I had a total of 5 Linux machines running here at home and 2 of them locked hard sometime near midnight UTC.
One is my main server running Debian Etch and had been up for several months. It had not crashed once since replacing the hardware over a year ago. We were watching a recording on MythTV when it locked-up. I walked over to my workstation, running Ubuntu Intrepid, to restart the backend and it was also locked-up hard.
Very bizarre until I looked at the logs and did the math. Both logs end just before midnight UTC.
Audio is completely subjective. Do whatever makes your ears the happiest. Personally, I grew up in the 80s and 90s listening to all my music through a tube amp. When I finally "upgraded" to more modern technology, I really wasn't paying much attention. At some point I came across my admittedly medium-fi 6V6-based tube amp again and got the itch to fire it up to see if it still worked. It wasn't until then that I realized what I was missing.
It's all in the ear of the beholder and no spectral analysis is going to change that for anyone.
I also own their K8016 function generator. The two were made to work together (for Bode plots, among other things) and I find that they work quite well. The only trouble I had was noise on the scope due to an inadequate power supply. It was rated 9V @ 1A, but actually dropped to 7V at that current. The scope draws 1A easily. I built a better PSU for it and now it is fine.
For that money, you can maybe do better but the Vellemans fit my needs nicely.
But REproduction is a different story. I've got preamps that are rated in parts-per-million distortion. I tweak all my tape decks for the flattest response possible, and work hard to get the best signal-to-noise ratio possible. That's because I like the final sound to be as faithful to the original as possible.
That is all a matter of opinion. I believe the proper way to (re)produce sound is the method that sounds the best to YOU! Recordings dated from the early 80s and back tend to be mixed (when mastered) to produce a certain sound on the equipment that was available at the time. Therefore, to hear it as intended, perfect reproduction is NOT what you want. This is the same reason many of the earlier CDs made from old masters (used to cut LPs) sound so horrible. They were mixed to sound as intended after being replayed on the vinyl medium. This is why many LPs sound better than CDs. It's not that the LP medium is necessarily better, but rather that the master were not remixed for the sterile CD medium.
Many triodes are far more linear than your typical BJT found in the opamps in your typical "hifi" equipment. I still haven't heard a FET circuit that I like. Manufacturers will never acknowledge this, as electron tube circuits are more expensive, need to be replaced periodically, and are inefficient in terms of power useage. Since they operate at high voltage and low current, transformers are required to match them to other modern equipment.
As far as distortion goes, not all "tubes" can be lumped into a single catagory. The triodes used single-ended, as in the case of this MB, have the desired even harmonic distortion. However, you can do just as bad with odd harmonics as a BJT or FET with a pentode in push-pull. The human ear generates its own even harmonics, which is part of the reason why they are musically more tolerable than odd harmonics.
Having friends and family in the recording industry, they can attest that having electron tubes at the mechanical-to-electrical interface can greatly improve the sound, since tubes overload softly. The signal coming off a microphone (or the load of driving a speaker) frequently goes FAR beyond its designed output level, most likely causing the annoying harshness heard in transistor amps. To put a triode preamp in a computer case is a little odd, but it may do some good cleaning up the annoying sound that comes from even the best DACs found on sound cards these days.
Anyway, like I said, the right technology is the one that sounds the best to you. I grew up (no, I'm only 27) listening to all of my music through a tube amp. When I "upgraded" to supposedly higher-end equipment, I didn't realize what I was missing until many years later when I fired up those old firebottles in my old, mid-fi amp. I will never go back.
The 6922 (E88CC to our UK friends) was originally designed for use as a cascode. However, since there is only one tube and it is likely (hopefully) a gain stage, then it is probably a single self-biased, common-cathode triode per channel. That would only require 6.3V (or 12.6V) for the heaters and an HT probably around 200V.
This does beg the question about the output impedence of this preamp, which in general isn't very good for common cathode amps operating at low current. On the other hand, the output capacitors (Hovland Musicaps?) look to be quite large, which implies that it can drive a fairly low impedance amp.
Properly shielded and assuming the inverter used to created the HT is electrically quiet, this preamp could make some nice sound.
