Anyone else experiencing problems with High current amps i.e. Bryston 7bs and or Levinsons, with speaker drop-out with certain material, stevie ray vaughn especially. It is easiely reproducible regardless of amp on vantages and prodigys...Otherwise works fine but same passges each time. Also changed the source to try to eliminate the problem. Anyone think there is an internal thermo-regulator that kicks in? Any suggestions...
ML speakers and High Current Amps
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Steve, for starters....welcome !
I'll plead ignorant (comes natural to me), I'm not sure what your getting at ???
Are you saying that the amps in question are having difficulty with certian freq and volume levels ?? instability issues ??
There's no such thing as having a 'too stable / too much current amp' for our Logans so I'm sure that I'm missreading your post.
I'll plead ignorant (comes natural to me), I'm not sure what your getting at ???
Are you saying that the amps in question are having difficulty with certian freq and volume levels ?? instability issues ??
There's no such thing as having a 'too stable / too much current amp' for our Logans so I'm sure that I'm missreading your post.
sounds like not enough amp gain
tonepub
Senior Member
Do you mean the amp is shutting off?
Are you playing at extremely loud volumes and is the amp pretty hot before this happens?
Also, just a silly question, but are the spade lugs to your speakers really close together on the binding posts? I remember once when playing an amp at full volume, it actually arced across the binding posts because the gap was pretty tight.....
Are you playing at extremely loud volumes and is the amp pretty hot before this happens?
Also, just a silly question, but are the spade lugs to your speakers really close together on the binding posts? I remember once when playing an amp at full volume, it actually arced across the binding posts because the gap was pretty tight.....
Welcome to the group, where answers to all of life’s big questions can be found. Unfortunately, the answer to your question is not in this post.
I’m with twich, not sure what is actually happening. You mention that the problem is more noticeable with certain artists and even passage specific.
I was auditioning equipment one time with an Anthem amp and one channel shut down due to overheating. It worked fine after allowing it to cool down. Playing the same music again did not induce drop-out.
Since you used two different amps, and two different speakers, and a different source, what's left? Can it be in the cables or preamp? What happens after drop-out to get the system working again?
Maybe the amp cannot handle those lightning SRV riffs. If that’s the case, stay away from John McLaughlin or Dream Theater.:guitar:
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Sorry about not being clear but on certain passages, i.e lots of bass,especially, SRV, the speakers (both simultaneously) cut off(for a second). Especially the track Crossfire. I have changed amps, i.e Bryston 500W 7Bs and Levinson 23s with same problem. I have eliminated any front end problem by feeding the CD/Dac into the amp directly and problem still persists. It happens even if the speakers and or amps are cold. The problem does not happen with my reference revels, only with the MLs... It is reproducible every time...
Gordon Gray
Well-known member
The Revels likely present a more consistent load and therefore, easier for your amps to drive the speaker.
With the ML's, you are probably overdriving the amp causing the protection circuitry to engage. Hence, the dropout.
Pretty simple assuming nothing else is going on.
GG
With the ML's, you are probably overdriving the amp causing the protection circuitry to engage. Hence, the dropout.
Pretty simple assuming nothing else is going on.
GG
Im thinking that the amp is running out of steam at LOUD volumes. That is where they really drop down to low impedance at 15khz and up. The Prodigies take and eat power like Nell carter at a buffet !
Does ML have a over limit protection in them? Maybe it could be that too???????
These speakers need A LOT of current and a amp that likes 1ohm. Especially the big ones to play loud. I hear the Prodigies a lot and the big Krell running them takes control of them like Hulk Hogan with Rocky !
I also think the Logan's in general fall away a bit at real high Volume. Maybe its not the amp but the ESL sound , Cones will always scream louder at high Decibel listening. I never heard of a Bryston running out of steam, Levinson may sound thin but its should not fall off. How Loud are you listening over 90DB ?
Does ML have a over limit protection in them? Maybe it could be that too???????
These speakers need A LOT of current and a amp that likes 1ohm. Especially the big ones to play loud. I hear the Prodigies a lot and the big Krell running them takes control of them like Hulk Hogan with Rocky !
I also think the Logan's in general fall away a bit at real high Volume. Maybe its not the amp but the ESL sound , Cones will always scream louder at high Decibel listening. I never heard of a Bryston running out of steam, Levinson may sound thin but its should not fall off. How Loud are you listening over 90DB ?
Kenscollick
Well-known member
I doubt the Prodigys have a over limit protection. Otherwise I would have tripped it many times. The prodigys that CAP refers to are mine driven masterfully by a Krell 400cx During one of our get togethers I stuck a meat termometer in the heat sinks and not really driving it too hard the temperture was 170 degrees. My prodigys have never kicked out during any playing of music, I believe that any problems would lie with the amps or the source.
My system:http://www.martinloganowners.com/~tdacquis/forum/showthread.php?t=169
I have made a couple changes and have not updated as of yet The Wadia is now a 581 with the GN Statement mod.
My system:http://www.martinloganowners.com/~tdacquis/forum/showthread.php?t=169
I have made a couple changes and have not updated as of yet The Wadia is now a 581 with the GN Statement mod.
Happens with the same material, with two different amps, and two very different speakers (Vantage has an internal amp for bass, Prodigy doesn't). Sounds like a problem with the source or preamp to me. Either that, or both of these amps have difficulty with capacitative loads (which is certainly possible, I suppose). You still haven't told us how loud you are playing the system when this happens. I have never heard of this particular kind of issue before with Martin Logan speakers. You might try emailing Jim Power at Martin Logan tech support and see what he has to say.
