- About me:
I am working in the computer industry for many years, I did a lot of PC mantianace but limited to part replacement and never did any chip level reparation.
I have used soldering couple times and know how to discharge a capacitor.
- About my equipment
I have a Yamaha C-80 preamp and want to recap it.
-Questions
Do you think I could do the recap by myself? (seems not very difficult)
Do I need to know audio theory or its circuit diagram before doing it?
Thank you so much for any help!
I am working in the computer industry for many years, I did a lot of PC mantianace but limited to part replacement and never did any chip level reparation.
I have used soldering couple times and know how to discharge a capacitor.
- About my equipment
I have a Yamaha C-80 preamp and want to recap it.
-Questions
Do you think I could do the recap by myself? (seems not very difficult)
Do I need to know audio theory or its circuit diagram before doing it?
Thank you so much for any help!
You must know how to identify capacitor types to replace as is. Do not beleive improvements from changing that, trust designers know what they are paid for.
All you have to do about caps, is same type, same values and some caps have polarity.
A most important aspect is: PCB potential damage.
Do you have the skill at desoldering ( mastering, the unsoldering pump and the unsolder tape ), soldering with a good iron with an appropriate tip, cleaned and at the right temperature.
The best is to train for this skill on salvaged stuff, and see what looks like a good solder joint. When you pull out a component, be aware, there is a risk to tear off the pcb track and master how to avoid that.
And be aware that, there are "good, bad and ugly" PCBs, for this job.
All you have to do about caps, is same type, same values and some caps have polarity.
A most important aspect is: PCB potential damage.
Do you have the skill at desoldering ( mastering, the unsoldering pump and the unsolder tape ), soldering with a good iron with an appropriate tip, cleaned and at the right temperature.
The best is to train for this skill on salvaged stuff, and see what looks like a good solder joint. When you pull out a component, be aware, there is a risk to tear off the pcb track and master how to avoid that.
And be aware that, there are "good, bad and ugly" PCBs, for this job.
Thanks for your reply mchambin, for the caps, the only one type I am worrying about is 35v 4700uf, the original components are huge, but currently we could not find that kind of caps. So for instead I gonna use "Nichicon Gold FW 4700uF 35v Radial Electrolytic Capacitor for Audio", this the best caps I could find now, but looks pretty small...
For the tools, I purchased a set of soldering for 30 bucks, and much other stuff, total over 100 dollars. That solder with 5 different tips and temperature adjustable. I also purchased a couple of practice board like radio, clock...I will solder and desolder them couple times for practicing, before handing on my preamp.
I don't know if it is enough for it...still doubt...
For the tools, I purchased a set of soldering for 30 bucks, and much other stuff, total over 100 dollars. That solder with 5 different tips and temperature adjustable. I also purchased a couple of practice board like radio, clock...I will solder and desolder them couple times for practicing, before handing on my preamp.
I don't know if it is enough for it...still doubt...
Industrial nichicon electrolytic caps are just fine for audio. also Rubicon Panasonic & Vishay. I don't like doing this job over & over, now that distributors will sell to individuals with debit cards, we can buy long life (3000 hours service life) caps for less than the pricey "audio" lines.
Wear safety glasses, solder can splash. Mark the location of the + or - on the board with a sharpie, if you get it wrong the new cap explodes. I use a solder sucker rubber bulb from parts-express now, those spring loaded sucker gadgets the tips are too easy to melt. If I burn this one it is $2. I have a R**** S**** solder sucking iron, but it doesn't work very well and is extremely hot.
I started by "just do it". The more I do it the better I get. Old components with lead/tin solder are a lot easier to work than ROHS compliant ones with silver solder. I've pulled a few pcb lands, and patched them back with solid core wire. the only thing I knew for certain before the internet was that the MacIntosh salesmen at the clinic said my 70 w amp put out 7 watts because the e-caps were dried up, followed maybe by an aged rectifier tube.
I started replacing electrolytic caps on a dynakit ST70 which is now worth $700 in junk non-working condition, so don't feel too bad about an old yamaha. What is the cost of an inop one on e-bay? That is your worst case scenario.
Wear safety glasses, solder can splash. Mark the location of the + or - on the board with a sharpie, if you get it wrong the new cap explodes. I use a solder sucker rubber bulb from parts-express now, those spring loaded sucker gadgets the tips are too easy to melt. If I burn this one it is $2. I have a R**** S**** solder sucking iron, but it doesn't work very well and is extremely hot.
I started by "just do it". The more I do it the better I get. Old components with lead/tin solder are a lot easier to work than ROHS compliant ones with silver solder. I've pulled a few pcb lands, and patched them back with solid core wire. the only thing I knew for certain before the internet was that the MacIntosh salesmen at the clinic said my 70 w amp put out 7 watts because the e-caps were dried up, followed maybe by an aged rectifier tube.
I started replacing electrolytic caps on a dynakit ST70 which is now worth $700 in junk non-working condition, so don't feel too bad about an old yamaha. What is the cost of an inop one on e-bay? That is your worst case scenario.
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Hi, thanks for all the reply, big help!!!
And I have another couple questions with pics:
1. My c-80 works very well now, a couple of weeks ago there is noise when turning the nob and distorting between channels, so I open it and spray some RadioShark cleaner and lubricant, then it works as before. I could feel heat after running it 30mins, I guess these are the signs that need be recapped right?
2. When open it you could see there are 4 hug caps, actually, they are same things, but looks different, are the top 2 almost burst？ So I decided swap these four first, am I right?
WechatIMG30 copy.jpeg - Google Drive
3. There is another place looks wired, looks burn out, but everything works fine, could anyone tell me what issue it could be?
