recapping vs not recapping

[sssboa]

Vint Age knows what he's talking about. I recommend following his advice.

You mean something like this?
Nichicon
Manufacturer Part Number
QYX1H222KTP
Description CAP FILM 2200PF 10% 50VDC RADIAL
Expanded Description 2200pF ±10% Film Capacitor 50V Polyester Radial

http://www.digikey.co.uk/scripts/DkSearch/dksus.dll?Detail&itemSeq=218533307&uq=636220739827005346

or for 47uF 50v BP:
KEMET
Manufacturer Part Number
R60DR54705050K
Description CAP FILM 47UF 10% 63VDC RADIAL
Expanded Description 47µF ±10% Film Capacitor 40V 63V Polyester, Polyethylene Terephthalate (PET), Metallized Radial

Damn, this one is over £6/1pcs

http://www.digikey.co.uk/product-detail/en/kemet/R60DR54705050K/399-12459-ND/5730950

 

[sssboa]

BTW. I read about an article from 1992 where test were made of electrolytic caps in audio and actually low ESR caps showed higher distortion. Maybe this explains why the expensive "audio caps" have higher than average ESR. They also have much higher ripple current rating, shorter life and lower temperature rating.

 

[Nashou66]

BTW. I read about an article from 1992 where test were made of electrolytic caps in audio and actually low ESR caps showed higher distortion. Maybe this explains why the expensive "audio caps" have higher than average ESR. They also have much higher ripple current rating, shorter life and lower temperature rating.

https://linearaudio.nl/cyril-batemans-capacitor-sound-articles

 

[sssboa]

I just descovered Nichicon PX series. They are same size as the caps from 1970, sometimes even bigger for lower capacitance. They have excellent specs and are rated at 20,000 hours!
Below compared to Panasonic FC series to show you the size difference for 470uF 25v.

 

[Hyperion]

They are 'long life', but size alone is not a recommendation.

My current favourites
Panasonic FC, FM & FR.
Nichicon HE, PM, KZ, FG, ES, KG.

 

[rottalpha]

I just descovered Nichicon PX series. They are same size as the caps from 1970, sometimes even bigger for lower capacitance. They have excellent specs and are rated at 20,000 hours!
Below compared to Panasonic FC series to show you the size difference for 470uF 25v.

View attachment 870615 View attachment 870616

The FC look like excellent endurance caps, but unless they make a BP version, these are not recommended to use in place of a BP cap.

Vint Age knows what he's talking about. I recommend following his advice.

I second that!

If film is not an option for any reason, try looking at teh Nichie's Muze ES series...those are the green BPs. That would be my second choice after film

 

[sssboa]

So I replaced some final caps (put in 2 bipolar 1uF and 100uF on power supply board and I lost relay delay. Have I shorted something? The relay kicks in the moment I flip the switch from off to on. I have sound as normal.

 

[avionic]

So I replaced some final caps (put in 2 bipolar 1uF and 100uF on power supply board and I lost relay delay. Have I shorted something? The relay kicks in the moment I flip the switch from off to on. I have sound as normal.

Relay driver transistor may be shorted. You may have installed a wrong size cap or created a solder bridge while recapping the PS/protect circuit.

 

[sssboa]

Relay driver transistor may be shorted. You may have installed a wrong size cap or created a solder bridge while recapping the PS/protect circuit.

The 2 BPs are C819 and C820, I used correct capacitance, maybe I shorted something, will be examining later. Also I replaced 3 other caps C810, C813, C808 but I think the 2 BPs are suspects.

 

[avionic]

TR811 is the relay driver transistor.

 

[sssboa]

TR811 is the relay driver transistor.

thx for this.
btw, now MJE253 is unavailable, is there a new replacement?

 

[sssboa]

Sub for a 2SA682
KSA916Y (120/120/5 800mA, 900mW, hfe 120-240, ft-120)

http://www.mouser.com/ProductDetail/Fairchild-Semiconductor/KSA916YTA/?qs=/ha2pyFaduhJa4fTi8HteUt1SNWLw3QaAzOMeavfEcw=

I found somewhere this suggestion.
2N4920
Would it do for 2SA682?
http://www.mouser.co.uk/Search/ProductDetail.aspx?R=2N4920virtualkey61000000virtualkey610-2N4920

 

[avionic]

Sure it should do the job. Just watch your pin out. In fact thats a much better choice.

 

[sssboa]

Sure it should do the job. Just watch your pin out.

Great cause this one I already have.
Sorry for my ignorance, but what about KSA992
https://www.digikey.co.uk/product-d...-semiconductor/KSA992FBU/KSA992FBU-ND/1048216
I will try to read something about what to compare when I have time so to ask fewer questions like this.

 

[avionic]

but what about KSA992

For....what ? the relay driver. I'd stick with the TO-126 like the OEM part.

 

[sssboa]

For....what ? the relay driver. I'd stick with the TO-126 like the OEM part.

Yeah, I know. I think 2N4920 is great choice in terms of specs and form.

 

[sssboa]

Relay driver transistor may be shorted. You may have installed a wrong size cap or created a solder bridge while recapping the PS/protect circuit.

Yeah, solder bridge between C820/1uF and TR812, sorted!

 

[avionic]

Yeah, solder bridge between C820/1uF and TR812, sorted!

Outstanding !

 

[sssboa]

I noticed one of my Yamahas CR-1000 has a glitch.
When I turn the turnover switch for bass from neutral I actually get less bass as if I was applying low filter. Only when I go between 3 and 4 on the bass slider scale I have no change in bass when turning the turnover switch like it was at zero. Above that I get bass boost.
What could be the cause of this? Dirty switch/slider or something in electronics. The small boards (tone, equalizer etc.) have been recapped, the main amp boards and power supply are mostly as original.
My other Yamaha CR-1000 (fully recapped) doesn't have this problem.

BTW. I still can perceive the partly recapped Yamaha CR-1000 has bigger, stronger sound than the fully recapped one and without any looseness or sloppyness. I attribute it to the fact that most of the original caps even after 40 years when I measure them they have the declared capacitance +10% to +50%. The new ones have usually the declared capacitance -5% to -10%. I noticed the same thing with my newly bought Marantz 2270. I think about buying one size bigger caps next time, what do you think?

 

[Manlif2_0]

Hello from a newbie...
Regarding the recapping operation, i saw a reccomandation to change 3-4 caps, then test the equipment, then change next 3-4 caps, test, and so on.
But there is a reccomandation, as a "best practice", in which order to change the caps:
- starting from power section, down the line (source selector, eq board, main amp, connection board)?
- or in reverse (starting from connection board and up toward power section)?
I'm thinking that, since changing 4 caps at a time, the behavior of new ones may stress the remaining old ones.

Or one could just change them in the order it can gain acces to them (the order in which the equipment boards may be dissasembled?)

Thanks!