Which capacitors do i need tho replace the old?

champ05 · Post by **champ05** » Tue Dec 18, 2007 1:44 pm

I bought an used Outlaw1845 and tried the white paper check on my capacitors. It seams like they are leaking, cause there is some liquid on the sheet :/
Now my question, do i need the same 2200yF, 16V and 105°C caps?
The problem is, i live in austria and have no idea if i can get the exact caps anywhere.
And should i also replace the 2 blue caps on the M100 side and the 2 black ones on the M50 side, just to be on the save side?

Every answer is helful, thx!

Post by **fuzzysnuggleduck** » Tue Dec 18, 2007 2:16 pm

I'd say replace all the pre-amp caps. The rail caps (big ones) will be $$ to replace and tend to take more abuse, or at least people don't seem to replace them as often.

Replace them with caps of the same voltage rating but you can easily get a higher farad rating and higher temperature rating. I think the Doc (Eric D) and Cecil like to use Nichicon brand capacitors due to quality.

Let Cecil ring in on this one, he's replaced more caps in his lifetime than I've taken shits.

Post by **Eric D** » Tue Dec 18, 2007 2:29 pm

I would suggest against replacing any preamp caps, as they don’t seem to fail often, and upgrading them for a sonic improvement is not noticeable to the majority of people.

You should however replace the power supply caps. These are the ones you have checked, and they sound ready to fail on you.

The rail caps (big blue and black) don’t fail often. I would leave them be if I were you.

I would guess there is a digikey.com for your country, they are in plenty other countries. They are your best bet for parts.

Post by **fuzzysnuggleduck** » Tue Dec 18, 2007 3:48 pm

Eric D wrote:I would suggest against replacing any preamp caps, as they don’t seem to fail often, and upgrading them for a sonic improvement is not noticeable to the majority of people.

You should however replace the power supply caps. These are the ones you have checked, and they sound ready to fail on you.

The rail caps (big blue and black) don’t fail often. I would leave them be if I were you.

I would guess there is a digikey.com for your country, they are in plenty other countries. They are your best bet for parts.

Errr, mistake on my part, the PS caps are the ones I was thinking of and I typed pre-amp instead. Thanks for clearing that up Eric.

1moreamp · Post by **1moreamp** » Tue Dec 18, 2007 4:24 pm

Hi Guys,
Eric, Fuzzy is thinking about his M-100 I recapped for him. I replaced every cap in the amp.
I take the time to measure caps < a matter of minutes only> and then decide the correct course of action required on a re-cap of a amp.

You see every amp is is different, usually by the use it has seen. But as a general practice I stocked all the proper values but higher grade 105 Nichicon.

The main abuse caps are the 2200uf 16 volt caps on the 12 volt side and the then the secondary side of the supply. Mainly the Big Blue ones and the 15 volt rail caps. You will find these near the big resistors located in the power supply section, They are the 100 ufd caps rated at 25 volts. If you check these while the amp is running you will find them be rather HOT to the touch.
Heat ages things, and I have found these so hot that the shrink sleeve on them had melted and pulled down over the can < this is way Hot>

So I would run with this sort of mind set at this point. And if in doubt, well the hand full of little caps used in this amp take longer to put in them to think about it thats for sure. But I know the amp I did for Fuzzy was as like new when it got back to him.

Electrolytic caps are the weakest component in any electronic device today. Even with the improvements made over the last 15 years, they are still a large issue in the failure picture.

I am lucky and can get high grade caps for reasonable prices locally here in the valley. The main suppliers online are not as forgiving price wise, so with that in Mind, do what seems prudent for your investment and need.

But for gosh sakes please replace those 2200uf 16 volt caps before they turn your amp in a BBQ. You can use 4700's and 5600's and my fav 6800's that all will fit as replacements in that given area. Please measure them in MM of height and width and worry about the height the most... Best of luck on you recap....C

Post by **Eric D** » Wed Dec 19, 2007 3:58 am

How can you measure all the capacitors so fast? Do you just remove only one leg of each cap and check it, or do you de-solder the whole thing and check it outside the amp. Either way, that is very time consuming.

champ05 · Post by **champ05** » Wed Dec 19, 2007 9:16 am

Thank to all!
So i'm going ahead and replace only the power supply caps.

1moreamp · Post by **1moreamp** » Wed Dec 19, 2007 9:51 am

Morning Eric, I have a in circuit ESR tester, and Octopus < device curve tracer>.
I test various caps through out the amp and based on there average discrepancies I decide weather to overhaul the lot. Then I shotgun the lot and be done with it. It takes about a hour of time sometimes more.

If I am in doubt I also remeasure out of circuit. I can safely remove 6 to 8 caps in about 2 minutes.

I don't do this to all amps, just the ones showing symptoms and stress, and need it. Or at a customers request of course....Hope this helps....C

Oh I also agree with you it takes time, and sometimes it can be a pain in the neck. But its part ans parcel of refurbing 15 year old amps. Usually I don't count on making any easy or fast money on old amps. They just need way too much re-work to be a profitable line of work.
Like you, its a labor of love for me to re-work a old amp.....C