New to tape, looking for advice on recording levels

W

weeping_wholes

New member
Greetings! I've been recording and mixing on DAWs for a couple of decades and have done a little on the big tape, but nothing extensive and definitely not at home. I just got a Tascam 424 mkii to play with and have noticed that I get funky results with type ii tapes. Funky being low playback levels and sometimes some amplitude up/down warbling. This doesn't happen with type I at all. I've tried a handful of different type ii tapes, including some of the newer Tascam 424-s. When I crank the levels quite a bit the amplitude issues go away and the playback level is a lot more reasonable. From what I understand it makes sense that I'd want to go hotter into type ii, but I'm hitting them with nearly +6 on the meter in order to have them sound like the type I does at 0 - +3.

Does this make sense?

There's a few issues with this recorder so I want to be sure this isn't an additional problem, but expected.

Thanks a lot.
 
Firstly I would make sure that the heads are scrupulously clean using cotton buds (aka Q tips) and isopropyl alcohol. If a thorough head clean doesn't solve the problem then it sounds like someone may have got at the internal level controls that feed the noise reduction or maybe the tapes you are using are different to the tapes that Tascam used to calibrate the machine. Do you see the same issue with the noise reduction switched off?
 
Different tapes need different bias current as well as different pre-emphasis. Your warbling sound is a bit strange though? I too wonder if somebody has tweaked? In fairness most people find that for their serious recording they stick with a brand and type of tape, and if their machine performs well on it, they stay on it. Ferric, chrome, ferric-chrome and the in between versions all offer something, but suit some machines better than others without realignment. The warbling is a new one though. Most problems with setup are constant so I lean towards some kind of issue with noise reduction, which could alter levels, but are you sure the warble is not just a dodgy tape? Most level change faults that go up and down are from head to tape contact, magnetic layer thickness changes and tape stiffness.
 
Years ago, I used quite a few Type II cassettes and never heard a drastic difference between TKD, Maxell and Fuji. I still have a few dozen of them is cases. They were used in a Harmon Kardon 200xm cassette deck with a bias adjust which usually didn't even get tweaked. There was never an issue with warbling or dropouts. That sounds like the tape not tracking true for some reason. I've heard it on reel to reel machines which had problems with alignment.
 
Side question on the topic. If I turn the track down -20db on tape, bounce it to track 2, the sonic data is changed. If I try to take track 2 and go back up +20db the track would lose quality. It is a common way to LoFi with tape machines.

Does this happen with digital in the DAW?
 
The snag with analogue tape is that the bias current adjustment to match a specific tape formation is designed to make sure that the range of levels from quiet to loud changes in a linear fashion - on a graph there is always an S curve and the portion between top and bottom is adjusted to be a straight line joining the bottom and top curves, as in a letter S. Once you drop your record level, you are recording on the non-linear section, and that will impact the sound quality - if you then bounce at the same level, you are getting a double quality hit. The range from top to bottom in digital is much greater, so the point where sound changes hopefully doesn't get discovered.
 
rob aylestone said:
The range from top to bottom in digital is much greater, so the point where sound changes hopefully doesn't get discovered.
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So , that means what? No?

In the DAW I can bring it up or down, without effecting the quality. To me that is odd.

What if you consolidated and exported the tracks into a new project ? that must effect the quality. Then would you need to consolidate the tracks for mixing? or freeze them first to get that behavior.
 
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LazerBeakShiek said:
In the DAW I can bring it up or down, without effecting the quality. To me that is odd.

What if you consolidated and exported the tracks into a new project ? that must effect the quality. Then would you need to consolidate the tracks for mixing? or freeze them first to get that behavior.
Click to expand...

If you use 32 bit floating point files you can attenuate them by well over 1000dB before you hit the point at which you start to lose useful audio data. If you use 16 bit files you would start to notice noise if you attenuated by 40dB and then increased the level by 40dB. The noise would be roughly similar in level to the noise from a decent reel to reel machine. If you use 24 bit files you would end up with the same level of noise if you attenuated the level by 88dB.
 
If the conversion is done totally in the digital realm, there shouldn't be an issue with converting down and up, unless you start trying to take a signal below "zero" which results in the same problem as if you exceed max level. If you have nonlinearity in D/A converters and went D-A-D, then you might have an issue, but I'm guessing that with current converters, those issues would be minuscule.

With a cassette, if you lower the level significantly, and then try to raise it, then you get into problems. First is you completely trash your S/N ratio. Plus you get into the non-linearity that Rob mentioned. If you have something like Dolby NR that isn't perfectly calibrated, then you can add that error. I can't see any circumstance where that would be a desirable goal. If that's what "LoFi" is all about, you can count me out. I lived with it for 20+ years, and the whole goal was to get better sound, not make it sound crappy.
 
I am at a loss to understand this "low level non-linearity of tape? My recollection,donkey's ago, of the 'level v distortion' curve of tape when optimally biased was of progressive distortion. Biased for 3% THD (mostly third as tape has a symmetrical characteristic) the % THD fell in inverse proportion to level i.e. at -6dB ref 3% THD was 1.5% and so on (the actual rate might not be 2:1, long time since I read the Miniflux Nomagraph) At no level does THD start to rise again and of course you hit the noise floor at about -55dB ref 3% depending on tape type.

Both being a 'magnetic process' transformers behave in the same way.

Maybe Sweetbeats can give us the right SP?

Dave.
 
TalismanRich said:
Years ago, I used quite a few Type II cassettes and never heard a drastic difference between TKD, Maxell and Fuji. I still have a few dozen of them is cases. They were used in a Harmon Kardon 200xm cassette deck with a bias adjust which usually didn't even get tweaked. There was never an issue with warbling or dropouts. That sounds like the tape not tracking true for some reason. I've heard it on reel to reel machines which had problems with alignment.
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Harmon Kardon tape decks are sooo good ! Hard to believe they are tape when listening to a good one.
 
mark de berard said:
try using Cr02 II tape, but on the type I setting ...
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That will give you too much high end - and it will be more distorted than it should be too. Fine if you like splashy treble but not if you want an accurate sound.

If you have separate bias and eq controls then you could try using type II tape with the type II tape bias but with type I eq. This was done for some commercial music cassettes because it gave a less distorted top end compared to using type II eq.
 
jamesperrett said:
That will give you too much high end - and it will be more distorted than it should be too. Fine if you like splashy treble but not if you want an accurate sound.

If you have separate bias and eq controls then you could try using type II tape with the type II tape bias but with type I eq. This was done for some commercial music cassettes because it gave a less distorted top end compared to using type II eq.
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yeah i was remembering using tape and always chasing clarity for bouncing.. Some tape decks use a dolby filter for cro2 ( hoping i used the right terminology ) and it just chopped the top end. I didnt have a problem using cro2 tape on the fe02 setting ( that i can remember ) It was when i used Metal tape it sounded really thin..
 
"Harmon Kardon tape decks are sooo good ! Hard to believe they are tape when listening to a good one."

That experience is common to any top end cassette machine I would say Mark.
I have had a Denon with Dolby HX and 'B' and 'C'. Later a Sony with B&C and a later, simpler Denon. All these machines WHEN BIASED AND SET UP CORRECTLY were capable of reproducing a CD with virtually no audible loss.

Depends to a degree on the music genre. Rock/pop you will never tell the difference, maybe a very wide dynamic range choral piece, Beethoven's Ninth say might be a bit strained at the finale.

I have tried virtually all the tape types over the years except metal but fixed on TDK AD as an excellent type for most recordings and TDK SA for the very highest quality results. AD is type 1 but needs an unusually high bias. SA is T2 and equally a high bias tape. Maxell, BASF, fUJI, Philips are also very good tapes but it is vital that the machine is biased correctly for them.

Myth buster. Dolby NR does NOT cause a treble loss IF the machine is properly setup and the system used correctly.

Dave.
 
but it certainly gets much brighter when it's switched off - I suspect this is why people used it on record and switched it out for replay. I remember one actress asking me what the tinny sound was - that. I said with meaning, is called treble!
 
rob aylestone said:
but it certainly gets much brighter when it's switched off - I suspect this is why people used it on record and switched it out for replay. I remember one actress asking me what the tinny sound was - that. I said with meaning, is called treble!
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Yes Rob I know! And this was the cause of much debate and misunderstanding in the 'hi fi' world back in the day.

Dolby B is a frequency dependent (HF) compansion system and when used properly gave a very worthwhile reduction in hiss for cassette and OR tape (though DBX seemed be the winner there despite being inherently flawed)

The problem was, ignorant people would buy Dolby processed music cassettes and either claim they were dull or overbright. Many did not realize they needed to turn the Dolby NR on! The fact was that even if the recordings were made to close tolerances WRT absolute level (ref Dolby level) and frequency response there was little chance that the punter's machine would be properly aligned. And of course, they rarely cleaned the heads!

Dave.
 
I worked for a time in a hifi store and everyone used the tape formulation switches and Dolby to change the tone! Then they invented graphics and everyone had the smiley face curve.
 
Don't forget the Fletcher-Munson "Loudness" button on most receivers back in the day. Turn the volume up AND press the loudness button to really get that really good bass.
 
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