Don't need a receiver/processor?

[impala454]

So I'm about to do some rearranging of my setup, as I used to have a ton of stuff and a bazillion wires, and over the past year have sold off all my game systems, as well as dropped cable tv and no longer run a windows media center comp (I know, I'm getting boring :P). I'm trying to go rather minimal and curious if there's any downfall to running without any kind of receiver or prepro. So my old setup at its height of amount of equipment was:

Samsung HLS6187 DLP tv, Denon 2307CI Receiver, Emotiva XPA5 amp, Behringer EP2500 amp (for sub), 5 various statements speakers, blah sub, HD cable receiver, oppo bp83, xbox 360, wii, nintendo, super nintendo, N64, atari, windows media center comp, network switch, belkin power center (PF60 I think), battery backup (for the TV's fan).

Now most of that stuff is gone, and the only source I have is the Oppo BDP83. I'd like to just do this:
Oppo -> HDMI -> TV (for video)
Oppo -> Analog Outs -> Emotiva XPA5 (for sound)
(possibly) Oppo -> analog sub out -> Behringer (not sure if I'll even use the sub, but might)

The Oppo has volume control, I guess a kind of level output control, is that sufficient? Or do I really really have to have some kind of preamp in between? I'd like to figure this out before I make a huge mess and then hook everything up all neat and pretty only to find that it won't work right Either way it seems like such a waste to have this big receiver sucking down power just to relay the Oppo's analog outputs to the amp. Ideas?

[jeepers]

If you are really trying to go minimal; have you considered selling your Emotiva XPA5 and Behringer and just buy a stereo amp ?

[impala454]

Ok well I didn't intend to mean minimal overall, just seems the receiver is no longer needed in this case. I still want the speakers and awesome amp of course! A simpler way to ask is, would the analog outputs of the Oppo provide enough signal to drive the Emotiva amp without issue?

[jeepers]

You might find this link interesting.

http://wiki.slimdevices.com/index.php/ConnectToPowerAmp

[Kevin P]

A simpler way to ask is, would the analog outputs of the Oppo provide enough signal to drive the Emotiva amp without issue?

Yes, it will. A "preamp" (or pre-pro) doesn't actually amplify* the signal; in fact, it attenuates it, unless you crank the volume all the way up. You can connect a source device directly to an amp, but you won't have any way to control the volume unless either the source device or amp has the capability.

The main purposes of the "preamp" (either as a component or as part of a receiver) is for source switching, volume and tone controls.

Some audio purists will use a "passive preamp" (which sounds like an oxymoron), but it's just an attenuator to act as a volume control, with no active components to add noise to the signal


EDIT: Jeeper's link has some interesting info in it as well, especially with regards to matching the source level to the amp's input sensitivity. If the Oppo's outputs are weak, you won't get full power out of your amp. If they're too strong, you could get clipping, distortion, or speaker damage (avoidable by not turning the Oppo's level up all the way).

Since you have the pieces, why not hook them up the way you proposed to see how it works? Just make sure to turn down the volume on the Oppo before putting in a disc, so you don't blow something up, like your speakers or eardrums. Then play some different material (CD, DVD, BD) and see if it plays loud enough without the preamp.

* The exception is the phono input, which does have an actual preamp to boost and equalize the signal coming from a magnetic phono cartridge. The phono preamp is what gives the "preamp" component its name.

[impala454]

Thanks for the responses guys that's exactly what I was looking for. I will try this out, just was curious on the answers before I started muscling around this massive amp. The oppo does have the volume control though so hopefully that will work. I'll report back what I figure out.

[impala454]

For some reason I couldn't go to bed without trying this out

It appears the Oppo's outputs have plenty of signal for the amp. It's not quite the volume control I had on the low end, but it seems to work great, and the sound is awesome! Now time for bed (can wait another day to start rearranging :P).

