[tfarney]

I have to admit that this really appeals to me. I'm looking for a source that just changes the bits to volts and doesn't add or subtract any tone in the process. This seems like it would deliver. But I'm about the furthest thing from an engineer you're likely to find. Here's the basic description...

Quote:

While most DACs feed the signal through an output stage consisting of an op amp (often with dubious power supplies and coupling caps), the magiDAC does not. In fact there are no active devices at all in the final output stage. No transistors, no op-amps, not even any tubes to get in the way of the musical signal. We use a custom built transformer instead. And it works very well indeed.

Here's the link:

httphttp://www.audio-magus.com/Aeolu...p/adac1.htm://

Tim

 

[grawk]

transformers impact the sound just like anything else.

 

[tfarney]

Sure. I guess the question would be is it easier to build a "transparent" transformer than a "transparent" output amp to bump the voltage up to line level. I sure don't know the answer.

Tim

 

[memepool]

Quote:

Originally Posted by grawk /img/forum/go_quote.gif transformers impact the sound just like anything else.

and no more so than cheap transformers which are generally much noisier. This is one of the reasons modern valve amps are so expensive because they need to use very high quality transformers to keep the distortion measurements as low as possible.

They mention a more expensive transformer option which would be a good idea as the current price seems a bit too good to be true.

It's an interesting product and what they say about the importance of output stages and using higher voltages is one of the issues Ken Ishiwata of Marantz is oft quoted on. This is one of the areas where DAC design has regressed in the last decade due to the dominance of the computer industry in defining the need for ever lower powered components which generate less heat.

 

[tfarney]

Quote:

Originally Posted by memepool /img/forum/go_quote.gif and no more so than cheap transformers which are generally much noisier. This is one of the reasons modern valve amps are so expensive because they need to use very high quality transformers to keep the distortion measurements as low as possible. They mention a more expensive transformer option which would be a good idea as the current price seems a bit too good to be true. It's an interesting product and what they say about the importance of output stages and using higher voltages is one of the issues Ken Ishiwata of Marantz is oft quoted on. This is one of the areas where DAC design has regressed in the last decade due to the dominance of the computer industry in defining the need for ever lower powered components which generate less heat.

Thanks for the reply. Not sure what you mean about the computer industry and low-power components, though. Are you referring to components that draw their power from the computer's PS through USB or firewire?

Tim

 

[Uncle Erik]

Quote:

Originally Posted by tfarney /img/forum/go_quote.gif Thanks for the reply. Not sure what you mean about the computer industry and low-power components, though. Are you referring to components that draw their power from the computer's PS through USB or firewire? Tim

Not so much for desktop computers; portable devices rule the day. Manufacturers push for low power consumption to get battery life up on DAPs and laptops. Those are huge sellers and the market is competitive. They'll gladly sacrifice audio quality, which is a low priority for most consumers.

Very interesting product, though. Transformers can be a great way to step up voltages, but they have to be very well made. There are a number of high-end products that take this route. I've been hacking on the Electra-Print Ultrapath preamp and the Ciuffoli SESS, both of which take the same approach.

 

[nikongod]

Quote:

Originally Posted by Uncle Erik /img/forum/go_quote.gif Very interesting product, though. Transformers can be a great way to step up voltages, but they have to be very well made. There are a number of high-end products that take this route. I've been hacking on the Electra-Print Ultrapath preamp and the Ciuffoli SESS, both of which take the same approach.

i agree transformers can be great.

I thoguht about using a transformer for the output of a Current output chip, and emailed cinemag. They said use an active solution. I like cinemag, others would have probably sold me something without caring how it sounds.

Their microphone stepups are awesome

 

[holland]

The CS4398 is a voltage out chip, so no I/V. The opamps usually associated with the CS4398 is for a filter and balanced to single ended conversion and to buffer the DAC chip from the external load. A transformer can do that, so I don't really see a problem with the picture.

This sounds interesting. Buy one and clue us in on how it sounds.

Balanced outs would have been nice.

 

[philodox]

My modded CD player uses Lundahl transformers on the output and sounds excellent, though I can't vouch for the particular unit you are asking about. One thing to be aware of is that this usually results in the output signal being weaker than the standard 2v which can be a problem if your amp doesn't have enough balls to pick up the slack.

 

[Vic Trola]

I use a transformer head amp / preamp from a company called BL Audio. It is definitely an acquired taste. Very mellow at rich, but, IMO, lacking dynamics. Transformer quality is critical, as was pointed out, so I would spend the $$$. The Audio Magus magiDAC looks interesting. If you purchase it, let us know how it works out.

 

[memepool]

Quote:

Originally Posted by tfarney /img/forum/go_quote.gif Thanks for the reply. Not sure what you mean about the computer industry and low-power components, though.

CMOS - Wikipedia, the free encyclopedia

When Marantz released their CD7 statement player about 10 years ago it was one of the first CD players to allow the user to choose from a variety of emulations of earlier classic Marantz players like the CD12 and CD94.

The CD7 used the then deemed defunct Philips TDA1541 chipset which caused quite a stir in the press at the time. The reason given was that Ken Ishiwata considered it more "musical" than the newer and cheaper Delta Sigma chipsets that are still industry standard today.

However the designers were ultimately unhappy with the fact that they couldn't fully recreate the sound of the earlier machines in hardware and the software emulations they ended up with didn't sound quite as good, which is why these classic players still change hands for big money on ebay.

Ishiwata attributed this to the differences in the design of the output stage, necessitated by using the then newer lower powered CMOS chips as opposed to older BMOS ones.

 

[tfarney]

I spoke to one of the guys at Audio Magus yesterday. He said the transformer upgrade adds refinement, but it's pretty subtle and missed on a lot of systems. They recommend going with stock first, upgrading later if needed. Here's what they say about the transformer options:

Quote:

The magiDAC is available with two custom transformer versions: The standard transformer puts the magic in the magiDAC with hand-stacked M6 line grain oriented steel cores and Class 155 magnet wire. For an extra dose of magic and an even more refined sound, we also offer an upgrade to the Crème de la Crème of custom transformers. Designed and hand-built by Bud Purvine, of high-end transformer maker Onetics. they are built around a 48-percent nickel core.

Would I expect this method to produce a less-colored analog output than most op amps? Transparency, on the cheap, is my objective.

I may be your test monkey on this one, but nearfield speakers come first...

Tim

 

[Vic Trola]

Here are my guesses based on what I know of what are essentially moving coil amplifiers:

You should expect transparency - low level passages and their rendition will be especially nice and usually without noise level.

You may be bothered by the lack of dynamics especially on demanding passages. Then again, based on what you listen to, you may not even notice it.

Cables, both power and RCA/Coax will be nit picky, annoyingly critical to get right. So chum up with someone to borrow cables and experiment. With this type of amp, it seems that cables become Part of the amp

Good luck.

 

[tfarney]

Thanks, Vic. Very interesting response. I have, so far, been convinced that my system, which is ultimately amplified by a vintage Harman Kardon integrated amp (in great shape, running up to specs, but 30 year-old specs) is not resolving enough to hear high-end cable. I usually use Radio Shack's gold stuff, which appears to be well-made but certainly isn't esoteric. I did recently try the internet's cable answer to the Playstation 1, the DIY cable made from a very specific Walmart outdoor extension cord! I just made speaker cables, but I have enough to make a set of interconnects left. I may do that soon and see what I get! Here's the internet Walmart cable voodoo link for anyone out there with the faith:

6moons audio reviews: DIY*Cables - The White Lightning Moonshine

Tim