Cassette's Not Dead, Apparently!

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Originally Posted by F307

Alex: I used to own a Tascam 122 & 234 cassette machine with higher speed..

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I'm sorry, dear, but I've listend to those two models myself, and sonically even with those higher speed than typical cassette decks, I was never impressed.

Btw. I was interested in those two models for three reasons.

1. They were Tascam, and I've heard that when it comes to reliability, pro version of Tascams were the tops, better than anything from professional repair people.

2. I was intrigued by the higher speed.

3. I just loved their 'Don't mess with me' looks, very sturdy, and 'professional' looking.

....till I've listened to their sound quality, needless to say I was way underwhelmed.

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Originally Posted by F307

Nick:
All that Metal & Chrome never bothered me, it bothered me when i had cassette decks but not open Reel. i buy the best tape for the R+R machine.

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What is your best tape for Open reels?

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Originally Posted by F307

I have noise reduction units but never use them on the machine.

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I am with you there. I never use NR.

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Originally Posted by TheVillageIdiot

My dear Alex, that deck looks like one of their TOTL from Uher, am I right?

Btw. I agree some of the TOTL cassette deck's sonic is as good as 7.5ips as may be hard to believe for some people.

My favorite deck certainly is.

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I think it's a modified Technics, but I may be wrong...

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Originally Posted by Alex Nikitin

And I suspect these did sound considerably worse than a good R2R.

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They were, 25 to 20k at their highest speed, using metal, +-3db.

http://tascam.com/content/downloads/...II_TECHDOC.pdf

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Originally Posted by Alex Nikitin

However the deck I've used at the show is nothing like those decks. The deck in the picture I would happily put against a good R2R at 15 ips (as 7.5 ips has very little chances). It is a cassette done right ;) . 20Hz-30kHz bandwidth, about 65-67 dBA SNR with a good Type II or Metal tape (without NR, obviously - the deck hasn't got any).

Cheers

Alex

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How did you even manage up to 30khz, even more, how did you still manage to keep bottom end to 20hz? I am not asking you for a trade secret, but did it have to do with modifying heads or just electronics?

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Originally Posted by Beechwoods

I think it's a modified Technics, but I may be wrong...

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I think you're right. I mixed up with Uher decks.

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Originally Posted by Beechwoods

Most people haven't heard cassette done well. For me the key thing is not so much to record, and play that recording back brilliantly, but to squeeze every ounce of fidelity from a pre-recorded tape from some other deck. In my experience, decks tend to record better than they can play back, which means you can retrieve shockingly good playback from old tapes recorded on moribund equipment, with the right playback machine.

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So do you think azimuth playback control helps?

It's useful, but I find I don't use it that much now I have it, most recordings have good azimuth, it's the quality of the transport that makes the biggest difference :)

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Originally Posted by DSJR

I've heard it, before and after, using real live analogue master tapes! you haven't, obviously :ner: In no way does vinyl come anywhere near the fidelity of the master-tape, even on a proper turntable, although the best ones (if not refining all the energy out in the process of £refining) do a great job, the limiting bits being the sh*tty black plastic played (most of the time) on them.

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I agree with you there. Do you think it's due to inferior channel separation of LPs compared to tapes?

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Originally Posted by TheVillageIdiot

I think you're right. I mixed up with Uher decks.

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It is actually a heavily modified Tascam 122mkIII, with Dolby chips removed and replaced by my special hybrid modules, a serious rework to other electronics, my ANT4066 chips for switching and additional screening on the transport and control buttons. Here are some photos and graphs from that deck. The DIN reference level (250nWb/m) is at -10dBFS on the graphs.

I choose the Tascam as it is well built, the transport is designed to run at 3.75 ips, the bias frequency is 150kHz and it has good calibration facilities and excellent discrete amorphous heads. In its original form it does sound like crap thought... .

Alex

P.S. - some explanation on the graphs - the first one shows the frequency response at 0dB DIN, +6dB, -10dB and -20dB using Sony Metal XR tape. As you may see the frequency response does not change with the level (no R2R at 7.5 ips can do that, only at 15 ips). The second graph shows a very good linearity of the unit - it is an intermodulation test with 10kHz+11kHz tones at -10dB DIN RMS level, using the same Sony Metal XR tape - a very difficult test even for the best tape recorders.

