Have a integrated Krell F.B.I sins it was new ca 2008.( but dident use it before 2011-2012 due to various reasons and health)
https://www.stereophile.com/content/krell-fbi-integrated-amplifier-specifications
And last 12 years it have been driven first my 1998 Von Schweikert VR-4 SR, and last 3 years my diy speakers 6 X Peerlees XXLS 12 inch modelnr:830847 ( 2 x 8 ohm coils, 3 per side tuned to 23 hz, in 100 liter reflex netto) each connected 16 ohm at the driver, and parallell to 5,66 ohm outside.
Active filter before amp, so Krell amp and XXLS 12 do the jobb up to 340 hz left and right ( Unother amp take midrange and top from 340 hz an upp left and right, passive xover in MTM)
Im a real high listener, mostly over 100 dB + the 15 dB peaks, so Krell amp have to work ”hard” and always get very hot on my 3-4 hours of playing now and then.
Suddenly when im listening the amp shutts down itself. (protection mode ?)
Started it up again after a few minuts, and all seems fine. Dident play as loud the rest of the listening, but it newer happend agian that night.
2 weeks after when i played as laud as i use to do it happend again, the amp” shutts down itself ( and now i begain to be worried)
Let it be for a few month ( dident have health to deal with it), and when deside to listening again i shifted the speakerconnetion so the Krell only do the mid¨s and top MTM ( for a more easy load)
It played my MTM for 2-3 secunds and then amp shutts down itself again…Grrrrr
Hade A friend brought the 55 kilo amp up from the basement & put it on my kitchen table for me, and i connected it only to 240 volt power and power it up ( no speakers or soundsourses connected) and everything seems normal (it has a 10 second start-up sequence before it goes to ready-mode)
Let it stand in ”power on mode” for an hour and them measure DC offset at the speaker terminals. The meter setting was 200 m, and both left and right speakeroutputs shows value from 010 minus to max 035 plus ( was ofted at 003)
My question is where do a go from here?
Connecting a soundsourse? Speaker ? and measure again?
Best regards John
https://www.stereophile.com/content/krell-fbi-integrated-amplifier-specifications
And last 12 years it have been driven first my 1998 Von Schweikert VR-4 SR, and last 3 years my diy speakers 6 X Peerlees XXLS 12 inch modelnr:830847 ( 2 x 8 ohm coils, 3 per side tuned to 23 hz, in 100 liter reflex netto) each connected 16 ohm at the driver, and parallell to 5,66 ohm outside.
Active filter before amp, so Krell amp and XXLS 12 do the jobb up to 340 hz left and right ( Unother amp take midrange and top from 340 hz an upp left and right, passive xover in MTM)
Im a real high listener, mostly over 100 dB + the 15 dB peaks, so Krell amp have to work ”hard” and always get very hot on my 3-4 hours of playing now and then.
Suddenly when im listening the amp shutts down itself. (protection mode ?)
Started it up again after a few minuts, and all seems fine. Dident play as loud the rest of the listening, but it newer happend agian that night.
2 weeks after when i played as laud as i use to do it happend again, the amp” shutts down itself ( and now i begain to be worried)
Let it be for a few month ( dident have health to deal with it), and when deside to listening again i shifted the speakerconnetion so the Krell only do the mid¨s and top MTM ( for a more easy load)
It played my MTM for 2-3 secunds and then amp shutts down itself again…Grrrrr
Hade A friend brought the 55 kilo amp up from the basement & put it on my kitchen table for me, and i connected it only to 240 volt power and power it up ( no speakers or soundsourses connected) and everything seems normal (it has a 10 second start-up sequence before it goes to ready-mode)
Let it stand in ”power on mode” for an hour and them measure DC offset at the speaker terminals. The meter setting was 200 m, and both left and right speakeroutputs shows value from 010 minus to max 035 plus ( was ofted at 003)
My question is where do a go from here?
Connecting a soundsourse? Speaker ? and measure again?
Best regards John
Attachments
Output offset seems OK.
I don't want to discourage you, but if you are not familiar with repairing these type of "beasts", I highly recommend handing it over to a good technician, familiar with Krell.
The only thing you could do is check your speaker connections. They should be firm and solid. No room for doubt there.
Hugo
That have become a big problem here in Sweden......To get a good technician, familiar with Krell. ( and all others)
25 years ago there was some, but the only 2 good guy¨s is almost 90 years old now and no longer work.
And if i contact the dealer in Sweden, I will probably have to send it abroad.
60 kilo shipping round trip!.......I can't afford it these day¨s, so i have to find someone closer and maby drive my self
Have work with a broken Pass Labs X-350 20 years ago, it had a broken silica gasket on 1 of the mosfets ( between mosfet and heat sink/short circuit )
Was thinking if there was some other steps on my Krell to do by myself?
It works when nothing is connected, so maby in any case find out which side or which circuit is failing.
That will also help me to explain to the tech guy when I call around for help.
Regards John
This problem seems thermally related, since it does not happen when idle with no load.
Electronic test equipment is usually necessary to troubleshoot such problems.
You could play only one channel at a time, to isolate the problem to one channel.
Possibly the thermal interface for the output devices is degrading.
Electronic test equipment is usually necessary to troubleshoot such problems.
You could play only one channel at a time, to isolate the problem to one channel.
Possibly the thermal interface for the output devices is degrading.
Do check your speaker cables. No pets around chewing cables? 😉
I presume you have an Ohm meter? Measure your speakers. If they are 4 Ohm, you should measure something around 3 Ohm,
if they are 8 Ohm, measurement should be +/- 6 Ohm.
Measure with and without cables attached to speakers, unattached to amp.
Further, what rayma said. 🙂
I presume you have an Ohm meter? Measure your speakers. If they are 4 Ohm, you should measure something around 3 Ohm,
if they are 8 Ohm, measurement should be +/- 6 Ohm.
Measure with and without cables attached to speakers, unattached to amp.
Further, what rayma said. 🙂
This weekend i did some tests with the amp.
Connected an portable old cdplayer with rca and connect a small satellite speaker to the right channel.
Everything worked perfectly and after 2 hours i also connected the left satellite speaker.
After 2 more hours i connect my Onkyo receiver to the amp with rca, and also tested with bigger 3 way floorstanding speaker.
Worked perfect 5-6 hours playing 100 dB music, and i feel confused!
The differance when the amp is connected in my basements musicroom (where the problem started) is
1) An 11.2 ch Yamaha AVENTAGE pre-amplifier is connected via XLR to an active xover (DBX 234 Xs)
2) From the DBX 234 Xs active xover "splitting signal" and sending everything under 340 hz to the "problem-amp" via XLR, and everything over 340 hz to to another amplifier also via XLR. ( the 3 xxls 12 woofers per side is 5,66 Ohm and MTM have a passiv 2 way xover inside)
Had worked about 1,5-2 years when the problem begaing AND when i insted connected a Crown xti amp to drive my xxls woofers, i did the connection direkt from the Yamaha AVENTAGE pre-amplifier via XLR and it was no problems.
Can the problem be in my DBX 234 Xs active xover? (After working for ca 2 years)
It´s the only logical, if the problems not being XLR vs RCA inputs on the Krell amp?
Here is a link to the active filter in using.
https://www.thomannmusic.com/dbx_23...LCJjdXJyZW5jeSI6NywibGFuZ3VhZ2UiOjJ9&reload=1
Best regards John