What do OTL and transformer-coupled mean?

[slwiser]

Quote:

Originally Posted by jcx /img/forum/go_quote.gif the Berning patent describes a switching converter between the tube output and the load - switching power supplies are regarded with suspicion in the audiophile world (some are OK if designed for low noise and plenty of filtering) I would be a lot more careful when the suggestion is to chop the analog signal at Hundreds of KHz and stick it in your ear right after the rectifier

This sounds like the age old fear of the switching power supplies and not the newer higher end designs that are now available.

The micro-ZOTL works and works very well. But I think very few really understand what Berning has done here and people tend to fear what they don't understand. This may be one reason no one has taken his patient and used it in a DIY situation. Those impedance mathcing devices are hand built and highly specialized. The micro-ZOTL probably works best with speakers. His amps have extremely high damping factors equivalents due to the impedance matching circuitry. Berning company is planning on coming out this next year with a new unit that will replaces the now out of production micro-ZOTL, a pre-amp from what they say. Should be really interesting but the price will surely be out of my range.

 

[sacd lover]

Quote:

Originally Posted by slwiser /img/forum/go_quote.gif This sounds like the age old fear of the switching power supplies and not the newer higher end designs that are now available.

What newer high end designs? Switching power supplies are noisy period.

 

[slwiser]

Quote:

Originally Posted by sacd lover /img/forum/go_quote.gif What newer high end designs? Switching power supplies are noisy period.

Fables are always hard to get rid of...especially when they were founded in fact at one time.

 

[Hellenback]

Quote:

Originally Posted by Skylab /img/forum/go_quote.gif One of the coolest things about the ASL OTL MG-Head III I have is you can switch between OTL and transformer mode on the fly.

Do you find there is much of a variation in sound between the two modes of operation this amp offers.

 

[Skylab]

There is a difference, but it's not as great as you might expect. No doubt though, OTL mode is more romantic sounding - it's the "tubier" sound for sure.

 

[wower]

I think transparency is defining characteristic of OTL designs but I don't see carefully built transformer-coupled designs as a step back. I'm delighted with my yammy's hand-wound in-house built transformer. I had to check this thread. thought ASR would be all over such differences.

 

[slwiser]

Quote:

Originally Posted by wower /img/forum/go_quote.gif I think transparency is defining characteristic of OTL designs but I don't see carefully built transformer-coupled designs as a step back. I'm delighted with my yammy's hand-wound in-house built transformer. I had to check this thread. thought ASR would be all over such differences.

I agree completely about the Yamamoto HA-02 being very nice transformer coupled even thought, years ago, when we started with transformers and before low noise ones they were always noisy.

Some transformers are still have to much noise today but generally they are not used in high end audio.

 

[sacd lover]

Quote:

Originally Posted by slwiser /img/forum/go_quote.gif Fables are always hard to get rid of...especially when they were founded in fact at one time.

Fable? Switching power supplies do generate high frequency noise. If that is not the case, what are some examples of high end switching designs that do not generate noise?

 

[wower]

Quote:

Originally Posted by slwiser /img/forum/go_quote.gif even thought, years ago, when we started with transformers and before low noise ones they were always noisy. .

I.did.not.know.that.

That is my tip of the day. I will impress all my friends tomorrow when I bring out that fact. ;p

 

[Podster]

Sky calls it more Romantic sounding and it is and really gives a smooth output with long slow decay which I relate to Romantic also:-0

Need to put Romancing the tube in my sig

 

[slwiser]

Quote:

Originally Posted by sacd lover /img/forum/go_quote.gif Fable? Switching power supplies do generate high frequency noise. If that is not the case, what are some examples of high end switching designs that do not generate noise?

For a start would you consider either the Lavry DA10 or Apogee miniDAC for both have these switching power supplies. We will go up from here.

 

[recstar24]

Quote:

Originally Posted by wower /img/forum/go_quote.gif I think transparency is defining characteristic of OTL designs but I don't see carefully built transformer-coupled designs as a step back. I'm delighted with my yammy's hand-wound in-house built transformer. I had to check this thread. thought ASR would be all over such differences.

This is kind of where I stand on the issue of OTL vs. transformer coupled, based on my experience between the two. When I compared the moth 2a3 with electraprint output trannies to the Eddie Current Zana Deux (both built by Craig Uthus), I perceived the Zana Deux to be more neutral and transparent to the source signal, bringing me just a tad bit closer to the music itself. However for some reason I still preferred the sound from the moth, as the sound had a musicality and cohesiveness that is somewhat difficult to put into words. The classic debate between "accuracy" vs. "musicality." Those terms are not mutually exclusive of course, and really amps fall somewhere on a long continuom between the two terms. Great amps are both very accurate and neutral/transparent, with great musicality, but in my experience, the OTL amps lean more towards the neutral side of the spectrum, whereas the transformer coupled amps lean towards the musical side.

 

[fierce_freak]

I'd love to see debate on OTL vs. transformer coupled output. I'm about to dive into a tube design and am not decided on output method yet (may even incorporate 'fets).

 

[wower]

I think my next amp will be a OTL because if one goes the route of OTL for speakers, I find the units just so temperment. Either they are super low wattage or if they have normal wattage they have so many tubes its like having an extra fireplace in you listening area. It's a rather simple process for headphone amps, such as the W003, but I'd probably go with a SP. I don't think we need a debate, people are going to choose whatever they want, but it's nice to have the info and impressions.

 

[fierce_freak]

Yeah, info and impressions are what I'm after.