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I had a total of 5 Linux machines running here at home and 2 of them locked hard sometime near midnight UTC.
One is my main server running Debian Etch and had been up for several months. It had not crashed once since replacing the hardware over a year ago. We were watching a recording on MythTV when it locked-up. I walked over to my workstation, running Ubuntu Intrepid, to restart the backend and it was also locked-up hard.
Very bizarre until I looked at the logs and did the math. Both logs end just before midnight UTC.
Audio is completely subjective. Do whatever makes your ears the happiest. Personally, I grew up in the 80s and 90s listening to all my music through a tube amp. When I finally "upgraded" to more modern technology, I really wasn't paying much attention. At some point I came across my admittedly medium-fi 6V6-based tube amp again and got the itch to fire it up to see if it still worked. It wasn't until then that I realized what I was missing.
It's all in the ear of the beholder and no spectral analysis is going to change that for anyone.
I also own their K8016 function generator. The two were made to work together (for Bode plots, among other things) and I find that they work quite well. The only trouble I had was noise on the scope due to an inadequate power supply. It was rated 9V @ 1A, but actually dropped to 7V at that current. The scope draws 1A easily. I built a better PSU for it and now it is fine.
For that money, you can maybe do better but the Vellemans fit my needs nicely.
But REproduction is a different story. I've got preamps that are rated in parts-per-million distortion. I tweak all my tape decks for the flattest response possible, and work hard to get the best signal-to-noise ratio possible. That's because I like the final sound to be as faithful to the original as possible.
That is all a matter of opinion. I believe the proper way to (re)produce sound is the method that sounds the best to YOU! Recordings dated from the early 80s and back tend to be mixed (when mastered) to produce a certain sound on the equipment that was available at the time. Therefore, to hear it as intended, perfect reproduction is NOT what you want. This is the same reason many of the earlier CDs made from old masters (used to cut LPs) sound so horrible. They were mixed to sound as intended after being replayed on the vinyl medium. This is why many LPs sound better than CDs. It's not that the LP medium is necessarily better, but rather that the master were not remixed for the sterile CD medium.
Many triodes are far more linear than your typical BJT found in the opamps in your typical "hifi" equipment. I still haven't heard a FET circuit that I like. Manufacturers will never acknowledge this, as electron tube circuits are more expensive, need to be replaced periodically, and are inefficient in terms of power useage. Since they operate at high voltage and low current, transformers are required to match them to other modern equipment.
As far as distortion goes, not all "tubes" can be lumped into a single catagory. The triodes used single-ended, as in the case of this MB, have the desired even harmonic distortion. However, you can do just as bad with odd harmonics as a BJT or FET with a pentode in push-pull. The human ear generates its own even harmonics, which is part of the reason why they are musically more tolerable than odd harmonics.
Having friends and family in the recording industry, they can attest that having electron tubes at the mechanical-to-electrical interface can greatly improve the sound, since tubes overload softly. The signal coming off a microphone (or the load of driving a speaker) frequently goes FAR beyond its designed output level, most likely causing the annoying harshness heard in transistor amps. To put a triode preamp in a computer case is a little odd, but it may do some good cleaning up the annoying sound that comes from even the best DACs found on sound cards these days.
Anyway, like I said, the right technology is the one that sounds the best to you. I grew up (no, I'm only 27) listening to all of my music through a tube amp. When I "upgraded" to supposedly higher-end equipment, I didn't realize what I was missing until many years later when I fired up those old firebottles in my old, mid-fi amp. I will never go back.
Russ W. Knize
The 6922 (E88CC to our UK friends) was originally designed for use as a cascode. However, since there is only one tube and it is likely (hopefully) a gain stage, then it is probably a single self-biased, common-cathode triode per channel. That would only require 6.3V (or 12.6V) for the heaters and an HT probably around 200V.
This does beg the question about the output impedence of this preamp, which in general isn't very good for common cathode amps operating at low current. On the other hand, the output capacitors (Hovland Musicaps?) look to be quite large, which implies that it can drive a fairly low impedance amp.
Properly shielded and assuming the inverter used to created the HT is electrically quiet, this preamp could make some nice sound.
Russ W. Knize