[impala454]

So I've got everything all hooked up and it sounds awesome! :T

Only one issue, and not a huge deal as I rarely use the sub in my apartment, but it seems that the Oppo's analog outputs drive my Emotiva XPA-5 just fine, but then the subwoofer output is very low, like almost non existent. I tried just putting the cable on the FL output and boom it sounds awesome. I also tried upping the gain on the subwoofer in the Oppo's menus to maximum (+10.0db) and still not good enough. Anyone have any ideas?

[jeepers]

I could not find the article I was looking for so I took another one.
Check item 4 (Scotty we need more bass) ...

http://www.bigpicturebigsound.com/How_To_Set_up_a_Blu-ray_Player_Using_Multi-Channel_Analog_Outputs_And_Why.shtml

[impala454]

Yeah without the receiver in the mix it's hard to do that boost. The Oppo lets me boost to +10db but it still doesn't seem to level match with the rest of the channels. Is there some kind of device I could use to amplify the input signal?

[Hdale85]

Yeah, receivers definitely do more then just attenuate the signal, they boost it as well. Signals from BD,DVD,CD so on are pretty low level generally.

[impala454]

I'm gonna start calling you Echo. :P

[madmac]

Yeah without the receiver in the mix it's hard to do that boost. The Oppo lets me boost to +10db but it still doesn't seem to level match with the rest of the channels. Is there some kind of device I could use to amplify the input signal?

I'm a little lost with this Can't you simply turn up the sub's volume?. As far as I know, all subs are powered correct???........

[Hdale85]

It's not about the volume of the sub, it's the input signal strength. The oppo might put out 1v signal from it's analog outputs, but a receiver will take that and amplify it probably at least to 4v outputs, sometimes as much as 8v depending on the receiver. That much greater output strength allows much more attenuation and much greater output, the sub's amp is only going to amplify what it receives and if what it receives is a low voltage it's not going to have the power that it should. Generally if you look deep into specs of an AMP it'll say what input level it needs to attain the specified wattage that it outputs.

[impala454]

Yeah the thing that has me baffled is that if I pull the cable off the sub output and plug it into a front LR, it's boom pow bang and plenty of signal. With it back on the sub output and the rest of the system at plaster cracking levels and the sub amp turned all the way up it's just barely starting to kick in.

I may just have to punt and go back to using the receiver, I just love the way the 5 channels sound hooked straight up to the Oppo. I've listened to a bunch of surround music and its sounds amazing. It's annoying to add another set of SIX cables to the setup when it's so nice and clean as is. I'd love to be able to spend the cash to grab a new processor like the onkyo or something but it's just not in the cards for now.

Oh and sorry Dougie my echo comment was kinda mean. Was in a bad mood :P

[impala454]

You know I just realized something, this sub is actually not much of a home theater sub. It's more like a competition car audio sub and doesn't go much under 40-45Hz (though it gets building shaking loud at those frequencies ). It may simply be that the Oppo only sends the subwoofer channel frequencies under (according to the manual) 80Hz, so it's simply not getting anything it can really play. Which also explains why it sounded like the room was going to explode when I had all the levels turned up playing the opening scene in Star Wars Episode II.

[Hdale85]

Also could be that the amp you're using with the sub requires a higher level input then what it's receiving, while the Emotiva amp has more gain.

[impala454]

The sub amp is a Behringer EP2500. Upon looking at the spec sheets on that and the XPA5, it looks like the unbalanced input impedance on the XPA5 is 23.5kohm, and the Behringer is 10kohm.

[Hdale85]

Yeah, the Emotiva amps have A LOT of gain, I'm not sure what the gain structure is on the Behringer stuff.

[JeremyG]

Hey, Chuck :later: So are you saying that the sub works fine at certain frequencies? If not, are you using the same cable to check the output from the Emotiva? I've heard nothing but good things about the Behringer, and haven't seen anything about input sensitivity issues with regular HT gear. The Emo does have quite a lot more gain. I had to do a little level balance trickery between my UPA-2, my BFD and my Crown sub amp, due to volume balance at mid and high volumes.

