I am putting that JVC through it's paces recording test tones onto some extremely old tapes. A 36 year old metal tape did surprisingly well. Right up to 22KHz!
That machine really allows the best results from any tape :-D 22khz is just mad! as most peoples hearing drops like a stone with age. I never expected the ordinary tape to go much above 8khz with a 0db playback amplitude. I can see why that jvc cost so much. What an amazing bit of kit.
No tape is ever going to do 0db at high frequencies without distorting nor does it need to. Real music never contains high frequencies at high amplitude and if it actually did it would destroy tweeters and be acutely painful to listen to. Frequency response tests and bias adjustments are usually done at -12 or -20db and should be relatively flat at these levels. Interesting to see the improvement both HX and Dolby-C make to the highs. This is to be expected since HX drops the bias when highs are present to reduce self-erasing and Dolby-C has an anti saturation feature for high amplitude highs.
Hello. I have a handful of Sony Cassette Decks and one of them is the TC-K666ES. I have the service manual and a little lost how to set the BIAS Trap. I haven't really seen any videos where setting or adjusting rec levels and bias adjustments internally so they are in range of where the external controls can be of some good. Thanks. Love the videos as I'm a big Sony user. Probably would have a retirement built now if I wasn't buying the older Sony ES equipment..lol
Impressive. I was told in my early learning days always calibrate 12.5 khz or 20 khz at minus 20db, no way you could get that at zero db without distorsion. I doubt you can get a good sinus curve at zero db with 22 khz on a metal tape, but, who knows now with Dolby HX and different saturation or bios methods. Its still impressive that a small tape cassette can deliver at 20-22 khz. I remember a recording of Pet Shop Boys in the 90's - Left to my own devices, it was a high frequence sound in the song and that made a "fzzz" sound on a normal tape, and a metal tape just barely made it sound correct. A Swedish trick for hard trying a microphone or a recording for distortion is to shake your locker (car/house) keys infront of the microphone. It will inject a lot of overtones.
Its amazing how well that vintage Sony metal tape performs. No comparison to that crapy Sony ME Hi8 tapes deteriorating while playing them back. Very interesting comparison.
I have a recording of a guy from BASF who said metal tape was formulated so they could try to produce recorders at 15/16 ips and double the length of cassettes - hence the concentration on HF. So we could be looking at C120, C180 and C240 cassettes. But they didn't do the machines. I think they were too expensive to make music work - difficult to regulate for W&F etc.. Interesting to see a quick evaluation of that machine and tape from that time :)
I do use some android app, spectrum analyser where it clearly shows, that 3rd harmonic is largely present during recording. Say, if I input 3Khz, there goes out 9 Khz as well, weakened but present. Can imagine what that di to music material, with full spectrum. Think that comes because head is inductive.
When you set 0 on your tone generator, were you setting 0db for the volume level of the tone? Also once we set the level and bias on the tape, do we ever change the input level when we are recording an audio source (I'm using a line level source). Is that big knob on the deck for output level or input level? I'm using a Nakamichi BX-300 by the way, so I just needed some help with calibration.
A "modern" Type IV from the late 80s could actually reach a SOL of over 0dB (at 250 nWb/m) at 10 kHz. Basic ferrics usually reached -6dB. Type II (be it pure Chrome or Cobalt-doped Ferrite) usually were between Type I and IV. Type IV was always expensive but they had one thing going for them: really low harmonic distortion at comparable levels. Which is why you could drive them really hot or use NR to enjoy music without noise and harmonic distortion. I have a well-aligned 909ES Sony in my collection and on a good Type IV like the '88 TDK MA-X and with Dolby S, that thing gives a DAT deck a run for its money. It goes to show that compact cassette's limitations were pretty high actually. But I also love Type Is for their punchy bass 😊
You would love the rare and hard to find type 3 fecr tape. Punchy bass from the ferric layer and sizzling highs from the crhome top coat. I aware fecr was run out of town by the big tape manufactures so they could push their head eating metal tapes.
@@12voltvids I have two vintage BASF FeCr in my possession. The old ones with the blue J-card and the security mechanism. Unfortunately, they had issues with shedding due to bad bonding between the Ferric and Chrome layers which also contributed to their disappearance. And yes, early Type IV formulations were very rough on the heads, especially the Ferrite heads of the late 70s ... Pioneer's CT-F1250 was notorious for headwear, even with standard tapes. But this was rectified with later Sendust and amorphous heads plus way better Type IVs.
I enjoyed this video and I have a JVC DD-7 that I had gone over by an excellent tech. The faulty capacitor on the Direct Drive was replaced and it was back in business. The DC amps are a great help in achieving the high quality recordings from the Digifine line of JVC cassette decks. Thank you for the excellent video!
@@randolphblack2554I just bought one of these on FB marketplace. Waiting for the idler and pinch roller to do a service on it. Hoping it’s as good as I’ve seen online. Seems like they record really well, but playback is damped by that volume control slider. Wondering if bypassing it would allow for better playback.
Is it possible to somewhat easily adjust a deck with only a record level dial, and internal bias pots? (e.g. my Yamaha KX-400U). It's calibrated to the TDK SA, and I have some NOS late 90s Maxell XLII-S tapes.
@@rogeriorogerio1007 What the metal tape? I worked for Sony at the time and they were clearing out old stock without detection holes. My old technics had manual switch so it didn't matter. Then new decks came out with auto tape and they wouldn't work. Without drilling holes.
We have come a long way from Edison cylinders thru Victrola 78s, microgroove, wire recording, tape recording, CDs high quality 96k samples per second with 24 bit depth digital. What is next?
