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#21
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On 12 May 2005 00:09:35 -0700, "Cartrivision1"
wrote: I think I meant "frequency response", not dynamic range. The Quantegy's did not seem to have the same high end response that some of the better Maxell tapes seem to. Also, Fuji made a very good Cro2 tape if I recall correctly, as did Denon. snip I remember 472 needed less bias than did Maxell UDXL-II or the Denon tapes, which were excellent. If you reduced the bias current a bit, I'm pretty sure your top end would come back up and noise would go down. As far as setting the bias correctly, I own what is arguably the finest consumer cassette deck ever produced (Teac V-8030s), snip I'll disagree there. The best cassette decks ever made were from Nakamichi and Denon. and it has a nice facility for setting both level and Bias, as well as automatic tape type selector. I really wanted to like the Quantegy's but they ended up being just average on the whole. snip Your Teac model does indeed have variable bias current, but no facility with which to test using standard 400/10KHz reference tones. Here's how to do it: "Run in" a cartridge, bulk erase it, then set it to the head and record a referece tone of 400 Hz at exactly -10 VU. Note the level on the playback amp with the meter while recording, possible only on a 3 head deck. Old 2 head decks have to be rewound and played back, a real PITA. Change the frequency to 10 KHz, while keeping the same output level from your oscillator. Note the dropoff or run-up of 10 KHz relative to the 400 Hz level. If the 10 KHz tone is now hotter than -10, you're underbiased; if lower, you're overbiased. "Overbiasing" is a pro trick used to nurse a little more headroom out of the tape, and does not work on cassette due to saturation and lack of HF equaliation trimming facilities. If you adjust the bias while recording the 10 KHz tone to make it equal to the 400 Hz tone, bias should be optimal for that partricular oxide and no other. This is what made cassette a bitch of a format for serious users; each tape oxide was different enough in sensitivity and bias requirements to make a machine calibrated for one not suitable for use with another. Sensitivity is another issue, and 472 is a little hotter than was Maxell UDXL-II, XL-II, TDK SA or the Denon CrO2 tapes. You can set your record amp internally to make a recorded O VU 400 Hz tone equal to O VU on playback, but you'll need a calibrated alignment tape to do this right, especially if you use Dolby "B". Dolby mistracking is responsible for more frequency response problems than is biasing, and a tape of different sensitivity than what the deck was calibrated for by more than, say, 1 dB will cause enough Dolby mistracking to cause high frequency response problems. This was the big advantage of dbx over Dolby "A" and "B"...no need for a reference fluxivity, since it was a linear 2:1 compandor scheme. However, like Dolby "A", dbx was unlistenable without decoding, whereas "B" was a "compatable" format...well, sort of, anyway. Dolby "B" tapes played on machines with no Dolby decoders (like 99% of the car decks out there) will sound artificially bright in the upper midrange, and simply "turning down the treble" by 10 dB will make the tape sound tubby. .. Any cassette deck made after 1981 will have a 0 VU reference of 250 nanoWebers/meter, and decks older than that are generally 160, about 4 dB lower. On most (not all) 250 nWb/m decks, "Dolby level" was 400 Hz at a +4, although everyone had their own idea of where "Dolby level" was supposed to be, making a service manual a must. Any recordist serious about cassette (or any other format, for that matter) should have a real alignment tape in their tool kit, not some fraud dupe off of eBay. The best alignment cassettes come from MRL (still in business), STL and Nortronics (now both gone). Head azimuth is ultra critical on cassettes, owing to the slow tape speed, and the only way to get a real perpendicularity reference is with a lab grade alignment tape. Our resident fraudster, Charlie Nudo (aka 66fourdoor on ebay), is still selling fake alignment cartridges for 8 track on ebay. They are poor quality homebrew dubs and will screw up your machine if you try to use them as a reference standard. He was also trying to sell dubbed alignment cassettes, too, but he's not trying that anymore. Hopefully, ebay will soon suspend him for selling bogus merchandise. dB |
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#22
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On 12 May 2005 07:13:41 -0700, "CAINE"
