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Bubo

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Everything posted by Bubo

  1. I think it was Twain that had something to say about this......
  2. I disagree. I have tested many A/B amplifiers to full rated output and there is ZERO crossover distortion in the output. In fact that is the whole point of biasing an amp properly. Just becaue one device goes into cut off doesn't mean that the output will have a notch at the zero point. I would go on and say that in an AB amplifier because of the bias point the tube is usually operated in it's most non linear region which would create distortion, which feedback then just fixes. So you are saying that Class A/B amplifiers do not have crossover distortion to be dealt with in some way? There are lots of tube amplifiers that do not have any feedback whatsoever because none is needed. Most, if not all A/B amplifiers have tons of feedback correction. EL Paso Tube has lots of great videos on Youtube, former NASA and MIL tech, probably an engineer. Anyway, he always seems to be able to zoom his scope to make the crossover visible, since it must be there. I think the argument is, how inaudible does it have to be before it's a non issue.
  3. I understand that Pass has an article on biasing on his web site with formula for determining class A output. This is a different discussion, about a different design(er) that Yamaha and apparently others used the "Hyperbolic circuit". I'm not feeling particularly good, so I'm going to pass on reading the 11+ pages, which would normally be interesting if nothing else. I think the gist of it is how to get Class A without a lot of heat in a solid state design, if you don't generate a lot of heat that may mean that you don't have a lot of surplus energy to dissipate. Again I'm under the weather, but what I got from your comment is that you think the design(s) given the biasing are unlikely to generate much if any Class A operation. This is one of the many research projects and discussions that is on my list, but I never get to. Mostly I'm ramping up to rebuild my racks of sweet sounding gear, then figure out what else I can do with an iron and a scope....if I don't die from flux poising. http://www.diyaudio.com/forums/solid-state/152734-yamahas-hyperbolic-conversion-amplification-hca-circuit.html This may be a better thread http://forums.phxaudiotape.com/showthread.php/535-Hyperbolic-Conversion-Amplification-Curcuit
  4. On my main system, my typical listening levels as measured on my McIntosh 2205 are typically at 200ths of 1 watt with my LaScalas peaking when I crank it up at around .2 watts. At 2 watts it's ear splitting and will drive you out of a 30 foot room. The LaScalas are circa 1980 so the rating is either 102db or 104db at 1W1M. The Mc will push 200W per channel all day long, I have never been able to test it. From what I have read, even though it is an AB amplifier the first few watts may be class A. If I understand it correctly, my Yamaha Amps which I love, also produce Class A for the first watts then switch into Class AB. On the MX-800 someone who has looked at it told me that the first 35 watts are class A. For what its worth, both the Mc and the Yammys have massive transformers and filter caps. Based on my observed power usage, I would think a really well made 20 watt class A amp would blow your socks off with the LaScallas. The argument for tubes, simplicity, is appealing and they have other performance characteristics. The Mc 30s that I sampled sounded great to me, they do come at a high price if they are refurbished. On the MC30 spec sheet, the specs for .5 watt are published and they are spectacular compared to anything.
  5. Any favorites on the class As that you can share?
  6. Jumping over the out connects to the in on the EQ and the out on the EQ connects to the IN on the Sansui cabling issue. Wire the EQ as Tape One, this way you can select and deselect it at will to compare if you like the EQ better than no EQ, I do this all the time. I don't know the Sansui, but Rec out and listen allow for lots of options if you have lots of devices, at least on all of my pre amps. Good luck.
  7. Given that Audio is a male dominated industry, I totally agree with you......
  8. Funny story about that, as a matter of fact. The first time I listened to Bang Bang (by Jessie J, Nicki Minaj, & Ariana Grande) after upgrading to a more appropriate amp and preamp, I realized just how empty-sounding the song is. It's a bit of an extreme example, but it goes to show just how much they engineer recordings for what the target demographic will listen to them with (mostly Beats headphones and car stereos). A good 2ch system can be a double-edged sword like that! (On the other hand, I listen to much more jazz and instrumental than ever nowadays) https://www.youtube.com/watch?v=U2LAdyE8lEU
  9. Mostly no, but sometimes yes. Depends on the Artist, some CDs are so dead on that anything makes them sound less. The EQ I am currently using has 10 presets, and 5 programmables. I have cycled through the presets more than once with guests, and they always select the same setting which is interesting. I punches up the bass and the female voice just a bit, but very noticeable. I do have to say that on some vinyl, if I toggle between the EQ and direct I end up on direct, perhaps a tribute to Dual, can't think if the name of my famous Danish cart and the McIntosh phono section from 1980?
