Sony ta-4650 Vfet .. Volume Problem. Need Help

tater8 · 26th July 2005, 03:17 AM

HI there,
My old Sony ta-4650 Vfet Integrated amp has a bit of a problem, and need some advice on how to fix.
The balance pot is not original.
When both channels are going the volume is not very high, but turn the balance pot to L or R and the volume goes up..... Alot!.

How do I fix this problem? as I really got to wind it up to 10 oclock on the dial to get moderate listening level, and the sound is not punchy as when I turn it to L or R on the balance pot.

Any advice will be great...
Otherwise anybody can recommend a decent Tech to fix it for me (that is in Perth Australia..... will be great also)

Thanks In advance
Tater8

PRR · 26th July 2005, 03:51 AM

> The balance pot is not original. When both channels are going the volume is not very high, but turn the balance pot to L or R and the volume goes up..... Alot!

Balance pot is the wrong value.

If it is a simple 1-gang pot, and if I had to guess, someone put in a 10K instead of a 100K.

If it is a 2-gang pot, it may be log/antilog. This can be wired two ways that look right: -2dB at center, or -17dB at center.

clem_o · 27th July 2005, 02:07 AM

Hi - why not just remove the connections to the balance pot. Its seldom that the balance between left and right channels need to be twiddled. Or, at least remove the connections until an original-equivalent control is found...

Cheers!

tater8 · 27th July 2005, 02:17 AM

Thanks for the info guys.
I don't know much about electronics, (but learning more everyday)
sounds like it is a easy fix.
Looking forward to getting the old Vfet working properly.

Cheers!

Leolabs · 27th July 2005, 03:19 PM

Try to post internal picture for us

26th July 2005, 03:17 AM	#1
tater8 diyAudio Member Join Date: Jun 2005 Location: Near the Beach, out west	Sony ta-4650 Vfet .. Volume Problem. Need Help HI there, My old Sony ta-4650 Vfet Integrated amp has a bit of a problem, and need some advice on how to fix. The balance pot is not original. When both channels are going the volume is not very high, but turn the balance pot to L or R and the volume goes up..... Alot!. How do I fix this problem? as I really got to wind it up to 10 oclock on the dial to get moderate listening level, and the sound is not punchy as when I turn it to L or R on the balance pot. Any advice will be great... Otherwise anybody can recommend a decent Tech to fix it for me (that is in Perth Australia..... will be great also) Thanks In advance Tater8 __________________

27th July 2005, 02:17 AM	#4
tater8 diyAudio Member Join Date: Jun 2005 Location: Near the Beach, out west	Thanks for the info guys. I don't know much about electronics, (but learning more everyday) sounds like it is a easy fix. Looking forward to getting the old Vfet working properly. Cheers! __________________

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26th July 2005, 03:51 AM	#2
PRR diyAudio Member Join Date: Jun 2003 Location: USA	> The balance pot is not original. When both channels are going the volume is not very high, but turn the balance pot to L or R and the volume goes up..... Alot! Balance pot is the wrong value. If it is a simple 1-gang pot, and if I had to guess, someone put in a 10K instead of a 100K. If it is a 2-gang pot, it may be log/antilog. This can be wired two ways that look right: -2dB at center, or -17dB at center.

27th July 2005, 02:07 AM	#3
clem_o diyAudio Member Join Date: Jun 2005 Location: Manila	Hi - why not just remove the connections to the balance pot. Its seldom that the balance between left and right channels need to be twiddled. Or, at least remove the connections until an original-equivalent control is found... Cheers!

27th July 2005, 03:19 PM	#5
Leolabs diyAudio Member Join Date: Dec 2004 Location: Bukit Mertajam	Try to post internal picture for us