KRELL 484081 and 484002 output transistors remplaces codes. HELP!!! - Page 2 - diyAudio
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Old 24th August 2007, 09:13 AM   #11
AndrewT is offline AndrewT  Scotland
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Quote:
Originally posted by fepablo
The KRELL is WORKING!!!!!

I replace the 3 x Krell 484081 with 3x MJ15024 and the Krell 484002 with MJ15025. All transistors are from output stage. Krell sells the transistors orginal´s
if the replacements are 15024/5 and they are working correctly then the original 484081/002 cannot be equivalent to 3281/1302. They must be equivalent to some other type.
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Old 24th August 2007, 10:02 AM   #12
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Quote:
Originally posted by AndrewT
if the replacements are 15024/5 and they are working correctly then the original 484081/002 cannot be equivalent to 3281/1302. They must be equivalent to some other type.
How long will it work?
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Old 26th August 2007, 02:05 PM   #13
Jozua is offline Jozua  South Africa
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Default How does it sound?

Hi

Do you detect a sound improvement after the change.

I have a similar amp-KSA200s which I find average sounding compared to other class A amps. I am beginning to wonder if it will sound better if one replaces some of the caps on the PCB with better caps ?

Any comments ?


Jozua
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Old 27th August 2007, 03:33 AM   #14
fepablo is offline fepablo  Argentina
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Hi guys. The original replaces of 484081/002 are 3281/1302 100% sure, but they are discontinued. The 15003/4, 15015/14, 15024/25, 21193/94 are very similar family of transistors. In the ECA VRT manual, MJ15015 is a direct replace of MJ3281, but i dont use this because he have 180w and the MJ15024 have 250w like the 3281.

The sound is better, i replace transistors of one channel, caps of both and work same the two channels. I have a Martin Logan Sequel II Speakers.

I use the amp few night for many ours without problems or high temp. I attach more pics of the process and my other baby, Marantz 2500.
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Old 27th August 2007, 07:19 AM   #15
AndrewT is offline AndrewT  Scotland
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Hi,
the 3281 is very different from those others. They are not equivalent.

The gain higher
The gain droop @ high current is lower
The speed is higher
The SOAR varies between types
The power and current ratings are different.

I still think you should have bought a matched set.
I hope this modification works out OK.
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Old 29th August 2007, 05:30 PM   #16
K-amps is offline K-amps  United States
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Compared to the 15024/25, Better match would have been 21193/4/5/6, or even 15003/4.

I never liked the highs and mids on the 15024/25 but they had killer bass...
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Old 29th August 2007, 05:52 PM   #17
AndrewT is offline AndrewT  Scotland
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Hi,
any one else want those half megabit pics removed?
They really slow down the page load on my broadband 500kb limited line.
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Old 3rd September 2007, 10:26 AM   #18
Jozua is offline Jozua  South Africa
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Default Caps

Fepablo

I have recently replaced my Krell 100 watter main Sprague caps and the improvement was very impressive. Faster and tighter bass. I got mine from Mouser.

I suggest that you do the same as that amp is about 10 years old and the caps have most likely deteriorated in time.

Regards

Jozua
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Old 4th September 2007, 05:32 AM   #19
djk is offline djk
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"MJ15015 is a direct replace of MJ3281"

Totally wrong, just look at the data sheets.
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Old 25th May 2010, 05:33 AM   #20
fepablo is offline fepablo  Argentina
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Hi Friends, finally, 2 years after, i buy the original transistor at Krell.

Thanks Federico.
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