First off, a big thank you to the community, Kevinkr in particular. There is loads of information here, and not too much trolling. Kevin helped immensely with my noob questions about the LS-1 line stage, and a handful of other things that showed my circuit experience began and ended at Computer Engineering Intro To Digital Systems.
So I picked up the S5 kit and liked it enough without any of voltseconds mods, that I scratch built the amp with most of his mods, I skipped the CCS. I liked the result a lot, most of my friends even agree that the sound is much more crisp and clear over my Onkyo TX-NR3009. In tinkering with PSUDII I found, and I may be misreading the results, that there is a little more than 5Vpp ripple at the first stage. Adding a an additional RC filter, and re-biasing the kathode to 330R, about 70mA, brought that down to about 260mVpp according to the simulator. Unfortunately my USB scope won't handle voltages greater than 30 so I have to rely on the sim.
The sound is definitely clearer, and there was more low-end extension, if there is interest I can post the changes I made. The amp is not dead quiet, there is some full time buzz in the left channel, and some volume related buzz in both, out of phase with the left channel buzz; it is not audible over ambient noise at full volume more than 2 feet from the speakers and not audible over music at all. At this point, DAC to amp, I can rattle my computer desk and the cabinets in the kitchen.
The next addition to the system was Kevin's LS-1 Line Stage, an extremely simple and almost noob proof project. As the amp plot shows, it beefed up the low end where it was weak but was almost flat the rest of the way across. All the way up, at over 12V, the sine waves will not clip. The sound is mellow, there is definitely more power, and the room is filled fuller with music; but it is in no way in your face like car audio or high powered digital systems can be.
So the system now is a Logitech Duet Network Player via Optical -> Schiit Bifrost DAC -> LS-1 -> K12-G -> Energy CF-70's. I'm a software engineer, I'm a high tech early adopter by nature, and I really do like the all digital media world *puts on flame proof suit* I don't even own a CD player, except for the one in the PC. Admittedly I'm a bit of a bass head, and I listen primarily to electronica and industrial.
The first thing I noticed with the new system was that the life span of a tone was changed, sounds, such as a cymbal, live and die closer to how they sound live. The next thing I noticed was that the background was dead quiet, one of my friends made the comment that the Onkyo sounds like we were in a small concert hall, but the tube setup sounds like the artist is sitting in a corner playing live without all the high gain equipment. The system is so detailed that I find myself listening to things I didn't hear before, listening only to the nuances, or panicking because they used noise in the mixing of the song and I think something is about to go pop. I do have to credit part of the detail and clarity to the Bifrost, the DAC on the Duet is no where near that clear. With only the Duet the woodwind in Symphony and Metallica is almost completely hidden, blended into the rest of orchestra, with the Bifrost it really comes to life. The Schiit really does bring out the...texture?...in music, and they are fairly active over at headfi.org and made near LA, and enough with my Schiit plug.
Attached are the amp plots, 1k square waves, and some final pictures...be nice I'm new at this. The underside of the K12 is so messy I won't dirty the board with pictures of that. I used a Velleman PCSGU250 to take the measurements, like all USB scopes it does have a little IM...maybe when I'm smarter than my scope I will figure out how to reduce that.
I look forward to more brownouts in San Diego County, and hopefully not getting kicked out of my apartment.
So I picked up the S5 kit and liked it enough without any of voltseconds mods, that I scratch built the amp with most of his mods, I skipped the CCS. I liked the result a lot, most of my friends even agree that the sound is much more crisp and clear over my Onkyo TX-NR3009. In tinkering with PSUDII I found, and I may be misreading the results, that there is a little more than 5Vpp ripple at the first stage. Adding a an additional RC filter, and re-biasing the kathode to 330R, about 70mA, brought that down to about 260mVpp according to the simulator. Unfortunately my USB scope won't handle voltages greater than 30 so I have to rely on the sim.
The sound is definitely clearer, and there was more low-end extension, if there is interest I can post the changes I made. The amp is not dead quiet, there is some full time buzz in the left channel, and some volume related buzz in both, out of phase with the left channel buzz; it is not audible over ambient noise at full volume more than 2 feet from the speakers and not audible over music at all. At this point, DAC to amp, I can rattle my computer desk and the cabinets in the kitchen.
The next addition to the system was Kevin's LS-1 Line Stage, an extremely simple and almost noob proof project. As the amp plot shows, it beefed up the low end where it was weak but was almost flat the rest of the way across. All the way up, at over 12V, the sine waves will not clip. The sound is mellow, there is definitely more power, and the room is filled fuller with music; but it is in no way in your face like car audio or high powered digital systems can be.
So the system now is a Logitech Duet Network Player via Optical -> Schiit Bifrost DAC -> LS-1 -> K12-G -> Energy CF-70's. I'm a software engineer, I'm a high tech early adopter by nature, and I really do like the all digital media world *puts on flame proof suit* I don't even own a CD player, except for the one in the PC. Admittedly I'm a bit of a bass head, and I listen primarily to electronica and industrial.
The first thing I noticed with the new system was that the life span of a tone was changed, sounds, such as a cymbal, live and die closer to how they sound live. The next thing I noticed was that the background was dead quiet, one of my friends made the comment that the Onkyo sounds like we were in a small concert hall, but the tube setup sounds like the artist is sitting in a corner playing live without all the high gain equipment. The system is so detailed that I find myself listening to things I didn't hear before, listening only to the nuances, or panicking because they used noise in the mixing of the song and I think something is about to go pop. I do have to credit part of the detail and clarity to the Bifrost, the DAC on the Duet is no where near that clear. With only the Duet the woodwind in Symphony and Metallica is almost completely hidden, blended into the rest of orchestra, with the Bifrost it really comes to life. The Schiit really does bring out the...texture?...in music, and they are fairly active over at headfi.org and made near LA, and enough with my Schiit plug.
Attached are the amp plots, 1k square waves, and some final pictures...be nice I'm new at this. The underside of the K12 is so messy I won't dirty the board with pictures of that. I used a Velleman PCSGU250 to take the measurements, like all USB scopes it does have a little IM...maybe when I'm smarter than my scope I will figure out how to reduce that.
I look forward to more brownouts in San Diego County, and hopefully not getting kicked out of my apartment.
