AVR Preamp vs Speaker outputs

[vsound5150]

Hi all,
I don't know if this is a stupid question that I'm just not getting. I connected an external amp to my AVR preamp output and currently driving front L/R speakers out from the external amp. Why does the AVR still allow me to adjust front speaker dB levels same as when I had the speakers directly connected to the AVR. Isn't the AVR speaker output separate from the preamp output?

 

[lovinthehd]

The avr speaker outputs are pre-amp then to the avr's amps. The avr's pre-amp goes to the avr's pre-outs (pre-amplifier outputs)....so of course your pre-amp controls the amp. Would you want it any other way?

 

[slipperybidness]

Hi all,
I don't know if this is a stupid question that I'm just not getting. I connected an external amp to my AVR preamp output and currently driving front L/R speakers out from the external amp. Why does the AVR still allow me to adjust front speaker dB levels same as when I had the speakers directly connected to the AVR. Isn't the AVR speaker output separate from the preamp output?

Why does the AVR still allow me to adjust front speaker dB levels same as when I had the speakers directly connected to the AVR

Your "AVR" is now being used as a Preamp/Processor. All you did was change where the amplification of the signal is done, you haven't changed anything on how the signal is processed (processed by the AVR before it goes to the amp channel, whether the amp is internal or external to the AVR).

Isn't the AVR speaker output separate from the preamp output?
Yup. The source goes to the AVR pre-amp input. The pre-amp output goes to the amp input. If you use AVR speaker connections then the pre-out goes to internal amp-in. If you use pre-amp outs to an external amp, then you use the speaker outputs on that amp.

 

[ski2xblack]

Not a stupid question, but the answer is pretty simple. The levels you are referring to are handled in the pre-amp stage, not amplifier stage. You would only need to change them if the external amp had different input sensitivity than the on-board amps.

 

[vsound5150]

I think I get it now, I'm easily confused for things like this. So does the same AVR preamp control both the front L/R speaker out and preamp out? But that means preamp out is L/R speaker's preamp and means I can only use preamp out as front L/R for external amp as far as controlling dB levels in settings, same channel all the way through.

 

[lovinthehd]

Yes, you simply choose whether to use the internal amps in the avr, or the external amps (both is even possible, as the pre-outs are generally always live). The pre-amp section controls the switching and dsp and room eq etc....the amps just amplify the signal from the pre-amp. There are op-amps at work, though.

 

[vsound5150]

Yes, you simply choose whether to use the internal amps in the avr, or the external amps (both is even possible, as the pre-outs are generally always live). The pre-amp section controls the switching and dsp and room eq etc....the amps just amplify the signal from the pre-amp. There are op-amps at work, though.

You said I choose the internal or external amps. When I connected the external amp I didn't have to do anything, did the AVR auto sense the presence of the external amp on its preamp output? Also, should I set the front L/R dB level setting on the AVR to maximum which only goes up to -12dB?

Edit: Correction it goes to +12dB

 

[ski2xblack]

When I connected the external amp I didn't have to do anything, did the AVR auto sense the presence of the external amp on its preamp output?

Nope, you didn't have to do anything. The AVR has no idea if you're using an external amp or the on-board amps. Without speakers connected to the L/R channels of the avr, those channels may be powered up but they won't amplify. A few rare bird AVRs allow you to actually de-activate on-board amps.

Also, should I set the front L/R dB level setting on the AVR to maximum which only goes up to -12dB?

Not unless there is a wild mis-match between the external amp's input sensitivity and that of the on-board amps. What specific pieces of kit are we talking about here?

 

[lovinthehd]

You said I choose the internal or external amps. When I connected the external amp I didn't have to do anything, did the AVR auto sense the presence of the external amp on its preamp output? Also, should I set the front L/R dB level setting on the AVR to maximum which only goes up to -12dB?

I just mean you choose to use the internal or external amp as you wish....The microphone used for setup would do the "sensing" of which amp to adjust level for; I'd let Audyssey set your levels in relation to the other speakers....may go down to -12 and up to +12, but I wouldn't put it at either extreme.....

 

[vsound5150]

Ok great thanks for your guys help and time. If I'm reading the specs. correctly they are:

AVR: Marantz SR7010 (125W/8 ohms, rated output 1.4V)

Amp: Crown XLS1502 (300W/8 ohms, s/n 103dB, sensitivity rms High/0.775V Normal/1.4V) - I have it set at High

Front L/R: SVS Prime Tower (250W/8 ohms, sensitivity 87dB, 2.83V)

 

[lovinthehd]

Why are you using the high instead of normal setting on the amp? I'd bet your Marantz can do well over 1.4V output, that's probably a nominal figure....

 

[vsound5150]

I was trying to get all the power I could, my turntable signal sounded weak compared to other sources. I will try Normal again now that I found I can adjust AVR dB level settings for front L/R it was fully down low. Also, the Crown manual said High is commonly used if source device is using RCA ie. my turntable, don't know if that counts coming from other side of the chain.

 

[ski2xblack]

my turntable signal sounded weak compared to other sources.

Your AVR lacks a phono pre section, so unless you have an external phono pre amp, of course it sounded weak.

 

[vsound5150]

Your AVR lacks a phono pre section, so unless you have an external phono pre amp, of course it sounded weak.

I considered an external phono preamp but unsure if I know enough to purchase something that would improve it. My AVR's phono preamp (MM) is rated 2.5mV input sensitivity and my turntable cartridge has an output of 4.0mV. I assume the signal is normal (coming from a turntable) I can crank it to rock concert levels, just compared to other sources like CD or AirPlay/iPhone music the turntable signal is weaker, guessing about 25% weaker.

Edit: 15% weaker is more accurate.

 

[lovinthehd]

I was trying to get all the power I could, my turntable signal sounded weak compared to other sources. I will try Normal again now that I found I can adjust AVR dB level settings for front L/R it was fully down low. Also, the Crown manual said High is commonly used if source device is using RCA ie. my turntable, don't know if that counts coming from other side of the chain.

I have a similar avr and the XLS1500, no issues with the 1.4V sensitivity. Your phono section in the avr should be fine for the MM cart with that high an output no problem; it still may not compare to the level of other line level sources, tho...you have an input level adjustment you can use to make it more inline with other sources.

Your AVR lacks a phono pre section, so unless you have an external phono pre amp, of course it sounded weak.

Specs show a phono input....but no adjustments for matching to a particular cart....