I found a Yamaha CA1000 in the garbage next door. It was dead. All cards were removed, cleaned and resoldered. Few components were changed. It is working now but there are two issues.
1. The input section doesn't work properly, with its three separated ones. Sometimes there is a hum, sometimes not, I try different sources. So I use tape inputs, which work very well.
2. On the left channel there is a noise like a light wind.
1. The input section doesn't work properly, with its three separated ones. Sometimes there is a hum, sometimes not, I try different sources. So I use tape inputs, which work very well.
2. On the left channel there is a noise like a light wind.
Some contacts could be worn out, rather than just dirty. That's why cleaning it may not work,
and the tape input would still be ok since most don't use it. This is common with older equipment.
Sometimes the RCA jacks are worn and cause hum. Freeze spray is good for finding noisy resistors etc.
and the tape input would still be ok since most don't use it. This is common with older equipment.
Sometimes the RCA jacks are worn and cause hum. Freeze spray is good for finding noisy resistors etc.
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Good Idea !
Indeed, few switches was worn out like Class A/B one. I will give a look on Mode. I realized during I was reading your post that the a and b position for Mono input (the second position from left) on this switch don't work properly, a channel missed and the same on the first position, if I push a little bite the knob.
Thank you for Montréal by sunny 12 F afternoon.
PS Do you have a Crystal ball ?
Indeed, few switches was worn out like Class A/B one. I will give a look on Mode. I realized during I was reading your post that the a and b position for Mono input (the second position from left) on this switch don't work properly, a channel missed and the same on the first position, if I push a little bite the knob.
Thank you for Montréal by sunny 12 F afternoon.
PS Do you have a Crystal ball ?
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If you can't get it working by only cleaning, it will be difficult to find new switches and replace them.
You can just use the existing inputs that work reliably, or else bypass the preamp completely and
only use the power amp section, with an external preamp or volume control (depends on what sources
you are using).
I have three Harmon-Kardon 430 receivers from the 70s ($300 at the time), each of which has identical
problems of worn switches and controls. I've converted them all to tuner/power amplifiers, and use an
external volume control/selector switch with each. They work great without any further refurbishing.
I got them all for free because they each had those same problems.
You can just use the existing inputs that work reliably, or else bypass the preamp completely and
only use the power amp section, with an external preamp or volume control (depends on what sources
you are using).
I have three Harmon-Kardon 430 receivers from the 70s ($300 at the time), each of which has identical
problems of worn switches and controls. I've converted them all to tuner/power amplifiers, and use an
external volume control/selector switch with each. They work great without any further refurbishing.
I got them all for free because they each had those same problems.
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The RCA inputs on an old Marantz amp went bad, they were cracked inside and you couldn't see they were broken inside until I replaced them. Main symptom of this problem was it would sometimes hum. When I moved the amp, sometimes the hum would go away.
Switch worn out
It was possible for the Class A/B switch to invert the mechanism inside the switch case.
It was possible for the Class A/B switch to invert the mechanism inside the switch case.
The CA-1000 switches can be problematic especially the coupler. Next in
line are the mute and Bass turnover and function selector. Function selector
probably needs complete strip down and clean, a delicate job not to bend
the sliding contacts.
The wind noise is either a polar tantalum capacitor used on tone, filter and
function boards, possibly a noise prone transistor (2SC458LG maybe 2SC1345) but more likely a tant. Use CA-1000 as pre/connect to another power amp, expect wind to still be present.
CA-1000 is a nice amp when working normal, well worth the effort.
line are the mute and Bass turnover and function selector. Function selector
probably needs complete strip down and clean, a delicate job not to bend
the sliding contacts.
The wind noise is either a polar tantalum capacitor used on tone, filter and
function boards, possibly a noise prone transistor (2SC458LG maybe 2SC1345) but more likely a tant. Use CA-1000 as pre/connect to another power amp, expect wind to still be present.
CA-1000 is a nice amp when working normal, well worth the effort.
Attachments
Just thinking aloud, inn the 80´s many added extra features for marketing purposes which weren´t *really* needed.
Today we live in a simpler world.
IF giving you trouble, I would just hardwire a few of the switches to the position you will always use and call it a day.
Who needs to select between A and B speaker systems? (typically the main one and a second set out in the garden or in another room), flip right to left and viceversa, select between 7 pairs of inputs, even select different tone control turnover frequencies, "tilt", etc?
Since actual modules are functioning properly, turn a 300 option amp into a trouble free good sounding straightforward one.
I would.
Today we live in a simpler world.
IF giving you trouble, I would just hardwire a few of the switches to the position you will always use and call it a day.
Who needs to select between A and B speaker systems? (typically the main one and a second set out in the garden or in another room), flip right to left and viceversa, select between 7 pairs of inputs, even select different tone control turnover frequencies, "tilt", etc?
Since actual modules are functioning properly, turn a 300 option amp into a trouble free good sounding straightforward one.
I would.