Yamaha AX-397 & Pioneer VSX-815 sound problem

[ramirom]

First of all hi to all the people in this forums

now to the point.

i have a Yamaha ax-397 driving a pair of cerwin vega ve-8, this is connected to the front analog out of my soundblaster x-fi.

on the other hand i have a Pioneer vsx-815, this is connected to the center/sub, surround rear analog outs of the soundcard, driving a pair of crappy speakers at front, a yamaha for center, a pair of sony bookshelfs for surrounds and a yamaha sub.

i have connected from the 397 REC OUT to the 815 front 5.1CH line in, to be able to use the front speakers that are connected to the 815, and here is where the problem appears.

when the above mentioned connection is done (397 rec outs to 815 front in), the sound from the 397 to the ve-8's comes a little distorted, enough to notice it, at first i thought that it was the amp that was bad, but when i stopped playing music i noticed that a popping noise came out of the ve-8`s, it wasnt loud but you could hear it well.

first i thought that was the tv connected to the 815, unplugged it and the same happens, only that the popping noise was gone, but the distorted sound from the 397 was still there as long as i had the REC OUT connected to the 815.

is it possible that the 815 is picking noise from something and the 397 is picking it from the rec outs? is my 397 faulty because is it picking noise from an output? or is the 815 the faulty one?

just to clear it out, the 815 has only the speakers, sub and PC connected to it, nothing more.

and when i unplug the connection between the two the 397 sounds clear again :S

any help would be appreciated, i dont know if it will damage my equipement.



P.S: sorry for my bad english, i explained it the best i could.

 

[TLS Guy]

First of all hi to all the people in this forums

now to the point.

i have a Yamaha ax-397 driving a pair of cerwin vega ve-8, this is connected to the front analog out of my soundblaster x-fi.

on the other hand i have a Pioneer vsx-815, this is connected to the center/sub, surround rear analog outs of the soundcard, driving a pair of crappy speakers at front, a yamaha for center, a pair of sony bookshelfs for surrounds and a yamaha sub.

i have connected from the 397 REC OUT to the 815 front 5.1CH line in, to be able to use the front speakers that are connected to the 815, and here is where the problem appears.

when the above mentioned connection is done (397 rec outs to 815 front in), the sound from the 397 to the ve-8's comes a little distorted, enough to notice it, at first i thought that it was the amp that was bad, but when i stopped playing music i noticed that a popping noise came out of the ve-8`s, it wasnt loud but you could hear it well.

first i thought that was the tv connected to the 815, unplugged it and the same happens, only that the popping noise was gone, but the distorted sound from the 397 was still there as long as i had the REC OUT connected to the 815.

is it possible that the 815 is picking noise from something and the 397 is picking it from the rec outs? is my 397 faulty because is it picking noise from an output? or is the 815 the faulty one?

just to clear it out, the 815 has only the speakers, sub and PC connected to it, nothing more.

and when i unplug the connection between the two the 397 sounds clear again :S

any help would be appreciated, i dont know if it will damage my equipement.



P.S: sorry for my bad english, i explained it the best i could.

Obviously there is no buffer amp to the record outs, there usually isn't on these ghastly receivers. The record outs are designed to feed a tape recorder, so for one thing the volume on the rec out will not work on the rec outs. It seems the input impedance of the of the Pioneer is two low for the rec out input of the Yamaha, and providing an excess load to the pre amp stage of the Yamaha.

Your only solution is to build a two channel buffer amp between the Yamaha and the Pioneer, or forget this hook up.

 

[ramirom]

thank you so much! i was getting worried.

just to let you know, the pioneer manual states this:

input sensitivity/impedance: 200mV/47kOhm

and the yamaha:

output level/impedance: 165mV/1.6kOhm or less

is it possible that while it was connected one to the other, having caused damage to anything? it was a couple of hours and not at high volume.

i will look into the buffer amp as i dont know too much, but for the meantime the connection is gone.

again thank you!

 

[TLS Guy]

thank you so much! i was getting worried.

just to let you know, the pioneer manual states this:

input sensitivity/impedance: 200mV/47kOhm

and the yamaha:

output level/impedance: 165mV/1.6kOhm or less

is it possible that while it was connected one to the other, having caused damage to anything? it was a couple of hours and not at high volume.

i will look into the buffer amp as i dont know too much, but for the meantime the connection is gone.

again thank you!

Those impedance and voltages should match. Somehow though the Pioneer is stressing the preamp stage of the Yamaha when connected to it.

Can you solder. If so try soldering a wire up with 50K resistors in the live line of the RCA plug going into the Pioneer, so that the resistor is in series in the signal path. See if that stops the distortion.

 

[ramirom]

Those impedance and voltages should match. Somehow though the Pioneer is stressing the preamp stage of the Yamaha when connected to it.

Can you solder. If so try soldering a wire up with 50K resistors in the live line of the RCA plug going into the Pioneer, so that the resistor is in series in the signal path. See if that stops the distortion.

yes i can do some soldering like that, i will try it but first i have to buy the resistors, dont have any at home.

to make clear that i dont misunderstand, i have to solder 1 50k resistor in series only in the live line of the two rcas? this is the red plug right?

i thought the same as you, that the impedances should match but somehow the pioneer is still making trouble, its strange.

as soon as i make the soldering i'll come back with the feedback!

thanks!

 

[TLS Guy]

yes i can do some soldering like that, i will try it but first i have to buy the resistors, dont have any at home.

to make clear that i dont misunderstand, i have to solder 1 50k resistor in series only in the live line of the two rcas? this is the red plug right?

i thought the same as you, that the impedances should match but somehow the pioneer is still making trouble, its strange.

as soon as i make the soldering i'll come back with the feedback!

thanks!

No, both plugs. One is left and one is right. Put the resistors at the Pioneer connection. The resistors are in series with the tip connection.

 

[ramirom]

No, both plugs. One is left and one is right. Put the resistors at the Pioneer connection. The resistors are in series with the tip connection.

youre right dont know what i was thinking, will do that asap and see what happens.