zero impedance

[jtwrace]

Has anyone used these?

http://www.zeroimpedance.com/index.html

I'm really thinking of trying them with my big Class A amps but then I could easily (in theory) use them with a really nice "underpowered" tube amp. Say 125w.

Thoughts?

 

[C.A.P]

They are popular with the Maggie crowed. As well as his speaker wire that is supposed to be good.

 

[tonepub]

More snake oil...

These transformers probably cost him about 35 bucks each. I'll do a little digging and find out.

Something like this might make sense on an OTL designed amp (which almost no one makes anymore)
because of the damping factor and impedance mismatch issues. But that's why almost all tube amps have output transformers in the first place.

A well designed solid state amplifier shouldn't need anything like this and on one level it is somewhat similar to what McIntosh uses in their SS designs. THey are pretty much the only ones doing this.

 

[jtwrace]

I'll do a little digging and find out.

I will be curious to hear what you find out...Ralph from atma sphere supposedly really likes these.

 

[tonepub]

Im sure he does, as it opens up the amp to more people, but the beauty of that amplifier is that it was designed to be tranformerless...

Putting a transformer on another speaker so it is compatible is a definite work around, but it robs the amp of the last bit of delicacy that it is capable of. When you go OTL, the best bet is to find the right pair of speakers.

Trust me, those amps with the right speaker (no XFMR) is really a slice of heaven!

 

[MiTT]

Im sure he does, as it opens up the amp to more people, but the beauty of that amplifier is that it was designed to be tranformerless...

Putting a transformer on another speaker so it is compatible is a definite work around, but it robs the amp of the last bit of delicacy that it is capable of. When you go OTL, the best bet is to find the right pair of speakers.

Trust me, those amps with the right speaker (no XFMR) is really a slice of heaven!

Best example I have heard is the latest version of the Merlins paired with Joule Electra. That is a slice of audio heaven indeed.

 

[Dan Osib]

I disagree. I use the Zero Autoformers with my Martin Logan CLS IIz and the sound just blows me away every time I listen. Don't take my word for it but Hi-Fi Choice magazine in the UK was also impressed by them. CASE CLOSED

 

[risabet]

CASE CLOSED

When is a case ever closed in audioland:ROFL:

 

[tonepub]

I disagree. I use the Zero Autoformers with my Martin Logan CLS IIz and the sound just blows me away every time I listen. Don't take my word for it but Hi-Fi Choice magazine in the UK was also impressed by them. CASE CLOSED

Good to know that you are the ultimate authority on everything....

What amp are you using?

 

[twich54]

Best example I have heard is the latest version of the Merlins paired with Joule Electra. That is a slice of audio heaven indeed.

Ditto with Tim, one of my favorite rooms @ RMAF this past year.

 

[Gordon]

A well designed solid state amplifier shouldn't need anything like this and on one level it is somewhat similar to what McIntosh uses in their SS designs. THey are pretty much the only ones doing this.

Jeff, why do you think this is? Could it be corporate mind set or making the amps more "flexible" and usable on more speakers?

Gordon

 

[tonepub]

Ron Cornelius at McIntosh can give you more of an overview of why Mc does the output transformers on their solid state amps.

I don't think it makes them more compatible though, as they have 2, 4 and 8 ohm taps. Most of the better high power solid state amps will play with a 2 ohm load anyway.

If I recall Ron's explanation, it gives the output transistors in their configuration more of a steady load, because driving the transformer primary is easier than driving a speaker. They've also said that the transformer provides more protection to the speakers should something bad ever happen.

A lot of older high powered Mc amps were used for sound reinforcement as well as in commercial applications, so I can see where this would be a plus.

However to get the straight story, you'll need to ask Ron.

Other amplifiers are not designed with an output transformer in mind though. I've tried these and all they've ever seemed to do is muddy up the sound and slow the pace considerably. Sure, you can use your favorite 30 watt tube amp to drive your magnepans, but they still won't play loud and it's a band aid at best.

I know the people who love these things are crazy about them, but I'd rather just get a high current amplifier that can drive stats or magnepans in the first place and not have to add an output transformer to the system.

 

[Dan Osib]

tonepub,
I'm using Odyssey Stratos Monoblock SE power amps

 

[Dreamer]

Dan,

I'm surprised that the Autoformers really make that much difference with your Odyssey monoblocks driving your CLS's. The Odyssey amps are pretty gutsy, and can handle just about any load you throw at them with authority and grace. Those Odyssey's are beasts, plain and simple.

I'm not doubting your ears, I'm just surprised that your rig would "need" the sort of tweek that the Autoformers represent. If you were driving your CLS's with amps that weren't really designed to drive tough loads, then it would make more sense, but those Odyssey monoblocks put out enough current to drive just about any speaker out there...

--Richard

 

[Dan Osib]

Well they sound great to my ears. My monoblocks pump out 180 WATTS per channel into 8 ohms. You've got to remember that CLS IIz's still present a difficult load to the Odysseys. Without the Zero Autoformers you should be using a minimum of 250 Watts per channel with CLS's. My Odysseys fall a bit short of that figure.

 

[MiTT]

Well they sound great to my ears. My monoblocks pump out 180 WATTS per channel into 8 ohms. You've got to remember that CLS IIz's still present a difficult load to the Odysseys. Without the Zero Autoformers you should be using a minimum of 250 Watts per channel with CLS's. My Odysseys fall a bit short of that figure.

Huh? My owners manual says that the recommended amplifier power is "80-200 watts". Where are you getting that "minimum of 250 Watts per channel" figure from?

I don't need to worry about it, my amps are pumping out plenty more than that, especially at the lower impedences that the speaker is usually presenting. I've heard CLS's driven by 100 watt tube amps that sounded absolutely amazing though.

 

[Dan Osib]

Pedro from Absolute Sounds (Martin Logan UK distributor) told me that you need 250 watts minimum if you you want to hear the CLS IIz at their best

 

[DTB300]

Hi Dan...Long time no see you on the site.

Numbers do not equate to sound quality IMO. As we are all aware of here, it is all about good power, not quantity or numbers. But if you want some higher dB levels, then that 5 Watt SET amp just may not do it for someone....

 

[twich54]

Pedro from Absolute Sounds (Martin Logan UK distributor) told me that you need 250 watts minimum if you you want to hear the CLS IIz at their best

you know what.... that might just be the biggest bunch of 'bull' I've heard this week, and I've had alot of customers and vendors trying to shove it down my throat this week ! LOL !

Seriously, if Pedro made that statement he either dosent know good amplification capabilities or he's got an inner ear infection !

 

[Retro]

When i bought my pair of CLS
i had not chosen which SS high current amp i would buy to match there needs, i was forced to use my Dynaco Stereo 35..., to be hournest the ST35 did to my surprize actully perform a lot better better than i ever expected.
(valve amp rated 2x17.5W/8Ohm)..., it made the "great picture"

I believe the ZI transformers when used with an high current ss amp just will do the same by adding a slight curtain making the sound more relaxed ...., less detail, will turn the focus to the great picture of the music
Just my pov.