WechatIMG44 copy.jpeg - Google Drive
4. The pic down below is the new cap I want to buy, but they are really small compared with the original ones, so does this matter?
Screen Shot 2019-04-05 at 10.48.03 PM.png - Google Drive
Thank you so much!
And I have another couple questions with pics:
1. My c-80 works very well now, a couple of weeks ago there is noise when turning the nob and distorting between channels, so I open it and spray some RadioShark cleaner and lubricant, then it works as before. I could feel heat after running it 30mins, I guess these are the signs that need be recapped right?
2. When open it you could see there are 4 hug caps, actually, they are same things, but looks different, are the top 2 almost burst？ So I decided swap these four first, am I right?
WechatIMG30 copy.jpeg - Google Drive
3. There is another place looks wired, looks burn out, but everything works fine, could anyone tell me what issue it could be?
WechatIMG44 copy.jpeg - Google Drive
4. The pic down below is the new cap I want to buy, but they are really small compared with the original ones, so does this matter?
Screen Shot 2019-04-05 at 10.48.03 PM.png - Google Drive
Thank you so much!
Wrong capacitor. Look for something like this.
Aluminum Electrolytic Capacitors - Snap In | Mouser
Aluminum Electrolytic Capacitors - Snap In | Mouser
Yes !
The big power supply caps are the one suffering. In many cases, that is the only real need for recapping.
Good move with the RadioShark contact ckeaner.
Electronics tends to warm up when plugged in, you know. This is a sign of approximately nothing.
Without any measuring equipment your best way to tell if caps are going bad is to visually inspect them and to listen and evaluate the sound of preamp.
No. Those are signs that you have dirty switch contacts or dirty volume control tracks. Nothing to do with capacitors. Some heat is to be expected.zhloea said:
Yes. If a cap looks like it is trying to burst out of its can then it definitely needs replacing. These may be the only caps which need replacing.
Could anyone help me double check that LKG1V472MESBBK Nichicon | Mouser
Is this the right part to recap those huge caps? Thank you!
Is this the right part to recap those huge caps? Thank you!
On the picture I see some discoloration and signs of corrosion on the resistors leads, but no signs of burning. Maybe the picture just doesn't translate the right colors.
Alcohol is not very helpful, usually it needs to be removed mechanically.
For the capacitor - ripple current rating (higher is better), hours of operation and the right dimensions are the most important specs.
Greetings zhloea,
These Yamaha stuffs sounded good. One of the good brand which cared when chosing caps to reach the tonal balance of their "natural sound" line. They used some good caps from Elna and some others... Try to keep all the other caps of this board.
You should choose the same cap brand at the area you want to fix if you want to stay close from the genuine result. Saying that, LKG are good caps (subjectivly better imho than the previous FW you linked).
You need to check several things before swapping a capacitor:
-use same values : capacitance/voltage/degree/tolerance (here certainly M so 20%)
- take care to the size of the new cap : it must fit in the area : check first the gap between the legs of the former cap then control if the new cap has the same spacing. Of course diameter of the cap and length if you have small room between the former cap and the metal case.
-use flux to protect the pcb trace and a good pump as well.
- don't use exotic solder with Ag.
These Yamaha stuffs sounded good. One of the good brand which cared when chosing caps to reach the tonal balance of their "natural sound" line. They used some good caps from Elna and some others... Try to keep all the other caps of this board.
You should choose the same cap brand at the area you want to fix if you want to stay close from the genuine result. Saying that, LKG are good caps (subjectivly better imho than the previous FW you linked).
You need to check several things before swapping a capacitor:
-use same values : capacitance/voltage/degree/tolerance (here certainly M so 20%)
- take care to the size of the new cap : it must fit in the area : check first the gap between the legs of the former cap then control if the new cap has the same spacing. Of course diameter of the cap and length if you have small room between the former cap and the metal case.
-use flux to protect the pcb trace and a good pump as well.
- don't use exotic solder with Ag.
just saw a post, they recommend LLS1V472MELZ Nichicon | Mouser
because of a long lifetime 3000hrs, LKG just have 1000hrs.
How do you think about this?
because of a long lifetime 3000hrs, LKG just have 1000hrs.
How do you think about this?
the KG will last 20 years or more, the LL (if it is for Long Life) 30 years or more...
There is a logic to choose the LL just after the diodes bridge. They have a higher ESR (serie resistance) which is not a bad idea at that position.
It's not certain than the "audio" KG cap will give you a better sounding result here.
Look also at the temperature ratting : 105C° is less fragile than 85°C for instance.
But if the former cap is 85°C, be sure the designers are sure it is enough !
If the caps are splitted in serie by resistor for better ripple filtering : Cap - Resistor - Cap, you can choose the KG for the second and Long Life for the first which is just after the rectifier diodes. But I will be surprise to find a CRC circuit in that Yam. So LL could be your best bet . But are we sure that Nichicon LLS marked is for Long Life ????
There is a logic to choose the LL just after the diodes bridge. They have a higher ESR (serie resistance) which is not a bad idea at that position.
It's not certain than the "audio" KG cap will give you a better sounding result here.
Look also at the temperature ratting : 105C° is less fragile than 85°C for instance.
But if the former cap is 85°C, be sure the designers are sure it is enough !
If the caps are splitted in serie by resistor for better ripple filtering : Cap - Resistor - Cap, you can choose the KG for the second and Long Life for the first which is just after the rectifier diodes. But I will be surprise to find a CRC circuit in that Yam. So LL could be your best bet
. But are we sure that Nichicon LLS marked is for Long Life ????
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