an amp to power the front speakers. (I wondered how the power could return to the AVR using only a preamp.)  Likewise I wasn't sufficiently knowledgeable to understand how volume would be an issue if the outboard pre didn't have an HT Bypass. Thanks.

 

sadbird OP

keep in mind, others follow these threads, so I write responses for both OP and others.

btw

IF you are not using the system for anything other than Video, and simply want a 'better' amp to power your front speakers, no preamp is needed, you can go straight to your amp(s), the AVR handles the volume to the amp.

AVR selects Over the Air TV; Cable; Blu-Ray Player, i.e. it is the pre-amp/source selector of any/all things video, passing the front to the better amp, no HT Bypass needed as AVR is the ONLY source.

AVR itself amplifying the center, surrounds; and pre-out to self-powered sub(s). Repeat: AVR controls the Volume of all speakers, INCLUDING pre-adjusting/balancing the relative volume of each speaker to the others, including the signal strength of it's Front Pre-Out. Thus, the AVR IS processing the signal before sending out it's Front Pre-Out.

IF you have other sources, for 2 Channel MUSIC as well as Video, then an external pre-amp/source selector is needed, those sources direct to that Pre-Amp (or Integrated) skipping the AVR entirely. 

Keeping the AVR out of 2 Channel Music is what HT Bypass is all about, but be aware, for Video, AVR Processing is happening.