I hope this is the right place to post this. I have a Kenwood KA-1070 Integrated Amp and the right channel is very quiet and scratchy sounding.
Here are photos of the amp:
Kenwood KA-7010 - Album on Imgur
Is there anything I can do to test or repair this amp? For a while, the right channel was cutting out periodically. It wouldn't go completely out, it would just sound garbled and the audio was very quiet. This went on for about 6 months, and now it's this way all the time. The right speaker is super quiet and scratchy. I tried different RCA input ports, different RCA wires, different speaker wires, switched out the speakers, switched the speakers around, A and B inputs, different audio source, pressed all the buttons, turned all the knobs, etc.. no matter what, everything right channel is super quiet and garbled sounding. I know this amp is old, but I absolutely love the power of this amp and how it rattles my wife's dishes, I'd like to save it if at all possible. Thank you!
https://drive.google.com/file/d/0B3bQx2cOIQ02SGt5VjUwY0RnVVk/view?usp=sharing
Here are photos of the amp:
Kenwood KA-7010 - Album on Imgur
Is there anything I can do to test or repair this amp? For a while, the right channel was cutting out periodically. It wouldn't go completely out, it would just sound garbled and the audio was very quiet. This went on for about 6 months, and now it's this way all the time. The right speaker is super quiet and scratchy. I tried different RCA input ports, different RCA wires, different speaker wires, switched out the speakers, switched the speakers around, A and B inputs, different audio source, pressed all the buttons, turned all the knobs, etc.. no matter what, everything right channel is super quiet and garbled sounding. I know this amp is old, but I absolutely love the power of this amp and how it rattles my wife's dishes, I'd like to save it if at all possible. Thank you!
https://drive.google.com/file/d/0B3bQx2cOIQ02SGt5VjUwY0RnVVk/view?usp=sharing
Try using the TAPE 3 input, preferably with Source Direct turned on. That should remove the source selector and a good bit of the preamp section from the picture.
Also connect some headphones. Same problem, I guess?
Turn down the volume and listen for hiss levels at both the left and right speaker's tweeters. Is right much quieter or about the same?
This is looking like a bad solder joint or bad transistor in the right channel power amp, or maybe a bad pre-power connection. While 25+ years old at this point, the '7010 is a nice (honest) 100 Wpc amp and ought to be worth fixing. A quick search turned up no service manual on the web (KA-701 does not apply!), but there is one for its successor of a year or two later, the KA-7020 - probably reasonably close.
What sort of tools and experience do you have? You would have to be able to poke around inside the unit with a multimeter and take measurements without accidentally shorting anything out (enlist someone to help if needed).
Also connect some headphones. Same problem, I guess?
Turn down the volume and listen for hiss levels at both the left and right speaker's tweeters. Is right much quieter or about the same?
This is looking like a bad solder joint or bad transistor in the right channel power amp, or maybe a bad pre-power connection. While 25+ years old at this point, the '7010 is a nice (honest) 100 Wpc amp and ought to be worth fixing. A quick search turned up no service manual on the web (KA-701 does not apply!), but there is one for its successor of a year or two later, the KA-7020 - probably reasonably close.
What sort of tools and experience do you have? You would have to be able to poke around inside the unit with a multimeter and take measurements without accidentally shorting anything out (enlist someone to help if needed).
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Thanks, I'll try what you suggested when I get home. I've replaced a screen on my son's handheld Nintendo 3DS, that was very difficult for me. I've built ~100 PCs and have a basic understanding of how boards and connectors work. I work with a HAM operator guy and I'll enlist his help for any multimetering, he practically wears a multimeter on his hip.
Clean the two switches with blue plastic ribbons going into them. These are notorious for taking away the sound when they get old and corroded. Bathe them in alcohol and move them back and forth for a very long time.
Nice it works! So now it's running in 'Mono' mode right? At least it's tolerable. Left and right channels work with source direct turned on and off when I use the tape input, I can even use my balance knob again. I just hit the ADPT/TAPE 3 button and it completely ignores the source selector switch.
Looks like the problem is just the source selector switch then, which I assume is going to be one of those that Welcome referred to - the other would be the rec selector. Be careful when desoldering and opening one of these, they've got a bunch of legs and internal parts can be small and must be reassembled correctly.
And no, Tape 3 is a regular stereo input, nothing mono about that. If you only need one anyway, that would be a decent workaround for now.
And no, Tape 3 is a regular stereo input, nothing mono about that. If you only need one anyway, that would be a decent workaround for now.
I do only need one for this amp. That's great news! 🙂 I'll add this to my growing list of someday projects. I plan on converting that area into a theater anyway so this amp will be extra. I ordered a Yamaha RX-A830, should be here Friday. Can't wait, thanks for your help!
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