* I do not have a good relationship with Tom Christiansen.
That's unfortunate. I hear he's a really nice guy...
You're right, though. You and I don't see eye-to-eye. Part of that is that I've pointed out the fallacies in your arguments and refused to take your word as gospel. I approach audio design from a perspective rooted in science and engineering. I also have the perspective of someone who has designed circuits for mass production. The circuits I designed for National Semiconductor and Texas Instruments have been produced by the millions. I apply this perspective and the learnings from my experience in my designs. I have no plans to change that.
It's sad that you find it necessary to trash my reputation both here and on DIY Audio (https://www.diyaudio.com/forums/class-d/347137-brainstorming-purifi-1et400a-amps-post6079964.html
), but that is your choice. (BTW, those who know Maty and his communication style may find my response insightful, if not quite entertaining. It also outlines the root of our disagreement: https://www.diyaudio.com/forums/class-d/347137-brainstorming-purifi-1et400a-amps-post6080256.html
I have always been a very questionable person, of those who preferred to sit in the front row.
You and I actually have something in common then. However, in my experience, such students tend to fall into two categories: 1) Those who reflect on the topic taught and ask questions to test their understanding; and 2) those who crave the attention of the instructor and want the lecture to be about them and their issues. I've always preferred students who fell in the former category and do my absolute best to be a member of that category as well.
He always responded with good manners and giving the explanation I was looking for. It is very important to know that you are going to have a good after sales service, just like Danny Richie or Frank Van Alstine (AVA Hifi), at least for me.
It's interesting you mention that, actually. In my market surveys, a vast majority of my customers find me to be polite, honest, and to the point. Many also commend me for my ability to deal gracefully with the various noise makers in forum threads (one guy referred to this as my BSRR, which I found to be a fitting term). I tend to get around 100 participants in my surveys before they close, so I think I'm reaching a representative sample of my customers.
That said, my communication style does tend to be pretty direct, fact-based, and science-based, which rubs some the wrong way. Also, while I do my best to be patient, my patience is finite. So I probably become a bit rough around the edges when someone forcefully argues that I should change my products to suit their pet ideas - in particular when they completely lack perspective and it becomes impossible to reach them with fact- and science-based arguments. See this discussion for example: https://www.audiosciencereview.com/forum/index.php?threads/review-and-measurements-of-neurochrome-modulus-286-amp.6443/post-143471
It's unfortunate that you don't like my direct, no-BS approach. I have no plans to change. I would rather sell my products with evidence-based arguments than with sappy marketing verbiage. You're free to disagree.
Now back on topic: Here is one review of my Universal Buffer + Purifi 1ET400A: https://www.diyaudio.com/forums/class-d/347137-brainstorming-purifi-1et400a-amps-32.html#post6064187
with further clarification here: https://www.diyaudio.com/forums/class-d/347137-brainstorming-purifi-1et400a-amps-post6064216.html
. Here's a summary:
The first impression is that it is smoother and the sound more "plastic" than with the EVAL1 buffer, or bypassed. Plastic as in plastic arts, in particular sculpture, not as in the synthetic material. [...] [T]he soundstage is very precise and natural, wide and deep, with very precise layers and everything has the right size and placement. As if sculpted.
The noise floor is also lower (my test was not too scientific but it is still a measurement: I bypassed the autoformer on the tweeter of the B&C coaxial so that it has a 110Db sensitivity, then measured the noise with my umik microphone and, with gain matched, I get a measurement of the hiss which is almost 10Db lower).
With the gain at unity it sounds relaxed and with slightly understated dynamics – with the gain at 7.3 or 13 it is much more dynamic. I chose to keep 7.3. I matched the level with the DAC's control, so this may also be due to the DAC behaving in a different way at various attenuation levels, but I would consider this case unlikely.
It's good to know that at least one person in the world likes my circuits and is willing to work with me.
He and I are currently working on a buffer designed specifically for the Hypex NC500 and Purifi 1ET400A.
Neurochrome - www.neurochrome.com
Tom Christiansen Audio - www.tomchr.com