@@12voltvids Main problem with all the tape media is it is failing after 40 years the binder fails and the tapes self destruct. Cassette tapes loose all the high end with age and the Dolby no longer tracks properly. This is why I am converting all my important tapes to 24 bit 44.1 digital. Digital storage has it's life expectancy too. Optical media fails as oxygen leaks in to the aluminum and destroys the pits and lands. Hard drives fail and loose data, even digital solid state devices will fail and corrupt data. I have more dead CD players kicking around here than analog devices, including a Denon DCD-1560, Sony CDP-X111ES, and a Sony CDP-350. I did put $300 into a new laser transport for my Sony DVP-S9000ES which is an incredible machine for SACD and audio for bargain prices now days. OPPO killer.
@@zulumax1 I have CDR media over 20 years old plays perfect. I keep everything backed up to multiple hard drives. Good quality CDR media lasts a long time. Cheap ones don't last. Probably the longest lasting medium of them all vinyl records. I have some shellac and bakelite 78 rpm records over 100 years old.
Waiting to see what you say about the three head one. All that is all very well, but in the end I gave up with cassettes and only used then in the car to listen to music on the go. With all the road noise and engine noise it didn't really matter. I had a cassette player in the car that took better tapes, but in the car it was hard to tell if it was any better. I played it so loud it was probably distorting anyway! lol But yes I get your point. The thing about tape, I always heard the hiss, no matter what I did, even metal tapes were not all the good. Except on a crap Akai deck (well I thought it was crap) but it did play metal tapes a lot better than others, but I couldn't be bothered listening to cassettes.
I have never been a fan of cassette tapes. Always referred to them as tacky little plastic things. Used it in car and on a walkman and once dat tapes came out I switched to dat. Had a dat player in the car and a day walkman too. I did have a few high end cassette decks but used them in video production for sound track work mostly because clients would supply stuff on cassette. I used dat, minidisk and cd. The hiss drives me crazy. I own a total of less than 50 cassettes.
what do you set the sine wave amplitude to pk-pk? I usually just set my signal generator to like 840mV, because that's supposed to be somewhere around consumer line level, but I have no idea if that's correct
@@12voltvids Thanks. That's what I read on wikipedia, but I am just assuming that I'm supposed to set the input to line level. I'm setting the bias at ~894mV@-10dBV. Do you think that's fine, or should I be aiming higher, like 0dBV? Or does it not really matter?
I used to have an Aiwa F660 that had slightly different levels between the left and right and I never could fix it and never knew why. Over 30 years later, I have an explanation.
Wasn't better to check the output with the oscilloscope? To gauge the quality of the signal. 22khz must be only lower frequency noise back... What about dolby, which one do you prefer? Ever tried dolby S?
@@12voltvids True. But DBX (and Dolby C) requires a fully complementary and perfectly calibrated system. It's hard to achieve on compact cassette. And DBX is incompatible with non-DBX system.
16:04 I thought the 19kHz pilot stereo indicator signal interfered with Dolby tracking that was my understanding of the MPX filter. Also leaking pilot signal will be very weak unless the high cut 15kHz roll off filter on the tuner is poorly designed.
@@12voltvids Thanks for the reply So the main ideal is getting back what is going in ? Signal wize ... So for level its 440 hz ? And for bias it’s what exactly?
I have noticed a big difference in sounds quality of pre recorded cassettes stuff on Warner brothers label and manafactured in German seem to have superior sound quality to other record labels even a type 1 fleetwaood Mac tape sounds great compared to most type ones and chrome tapes on the Warner label sound superb some of the other record labels do not have such high quality recordings .
Some companies didn't wanna change their cheap ferric tapes to cobalt doped "super ferric" for their pre-recorded tapes releases. Another thing, your better sounding tapes might have been digalog (direct from digital copy) versions.
@@12voltvids BASF made pure chrome audio tapes until the late '90s. Some Korean brands (SKC or Saehan) even after 2000, but those were cobalt doped chromes, but they contained chrome, not just ferric cobalt. Actually BASF/EMTEC also made pure chrome tapes until the '00s, but not audio tapes, just VHS. Strange thing about pure chrome tapes that a lot of them became unusable, the particles deteriorated in a way, that it sounds nice with the old recording on it, but if you record something to the same tape nowadays, it will be distorted even at -4dB, no matter how well you calibrate your deck to it. Some of them I can't even calibrate to, because if I set the bias to minimum, and the level to maximum, it's still not right, while I can easily calibrate to an other example of the very same BASF tape type, which was probably stored under better conditions.
@@mrnmrn1 We used to love those "vidiots" that used those BASF chrome VHS tapes because they thought they got a better picture. All they eded up doing was replacing the heads in their VCR every 10 months. One guy I changed the head, at 125.00 a pop at least 5 times, and the guywas bitching about how often he had to change it. I said "Use BASF tape" He said YES. I said thats the reason. Buy better tapes. He said he uses BASF because the picture was better in EP for his wifes soaps, and my reply was well, then I will see you in another 9 or 10 months. That tape was evil.
What kind of Mickey Mouse test is this? I can hear de 10kz signal at 1:36 but then you turn on the notch filter, I can't hear a thing... Furthermore, when you switch from source to tape at 3:23 there's no difference in the VU-Meters !!! Regardless, type I tapes cannot hold more than 12 khz for more than a week, the tape tends to auto-erase itself... Sorry, but I don't see the point of this test with early 80s tapes and the notch filter on, I can't see any change in the VU-Meters when you say it changed from -4 to Odb...
The notch filter was only put on to satisfy the snowflakes that will complain like Donald Trump is about the election result that their ears are hurting. (In other words a bunch of cry babies)
