So your amp meets factory specs. Quit you whining and enjoy it!
What do you care what color the caps are??
What do you care what color the caps are??
It would matter if the quality of the two different cap had different sounds, matched Cap specs don't always predict matched sound. I read of people using "better" sounding caps to modify their amps while adhering closely to the original specs. I have even heard of Capacitor comparison shootouts.
In this case if you couldn't hear a difference, then the two cap types have comparably close sonics by definition (to your ears anyway). Thus they are nothing to worry about. If you have an open or see through cover then aesthetically it may matter to you, and many of us want gear that looks good and sounds good too.
Sounds like a electrolytic power supply capacitor - sincerely doubt if you have anything to worry about, if installed originally by Krell I'm sure they meet spec. most of these come in standard values and sizes from many different manufactures.
Mechans the capacitor shootouts you are referring too are about capacitors for speaker crossovers and maybe coupling capacitors etc for tube amps and the best of them can be found here.
As long as the power supply caps meet Krell design specs, you shouldn't have any reason to worry. These are power supply caps, not caps in the audio circuit chain. This is really not a big deal or problem. Power suppy caps can be very expensive, especially if the rail voltages are high. The higher the rail voltage, the more expensive the caps would be. So, they probably saw that one channel was damaged and the power supply caps on that side were questionable. So they replaced the caps on that side. If the other side's caps were okay, then why spend the money to replace them? I would have asked the customer if they wanted me to replace them all, which is probably what Krell's Technician did. The customer may have said no due to the costs. If they are quality caps, you would be hard pressed to hear any difference. Same capacitance rating, same or higher voltage rating and you are good to go. Take a quick look to see how much those suckers costs. Say a 33,000 micro farad cap rated at 100VDC. Go ahead and check.
Opening (just curiosity) recently a fellow's Parasound Halo JC-1s (purchased brand new, factory sealed, from authorised dealer), we both were surprised seeing all four power supply main caps (4x33000 mfarads) altogether different, named Rubicon CE LSQ, instead of original Nichicon Gold Tune
On another forum we've been told that at a time Parasound factory was short of original caps, so they implemented the closest match.
To be honest, amps work flawlessly more than two years, for now..
I am surprised that a well known name like Krell would mix components within a single unit, but if you don't hear a difference and it was factory done, I guess it's no harm no foul.
I would have expected a manufacturer would just use all black caps of the new line in making a new amp and save the extra blue caps for incoming spares to be used on amps to be serviced that used the blue caps.
Hey, if you want to and agree to pay the costs to replace all of the power supply caps to match them, then more power to you. It is very expensive and totally unncecessary. Same quality caps, same ratings, same or higher voltage rating, you will not hear or experience a difference. Take for example a brand new amp, where one power supply cap failed after say... three months. Still under warranty, but the manufacturer got a better deal on power supply caps from a new parts supplier. Same ratings. So, I'm going to replace all the caps? No. I will replace the caps on a particular side only. to expensive otherwise. Understand, I'm talking about power supply caps, not caps in the signal/audio circuit path. Even then, unless I was doing a total upgrade on a amp, I probably wouldn't replace all of the signal caps just because one cap failed. I would install an equal quality or better quality cap, test the amp to make sure it meets spec, listen for any issues and I'm done. Just me, but I think you are making a big deal out of a small issue. But, that's me. Again, on power supply caps, if they were old or showing wear, I would ask the customer if they are willing to spend money to replace them all. I definitely wouldn't replace them all without asking first. Too much money involved.
I'd love to have you in a double blind test on PS capacitors in a power amplifier - large electrolytic ones - if you can tell any difference from a Cornell to a Mallory to a United Chemicon, Rifa, or any other reputable manufacture and repeat your findings - well then your ears are with out a doubt golden.
Thank you Peter and yes I am blessed. I can also hear the difference
between pieces of wire! Get this, even the footers under the amp! This last
one will really blow you away. I can hear the difference from day one on a
new cap and day 30! So as you might imagine hearing the difference
between cap brands is quite easy for me and can be done with one ear
behind my back:-)
I get that one can tell a difference between wires , interconnect and speaker cables that is - power cords - well - if of decent gauge and with quality connectors - then not so much. I can certainly also agree that proper mechanical isolation of components is important, and yes stuff breaks in.
I'd put power supply capacitors right up there with my take on power cords i.e.. if they are of good quality and properly installed then I doubt if anyone would be able to tell a difference between a blue one and a black one, never mind how golden eared one are.
Peter, in my experience with mods I can indeed hear differences in power supply caps. This has been true with caps like Black Gate and some of the newer ones from Mundorf. My wife must also be golden eared and blessed like me for hearing a difference. Power cords of good quality sound quite different indeed.
First thanks for keeping this a civil discussion of opinions unlike others that have chimed in on this thread.
I took a look at your earlier posts and reviews and it appears that you favor tubed equipment where in some cases the power supply caps are the only "regulation" in the power supply, and I'll agree that capacitors can sound different in this case.
In my own designs which are all solid state with heavy regulation in the power supplies - just like the original poster's case with the Krell Amplifier - I sincerely doubt that there will be any sonic difference if similar spec capacitors from two different manufactures are used.
As far as power cords are concerned I have not experienced much difference as long as the cords are of proper gauge and are terminated with quality connectors, and before spending serious $ on power cords I'd make sure that whats in front of the cord is taken care of first. Dedicated lines, etc. In most cases this will cost less than many of the high $ power cords and it will have a much greater positive effect than the last 5 feet of wire feeding the equipment.
As always, Good listening
We agree on the importance of dedicated lines as I also have two 20 amp dedicated lines into my music room. This should be first and aftermarket cords second. I was stunned at the difference power cords make as I tried various ones in my system. Each of them highly regarded, but changing the overall sound in some cases. I have settled on heavy gauge, solid core copper on all my wire. Multiple runs of heavy gauge! solid core is very stiff and a pain to deal with, but sounds right to me.
Well, I have changed out out power supply caps in a past Sunfire Signature SS amp and had them upgraded in an old Hafler amp and both realized nice improvements. You have much more knowledge on technical matters then I do, so what you say may be true in many cases.
When you replaced the capacitors on your two solid-state pieces, did you use a equivalent capacitor or a better one. If equivalent, and an improvement in sound - then you replaced a older dried out one with one that was up to spec and therefore got better sound. I you used a better one - high temperature - lower ripple - higher capacitance etc. in combination with replacing a old dried up one no longer to spec - well then of course you get better sound.
The OP was "disappointed" that he had a mixture of blue and black capacitors- what I have been trying to communicate that if the blue cap and the black cap have the same specs but are from different manufactures there will be no difference in sound.
As always - good listening.