Yamaha RX-V677, Distorted sound at higher volume

[srt1]

hi,

i got Yamaha last week, its have sound distortion problem, in lower volume sound is fine but when i am increasing the volume sound getting distorted especially when lower beats coming , i appreciate your support on this i, I already check all rail voltages in amplifier its all in within limit as per SM, but when i check at AMP-LMT , getting 2.6 VOLT but i am not sure its normal or not ,i appreciate all of yours support on this.

[srt1]

Re: Yamaha RX-V677, Distorted sound at higher volume

In my understand it is audio clipping somewhere , i am suscpecting its in pre amp stage or in electronic volume ic ,,any one had same experience ?

[Andrew F. Ali]

Re: Yamaha RX-V677, Distorted sound at higher volume

When you say increasing the volume what exactly do you mean?? Louder than normal level at perhaps loud as a party volume level??

[stj]

Re: Yamaha RX-V677, Distorted sound at higher volume

test it on headphones.
if it's only with speakers then it could be failing smoothing caps not providing the current.

[srt1]

Re: Yamaha RX-V677, Distorted sound at higher volume

When you say increasing the volume what exactly do you mean?? Louder than normal level at perhaps loud as a party volume level??

Its not lounder than normal level .its in normal level only that mena if i cramk the volume to -45db its starting distortion especially in bass tones

[srt1]

Re: Yamaha RX-V677, Distorted sound at higher volume

test it on headphones.
if it's only with speakers then it could be failing smoothing caps not providing the current.

Today i checked power suplly of ic173 its in within limit as per SM that is +7volt and -7 volt.then i again checked pre amp stage power rails i found ther a negative rails missing ( before i couldnt find or i miss it)i colundnot get -56 volt i found that transistor q1068 ( in schematic) gone bad.. what i did that now i just by passed collector to emitor by using a 2.2ohm resisitor , i got sound without any distortion ..so the peoblem is bad q1068 but i dont know why its blown.when i checked with multimeter I found short between base and collector ..

[budm]

Re: Yamaha RX-V677, Distorted sound at higher volume

No sign of over heating? How about the Voltage at the Emitter and the Collector of the transistor used for the + supply for the pre-amp?
So circuits take +/-61V input and drops them down to +/-56V.

[srt1]

Re: Yamaha RX-V677, Distorted sound at higher volume

No over heating , the voltages at emitter and collector of transistor is around 56 volt , for pre amp stage reducing the voltage from +/-61 rails
i attached here amp schematic

[budm]

Re: Yamaha RX-V677, Distorted sound at higher volume

You should also test Q1071 (2N5401)off the board to make sure it is good.

[srt1]

Re: Yamaha RX-V677, Distorted sound at higher volume

You should also test Q1071 (2N5401)off the board to make sure it is good.

I CHECKED That transistor , it is not blown , and i replaced A1837 now amplifier is ok no distortion at all........