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Yamaha Ca1000 need a recap?

multirock

multirock

Active Member
Hello,
Last week I bought a Yamaha CA1000 amplifier, to replace my Yamaha A-5 (1979), because I needed a two phono input amplifier.
Seems that all switches and control knobs works ok, but after some hours of listening and tests (with two turntables and cartridges) I notice some sounds issues.
The first it's that when I crank the volumen up a loud hum appears form the speakers. I need to apply the Low filter or reduce the bass on the tone knob to make it disappear.
Also the bass response isn't good. The bass sounds boomy with almost no pounch. Bass notes are loud, but have little impact
For its part the treble sounds a bit harsh, and the surface noise it's louder than in my previous Yamaha.

I came back to my Yamaha A-5 and the sounds it's a lot better. The bass has more pounch, the drums more attack, and the treble sounds more natural. This surprise me. According to this site (http://europe.yamaha.com/en/products/audio-visual/hifi-components/hifi-history/integrated-amplifier/) the A-5 it's a nice amp, but the Ca1000 it's one of the best amps that Yamaha ever made.

What do you think?

Thanks
 
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The rumble you hear is feedback from your turntable. When you turn up the volume it is causing vibrations that are picked up by the turntable. Move your speakers farther from the turntable or move your turntable to a more stable location.

Given the age of your CA1000, recapping should make some improvement but you may also have a mismatch between your phono cartridge and CA 1000.
 
Try exercising the coupler switch on the rear panel. Notorious for getting dirty.
 
wmgwizard said:
The rumble you hear is feedback from your turntable. When you turn up the volume it is causing vibrations that are picked up by the turntable. Move your speakers farther from the turntable or move your turntable to a more stable location.

Given the age of your CA1000, recapping should make some improvement but you may also have a mismatch between your phono cartridge and CA 1000.
Click to expand...

I have two turntables connected to the CA-1000. One has a Pickering XV-15, and the other a Shure MD91e. The hum it's louder with the Pickering.
Before I never listen hum with the same cartridges and the Yamaha A-5. The speakers are in the same position. The turntables are mounted on the wall.

More than the hum, I most worried about the sound response. Doy you think this may improve with the recap? What can I do to obtain the great sound for that this amp has it's reputation?

Best regards
Esteban
 
A recap may quiet it down a bit. May have some solder connection issues with the phono RCA jacks.Phono select switch and function switch on these are usually pretty tarnished on the internal switch contacts. Disassembly is the best method for cleaning those switches.
 
Esteban

How does the amp sound with other sources? Does it compare with your other amp?
I looked at the service manual and the boards seem to be relatively easy to remove. The MC board is on the back right side and it looks like just remove 2 screws and pull the board out. If the issues are mainly with the phono preamp, it makes sense that the issues maybe on that board. If you have skills in working on electronics, I'd pull the board out and look at it. Are there any signs of component stress. How do the caps look? Is there glue that is corroding other components? You can clean the contacts and maybe get at the capacitance switch on the back panel and get some contact cleaner in the switch and work it back and forth 20 times.

I would not hesitate to recap this board because of it's age, this of course, depends on your skill level in soldering and finding the right caps.
 
I have recapped quite a few amps and this generally does improve the sound and the bass response but it really does depend on the amplifier. Ie: if the amplifier has a particular "sound" a recap may not help - but its worth trying in the meantime.
 
bradfro said:
Esteban

How does the amp sound with other sources? Does it compare with your other amp?
I looked at the service manual and the boards seem to be relatively easy to remove. The MC board is on the back right side and it looks like just remove 2 screws and pull the board out. If the issues are mainly with the phono preamp, it makes sense that the issues maybe on that board. If you have skills in working on electronics, I'd pull the board out and look at it. Are there any signs of component stress. How do the caps look? Is there glue that is corroding other components? You can clean the contacts and maybe get at the capacitance switch on the back panel and get some contact cleaner in the switch and work it back and forth 20 times.

I would not hesitate to recap this board because of it's age, this of course, depends on your skill level in soldering and finding the right caps.
Click to expand...

I found the same differences with other sources (Aux, Tuner), even when I connect a pre amp through the aux input. Boomy bass, lack of attack, right channel softer.
The only try that pass my ear test, and sounds like I think it should be, was when I plug the Pre amp through de Main In jacks. I get a extremely loud volume, but the bass sound perfect, as the mids and treble.
What does this mean?

Thanks for all your answers.
 
slimecity said:
I have recapped quite a few amps and this generally does improve the sound and the bass response but it really does depend on the amplifier. Ie: if the amplifier has a particular "sound" a recap may not help - but its worth trying in the meantime.
Click to expand...

Maybe some Yamaha CA-1000 owners can says if this is the natural sound of this amp. I doubt that...
 
multirock said:
I found the same differences with other sources (Aux, Tuner), even when I connect a pre amp through the aux input. Boomy bass, lack of attack, right channel softer.
The only try that pass my ear test, and sounds like I think it should be, was when I plug the Pre amp through de Main In jacks. I get a extremely loud volume, but the bass sound perfect, as the mids and treble.
What does this mean?

Thanks for all your answers.
Click to expand...

So, you plugged a separate pre-amp into the CA-1000's 'Main In' jacks and it sounded fine? If so, it would mean you have an issue with the pre-amp section of the CA-1000. I would first do a complete switch cleaning in the pre-amp and go from there.
 
My apologies, I had assumed the cleaning/inspection/solder reflow had already been done.

Start by cleaning and lubricating ALL switches and pots. Check for any runaway assembly glue, this can cause corrosion and poor connections. Inspect for any signs of excessive heat. Check and reflow as many solder connections that you can, pay close attention to anywhere a connector, switch or potentiometer is soldered.

The CA1000 is one of the early Natural Sound pieces and as such may be deemed "sterile" or "neutral" sounding. Not a bad thing just not like anyone elses either.
 
Electone said:
So, you plugged a separate pre-amp into the CA-1000's 'Main In' jacks and it sounded fine? If so, it would mean you have an issue with the pre-amp section of the CA-1000. I would first do a complete switch cleaning in the pre-amp and go from there.
Click to expand...

Yes, it sounds fine.
Then I tried using the CA-1000 as pre amp, through the Pre out jacks to the Aux in of the A-5, and sounds fine too (no differences between coupler switch on or off). Only problem it's that when I rise the volumen feedback or hum appears.
 
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