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Originally Posted by Alex Nikitin

I choose the Tascam as it is well built, the transport is designed to run at 3.75 ips, the bias frequency is 150kHz and it has good calibration facilities and excellent discrete amorphous heads.

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I believe 122 used direct drive transport. I don't think Dolph approved of direct drive transport for sonic reasons.

Btw. Even though normally I would agree with dolph on direct drive vs. belt drive, not absolutely. Nagra T-audio had the best sonics I ever listened to, but it's totally direct drive.

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Originally Posted by Alex Nikitin

P.S. - some explanation on the graphs - the first one shows the frequency response at 0dB DIN, +6dB, -10dB and -20dB using Sony Metal XR tape. As you may see the frequency response does not change with the level (no R2R at 7.5 ips can do that, only at 15 ips).

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I am very impressed with the curve, especially the flatness. However, I do notice that measured from 20hz, within 3db, the top end goes up to 'only' about 25khz. Not 30khz. Please don't get me wrong, 20 to 25khz within 3db is still spectacular, especially considering the original spec was only 25hz to 20khz within 3db.

EDIT: My apologies, dear Alex, within 3db, your frequency curve actually goes to close to 30khz, I've been working all day on computers without break so I missed it. Also, my favorite deck's frequency curve is 30hz to 20khz within 3db. Still, I believe there was only a dimple at the bottom end, not 'bump' like most frequency curves. I am sorry for unintentional inaccuate statements from me. I still have to find that graph just to see how 'flat' is my deck's curve.




I believe that Beocord 9000 and one of the TOTL Naks go up to 25khz within 3db. (Actually I was informed by one of Nak specialist one TOTL Nak model goes up to 27khz.), that is, only utilizing the standard cassette speed lower than the higher speed available on Tascam 122.

Btw. For what's worth, my favorite deck's spec is only up to 22khz using metal tapes, but I still prefer the sonics of my favorite deck over Beocord 9000 and TOTL Naks.

One particular audiophile society that tested my favorite deck over the other TOTL decks when dubbing LP to cassettes claimed that my favorite deck was the only deck that faithfully coped LP to cassette. They also noted that my favorite deck's flatness of frequency curve was better than anything available, not just in cassettes, but also open reels, especially on bottom end, basically there wasn't much of a 'bump' you see in frequency curves.

When I got the 7th of my favorite model(now I am on 9th), I finally managed to get the original test frequency curve graph along with it, and no, the typical 'bump' you see on the bottom end of the frequency curves was not there, only a tiny dimple, and if I remember it correctly the rest of the curve was just as flat as your modified 122's frequency curve, if not flatter (Of course, my favorite deck only went up to 22khz within 3db unlike yours, which went up to about 25khz within 3db of 20hz.)

I am going to dig out the graph somewhere and compare it with yours.

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Originally Posted by TheVillageIdiot

I believe 122 used direct drive transport. I don't think Dolph approved of direct drive transport for sonic reasons.

Btw. Even though normally I would agree with dolph on direct drive vs. belt drive, not absolutely. Nagra T-audio had the best sonics I ever listened to, but it's totally direct drive.



I am very impressed with the curve, especially the flatness. However, I do notice that measured from 20hz, within 3db, the top end goes up to 'only' about 25khz. Not 30khz. Please don't get me wrong, 20 to 25khz within 3db is still spectacular, especially considering the original spec was only 25hz to 20khz within 3db.

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The response goes to about 27kHz (-3dB) even with a Type I tape, as the attached hi-res graph shows (and if I would reduce the bias a bit than it is easy to get 30 kHz in the +/- 3dB margin). However what important is not the actual extent of the frequency response (it is possible to get over 45 kHz at -20 dB DIN with these heads and 3.75 ips) but the same response even for 0dB input and relatively slow slope, indicating a limited HF lift in the REC EQ amp - it is only about 7-9 dB at 30 kHz. That improves the overload behaviour and phase response.

The Tascam 122mkIII has a DD capstan, however it has very good W&F results, even non-wtd DIN (q-peak) W&F is less than 0.1%, DIN wtd is about 0.05-0.06% at 3.75 ips .

Cheers

Alex