So the concenus is that there is some lind of protection circuit that kicks in.. Again I am not playing at high volumes. To be clear I am using one levinson (matched)/speaker and one Bryston/speaker and both Madrigal and Bryston technical guys that I know a long time are implicating the MLs...
OK , What do you use for a DAC/ CD player ? What kind of Preamp do you use? You mentioned that you ran the CD player directly to the amp. That would not be a tube Cary would it? There are very few CD players that have the ability to hook directly to an amp. 95% of them are SS designs. Wadia, Krell, are the big players who did that well. I know some tubes do not mate well with solid state amps at weird impedance. Some will shut down some will clip. Lets here what you have then we can start from scratch !
tonepub
Senior Member
It seems somewhat odd, as both Levinson and Bryston are good amps, well built with big power supplies, etc. It just seems odd that they would be cutting out, especially at moderate volumes.
patlad
Well-known member
Sounds like the impedance of the speakers drops very low and the amps cannot deliver the demanding current.
From the Bryston web site (http://bryston.com/BrystonSite05/BrystonDocs.html) 7B SST specs/brochure, "the 7B SST is also available in a special version for very low impedance loads, i.e., 2 Ohms and below".
Do you get this particular model of the 7B?
As for the Levinson I couldn't find any specific info regarding how it handles very low impedance.
Maybe somebody else could try to play the same track on his system to double check? I think I'll give it a try but I need to find the reference of the CD.
From the Bryston web site (http://bryston.com/BrystonSite05/BrystonDocs.html) 7B SST specs/brochure, "the 7B SST is also available in a special version for very low impedance loads, i.e., 2 Ohms and below".
Do you get this particular model of the 7B?
As for the Levinson I couldn't find any specific info regarding how it handles very low impedance.
Maybe somebody else could try to play the same track on his system to double check? I think I'll give it a try but I need to find the reference of the CD.
Steve -- my brother has a 4bsst w/ascents - never a problem ....ever..... You don't by any chance have your amps plugged into any type of power conditioner/power strip/protector etc..... Maybe I missed that. I agree with TonePub.... these are good amps and the Brystons can deliver the juice.... the thing is - I don't think it CAN be the speaker.... for something to drop out, I would think it would come farther up the chain.
So, I am guessing you have the levinsons on the panels and the bryston on the woofers???
Can you just have the Bryston power the panels/woofers - and see if you get the issue?
But first - what about the power conditioner question... I would suspect that is a lot of juice you are pulling from the wall with both levinsons and the bryston....
or -
Guys - could it have anything to do with the comination of amps he is using
I'm not sure there is any consensus at this point. Please explain in more detail what you mean by "I am using one levinson (matched)/speaker and one Bryston/speaker." Are you bi-amping the speakers with one amp powering the highs and one amp powering the lows? Or do you mean that each time you used a different amp, and that amp was powering the highs and lows of both speakers?
Please explain the details of the entire setup you are using each time this happens. You are providing very limited information in a piecemeal fashion by which we can help to diagnose the problem. In order to help you figure it out, we need to know exactly the details of your complete setup each time this has happened.
You say you have talked to tech support guys at Madrigal and Bryston, so why haven't you talked to the tech support guys at Martin Logan?
Since this problem has never been reported on this site before (with literally thousands of Martin Logan users) I hardly think it is the speakers that are causing the problem. If it was just one pair of speakers, maybe. But you state it has happened with both Prodigies and Vantages, when it has never happened to anyone else on the site. Which means it is either an amp, preamp, source problem, or an issue with the electricity in your house (hence the question about power conditioners) or a problem with the way you have everything connected.
You do understand that you are not supposed to bi-amp the vantages, right? If the problem is happening with one amp running the speakers, have you tried bi-amping the prodigies using both amps to see if that makes a difference? Have you tried switching out the source player to see if that makes a difference? Have you eliminated the possibility that it is an issue with the CD itself?
Sounds to me like possibly an issue with the ability of the amps to handle Martin Logan's capacitative loads, but it could also be a power issue if you are using a power conditioner. But honestly, I have driven my ascents with a cheap yamaha receiver and never had a problem like this. I imagine either one of your amps could handle the ML loads better than that receiver. So something else is going on.
shoafb
Active member
I use a Proceed HPA2 250watts dual mono ( cheap levinson :rocker: ) and back when I had it in a rack I drove it to thermal shutdown once. It took about 20 minutes for it to cool down and reset.
Since then it has been on an amp stand and I have had no problems listening at pretty high volumes, say 12 to 1:30 on the volume of a Audio Research refII.
Speakers are Ascent.
Since then it has been on an amp stand and I have had no problems listening at pretty high volumes, say 12 to 1:30 on the volume of a Audio Research refII.
Speakers are Ascent.
Place it in a smaller room, close the doors and windows. Half your sound and sound levels are reflected energy.
I'm wondering if the problem will occur if you power only the woofer of the Prodigy (shotgun into the woofer and remove the jumpers). Perhaps the energy needed by the woofer is draining the power needed by the panel. After all, i thought that you stated that it occurs during heavy bass passages. If it is due to the high current as demanded by the panel, powering only the bottom will eliminate this need. In theory, the system should not shut down. If it doesn't, you have shown that it is due to the requirements of the panel. If it does, it may be related to the woofer, perhaps a protection function within the prodigy's amp.
I freely admit that i am nowhere as knowledgeable or experienced as other people commenting. The above suggestion may have floors, but is just a thought that i wanted to share.
This is a very unique situation and i am very curious as to the reason.
I freely admit that i am nowhere as knowledgeable or experienced as other people commenting. The above suggestion may have floors, but is just a thought that i wanted to share.
This is a very unique situation and i am very curious as to the reason.
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