Yamaha CA-1000 HELP!

visman

AK Subscriber
Subscriber
Over the weekend at GW I scored a very nice looking Yamaha CA-1000 and Yamaha CT-600. The CA-1000 is easily a 9/10 in appearance. :banana:

Yesterday I opened her up and did a minor cleaning and deoxit the switches.

Then hooked it up and ...... well I have a project.:tears:

Power comes on - red light works, relay clicks - and BOOM loud hiss out of left channel (with 0 volume) and nothing out of right channel.

This is a really nice looking amp that I would like to restore but I am afraid it may be out of my league.

Any thoughts - maybe a recomendation on someone in SoCal that can look at or work on this amp?
 
Try adjusting the DC offset first - I have an 820 that I got for cheap because "one channel was out"... simple fix.

There may be other problems, but that is where I'd start.
 
Just a suggestion for you, which is a strict rule with me:

Any time you bring home an amplifier of unknown working condition, DO NOT hook it up to speakers before checking the DC offset at the speaker terminals. You can VERY EASILY smoke a perfectly good speaker or two if there is any significant DC voltage riding on the outputs. It takes maybe a minute to check both channels.
 
Yamaha is in Buena Park. They accept walk ins. Fred Longworth is in San Diego.
 
Just a suggestion for you, which is a strict rule with me:

Any time you bring home an amplifier of unknown working condition, DO NOT hook it up to speakers before checking the DC offset at the speaker terminals. You can VERY EASILY smoke a perfectly good speaker or two if there is any significant DC voltage riding on the outputs. It takes maybe a minute to check both channels.
He did say the relay clicks and its a safe bet there is no appreciable DC-offset to do any harm in that case. Having said that it NEVER hurts to measure.
 
Thanks - I will check out the DC offset tonite and appreciate the advice - seems pretty simple - I'll report the results.

Has anyone used Yamaha corporate in Beuna Park to repair vintage equipment - quality? price?
 
Alright - I called Yamaha and they will not work on anything as old as the CA-1000 - FYI
 
I'm going to bump this because I'm sure there's someone on AK from CA who can fix this amp....:scratch2:

Maybe a picture or two would help?
 
The CA-1000 uses a relay to switch between Class A and AB, take a good look at it to see if by chance the contacts are welded together from being switched with the power on.
 
Another name that I have heard, if I recall correctly, is Tom Ishimoto and he is in Northridge. That's a fair hike for you but I drove out there once for Dynaco repair when I lived in Claremont. Tom has posted here before but under a different name maybe. I have not met Fred Longworth but I did meet Jordan who works with him and I would take it to San Diego if you cannot find closer. The CA-1000 is worth saving. My CA-1000 runs OK but could use a cleaning of the switches again. I just work them a few times (NOT the Class A one) and it gets well. One of the many projects on the list.... Good luck and keep us informed.
 
The CA-1000 uses a relay to switch between Class A and AB,
:no: the CA-1000 uses a couple OMron microswitches and a lever switch. The CA1010 uses a relay..:yes:The relay in the CA-1000 is the speaker protect relay.
 
I would second the Fred Longworth recommendation. He will take ship in or walk in as well so if you can pack it well, you could ship it.

Otherwise, its probably about the same drive time (about 75 minutes to Northridge or worse and about 100 minutes to San Diego). But the San Diego drive is much nicer!!

Bart
 
:no: the CA-1000 uses a couple OMron microswitches and a lever switch. The CA1010 uses a relay..:yes:The relay in the CA-1000 is the speaker protect relay.


Then it is the same as the CA-800 and I was able to get new switches from Mouser, also was able to fit ones with a higher rating. The old ones were really burnt up inside.
 
Well the news is not good :tears:

While setting up to check the DC offset .... I noticed a little plume of smoke coming from near the left channel heatsink - transistor?

Anyway unplugged the unit and now time to call in the experts.

By the way my garage speakers (Polk Monitors) are fine - and that is the last time I will hook speakers up to an untested Amp.

Just for the fun of it - here are some pictures of the amp - she sure looks good (on the outside). Also one of the CT-600 which seems to be working fine.
 

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Then it is the same as the CA-800 and I was able to get new switches from Mouser, also was able to fit ones with a higher rating. The old ones were really burnt up inside.

:yes: Thats what I've been doing.. 15 ampere OMRON's
 
Anyone have a part number on the omron micro switches from mouser? My personal (office) CA-1000 is doing the 'sizzle' in class AB (not class A).

Thanks!
 
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