wrote: The externally adjustable bias knob on the cassette decks is a nice feature- but I leave it set to zero with good results. My one Technics deck has that option. snip Charlie Nudo, aka "CAINE", aka 66fourdoor, et al, doesn't know what "bias" is to start with. Last year, he pooped himself by stating the "playback bias" had to be set (see the archives). Any idiot knows there is no such thing. Go eat some more dog turds, Noodles! |
#23
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DeserTBoB wrote: On 12 May 2005 00:09:35 -0700, "Cartrivision1" wrote: I'll disagree there. The best cassette decks ever made were from Nakamichi and Denon. Even the later model Nak decks did not have Dolby S as my Teac does. The Teac V-8030s originally retailed for $1100 in 1995, and this model represented the latest in cassette technology at the time that cassette decks were on the way out. If you look at all of the features and specs of a Nak Dragon compared with the Teac, I am sure the Teac would win out easily. Plus you don't have the capatability problem with other decks with the Teac as you do with Nak decks. and it has a nice facility for setting both level and Bias, as well as automatic tape type selector. I really wanted to like the Quantegy's but they ended up being just average on the whole. snip Your Teac model does indeed have variable bias current, but no facility with which to test using standard 400/10KHz reference tones. Here's how to do it: The Teac has an excellent facility for setting optimal bias and sensitivity settings for each kind of cassette tape depending on both the tape type and manufacturer. But I do think that you are right that setting the bias a bit higher will produce better high frequency results. LP |
#24
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On 12 May 2005 13:59:53 -0700, "Cartrivision1"
wrote: DeserTBoB wrote: On 12 May 2005 00:09:35 -0700, "Cartrivision1" wrote: I'll disagree there. The best cassette decks ever made were from Nakamichi and Denon. Even the later model Nak decks did not have Dolby S as my Teac does. The Teac V-8030s originally retailed for $1100 in 1995, and this model represented the latest in cassette technology at the time that cassette decks were on the way out. snip Rare indeed. If you look at all of the features and specs of a Nak Dragon compared with the Teac, I am sure the Teac would win out easily. Plus you don't have the capatability problem with other decks with the Teac as you do with Nak decks. snip Interesting indeed. Probably Teac's magnum opus? I remember earlier Teac cassette decks being similar to their semi-pro RTRs...kinda weak. If you say this Teac beats a Nak Dragon, that's a pretty high powered praise, indeed! The Dragon's a pretty sophisticated machine. The Teac has an excellent facility for setting optimal bias and sensitivity settings for each kind of cassette tape depending on both the tape type and manufacturer. But I do think that you are right that setting the bias a bit higher will produce better high frequency results. snip Hmmm, hard to say. If this model has autobias capability, it should be able to set itself up perfectly. Like many autobias schemes, though, internal calibration is everything. Maybe all it needed was a little recalibration? I cannot figure out why you're getting the results you were getting on such a capable machine when I got sort of the opposite. By the way, increasing bias current over optimal will kill the top end on modern tape, not raise it. Underbiased tape will have exaggerated top end and higher third harmonic distortion up near saturation. Overbiased tape will have a rolled off top end, low distortion, and higher "bias noise". Does this Teac have a manual override of the autobiasing function? All this is probably academic anyway, since you've long since gotten rid of 472...and there's none on the market today in most places! Ever try TDK SA? dB |
#25
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If you were using a reel to reel deck, and had the choice of either
1-7/8 IPS or 3.75 IPS on the speed selector switch, which one would you choose for the best fidelity ? Answer: the 3.75 IPS which is why, an 8-track cartridge sounds better than any cassette in the universe. cassettes have a slight reliability advantage- at first- but with time, any cassette tape made ends up a crinkled POS mess that squeals like hell. once an 8-track is gone over and maintenanced properly, it will run for another 20 years. The tape strength and durability is far superior for the long run, over a cassette old engineers' adage- want to make something stronger ? Make it from better material, or make it bigger, or both. In the case of the 8-track, it's bigger. And moves at twice the speed. Speed is everything in analog formats. The same reason why 45's sound better than LP's, and a clean 78 will pale a 45, in the vinyl format. analog tape- wider is better, faster IPS is better- that 8-track tape is basically 1/4" open reel tape with a graphite backing- stuffed in a plastic shell- and minus one reel |
