KSP-400 amp repair

[Aswego]

Sorry it has taken so long to follow up on my post, but I have had a hard time finding some of the parts I needed and had to settle on a beefier bridge rectifier. Also started a new job and had a hard time finding time lol. So I will start off by saying the operation was a success. And now I will post pics of the damage.

As you can see the Bridge rectifier went and took the caps with it. if you look close enough you can see that the current blew out the bottom of the caps

Edited May 1, 2017 by Aswego

[Aswego]

So I replaced the caps with the same rated caps and since nobody make the bridge anymore I took the specs and found one rated a little higher http://www.ebay.com/itm/321893502269?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT  that is the link to the bridge on EBAY. I also opted for Panasonic caps instead of Soundia mostly because I couldn't find the Soundia's . after the fix the amp hummed for almost 10mins then settled in to normal operation and sounds great now

[T2K]

 

Thanks for responding Aswego. Often times we're left in limbo without a follow-up. And follow-up you did! Great pictures. They visually explain your repairs. Now the next guy that comes along will be able to search and find the information you shared.

Now I'm wondering how the repaired speaker sounds.

 

Good luck to you.

 

Keith

[Matt Wheeler]

Old thread but useful knowledge.  Sybesma's Electronics in MI for repairs.

[Pashco.Ceo]

On 3/24/2017 at 3:33 AM, Aswego said:

I am always on the lookout for the 400's and the 300's . I search local Craigslist and ebay on a regular basis. when I find anything posted for them I inquire on them. I like them a lot. I also have RB 51II's and a RC-25 and the aforementioned SUB-12. I would like to trade in my rb-51's for a set of the ksp-300's

 

I realize this post is about 5 years old, but I wanted to share what I'm finally letting go because I've got four 15" subs in each corner, and a rear-middle 10". I've been offered $1000 for my Klipsch RP-5 towers, RC-3 center, and RS-3 surrounds, which is a decent deal considering they're in perfect condition.  Anyway, this means I'm also selling my perfect set of KSP-300's both with brand new amps installed 3 months ago with 10 mins of use. One of my 15" subs is my KSW-300 (subwoofer) that's been restored to like new condition, but the prize grab are my entire K-6 set with the KC-6 center, KS-6 600 watt max surrounds, and the famous KSP-400 towers in the cherry wood.  I was lucky and found 1 brand new unopened European KSP-400 amp, and all I had to do was switch transformers and it's back to new.  The other amp is being worked on, and why that's going on I decided to have the wood sanded and refinished to look like new.  They'll turn out looking better than my 300's.  I've been offered $900 for the K-6 set, but that was before I decided to have the cabinets and the 1 amp fixed.  Anyone's more than welcome to see pictures, stop by and test them out (northeast of Indy), or shoot me an offer.  I ended up with an extra new amp for the KSP-300's because the guy thought he had 2 European amps of both the 300's and 400's, but he had 3 and 1.  My name is Paul Shane Cole, and you can easily find me with that name on Facebook, or put it all together and send it over electronic mail...lol. 

[OO1]

On 2/12/2022 at 8:34 AM, Pashco.Ceo said:

I realize this post is about 5 years old, but I wanted to share what I'm finally letting go because I've got four 15" subs in each corner, and a rear-middle 10". I've been offered $1000 for my Klipsch RP-5 towers, RC-3 center, and RS-3 surrounds, which is a decent deal considering they're in perfect condition.  Anyway, this means I'm also selling my perfect set of KSP-300's both with brand new amps installed 3 months ago with 10 mins of use. One of my 15" subs is my KSW-300 (subwoofer) that's been restored to like new condition, but the prize grab are my entire K-6 set with the KC-6 center, KS-6 600 watt max surrounds, and the famous KSP-400 towers in the cherry wood.  I was lucky and found 1 brand new unopened European KSP-400 amp, and all I had to do was switch transformers and it's back to new.  The other amp is being worked on, and why that's going on I decided to have the wood sanded and refinished to look like new.  They'll turn out looking better than my 300's.  I've been offered $900 for the K-6 set, but that was before I decided to have the cabinets and the 1 amp fixed.  Anyone's more than welcome to see pictures, stop by and test them out (northeast of Indy), or shoot me an offer.  I ended up with an extra new amp for the KSP-300's because the guy thought he had 2 European amps of both the 300's and 400's, but he had 3 and 1.  My name is Paul Shane Cole, and you can easily find me with that name on Facebook, or put it all together and send it over electronic mail...lol. 

