CA-1000 Class A Issues

[avionic]

Excellent!

 

[Fhamre]

I have been playing the unit for a couple of hours now. Every once in a while I get a pop/short crackle. Like every 10 minutes or so.
I will change the 458's on the amp boards when my BP caps come.
Any other suspects?
How about on the PS board?

 

[avionic]

I have been playing the unit for a couple of hours now. Every once in a while I get a pop/short crackle. Like every 10 minutes or so.
I will change the 458's on the amp boards when my BP caps come.
Any other suspects?
How about on the PS board?

Are the noises on both channels ? If yes I would suspect a power supply issue. ie. noisy regulator transistors.

 

[Fhamre]

Do you know off the top of your head what are good substitutes for those regulators?

 

[petehall347]

i would check the soldering first and clean the fuses/holders

 

[avionic]

Just in case.....Suspect noisy regulator circuit transistors ***
TR702 ---> 2SA673S---> KSA916YTA ***
TR703---> 2SC1213S---> KSC2316YTA ***

Series Pass transistors
TR701 ---> 2SA671S ---> TIP32C
TR704---> 2SC1061S ---> TIP31C

 

[avionic]

i would check the soldering first and clean the fuses/holders

Especially check the solder connections of TR701 and TR704.In fact I'd reflow them just for shits and giggles.
Those TO-220 transistors run hot and hang upside down. Unsolder themselves over the years.
Would definitely causes pops if they're were cold solder connections.

 

[Fhamre]

Great info! I will try and get at it tomorrow.
Wife's home tomorrow so I could be doing domestic duties instead of that "stereo crap".

 

[Fhamre]

Especially check the solder connections of TR701 and TR704.In fact I'd reflow them just for shits and giggles.

Well I didn't shit or giggle but the reflow seems to have worked.
Had a couple of pops when I first tested it within the first minute or so but have not heard any for the past hour or so.
Will continue to test.

 

[Fhamre]

So the Ca 1000 seems to be testing fine. Now when I was working on this piece I borrowed a function board from another unit I had.
I went to test that CA 1000 and I notice that when I first power it on the right channel is missing but shows up in a few moments after the left comes on. If you shut it off and power it back up both channels are there.
Would you suspect a dirty relay?

 

[avionic]

Could be..

 

[petehall347]

regarding the first one try letting it cool overnight and testing again .. do this a few times .. i have had in the past a few times transistors with bad connections inside and the heat from soldering them has effected a temporary fix ..
sorry if i am being negative but this sort of thing can and does happen ..

 

[Fhamre]

I changed the relay on the latest,replaced 2 fusistors, 2 458's and reflowed those transistors Av suggested.
Looks Like tomorrow I will be tested two units,again!
Thx guys.
Have any experience with Luxman receivers? Started a post on a R-1070 I picked up on my travels years ago.
How can you tell my wife is putting the pressure on to reduce the projects?

 

[Fhamre]

The two Yammies appear to be behaving themselves.They look and sound mighty nice.
Appreciate all the advice.