#26
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Man 0 man- Ebay is going CRAZY lately- I can barely keep up with the
sales ! Last month hit $2700 !! thanks guys, could not have done it without your help thanks for bumping the for sale threads for me... |
#27
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DeserTBoB wrote:
On 12 May 2005 13:59:53 -0700, "Cartrivision1" wrote: Hmmm, hard to say. If this model has autobias capability, it should be able to set itself up perfectly. Like many autobias schemes, though, internal calibration is everything. Maybe all it needed was a little recalibration? I cannot figure out why you're getting the results you were getting on such a capable machine when I got sort of the opposite. By the way, increasing bias current over optimal will kill the top end on modern tape, not raise it. Underbiased tape will have exaggerated top end and higher third harmonic distortion up near saturation. Overbiased tape will have a rolled off top end, low distortion, and higher "bias noise". Does this Teac have a manual override of the autobiasing function? Hi dB, no the Teac deck of mine has both manual bias and sensitivity setting(s)....for both chanels. The display gives a reference point for each type of tape (metal, Cro2, etc.) and you just twiddle the knobs until you reach the right level. That is good to know that overbiasing will ruin treble response. I am fairly new to high end audio and up until a few years ago I never even used the tape type selector when recording. No wonder all of my tapes sounded funny! All this is probably academic anyway, since you've long since gotten rid of 472...and there's none on the market today in most places! Ever try TDK SA? No actually I recorded on one of my 472's last night. The recording came out pretty well but for some reason the Quantegys just don't seem to have a good high end response. I guess I am just spoiled wih the TDK and Maxell tapes. And yes, I do like the SA's as they typically have very good treble response. Luke |
#28
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DeserTBoB wrote: On 12 May 2005 13:59:53 -0700, "Cartrivision1" wrote: Hmmm, hard to say. If this model has autobias capability, it should be able to set itself up perfectly. Like many autobias schemes, though, internal calibration is everything. Maybe all it needed was a little recalibration? No, the Teac has manual bias and sensitivity settings (for each channel even). The display shows a reference point and you just twiddle the knobs until you get to the right setting. And then just rewind and rerecord over the test tone. Overbiased tape will have a rolled off top end, low distortion, and higher "bias noise". Does this Teac have a manual override of the autobiasing function? That is good to know. You can learn a lot from usenet. I am fairly new to high end audio, and up until just a few years ago I never even used the "tape type" selector when making a recording. No wonder all of my tapes sounded funny! On the same note, I thought I read somewhere that prerecorded tape manufacturers would sometime use normal tape bias settings when recording on a Chrome tape for a better outcome. Or maybe it was the other way around? All this is probably academic anyway, since you've long since gotten rid of 472...and there's none on the market today in most places! Ever try TDK SA? Yeah, the TDK SA is a very good tape and I have always had good results with those. As well as the Maxell XL II S which is a very good all around tape. I also used to like the Denon HD8....except those are impossible to find nowadays. Luke dB |
#29
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just one question Luke, why are you talking about cassettes in detail,
on an 8-track tape cartridge collecting site ? |
#30
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On 12 May 2005 19:29:37 -0700, "UNIVERSAL GENIUS"
wrote: Man 0 man- Ebay is going CRAZY lately- I can barely keep up with the sales ! Last month hit $2700 !! snip Copied and sent to the IRS. HAHAHAHAHA! |
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