symphonic line kraft and for a taste of greatness at budget amp pricing: odyssey audio amps. though klaus has been taking them a bit of a different direction than their symphonic line big brothers, he is very upfront about his amps being quality but the SL being _that_ much better
Amps stable down to 1ohm or below...
- Thread starter Mike
- Start date
W9TR
Active member
Any of the McIntosh autoformer amps will be stable into really low impedance complex loads. It's not just less than 1 ohm, its also the fact that some of these speakers present highly reactive loads. Electrostats are almost entirely capacitive at high frequencies.
I would really like to see what a 1 kHz or 10 kHz squarewave looks like when any of these amplifiers drive a capacitive load < 1 ohm. That will separate the posers from the real deal.
Tom
I would really like to see what a 1 kHz or 10 kHz squarewave looks like when any of these amplifiers drive a capacitive load < 1 ohm. That will separate the posers from the real deal.
Tom
- Thread Author
- #23
I’m not sure the Mc amps are stable down to 1ohm. 2ohm, yes.
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W9TR
Active member
On the 2 ohm tap modern McIntosh amps are stable to way less than 1 ohm. The autoformers help isolate difficult loads and present a reasonable load line to the amplifier circuitry.
When I was looking at electrostats, I tested my MC 602 into a 0.5 ohm resistive load and also a 10 uF film cap with 10 kHz square waves at 100 Watts. No overshoot or ringing on the 0.5 ohm load and some minor ringing into the 10 uF cap. Superb stability.
Tom
When I was looking at electrostats, I tested my MC 602 into a 0.5 ohm resistive load and also a 10 uF film cap with 10 kHz square waves at 100 Watts. No overshoot or ringing on the 0.5 ohm load and some minor ringing into the 10 uF cap. Superb stability.
Tom
knghifi
Member
Audio Flight #4 and #8? Myles Astor reviewed #4 several years ago.
In market for SS amp so visiting local Audia Flight dealer next week. Should be fun!
In market for SS amp so visiting local Audia Flight dealer next week. Should be fun!
atmasphere
Active member
Obviously this is some kind of marketing. The math doesn't work out, unless this amp is more powerful than advertised. If it really can support 35amps then it can make 2450 watts into 2 ohms but we see from the above specs it does not. So I suspect the 35 amp figure is really what happens for 10mS when the power supply is shorted and does not represent the actual current present in the output section. math: Power=current(squared) x resistance. so 2450 = 35(squared) x 2. By that measure we make an OTL that does 50 amps...
And of course it will limit current when its abilities are exceeded. It also has a minimum impedance, else the short protection for the amplifier would not function.
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There is the question of what is meant by 'stability'. Normally that means the amp won't oscillate. So I don't think the term 'stable' is being used correctly in this thread. Further, the speaker in question has a 1 ohm impedance above 15KHz being an electrostatic. Its impedance will be higher at frequencies less than 15KHz. Because there is so little energy at this frequency, far more amplifiers will work with this speaker than are listed in this thread- including many tube amps that don't have taps below 4 ohms!
Many of the better-built Japanese receivers made in the late 1970s will work fine (IOW no oscillation) on this speaker. Seriously the power that the amp makes is likely the bigger issue- how much power does the amp need to fill the room? That is less clear but IIRC Sanders made some pretty big amps. Any 100 solid state amp made today will otherwise work fine. The ability to double power as impedance is cut in half is not required here either- again, the energy at 15KHz and above is slight. In addition, there is the question of whether that is a desirable trait, since ESLs generally speaking have an impedance curve based on a capacitor rather than a speaker in a box. On that account, the impedance curve of an ESL is not also a map of its efficiency like it is with most box speakers. Many ESLs work better if the amp can make the same power in to 4 ohms as it does into 8; otherwise what can happen is the amp will be too bright on top!
Colekat
New member
Emm MTRX mono blocks ... stable under 1ohm and sound great !
johndoe21ro
New member
Balanced Audio Technology should do the trick! At least the big solid state amps...
Audioseduction
Active member
YES! Pass Labs does belong in the group. Top 3 I say from many years of listening and owning both Pass Labs and Martin Logans for years. My XA160.5 never runs out of steam no matter how loud I play them!
- Thread Author
- #30
Pass amps are awesome, but I’ve talked to them and they are stable down to the rated wattage (4 ohms).
Audioseduction
Active member
Never experience any issues at all over the years. In fact many Martin Logan owners own Pass Labs amps to accommodate their Speakers.
audio.bill
Active member
Martin Logans only exhibit an impedance of 1 ohm over a relatively narrow bandwidth, so they don't present an overall load anywhere near that low to the power amp. Their nominal impedance rating is more realistic in evaluating the load they present to an amp instead of just focusing on the lowest point of their impedance curve.
atmasphere
Active member
Heck, most tube amps of 100 watts or more can do the job assisted by a set of ZEROs (www.zeroimpedance.com). That's what we suggest when someone wants to use our amps on Martin Logans.
a.wayne
Well-known member
Takes alot of heatsink to handle 1 ohm loads , you can drop the small heatsink ones to begin with, Gryphon for sure can ....
a.wayne
Well-known member
a.wayne
Well-known member
a.wayne
Well-known member
Sanders magtech amplifiers are way too small to have a "fully" regulated PSU ......
a.wayne
Well-known member
Manny Huber amps are not 1 ohm rated TMK ....
a.wayne
Well-known member
Again both way too small for a 1 ohm load ...........
a.wayne
Well-known member
Agree,
Mcintosh been making amps to drive 1 ohm load from the 60's , fan cooling was a necessity too ...