Need help! Yamaha Ca series upgrade

[C0deXeus]

Good day to all

Here I faced with some problems while trying to refurbish Yamaha Ca-800.

1. I would like to upgrade the current RCA jack to gold-plated ones. Here's a picture of Ca-1000 rca board which is similar to 800 model.

Those jacks are soldered to pcb but I the ones I found are chassis mount.
https://www.parts-express.com/parts-express-chassis-mount-rca-jack-pair--091-1120
https://www.vampirewire.com/product-page/cm7f-b
http://www.partsconnexion.com/product9725.html

Will any of the replacements fit?

2. Binding post replacement
Here's the current speaker terminal:
Rear Side

Front Side

I'm looking at this: http://www.partsconnexion.com/WBT-75717.html

3. There's a noisy 2SC458 trans present at the left and right output board each. If I were to replace, is it necessary to replace ALL trans at the output board to make everything equivalent?

Help from gurus are highly appreciated.

 

[mbz]

Easy question first. Replace the 2SC458 with KSC1845. They are located on power amp board/heatsink and 3 on relay board underneath.

 

[mbz]

Apologies, only need to replace 2SC458. Outputs etc... don't need to be changed.

 

[mbz]

Regarding the binding posts, there was no datasheet that I could see. The biggest problem is the available space, I think you need items
that are about 13mm diameter. I went for cheap chinese insulated gold plated, ok, gold is not a great conductor. However if your budget
affords you silver posts then I assume you have budgeted for a quality refurb including,
- recap
- replace tantalums
- replace 4 power amp trimmers with multiturn types
- class A microswitch
- speaker relay
- thorough clean pots, switches
- check for dry solder joints
- set bias dc offset...
and ...

 

[clinic-audio]

Hello COdeXeus

1) do you have problem with the RCA connectors on your CA800 ?
2) If you want to replace them anyway , using gold connectors will bring you nothing more than original ones and will decrease the value of your amplifier. All the links you give are about non-adaptables RCA connectors (too big) and most not nice
3) changing binding posts : same answer , not necessary at all and will decrease the value of your CA800
4) There's a noisy 2SC458 trans present at the left and right output board each. Again many wants to change the 2SC458 TR because they are "noisy" .....Do you have noise on your both channels ?? Or you wish to copy a silly way to "upgrade" units ?
Many post here on AK show members who have changed all 2SC458 without any differences between before and after , this is silly to loose his time and his money for that .
5) you don't know CA800 (or many closer model using same circuits) because changing these 2SC458 will not change anything regarding those on relay protection board because they are not involved in signal quality and regarding the both amplifier modules they are used for temperature compensation and don't need to be replaced again . This is YAMAHA itself who did recommend that .If you use a substitute you have to remind to use the flat part of this new transistor or his ability to detect any change in temperature of the heatsink will be drasticly affected . Using other reference than original 2SC458 for this purpose is very complicate .
You better follow recommendations from AK members working on YAMAHA products since 42 years and not the comments we can read on the web everywhere

 

[avionic]

Those jacks are soldered to pcb but I the ones I found are chassis mount.
https://www.parts-express.com/parts-express-chassis-mount-rca-jack-pair--091-1120
https://www.vampirewire.com/product-page/cm7f-b
http://www.partsconnexion.com/product9725.html

Long answer . Probably not. You have to retain that rear circuit board. The rear boards mounting position is critical due to the function boards mounting arrangement and plug in pins.

 

[Bert 1100]

for speaker terminals with limited space, I use Pomona 3750-0 and 3750-2, mounted on an aluminium sub-plate that in turn gets mounted behind the rear panel.

Like in the Marantz 2325 I just did :





And as for the gold-plated jacks, I don't think there is much point at all. Just clean the original ones and give them a good deoxit treatment.

 

[avionic]

Pomona studs are to long for this app.They would need to be cut down to half that length.There is a power transformer right behind the CA binding posts.

 

[mbz]

4) There's a noisy 2SC458 trans present at the left and right output board each. Again many wants to change the 2SC458 TR because they are "noisy" .....Do you have noise on your both channels ?? Or you wish to copy a silly way to "upgrade" units ?

I will continue to preemptively replace known problematic parts, including 2SC458 wherever they may reside. Replacements are like 7 cents
and much easier while unit is srtipped down for recapping etc... rather than strip the amp down again in 3-6 months time. Been there, done that
absolutely no joy, all for 7 cents.

 

[C0deXeus]

Guys, thanks for the input

Look what I got


The 'slimmest' binding post I've found so far with 11.5mm diameter and 15mm in length. Might be a good one for minimum chasis mod and short enough not to make contact with the transformer. BTW, I'll check if I could move the transformer towards the front panel a few mm.

 

[C0deXeus]

for speaker terminals with limited space, I use Pomona 3750-0 and 3750-2, mounted on an aluminium sub-plate that in turn gets mounted behind the rear panel.

Like in the Marantz 2325 I just did :

View attachment 985161

View attachment 985162

And as for the gold-plated jacks, I don't think there is much point at all. Just clean the original ones and give them a good deoxit treatment.

Nice one! I would spray the support panel black so it doesn't look obvious from outside.

And as for the gold-plated jacks, I don't think there is much point at all. Just clean the original ones and give them a good deoxit treatment.

Will do. Still, It's hard to source deoxit in my country