  10. I recommend remastering tracks yourself for a while: a couple of months of greater than 20 hours/week is my recommendation. That translates into about 30-60 albums, minimum. I believe that about half of what you've said here will simply disappear or even reverse itself after you've spent a little time undoing what the mastering engineers have done in the past, typically never actually correcting the original EQ curves, but simply adding compression and limiting for "remasters". My remasters are actual remasters, starting with un-clipping the original stereo tracks and rebalancing the entire 20-20kHz band much flatter to be much less strident and much more natural sounding. See https://community.klipsch.com/index.php?/topic/155096-the-missing-octaves-audacity-remastering-to-restore-tracks/ as a starter. I learned a lot as time went on in that thread--up to the present (I was remastering Wish You Were Here this morning and took a short break on "Welcome to the Machine" to browse the forum. For instance, here is the current EQ "unmastering" curve for the SACD version of Welcome to the Machine (PCM layer) that I arrived at: Doing it for a while is a much different than repeating what others might have said about it. YMMV. Chris Nice write up on the link OFS. At Axpona, the guy selling the rebuilt reel to reel Tascam's was playing copies of original masters, I assume unbutchered, at the high speed, the Stones never sounded that good on any other system that I've heard.....the butchered released products? Mastering and remastering is the next frontier for me to explore. For now, learning electronics and repair has been keeping my busy. I have stacks of gear that I am at the beginning of rebuilding. The Gear is demanding love at this point, so it's rebuild first........ On the gear side..... get it working to spec, then see what can be improved, frequently the tech has improved over the past 30 years so simply putting better tech and better rated parts yields results for a few dollars. Once repaired and improved, the OP amps are worth revisiting, op amps have a significant impact on the analog systems and may be the "sonic signature" since they are the first component the analog transits before hitting the amp section. On the speakers, re-cap after 35 years seems mandatory, after that there is the question of replacing the diaphragms (phenolic for titanium or other metal), magic crossovers I'm not convinced so far. Not sold on modding the cabinets either.......... it would be less trouble to design and build some speakers from scratch like the Cornscalas, the sw from the project is readily available, but there is always the reality of "how do they sound" which PK was a master at optimizing for the components and cost aka declining marginal returns. If everything is working properly, the biggest bang for the buck with the least time and effort is a decent EQ with programmable settings and pre- programmed settings.
  11. Side note: I didn't like them when I could have seen them in the early 70s, and no matter how much I try I can't make myself like them now. About every ten years I try to like them and fail. The Mastering Engineers have to get the sign off from the performers for the final cuts on the music, so if the artist is deaf or has severe hearing loss you can frequently hear it on the LP, ridiculous high treble etc. There is also Loudness Wars which adds 12db noise and kills fidelity There is also quantization error which sounds increasingly metallic as the bit rates go down Psycho Acoustics added to the re-mastering; and for the low bit rate market mastering adds tons of hiss and other noise to mask just how bad low bit rate sounds over a $1 dac and $2 ear buds. The target market for a lot of the music. Bass Boost for the kids is one more way the re-masters butcher the music for low bit rate playback. And in some cases, bands that sounded great to us when we first heard them years ago, actually suck when played on a reasonably accurate sound system and no amount of adjustments can make them play better on the recording. GIGO Thoughtful remastering like the Louis Armstrong 20th Century Masters, can bring the music back to life and subtract out much of the noise hiss and clicks. I have been told that the other re-masters from this collection are equally thoughtful. Most re-masters releases actually sound noticeably worse than the originals as they add 12db of noise, kill the fidelity, bass boost and add hiss and sound effects to mask the limits of low bit rate. Back to EQ For me, yes sounds good is the goal. To see how I am doing, I like to listen to female voice and acoustic instruments. Girl and a Piano usually works well. Both peak out the performance on the gear, piano strikes are very demanding on amps, any blurring will show up instantly on female vocal. If it's a good recording, it should sound natural and clear as a Bell. Karen Carpenter sounds liquid on so many of her recordings and is the Gold Standard ( for me) when it comes to female vocals. Ronstadt is on the same level, but Carpenter noses her at the finish line. Noemi Wolfs, Nancy Sinatra (who I use to think was just Franks daughter) and some of Poe's tracks are excellent. Dianna Ross is stellar, but I don't think there are any Capella recordings or acoustic with just a piano at her peak. Wolfs early am radio promo for their LP roll out and concerts https://www.youtube.com/watch?v=v2Bs09twUmg&index=6&list=PLgugWBANrQyU39SWyIM6sCIJWo-A3GBlD Poe and piano, I've actually listened to her on showroom systems where her voice almost disappears completely. https://www.youtube.com/watch?v=AEv6NotxuC4
  12. The room and the gear always need EQ, the question is how to do it. The auction site has tons of vintage ones for not much money. In the newer ones, some like dbx, beringer has bang for the buck but has to be modded for heat, there are others.
