Amplifiers


Again a little out on a limb, I'm a fan of Single Ended Triode amplifiers.

Welborne Labs had a pair of Yote 300B amplifiers in need of a little TLC listed in their bargain bin at $1000. The simple addition of tubes and a couple of plate chokes was enough to get them both working again and they sound sublime. The 96dB sensitivity of the Supravox driver marries in well enough with the 8W output of the 300B tubes. While 8W does not sound like a lot compared to the power output of most solid state amps, it's more than enough to drive the Supravox drivers to ear splitting levels. I seldom need more than 85dB or so at the listening position, so can barely account for 1W of power from the amps.

The remarkable simplicity of SET amplifiers means that they reveal every nuance of detail from the source and throw an utterly convincing soundstage that's full of texture and tone. While SETs are not everyone's cup of tea, partnered with the right speakers they manage insight and dynamics that other topologies seem to smear. I have found the addition of these amplifiers driving the 3D Sonics speakers to be revealing of almost every change I have made to upstream components, making them a perfect base to use as a test system.

A Stevens & Billington transformer volume control provides volume attenuation rather than using software level volume controls in Vista. Unfortunately, software based volume controls attenuate the signal in the digital domain by dropping bits, which can lead to a loss of resolution as soon as the volume is moved below maximum output. I've found transformer based volume controls to be very close to sounding neutral, even outperforming shunt volume control made up entirely of 0.1% tolerance laser-cut metal film resistors.

Lastly, I suppose I should mention cables. Despite my attitude towards other components, I don't do funky high-cost cables and all the fuzz associated with them. For speakers, I use a single strand of solid core 24-gauge silver covered in a simple cotton jacket. The whole shebang costs a few dollars per foot from most good audio DIY outlets and sounds fine to my ears. Interconnects are made up using either Cat 5 cable or suitable solid core coax. Power cords are all generic off the shelf types, no special plugs or dielectrics needed.

The PC

There's nothing remarkable here: a Gigabyte X48T, 4GB of OCZ Platinum DDR3, a Corsair modular PSU, and an X6800 dual-core processor. A 250GB Western Digital Caviar hard drive stores audio files in WAV format. The operating system is Vista 64, which is not ideal for audio due to some of the open source software failing to function properly if at all. There have to be compromises somewhere and current study requirements keep me on the Vista coach just to keep up to speed with its administration. Anything using a dual-core processor running at over 2GHz is likely more than sufficient for an audio server. 4GB of memory is pretty much mandatory for Vista 64 to work efficiently when placed under any kind of load. Another caveat is that I have not managed to locate any USB-ASIO drivers for the Vista 64 platform. ASIO drivers are preferred to help lower latency by routing signals directly to hardware where possible. Vista 32 and XP are fully supported by USB-ASIO, so that's something to bear in mind if you'd like to keep latency as low as possible.

The Test System Outboard DAC solutions
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  • ccd - Thursday, December 4, 2008 - link


    If you want to be scientific, there is no substitute for double blind testing. It's as simple as that. The human psyche is just too susceptible to suggestion.

    I have been in stores and compared components. But as you should know, all sorts of games can be played with equipment. A common trick is connecting a speaker to a monster amp which makes it sound better. The other key to speakers placement. You can take a speaker that sounds great in the store and sounds crappy when you get home because the listening conditions are so different.

    The most eye opening experience I ever had was taking a home made speaker into a very high end store at the end of the day because on of the salesmen wanted to listen to the transducer I was using. The speaker which also used one made speaker wires out-performed speakers costing over $20,000! The Orions that I have mentioned in previous posts are better than this speaker and the Orion uses electronics which are hardly out of the ordinary. I would put that speaker up against anything, regardless of price. Listen to a speaker like the Orion and you will realize that "high end" audio is mostly snake oil.
  • goshwan - Thursday, December 4, 2008 - link

    Why should we take your 'subjective' (because that is what it is) opinion that the Orion's are that good? How is your opinion any different from when the author says his speakers or DAC's are great?
    Have you heard these components yourself? Have you heard any of the components used in the review?

    Humans are subjective animals and purchaing decisions usually involve sprinklings of logic and subjective preferences. Audio is one of the best examples of this. Even solid state amps sound different depending on topology and operating class. Your statment about monster amps reflects this. They indeed sound different.

    I have heard the TDA1543 on occasion, but I would not be foolish enough to think that every other DAC sounds the same.


    Granted, the Orion's are a indeed a fine speaker based on reports, but it's also possible the ones we see used in the article are too.

    To mee it seems as if everyone is forcing their own subjective opinion in reply. Some are objective, but theirs plenty of subjective, which is funny really.

    I think the article could have offered some more objective stuff. but at the same time, the listening conclusions of both DAC's were pretty much spot on. The TDA1543 is known to sound soft at hf sounds, especially in nonos. The room correction stuff really was great. In fact, I wonder how many readers got that far before exploding their thoughts via the keyboard.

    You have some interesting points on blind tests, arguments for and against seem to rage the web over. I wonder what people would accept though, how much evidence would be needed if something turned out to be spot on?

