Vintage Yamaha CA 1010 - SDA2A's hiss/crackle

WGDB

I scored a vintage yet well used Yamaha CA1010 with both a Pioneer TX8100 tuner and a cosmetically beat up Carver TX2 on CL for $150.00. After visual inspection of the CA1010 and listening through the sellers system I bought it, and set this "beast" up with my SDA 2A's. All is good until I crank dial volume past the 6 mark <very loud> and there's some hissing alternating thru both channels and an alternating crackle through the both channels. I didn't leave it at volume long ... just long enough to hear and know there's a problem. The kicker is: The hiss/crackle gets worse when I plug in the IC to the SDA's - again, I didn't leave it there long..... Sounds great at normal listening level. Anyone have thoughts or advice?

The Pioneer TX8100 tuner is empecable and looks like it just came out of the box - but... the signal VU Meters are misaligned. i.e the meter that shows signal strength as strong and the other meter shows low it's not in tune. Anyone got any advice.

These items were both "as is" so the fun comes now and I'm willing to put a little coin into these jewels - they look fantastic an at this point, to a degree - the CA1010 drives the SDA's very well.

F1nut

If 6 is one notch past halfway, turn it down.

dkg999

Turn it down and replace the output capacitors!

mhardy6647

No output capacitors on a CA-1010.

If you haven't done so, buy a can of DeOxit and clean all pots and switches in the CA-1010. The function switches are particularly prone to oxidation in the Yamahas (my CA-610 needs clean-up every few years) and this beast is nearly 35 years old. The CA-1010 has, I am pretty sure, switchable Class A and also a back-panel switch to separate the preamp and power amp; these need to be cleaned as well.

if the relay is clicking "in" a few seconds after power up and isn't cycling - all is probably OK... but this amp is direct coupled (hence no output caps!) and could apply lethal (to speakers!) DC to the outputs if anything's seriously amiss inside (e.g., shorted or failing driver or output transistors). If you have a DMM (digital multimeter), with no speakers connected but with the speaker switch "on" and the amp idling, check for any DC voltage ("offset") at the live speaker output terminals. A few millivolts is OK (say 50 mV or less), if you see much more (especially on the order of whole volts) and/or marked fluctuation in the DC reading, something's amiss.

The power supply filter caps might benefit from replacement but they are low voltage (although fairly high capacitance) and don't take the abuse of the filter caps in vacuum tube equipment - they are probably OK. Low frequency "Hum" from the speakers with the volume control set to zero is the hallmark of bad P/S caps.

DON'T switch between Class A and AB operation with the amp on! The switch will be prone to "premature failure" and you risk damage to speakers, too.

The CA-1010 is an excellent amplifier and should be a dandy match for even the power-hungry SDAs.

HTH, as they say.


EDIT: These primers may be helpful:

DeOxit: http://www.audiokarma.org/forums/showthread.php?t=207005
DC "offset" (more than you'll want to know): http://www.audiokarma.org/forums/showthread.php?t=5634

If you don't have it, CA-1010 OM is available at: http://sportsbil.com/yamaha/ca-1010-om-s.pdf

CA-1010 brochure: http://sportsbil.com/yamaha/ca-1010-br.pdf


oh, and a final thought - don't troubleshoot vintage amplifiers of dubious integrity on expensive/irreplaceable loudspeakers! Get a pair of cheap-jack test speakers or use (cheap) headphones. Direct-coupled solid state amps are quite capable of killing a loudspeaker almost instantly if there's substantial DC at the outputs or the amp is unstable and oscillating. Vacuum tube amps are somewhat more forgiving but still caution is dictated.

jhw59

my CA1010 served me well for 30 years until I went to a hybrid tube setup a couple of years ago. I ran it in Class A mode primarily. I had a few issues as the unit aged but it's still in my closet as I can't part with it yet.

mhardy6647

I've used a CA-610II since 1978 and it is still used regularly in our family room.
I've got a CA-2010 waiting for me to rehab it.

They are nice accurate sounding amplifiers (with unassailable cosmetics, too, IMNSHO - pretty amazing that the same decade that gave us leisure suites and BIG velour bow ties could have produced such elegant functional design).

WGDB

thanks MrH for all the great info - removed the SDA's and am running some small polk rm 20's until I get time to check the millivolts at the speakers.

xoaphexox

Do what Mark said - clean controls, make sure bias and offset are within tolerances - if you still get clicking and popping, hissing, it could be a leaky capacitor or more than likely your class A/B mode switch needs replacing (not a big deal).

WGDB

I spent an entire afternoon cleaning the entire amp. All connections are cleaned "Deoxited" - made a world of difference. Thanks

mhardy6647

heh... you'll get our bill ;-)