2 OHM LOAD WITH M-85
- Thread starter ASIMO7
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Don't do it until I can come and watch. After you destroy your amp we can plug the speakers into the power outlet.
stereofanboy
Addicted Member
I think I remember hearing that the MX-1000 was the same internally as the M-85. I also remember deciding that it wouldn't be safe using the MX-1000 for Kappa Nines. I think that was based on the published specs.
I may be misremembering or the information I had back then may have been incorrect.
I may be misremembering or the information I had back then may have been incorrect.
ASIMO7
Active Member
Yea, I agree it’s probably not the best idea. Mostly because they are almost 40 years old and have not been refreshed yet. They already have a knack for cooking transistors.
It does say in Yamaha’s marketing material that they can handle a 2 ohm load. They even have a meter output selector for 2 ohms. They don’t mention anything about using two amplifiers, though. So it’s not real clear.
Thanks for the response, stereofanboy!
The last guy I bought my MX-1000 was running Kappa 8's and had some clipping issues. That said, I have no Idea how hard he was pushing the amp?
Here's the part where I admit that I'm not trying to act like I know something here. I do know the Kappa 8 and 9's have been nicknamed the amp killers. I have read many times they can get lower than 2ohms thus ... the nickname. But always wondered if one bi-amped them vertically if that would work reduce the stress on the amp?
In any case, the 2 ohm Selector switch just calibrates the meters to more accurately display the proper meter readings for that load. Forgive me if you already knew that.
Garry~
ASIMO7
Active Member
I imagine it would depend on the demand you put on the amp. I’m definitely not looking to abuse them. My main concern would be if there was going to be a high current draw even at lower volumes creating constant high levels of heat. We all know that’s bad.
Yea, I was just pointing out the meter selector as an acknowledgment they can run at 2 ohms
Thank you for the response spiceman!
I have read the MX series amps can get hot. I have 2 MX-1000s and neither get hot. The guy I bought one of them from as I said, used it to drive his Kappa 8's. He sold the 8's and bought some B&W's, then built 4 large subwoofers. Suggesting to me that he loved the Bass and likely pushed it as much as he could without clipping. When I recapped the amp, I seen no evidence of excessive heat on the circuit boards.
None of what I said answers your question though. Still, the 85 is a powerful amp and will run 2ohm. It's the 1 and sometimes 1/2 Ohm that the Kappas can get to that really heats up those amps. From the reading I have done on the issues of course.
Garry~
None of what I said answers your question though. Still, the 85 is a powerful amp and will run 2ohm. It's the 1 and sometimes 1/2 Ohm that the Kappas can get to that really heats up those amps. From the reading I have done on the issues of course.
Garry~
ASIMO7
Active Member
I’d imagine the heat only gets up there if you’re really getting the volume up there. As with any amp, really. I feel if I’m listening at reasonable to loud volumes, they’d be ok. The more I think about though, the more I’m thinking it’s not worth it. It would be ok if I had 8 ohm speakers and would be driving 4 ohms. It’s also not necessary, the 85 powers my speakers and then some. Just wanted max headroom, and it’s just cool to have two
Thanks, Garry!
, and it’s just cool to have two
My B-6's are not reccomended for anything below 8 Ω .
... I'm running NS-1000M's in " bridged mode " . So the amplifiers have a 4Ω load. Been running it like that for years..
Try it.. If it runs to hot -- discountinue operation. Not rocket science
ASIMO7
Active Member
Could smoke one before I realize it’s too hotMy B-6's are not reccomended for anything below 8 Ω .
That’s what I want to avoid. Is there any added strain running two as monoblocks vs a single amp? Outside of the lower resistance?
Has either one been refurbished ?Could smoke one before I realize it’s too hot
Thats the gorilla in the room..
ASIMO7
Active Member
Yup. That’s exactly where I’m landing. I think box fresh M-85’s in 1986 would be just fine but this is 2022. I think that settles it. No need to press my luck. It would’ve just just been fun and cool.
ASIMO7
Active Member
Nope. Not yet.
ASIMO7
Active Member
The one I’m currently using is free of the excess glue and I haven’t opened up the second one yet. I will before I fire it up.
The MX1K will comfortably drive the kappa9s ask @MiamiBoy
I imagine it would depend on the demand you put on the amp. I’m definitely not looking to abuse them. My main concern would be if there was going to be a high current draw even at lower volumes creating constant high levels of heat. We all know that’s bad.
Yea, I was just pointing out the meter selector as an acknowledgment they can run at 2 ohms
Thank you for the response spiceman!
I will second Avionic: if not recently refurbished, don’t push your luck.
Your biggest problem with the m-85 is not if the circuit design or the electronics could handle the 2R loads, but how much would the corrosive glue and cold solder joints, affect performance.
Yep, absolutely agree with both Avionic and rottalpha. Both those guys have taught me way more then they realize. My experience is after recapping my MX-1000's then using both to bi-amp my speakers, differs in that my ADS L1530's are more efficient then the Kappas, and as such are way less demanding. However, there have been some that thought I lost my mind using a 260w amp on two 15w tweeters and 25w Midranges. Bless those level knobs on our amps ... A SIMO7. Truth is, its not permanent. At some point I will replace one of the Amps with a tube amp to control the Tweeters/Mids. In the mean time, I use discretion and am responsible about my volumes.
Wife has two names for me which help keep me in check. She'll call me Pookie when she's closing the door "Pookie, I'm gonna close the door". She calls me Jesus when she opens it "Jesus! ... does it have to be that loud!" Talk about the head room .... the difference between Pookie at 8:00 position and Jesus is when the volume knob is at 8:30.
You can see the amps at 1:44 I was close to 80spl (I don't claim my phone app is accurate) with control amp at 8:30. Most of this has changed. I've been remodeling the room. Still have much to do to finish. Top amp tweeters/Mids Bottom, Woofers.
Garry~
Wife has two names for me which help keep me in check. She'll call me Pookie when she's closing the door "Pookie, I'm gonna close the door". She calls me Jesus when she opens it "Jesus! ... does it have to be that loud!" Talk about the head room .... the difference between Pookie at 8:00 position and Jesus is when the volume knob is at 8:30.
You can see the amps at 1:44 I was close to 80spl (I don't claim my phone app is accurate) with control amp at 8:30. Most of this has changed. I've been remodeling the room. Still have much to do to finish. Top amp tweeters/Mids Bottom, Woofers.
Garry~