you'd be   Way Better off , posting an ad in the GARAGE SALE section

 

  Welcome to the Klipsch Forum

[Pashco.Ceo]

I wasn't really going for traction on a 5 yr old post, more hoping to give it life as it's the latest topic (I've seen) on the KSP 400's.  I've seen this question asked a lot with no answers, so maybe you could help.  What caps would/could you put back in place of the 6800uf 80v to reduce the chances of those going bad so quickly, and not compromising the amp or sound?  

[captainbeefheart]

On 2/24/2022 at 9:04 AM, Pashco.Ceo said:

I wasn't really going for traction on a 5 yr old post, more hoping to give it life as it's the latest topic (I've seen) on the KSP 400's.  I've seen this question asked a lot with no answers, so maybe you could help.  What caps would/could you put back in place of the 6800uf 80v to reduce the chances of those going bad so quickly, and not compromising the amp or sound?  

 

Variables that kill aluminum electrolytic capacitors quickly are temperature and operating current over time. As you will notice in these amps the caps are typically in close proximity to heatsinks and other devices that put out heat. You can't move their location but you can get better rated capacitors because typically they will use the cheapest general purpose capacitors they can get for production.

 

The original were most likely rated for 85°C operation. If you want to choose a capacitor that will last a lot longer find a long life (+10,000hrs) capacitor rated for 105°C and also has a low loss angle to handle higher currents. Typically the latter will be stated as "low ESR, high ripple current" in their product literature or description. When viewing capacitors in digikey after a search for "capacitance, voltage rating" you will see the results will have attributes listed and typically you will see ESR and hours of operation etc..  so you don't necessarily have to read through tons of datasheets, it's easy. If you do look at the datasheet many don't list ESR because it changes with frequency, instead they list tangent or loss angle, same thing. When current passes through the capacitor this heat build up across this loss angle which diminishes their life, the lower the loss angle the better current handling capabilities it has because it will build less internal heat.

 

Look for long life rated capacitors

 

Only buy 105°C rated capacitors

 

Look for one with as low a loss angle as possible or one that is sold as "high ripple current"

 

 

So to answer your question again these caps fail quickly because they are near heat yet not rated for long life with high temperatures, and the nature of these caps usually gets abused electrically seeing huge current pulses so low ESR or loss angle, high current rated capacitors will be best.

[captainbeefheart]

This has good information in it that answers your question in greater detail. It even has an equation for capacitor life if you were so inclined. Although the point of the paper is to compare wet vs dry electrolytic capacitors it will help you understand the life of them in an application.

 

https://epci.eu/wet-aluminum-electrolytics/

[henry4841]

Heat is the enemy of capacitors. Recently restored a receiver with new caps and most all if not all the capacitors were in tolerance but were replaced anyways being 45 years except for one board, tone control that was mounted upside down. All the caps on that upside down board were bad. Being upside down it held held heat generated by the receiver destroying them. Just showing how heat destroys electrolytic capacitors. 

[billybob]

Yes look for the dude that fixes them here.

No secret cool and dry is best for electronics.

[Pashco.Ceo]

Thank you for a detailed response and explanation as it really helped nail down the capacitors I went with!!!  They should be here Wednesday!  Best explanation I've found! 

[Aswego]

Not sure if this is still relevant.. but I would like to give an update on the health of my ksp-400 amps. I eventually did the repair/ upgrade to both amps. And I still listen to my ksp-400s everyday. They are very comfortable to listen to and sound so much better than most of Klipsch's modern midrange offerings. Still on the hunt for a decently priced pair of ksp-300s for the rear channels.  But as they are getting more and more harder to find.. when I do see them folks want a decent amount for them. So I'm hoping for a fixer upper set.