Low input signal strength into amp

[nebborjk]

It seems I can only get my amps (AudioSource AMP100) to power up when the volume is really high, as I back the volume down the the amps seems to lose the signal and the sound drops out. Is this caused by the avr sending a weak signal or does the problem lie with the amp.

Thanks in adavance.

[nebborjk]

Bump

Anyone have an opinion on what is causing this?

[zombie boy 2000]

Does your AVR use a passive (or low gain) preamp stage? If so, what is the amp's sensitivity?

[Gaara]

Clarify a little more, do you mean turn down the volumes on the amps or the rcvr?

The amps sensitivity is good at 1.4v. I got a feeling that it is a combo of the low power and dual attenuation.

[zombie boy 2000]

Plus... what are you using as a source? I'm assuming at least 2.0v from a CDP are in order. But you never know.

[nebborjk]

Okay here's where I'm at. The AVR (Kenwood VR-7070) spec reads Pre-Out...1V / 500Ω. The Amp specs read 8Ω input sensitivity: 1.4V RMS, 4Ω input sensitivity: 1.2V RMS. As for the source it doesn't seem to matter. It will behave the same on the DVR, HD-DVD and CD-DVD Player. The connection type doesn't seem to matter either; toslink, 2-channel analog or 6-channel MC analog from DVD-A all act the same way. Is my problem the difference between the AVR outout,1V and the amp's input 1.4V? If so which one isn't "normal"?

Thanks for your responses.

[hypertone]

8 ohms input?? Amplifier input impedences are usually in the Kohms. An 8 ohm input wouldn't get any power as there is no way any line level source could drive a load like that.

[nebborjk]

I think it was refering to the speaker being an 8 ohm load.

[Gaara]

Okay here's where I'm at. The AVR (Kenwood VR-7070) spec reads Pre-Out...1V / 500Ω. The Amp specs read 8Ω input sensitivity: 1.4V RMS, 4Ω input sensitivity: 1.2V RMS. As for the source it doesn't seem to matter. It will behave the same on the DVR, HD-DVD and CD-DVD Player. The connection type doesn't seem to matter either; toslink, 2-channel analog or 6-channel MC analog from DVD-A all act the same way. Is my problem the difference between the AVR outout,1V and the amp's input 1.4V? If so which one isn't "normal"?

Thanks for your responses.

The differences in sensitivity isn't that much, it just means that the amp won't be able to get to full power. You might lose a few db of available volume, which will equate to around 15wpc or so in this situation. This could be a problem though if the unit is sent to auto sense the signal.

Is there a way to bypass the signal sensing feature? This could definitely be what is causing the problem. If it is set to on and the avr volume is to low it thinks there is no signal and shuts off.

Again, how do you set your volume? Are the amps set to max and then you control with the avr or do you use the volume controls on both?

[nebborjk]

Gaara,

I have the amps volume set to max and use the avr volume control. Should I try to lower the amp volume level and increase the volume at the avr. In theory I should be able to get the same spl during playback once calibrated.

[Gaara]

First things first, is there a way to turn off the signal-sensing feature, and do you need it to be on? It sounds like this is the problem, and if you set it to not to this it wouldn't shut off.

Decreasing the volume on the amp and increasing it on the AVR should work also, as you will have the same spl (as long as you calibrate after the change) but the signal being sent from the AVR will be stronger.

[jakelm]

I'm having the same issue with both my subs, I dont like it, but I just have to leave them on (all the time). Watching a movie at low volume or first turning on the system and never having the volume loud enough to turn the subs on, was unavoidable other than leaving the sub amps on.

[Gaara]

I'm having the same issue with both my subs, I dont like it, but I just have to leave them on (all the time). Watching a movie at low volume or first turning on the system and never having the volume loud enough to turn the subs on, was unavoidable other than leaving the sub amps on.

I had the opposite problem with my sub, it was getting to much of a signal. I had the thing dialed in just below off and if I turned the volume knob any lower it would be off. I ended up adding a attenuator to fix the problem.

Can you possibly up the signal from the HK, perhaps through speaker level settings? If you could pump it up say 6db and then adjust the volume knob down accordingly it should help alleviate the problem.

[jakelm]

Can you possibly up the signal from the HK, perhaps through speaker level settings? If you could pump it up say 6db and then adjust the volume knob down accordingly it should help alleviate the problem.

Raising the AVR level and lowering the subs volume level was counter productive. Cancelled each other out. Raising one and not the other, effected callibration. The only thing I found was leaving the amp on.

The only way I can see to fix this issue, is to change the sinsetivity on the plate amp. But without having to change resistor/cap values, it would be unchievable.