    I'm interested to see where AT go with the audio stuff.
  • ccd - Saturday, December 6, 2008 - link


    I guess we will have to agree to disagree. Moving right along, I do not have any issues with open baffle speakers. I'm not a techie, but there are theoretical advantages to open baffle speakers. The trick is getting the baffle wide enough so that the baffle simulates the driver being in a wall. The problem with open baffle speakers has been aesthetics, as an open baffle speaker usually have to be very wide. I've seen open baffle speakers with hinged sides to the speaker need not be really wide except in use. The test speaker uses clear sides which would limit the impression of width.

    Actually, my issue with the speaker is that it is full range. I have not heard this speaker, but full range speakers generally have really nice mid ranges and suffer in both the upper range and lower range. I do like that he paired his speaker with a sub. However, full range speakers usually need a crossover at a high frequency than I would like and the higher the crossover, the trickier the integration. In case you haven't guessed, I've hung around DIY circles for a number of years, though not recently.
  • goshwan - Saturday, December 6, 2008 - link

    Well seeing as neither of us have heard the speaker in question it's a subjective assessment. Of course, individual drivers tailor made for the frequency range in question should be more proficient. Given that we hear little over 15Khz though, I bet they sound pretty cohesive. Yes higher range crossover integration does become an issue, but if one is not needed 'subjectively' then why bother?
  • ccd - Saturday, December 6, 2008 - link


    The speaker used in the article could be good, very good for all I know. Since I have not heard it, I can only talk in generalities. The tradeoff is between a full range transducer with no crossovers and a frequency response that is not nearly as flat as a multi-driver speaker with crossover points. Neither speaker is perfect.

    Full range drivers, at their best, have gorgeous mid-range performance which is highly valued by those who favor them. The tradeoff is a fall off in the upper and lower ranges. The limits of human hearing help cover the failings in the upper ranges and there are tricks like the use of transmission lines to extend the lower range, but there are limits.

    The multi-driver speaker has a different set of issues. One is finding drivers that complement each other. Merely matching frequency response is not enough. The other is determining the right crossover points and slopes. Not a problem for an expert, a great challenge for the amateur. From what I have personally heard and from what I know about speaker design, a well designed multi-way speaker, particularly hybrid active (passive crossover between the tweeter and mid-range and active between mid-range and woofer is just a better solution than a single full range driver. Right now, I'm sitting in front of a speaker with one of the widest frequency ranges of any driver and it is still a 3-way design.

    Again, I have not heard the speaker in question. But I also know it is VERY hard to overcome the limitations that come with certain design choices.
  • goshwan - Saturday, December 6, 2008 - link

    That's the beauty of audio, final choices are often based upon what you favor. There is no one speaker that will appeal to all tastes. Which is why I don't diss on people going one way or the other. The calculated final response with sub and DRC was pretty flat. Impressive.




  • ccd - Thursday, December 4, 2008 - link

    This gets back to my original post on this article. A lot of this is very subjective and there will never be any agreement on it. IMHO, things like DAC reviews should not be a part of this site, it would not matter whether I had heard the components or not. However, the DRC part should definitely be featured on this site and was great.

    BTW, I used the Orion as an example of a kit speaker which is both generally regarded as one of the best kit speakers available and one whose design runs counter to many of the assumptions made by this author. I encourage you to listen to the speaker and come to your own conclusions.

    Double blind testing is the only way I know of to accurately determine whether equipment changes actually make a difference. It is opposed by many in the high end because they don't like what double blind testing tells us: much of what they tout just doesn't make an audible difference.
  • goshwan - Thursday, December 4, 2008 - link

    I 'subjectively' disagree, the DAC kits are designed to run off the USB bus. Tha means a computer is involved.

    I don't follow your 'assumption' accusations either, like yours the opinions stated are subjective. Linkwitz backs his up on his site true, but the adoption still involves approval by human ear - not just visionary acceptance of theory. That means verbal expression in the form of words which you too have used to encourage people to listen to the Orions. I have no doubts those speakers sound great. But I have heard great things about open baffle speakers too.

    I agree with you on this, in that guess we can agree to disagree.

  • Flyboy27 - Wednesday, December 3, 2008 - link

    How much energy do you have to put into a system before you can actually start enjoying your music. I realized many years ago that I just needed to listen to my music instead of worrying so much about sound fidelity. Since then my enjoyment of music has increased so much. I am a musician, have been trained as a recording engineer, and work in the music industry. There comes a point when you have to stop worrying about your gear and just enjoy your music.

    Having said that it is a shame that so many people listen to 128kbps mp3s. I'm planning on re-ripping my entire CD library in a lossless format. This is part of the reason for me why it is so important to have a physical copy of my music. I'm not "stuck" with a low bitrate crapy itunes copy.
  • kompulsive - Wednesday, December 3, 2008 - link

    You guys should definitely check out the M-Audio Audiophile 192 or Audiophile 2496 depending on your needs. I've been using these and similar products for years in my small studio at home and the price, quality, and value are superb. I think Creative products are grossly overrated and overpriced.

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