[JeremyG]

Another thought: maybe check subwoofer phase? If the AVR was previously adjusting phase, maybe you have an issue there.

[impala454]

Yeah I can literally take the cable off the subwoofer output of the Oppo, then plug it into say, the LF output of the Oppo, and it's a night and day difference (louder). I supposed I could drop the gain on the 5.0 outputs down in addition to boosting the sub output (though it's too late at night to try that right now ).

[madmac]

Yeah I can literally take the cable off the subwoofer output of the Oppo, then plug it into say, the LF output of the Oppo, and it's a night and day difference (louder). I supposed I could drop the gain on the 5.0 outputs down in addition to boosting the sub output (though it's too late at night to try that right now ).

Sub output and into LF output of the Oppo ??. You've lost me there?? . LF output is what the sub should be connected to no?. Also, Car audio is a completely different bird impedence and power requirement wise too. The two do not blend well together. I believe that's where your volume problems are coming from.

[Kal Rubinson]

Sub output and into LF output of the Oppo ??. You've lost me there??

He means LF = FL = front left = full range.

[Kevin P]

Sub output and into LF output of the Oppo ??. You've lost me there?? . LF output is what the sub should be connected to no?. Also, Car audio is a completely different bird impedence and power requirement wise too. The two do not blend well together. I believe that's where your volume problems are coming from.

"LF" = left front output. He hooked the left front channel output from the Oppo to the sub just to test the level, which was a lot higher (louder) than the sub (LFE) output on the Oppo.

I would say using the car sub could be at least part of the problem, but if it were the entire problem, feeding the sub one of the other outputs (such as the LF) would also be too quiet.

Can the Oppo create test tones for balancing speaker levels? How is the sub level with those? Or with a calibration disc?

[impala454]

If I turn off the 5.0 Emotiva Amp (so as not to blow all my speakers), then turn the volume all the way up on the Oppo, it seems to get reasonable output on the subwoofer channel. As mentioned I may try and just lower the signal on the 5.0 channels and then boost it on the sub and see how that goes. It was just too late last night to try it

Surpsingly, no, the Oppo cannot do test tones, but I do have a test disc.

And yeah the car sub is not really good for this application, but it's one of those deals where it'll either sit there and do nothing, or I can plug it in and have a little fun It really is awesome for bass heavy music though.

Here it is if anyone cares to see, it's from a tiny little mom & pop shop in the dallas area. I got it in college as a boom crazy stereo dork because my roommate's friend owns the business. Supposedly won some world car audio competition a long time ago with this design. It's quite the building shaker at 45 Hz

http://www.toby.com/CarAudio/Ranger%20Info.htm

[JeremyG]

Yeah, Toby's speakers are pretty good. They're out of Fort Worth, and when we lived there I'd go down there every now and then and check out what they have. I think they build their drivers in house. They have some pretty good sounding OB two ways, and one guy there even built a electro-static speaker. Wound the wires around up and down a baffle and everything. They also built the FOH PA at the Bass Performance Hall in Fort Worth. Pretty neat.

Anyway, if the Oppo doesn't have any bass management type stuff, you could have a 10dB down output issue. I have a Sony BDP-550, and if I use the analog outputs the LFE is 10dB down on purpose. It has something to do with BDP mastering for bass management I believe. It used to be a big deal with BDP's HD tracks and SACD's. Regular DD and DTS were not effected that I could tell. If I had the BDP decode the HD tracks, stream PCM to my Marantz, and use it to decode the LPCM, then I get great LFE because the Marantz is decoding and using bass management.

[impala454]

Oh nice to hear someone else who knows of Toby! Yeah they do manufacture their drivers in house.

I haven't tested a regular DD or DTS track yet, but did notice the same issue even with just a plain old CD.

[madmac]

He means LF = FL = front left = full range.

Oops......Everyone's allowed a dumb moment right??!!! :lol: