View Full Version : 20 to 20,000hz with type I . . . what decks . . .


tubeboob
03-01-2013, 06:24 AM
I'm looking for a list of cassette decks with a frequency range of 20 to 20,000hz with type I tapes, and yes, I know that's a tall order, but here are the one(s) I know about:

Aiwa XK-S9000

Uh . . . can't think of any more right now . . . :scratch2::scratch2::scratch2:

But I know there are more out there . . . :yes::yes::yes:

Cheers

Soren Hammer
03-01-2013, 06:29 AM
The B&O Beocord 9000 can do 20-20,000 Hz +/-1.5 dB with all types and 20-25,000 +/- 3 dB with metal.

tubeboob
03-01-2013, 06:44 AM
Oh yes . . . and the Harman Kardon CD491 . . . almost forgot about that one . . .

Cheers

jegor
03-01-2013, 06:46 AM
Hitachi D-3300 & D5500M.:nutz:

dr*audio
03-01-2013, 06:52 AM
I think many of the Akai GX-F decks will do that. But the type I tapes available today are crap, why would you want to use them?

tubeboob
03-01-2013, 06:59 AM
I think many of the Akai GX-C decks will do that. But the type I tapes available today are crap, why would you want to use them?

Mostly due to the fact that I have 1000s of pre-recorded tapes that need to be put to work . . .

I do most of my own recording on type II or IV.

Cheers

pdm4606
03-01-2013, 07:18 AM
Don't believe all the hype. Closely look at a frequency plot for this machine.
I don't think you'll get anything useful above 13k or 15k. It may have a large distortion component if anything. Tape is tape and there are limits.
Particularly an old machine where the heads have some mileage and circuits are marginal due to age.
If you focus on a more reliable machine I think you'll be satisfied.

Paul

dr*audio
03-01-2013, 07:42 AM
Do not use pre-recorded cassettes. Most of them are inferior tape stock with abrasive tape. They will ruin your heads. I have replaced so many worn heads on decks that came in with a pre-recorded tape in the deck. If you look at the surface of the tape and compare it with Maxell XLII or TDK SA tape you will see the pre-recorded tape is dull and not shiny like the others. More abrasive. It's a dirty little secret; manufacturers buy the cheapest tape for mass reproduction. If you are making thousands of tapes you are going to use a $.50 tape instead of a $3.00 tape.

Wilhem
03-01-2013, 08:17 AM
The tape stock used for most pre-recorded tapes was either Agfa 649/949 or BASF DPS/LH-D, but Sony and Capitol produced their own tapes. Ampex, Aurex, and SKC also supplied a good deal of tape; and the share of Aurex and SKC increased in the 1990s as BASF refused to compromise on either quality or associated cost. RCA/Sonopress, Capitol, MCA, Sony/Columbia all used more non-BASF tapes than other labels did.

The surface calendering of Agfa, Aurex, BASF, and SKC tape was of very good quality; and profilometer measurements showed little difference between them. The surfaces of all of these tapes were shiny, but the shiny surface is not an indication of abrasive quality. There are far more significant factors involved in head abrasion than the shine on a tape, and shiny ferric-cobalt formulations did, in fact, cause more wear on Sendust heads because of chemical reaction than because of surface friction.

There is no need to worry about pre-recorded tape. Most of them used the same Pfizer oxide as Maxell and TDK did, although surface treatments, processing, and coating methods differed.

Putterman
03-01-2013, 08:20 AM
Do not use pre-recorded cassettes. Most of them are inferior tape stock with abrasive tape. They will ruin your heads. I have replaced so many worn heads on decks that came in with a pre-recorded tape in the deck. If you look at the surface of the tape and compare it with Maxell XLII or TDK SA tape you will see the pre-recorded tape is dull and not shiny like the others. More abrasive. It's a dirty little secret; manufacturers buy the cheapest tape for mass reproduction. If you are making thousands of tapes you are going to use a $.50 tape instead of a $3.00 tape.

I wasn't really aware of that. I just found that prerecorded tapes were much lower quality than those I made myself. I would also posit that the OP is unlikely to hear the difference between a deck going 20hz to 20khz vs. say 20 to 18k except to the degree it may be a better quality deck.

dr*audio
03-01-2013, 08:28 AM
The tape stock used for most pre-recorded tapes was either Agfa 649/949 or BASF DPS/LH-D, but Sony and Capitol produced their own tapes. Ampex, Aurex, and SKC also supplied a good deal of tape; and the share of Aurex and SKC increased in the 1990s as BASF refused to compromise on either quality or associated cost. RCA/Sonopress, Capitol, MCA, Sony/Columbia all used more non-BASF tapes than other labels did.

The surface calendering of Agfa, Aurex, BASF, and SKC tape was of very good quality; and profilometer measurements showed little difference between them. The surfaces of all of these tapes were shiny, but the shiny surface is not an indication of abrasive quality. There are far more significant factors involved in head abrasion than the shine on a tape, and shiny ferric-cobalt formulations did, in fact, cause more wear on Sendust heads because of chemical reaction than because of surface friction.

There is no need to worry about pre-recorded tape. Most of them used the same Pfizer oxide as Maxell and TDK did, although surface treatments, processing, and coating methods differed.

So... the cause of the worn heads I replaced could be poor care by the user or poor quality heads? Wilhelm is really knowledgeable on this and I guess I have to go with what he is saying.

Alex Nikitin
03-01-2013, 08:35 AM
The frequency response in the specifications of cassette decks usually quoted for the recording and playback cycle at -20dB level. Obviously the playback only response would be at least as wide and usually wider than the best in specifications (i.e. if the deck is specified for 20Hz-20kHz range for Metal tapes it should play back that range from "any" tape, including Type I). There are many decks with a specified 20Hz-20kHz response - almost all Nakamichi decks, including 2-headers have that, many Harman/Kardon decks, Aiwa decks etc. The recording performance is a different matter - there are decks capable of 15Hz-27kHz recording on a "modern" Type I tape (the Nakamichi 1000ZXL for example).

Cheers

Alex

Lapis
03-01-2013, 08:39 AM
Most Nakamichi decks are capable of reproducing 20-20khz, especially Nak's first two cassette decks (700 and 1000) from 1973 as well as most 2-headers.

oldvinyldude
03-01-2013, 09:22 AM
I have learned to be careful not to place too much emphasis on published specifications for frequency response on tape decks.

Akai, for instance, was famous for quoting some incredible frequency numbers for their later reel to reel decks. Other decks of the same vintage, did not compare favorably, even the Revoxes and Studers, when focusing on the raw frequency response figures. However, Akai left out key associated specifications, or people like me did not see the significance of them. It was much more impressive to see an Akai 636 quoted at 30-27k hz at 7 1/2 ips, even though it might be +/- 3db, recorded at -20db level. A Studer A820, one of the finest mastering recorders ever, quotes 30-16k response, +/- 2db, and 30-12k +/- 1db, at 0db level. The recording level and tolerance have a huge effect on quotable response, but it took a long time for me to appreciate this.

I will take the 30-12k +/- 1db, at 0vu any day, over 30-27khz quoted for the Akai. Don't get me wrong-I have 3 Akai's, and they are good machines, but I lust for an A820.

However, for comparative purposes, with consumer cassette decks, the quoted frequency response numbers are usually given with similar +/- db and levels (or no level is given, but can be assumed to be -20db). Therefore, one can make valid comparisons between frequency response of various decks. However, effective response for the listener, is likely far lower at the top end, than the specs might suggest.

I would expect the subjective sound of a TOTL machine made by the top manufacturers to be clearly superior to the sound of a modest deck, even though their response might be only 1 or 2khz apart. There are so many other factors that effect that sound, and the frequency response is only one of them.

jan_stevns
03-01-2013, 09:28 AM
So... the cause of the worn heads I replaced could be poor care by the user or poor quality heads? Wilhelm is really knowledgeable on this and I guess I have to go with what he is saying.

Or the very simple answer - they are worn because they have been used !

no big deal there ..........

1tumbleweed
03-01-2013, 09:37 AM
There's something else to consider here:

Prerecorded cassettes in general don't have very good high ends - certainly not anywhere near 20kHz, so if all you want to do is play prerecorded cassettes, why bother? (Caveat: unless they're some of the few recorded on CrO2...but even then I doubt you'd hear much past 15kHz.)

KentTeffeteller
03-01-2013, 04:41 PM
And ReVox frequency response on their tape machines are conservative a la Studer. Remember, they will meet their ratings at 0 db. No Akai will ever do that. Likewise Otari and Ampex on their ratings. In short, honest.

Lapis
03-05-2013, 11:01 AM
There's something else to consider here:

Prerecorded cassettes in general don't have very good high ends - certainly not anywhere near 20kHz, so if all you want to do is play prerecorded cassettes, why bother? (Caveat: unless they're some of the few recorded on CrO2...but even then I doubt you'd hear much past 15kHz.)

It is caused by azimuth. Plain and simple. Every tape are recorded at different angles, NOT AT 90 degrees.

Wilhem
03-05-2013, 04:30 PM
Every tape are recorded at different angles, NOT AT 90 degrees.

Cassette tape recorded at high-speed is generally at 90 degrees--proper azimuth--unless the technicians are dreadfully sloppy. It's pretty easy to get this measurement correct, and the music duplicators I worked with got it right. Every cassette programme produced from an accurately aligned slave will have exactly the same geometry.

As for the azimuth tracking in cheap housings, that is another issue altogether.

Lapis
03-06-2013, 05:35 AM
Cassette tape recorded at high-speed is generally at 90 degrees--proper azimuth--unless the technicians are dreadfully sloppy. It's pretty easy to get this measurement correct, and the music duplicators I worked with got it right. Every cassette programme produced from an accurately aligned slave will have exactly the same geometry.

As for the azimuth tracking in cheap housings, that is another issue altogether.

There are some pre-recorded cassettes that you deliberately have to misalign the heads as tapes recorded anything other than 90 degrees is wrong. Same as both sides as well. That is why there are auto azimuth adjustment decks like Marantz SD-930 or Nakamichi Dragon (These decks are used to seek the loudest high frequency volume from EVERY tape no matter if is 90 or not).

Some shells if they are warped, that can causes another trouble. Just like warped reels affect azimuth.

portnoy
03-06-2013, 06:29 AM
This is a high end discussion about a low-end medium... from my limited personal experience, I'd recommend the original poster to buy a cassette deck that includes dbx recording and playback. I understand he's going to be playing back lots of prerecorded type I or II dolby tapes, but if he records even one vinyl album I think he'll be much happier with the results from dbx. My Yamaha K-960 was a very good midrange deck back in the day, also many Teac cassette decks included DBX.

happy hunting

KentTeffeteller
03-06-2013, 07:45 AM
But dbx is also incompatible with machines not equipped with it and many of the best decks don't need it. Get an outboard unit if you want dbx. And it demands careful attention to recording levels. No cassette machine can do 20-20,000 hertz with any tape type at more than -20 vu levels at 200 nanowebers. None.

Wilhem
03-06-2013, 08:09 AM
Lapis--you are wrong. You did not understand what I wrote, and you clearly do not understand the intricacies of azimuth geometry.

Chip Chester
03-06-2013, 08:36 AM
Don't overlook high-speed duplication as a contributing factor to pre-recorded cassette frequency response. Additionally, many cassettes were duplicated on raw stock prior to loading in the cassette. (Loop bin duplicators.) Cassettes recorded in this manner probably had pretty good azimuth settings, as they are not dependent on cassetted decks or shells at all -- for recording. "Accurate playback is left as an exercise for the reader."

Chip

Wilhem
03-06-2013, 09:56 AM
Don't overlook high-speed duplication as a contributing factor to pre-recorded cassette frequency response.

That was my point from an earlier post. The azimuth adjustment on the slave heads is readily accessible and frequently checked, so there is very little inaccuracy on a tape pancake. (The same is true for wow and flutter--not much at 150 ips.) Almost every pre-recorded cassette was recorded as a pancake and loaded into a housing afterwards. The few that were recorded in cassettes were those from some audiophile labels or from small church organizations.

A limiting factor for pre-recorded cassette frequency response was the bin master tape recorded at 3.75 ips that could lose some high end towards the end of its life. Chrome bin masters were better in that regard, but the best source was the digital bin. In that case, it was a simple matter to get frequency response to extend to 18kHz at 20dB below the reference level even on the better ferric tapes. Those signals can be on the tape, but only a playback head capable of response out to 18-20kHz or so would be able to resolve them. The width of the playback gap is the most critical factor, then the accuracy of the housing.

Lapis
03-07-2013, 04:20 AM
Lapis--you are wrong. You did not understand what I wrote, and you clearly do not understand the intricacies of azimuth geometry.

I'm explaining in laymen's term and in a more informal way. If the shell is warped or cracked, I can understand why azimuth would be bad but a good condition (not cracked and warped) shell should be aligned. Even I have good condition shell, some pre-recorded cassettes just sound bad on both sides even the shell is good.

Lapis
03-07-2013, 04:33 AM
This is a high end discussion about a low-end medium...

So as reel to reel and other magnetic tapes as well if recorded at 3.75 ips with a reel to reel poorly.

just dave
03-07-2013, 05:51 AM
I think the main point is that pre-recorded are usually low quality and their freq. response is never 20-20k so even if you had a deck that could do 10-30k it's not gonna make a bad tape sound better.

Wilhem
03-07-2013, 08:43 AM
The housing has a tremendous influence on the azimuth geometry, and its contributing point vary depending on whether the transport is a single- or a double-capstan design. "Good condition" for a housing requires perfectly vertical contact points on both halves if the housing is a mirror image type, perfectly vertical roller pins (uncommon), well-formed rollers with freedom to move uniformly, and perfectly flat contact points on the frame are just a few of the more important measurements calculated in microns for accuracy. Justing being "flat" and "uncracked" is not nearly enough to quality as "good condition."

Most, but not all, pre-recorded cassettes are of an audio quality lower than that of the first half of a half-speed mastered vinly LP. That does not mean "low quality" because the intrinsic audio quality of the releases of the major labels was better than that of personal recordings made on drug-store, no-name cassettes. The tape stock and the housings were better. Once digital bins became more popular as masters and the ITA procedure for measuring azimuth quality became common, pre-recorded cassettes too a big jump in quality and outperformed a lot of available vinyl records and certainly all the LPs manufactured from reground vinyl.

The frequency response of tape bin masters was unlikely to be 20-20kHz because their recording speed was 3.75 ips; but the digital sources used for bin masters were capable of that frequency range. An LH-D ferric tape recorded from a digital bin could reproduce 18 kHz on a Nakamichi deck if the source were capable of it and the housing were good. A chrome tape under the same conditions could reach 20 kHz.

daniel thoma
03-07-2013, 09:06 AM
If you want cassettes with 20-20khz, you'll need a Nakamichi. Simple as that.

Last weekend, I bought a Nakamichi Cassette Deck 2 ($60) for my mother's 60th birthday, and it sounds absolutely fantastic. I created my first mix tape since the 1980s, had a blast recording audio from radio, my laptop, my laserdiscs, and Youtube. I used a TDK S-60 cassette, Dolby C, and the Nak passed with flying colors. It really is a quantum leap beyond the cheap tape decks and boom boxes we all had as kids in the '80s.

My advice: find yourself a Nak with Dolby C and adjustable bias. If lucky, you'll only have to pay $50-$100 for something in excellent condition. The Cassette Deck 2 is an excellent choice.

FONSguy
03-07-2013, 09:07 AM
This would NOT be at 0dB but probably -20 or -30dB to get out to 20kHz.

jan_stevns
03-07-2013, 09:07 AM
I'm explaining in laymen's term and in a more informal way.

If that causes the wrong informations are reaching the laymen, maybe you should try another way ....

warped reels on a tapedeck can not affect azimuth, what gave you that impresion ?

jan_stevns
03-07-2013, 09:14 AM
If you want cassettes with 20-20khz, you'll need a Nakamichi. Simple as that.

or Luxman K05 or Alpine AL85/90 ....


Type IV frequency response :

20Hz...22Khz ( 1,5dB)


Type II frequency response :

20Hz...20Khz ( 1,5dB)


Type I frequency response :

20Hz...20Khz ( 1,5dB)


.... Nak's aren't the only fine decks on this planet :)

KentTeffeteller
03-07-2013, 02:18 PM
True, Advent is why we had hi fi cassette machines to begin with. Henry Kloss pioneered the category back in 1971.

GYMusic
03-07-2013, 02:48 PM
I think the main point is that pre-recorded are usually low quality and their freq. response is never 20-20k so even if you had a deck that could do 10-30k it's not gonna make a bad tape sound better.

Cassette machine specs are never at operating level. If cassette machines had a frequency response of 20 - 20 kHz +/- 1.5 dB, recording studios would be using them for mastering. They don't.

NEMOaudio
03-07-2013, 02:51 PM
Let me add my PHILIPS N 2552 that is specified 20-20.000 Hz
with all tape types. (I, II, IV)

http://www.audiokarma.org/forums/picture.php?albumid=1692&pictureid=13102

perryinva
03-07-2013, 03:23 PM
Most any higher end 3 head Nak can do 20-20kHz +- 3db at -10dB (0dB 200nWb/m) with a good Type IV and no NR. I set them up all the time. With Type I, you will be limited to around -20dB. I think the OP means that he wants to record OVER many of his pre-recorded tapes, and wants to know what decks to consider. The point to make though, is that there IS NO music content greater than -20dB at 15-20kHz when the average level in the under 1kHz range is at 0dB, so there IS no real reason to spec the 15-20kHz greater than at -20dB. Frequency response is easy to visualize and understand, but in reality is a pretty poor way to jusdge how good a tape deck is.

Lapis
03-08-2013, 07:38 AM
If that causes the wrong informations are reaching the laymen, maybe you should try another way ....

warped reels on a tapedeck can not affect azimuth, what gave you that impresion ?

It is how the tape travels in a R2R,

TS

jan_stevns
03-08-2013, 09:20 AM
It is how the tape travels in a R2R,

TS

so the guides are just gimmicks ?

tubeboob
04-30-2013, 11:28 AM
I did happen to pick up one of the decks that I was coveting, a Harman/Kardon CD491, in excellent cosmetic and operational condition.

This deck is a revelation to me, as cassettes sound absolutely phenomenal.

The published specs do seem to be correlated to actual performance.

I'm now on the lookout for more "high end" cassette decks, as I am now really appreciating the superb sound emanating therefrom . . . :yes::yes::yes:

Cheers . . .

perryinva
05-02-2013, 05:22 PM
Let me know if you still want to bring your 491 to the next level..

BOUXY
05-02-2013, 05:25 PM
If it sounds good to one's ears then that's all one can ask for:)