2. amps-preamps
  3. 1171701564

Kharma Matrix MP 150 issues???

May anyone know the issues?
I'm having a small issue with my kharma system and wondering if you can help? I will try to expain the best i can due to my poor english. First, when i turn the system on and play for 10-15 mins. I hear a LOUD POP sound out of my right channel speaker. Than, i know right away my right Matrix 150 right side amp LED light turned off. I ran over there quick and turn the power off first. Than, i check the fuse box and the fuse was ok. This don't happen too offen, but now i am very worry it might pop again when turn back on. So, it did pop again after i turned back on for 5mins.

I am guessing it could be a cable connection was shorted? Just guessing? My friend is saying it could be a DC problem? which i don't really know what that means? or, it could be a simple issue that i don't even know how to fix? So, i decide to email for help. Will you kindly and help me resolve my issue? I'll be very happy to provide more detail if needed.

I hope i'm lucky and get it fix soon. I will be patience and wait for your respond. Many thanks to the person reading this.

My setup:
Kharma CRM 3.2 speaker
Kharma 1.0 subwoofer
Kharma Matrix Mp-150 Class D mono amp
Conrad johnson ART dual mono preamp. Just re-tubed nos with Telefunken
Conrad johnson premier phono amp
Marantz SA-11 cdp
Oracle Mk V turntable
Nordost Heimdall compete cables including speaker
Cryo audio technolgy compete power cord
jimbox
clark_h's avatar
clark_h
1 posts
 
Hello from Canada. The Kharma Matrix MP 150 amps have a switchable DC buffer that is installed but not switched on. The amp sounds better with it switched off but some tube preamps will leak DC and stress the amp. If You fix the CJ preamp and the problem still occurs try turning on the DC buffer. I have the Nola Viper Reference speakers and am considering buying the Kharma amps to tighten up the bottom end a little. My Bel Canto EVO2i needs better grip. Looking for a good CD Player? Try the Meridian 808
or if Your CJ pre is dead then kill two birds with one stone and consider the Aurum CD/Preamp. All the best, Clark.
jimbox OP
5 posts
 
Hi Clark_h,
If you say there is a switchable DC buffer inside. How come Bill at GTT Group said; He can ad $50 service fee + shipping to engage the dc protection circuit in my amp?? Is there something i should know, but didn't know of? I call Cj and left them a message today. I hope i will hear from them soon. I wonder what the problem is on my ART? The lower chassis right channel tubes does not light up? I check the tubes with my tester. They work fine. I just hope is just is not a big problem or i can just go and hang myself. J/K

Thanks for the input. BTW, where is the switch located? Inside? I will look in to the 808 CDP. I want to thank you for letting me know something that i should have know of. I apprecitated! Jim
jimbox OP
5 posts
 
Thanks everyone for your support! The issue has been resolve. Their was a DC leaking out from the kharma class D monoblock. I am so lucky nothing serious as damge my gears. Thank god!! In a review by: POSITIVE FEEDBACK ONLINE - ISSUE 25, reviewed by Marshall Nack; The MP150 is a purist design with minimal parts in the signal path. (Which was a surprise. Not so sure why, maybe it's because their appearance is so unassuming.) Like other purist designs, the MP150 eschews the usual DC protection. Most amps have a capacitor buffer stage up front to cancel any stray DC from the preamp. Especially when there are tubes upstream, there's the potential for DC leakage. If your pre-amp causes the MP150s to cycle on and off repeatedly, two minutes on your dealer's workbench is all it takes to engage the protection. The amps are shipped with the buffer stage in place but disengaged, because Kharma feels the extra capacitors degrade the signal. My class D now has a DC filter switched on. Everything should be fine now. In the long run, i might consider getting a soild state pre amp to go with my Class D. I really think the Class D matchs the best with my 3.2 speakers. I would give up my ART for the kharma class D and the 3.2. I hope i wont regret selling my Cj ART pre-amp later.
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