AHB2 looks very impressive (from the description in the website), congratulations. Also on your learning and DIY efforts.
-Alex
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In retrospect, the non-oversampling rolloff might have been one of the reasons why I liked my first diy dac so much. But I don´t think it is the only reason.
They have a very pleasant sound to them. They're certainly good. But I doubt they float everyone's boat.
I don't think Dave Hill probably knows about how the Q word is taken here. He makes good gear though. That box is intended for mastering, which is why it has the stepped attenuators. Mastering engineers tend to want stepped knobs on everything for 'recall' use. The keep a log of all the settings for each piece of gear.
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Isn't Beryllium really toxic? BeO insulators were great but actually dangerous if cracked or broken. The dust is really toxic. Now that I know this I'll be much more cautious around them. Shouldn't this be on an MSDS that is publicly available?
I don't think that the ceramic tube itself is made of anything 'exotic'. You are probably right about the soft exterior wrapping, but I am not sure. It doesn't really matter anyway, because almost nobody here is going to buy or use a Bybee device of any type, and we are just talking about one early type that most people don't use that much anymore. I just carried it this far to give you a glimpse of something 'different'.
When it comes to safety, I am now watching a Nova program on Lithium batteries. Now there is a dangerous device! Yet we give them to children to play with (in their cell phone).
When it comes to safety, I am now watching a Nova program on Lithium batteries. Now there is a dangerous device! Yet we give them to children to play with (in their cell phone).
Hah, yeah, I saw one of the profs that was down the hall from my old lab. And a huge portion of the show focused on safety.
It is deadly only if it is breathed into the lungs. Thus machining of it causes dust that needs to be done and captured in an enclosed box. It is a known cancer causing substance (lung cancer).
Just touching it isnt a problem.
THx-RNMarsh
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To get the required effect from a quantum resistor you don't have to make it from an exotic material; you just have to make it from a material which Joe Public thinks is exotic, and which you can truthfully claim is used by the military. You just forget to mention that the material is widely used in RF power transistors so almost certainly present in all cellphone base stations, emergency service vehicles, ham radios etc.
One cord by itself may not cause too much concern, but even a modest system has several power cords and they are in the back mixed in there along with the I/O from the gear.
You can buy shielded cords.... twisted wires within preferred. However, it is not hard to slip a metal braided sleeve over each cord for shield and ferrite (#47 etc) on the cord. One at each end.
THx-RNMarsh
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Excellent suggestions, although grounding the braid may be problematic and I would discourage any ungrounded metal around an AC cord. Mouser and others offer quality twisted, shielded AC power cable assys for $5-$6. Also, mix 31 ferrites, or even mix 75 ferrites would offer higher impedance in a single-turn application than other ferrites in the sub-100 MHz range where interaction with audio is worst. The Fair-Rite mix 31 Snap-Its have very broad-band impedance curves in this application and can be applied to pre-made cables. Full disclosure, we sell them in our web store: Fair-Rite Mix 31 Ferrites - Pro Audio Engineering. Used in conjunction with powder-iron cores the resulting broad-band attenation is very useful. Avoid unmarked ferrites, In my experience most offer poor impedance in the sub-100MHz range and are a waste of time.
Ferrites applied in this manner offer mainly common-mode impedance, although they do offer some useful differential-mode impedance as well. And although I have read in some audio blogs that people don't like the "sound" of ferrites on AC cords, consider what that means: they prefer IMD or other interference caused by RF entering their equipment via the AC power inlet. Pavel could wax poetic on this subject. This is hardly a reliable sound tweak given the variation in ambient RFI. Interestingly enough some of these same reports are most likely using equipment with dedicated ferrite common-mode chokes in the power supply.
In our studio installs we often specify Tempest-grade AC line filtering: Tempest Filters - EMI Filters for the entire technical power system in conjunction with isolated-ground metallic-shielded cabling. These filters offer significant filtering from the low KHz range to over 1 GHz, but are pricey. In high-RFI areas we also specify EMI room shielding, especially for the tracking rooms. Some single-coil guitars and other instruments with unshielded high-impedance outputs make fantastic RF antennas. All of these measures can be violated by a single cell-phone set down in the studio in the wrong place.
So it goes...
Howie
I wanted to add that in my home system I use a Monster HTPS7000 MKII which I believe our own Mr. Marsh had a hand in the design of, and it really cleaned up the noise floor of the system. And this from someone who has reason to dislike Monster Corp. in general for personal reasons...
Howie
Howie
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