  13. Depends on the features you want. Auto start and drop Auto pick up Manual Start and drop and auto pick up and off Manual start and finish Belt vs direct drive How the arm is mounted, gimble How tracking and weight are adjusted, and how accurate. Weight of the platter, aka flywheel Dust cover, hinged or not etc etc.
  14. You can pick up an excellent condition used totl surround receiver, preferably THX certified, for whatever you feel like paying off of Craigslist. Read the reviews on the units that catch your eye and check for comments on the forums, just search on Google with the model info AVS will probably pop. Pioneer Elite, Yamaha and the TOTL Sonys come to mind. This gets you a class AB integrated with all of the decoders and interfaces for a couple of hundred dollars, you can set them up to run as stereos.....2.0, 2.1, 2.2. My Mac, Yamaha MX amps and Pioneer Elite AVRs are all dead quite on full volume with no music.
  15. Hum is typically a grounding problem, at least on solid state it is.
  16. The best deals in amps are the used Surround Receivers, some costing thousands of dollars new with THX certifications and clean powerful AB amp sections. Yamaha, Pioneer Elite and the TOTL Sonys come to mind, read the reviews and then go on the hunt. You can pretty much name the price for used ones on Craigslist especially totl units without HDMI interfaces. Also included are the DAC and Decoder Chips sets for every format, SN may be in the 120db range. Also almost every connector is supported. Check the manuals, but most good ones can be configured to run as stereos and dowmix 5.1 and 7/1 to 2.0 or 2.1. There is no shortage of good stand alone phono pre amps, Emo has a good one for about $140.
  17. If the only goal is to max the bass, on the floor in the corner. If you want the horn, where the angles sing, at ear level, and improved bass.......... it's on a table in the corner.
  18. My thinking has evolved quite a bit on this topic. I ran downmix out to my LaScalas for years after I discovered it sounded better than running stereo off of a DVD into my Mac gear (which usually sounds good with almost anything). If I put my best stuff together, it would probably be the Elite as a pre amp feeding the venerable Mac MC 2205; feeding the LaScalas. This would yield the best connectivity, support for all formats and best SN and THD. After sampling a pair of MC-30s with a surround pre amp, I would run a tube amp with a surround pre amp. for the reasons stated above.
  19. as this is the 2 channel area, I'd guess he won't need decoding and signal processing. Hmmm I down-mix DTS to stereo, and I decode the CDs to stereo using a DAC which is integral to the surround receiver. My surround receivers support using only two speakers.
  20. So put it on a table and put it in the corner?
  21. Two thoughts: If used for multiple inputs and decoding use a surround processor for the pre-amp If used for one source use a pot switch as the volume control. Emo makes one with a poor quality switch for $50, or build you own with a totl pot for $20. Either way better signal in is better signal out.
  22. Buy two Ikea end tables in black for $9 ea, forget the model number...... See how it sounds.
  23. A few thoughts on the tech. Class D is gaining acceptance with the manufacturers of "high end" gear. If the Reel to Reel guys are successfully transferring the masters to Reel at it's highest speed setting, tape may be the highest resolution sound available outside of the Mastering Room.
  24. I spent a couple of hours listening to the 820c Altecs that you are referring to, the repair shop out in Rockford is the owner, nice guys. I was very impressed with the Altecs when I heard them a couple of years ago. So much gear, so little space to put it in.
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