Calibrating a deck recording

[Alex SE]

My decks are finally serviced and adjusted but there is one thing I'm curious about.
I have tried to adjust BIAS using Maxell UDII-90CD (the one with a clear shell) and TDK SA60 from 82-83. It didn't worked well because... no matter.
Another Phoenix member which I appreciate a lot told me to try with BASF FE tape since it is ferric and should be pretty flat in response. That did a trick.

Now, I would record some songs on the same Maxell UDII-90CD and TDK SA60 and when calibrated correctly a BIAS pot (external) is at +1600 hours for Maxell and 1500 hours for TDK SA.

Now I'm wondering, since that max BIAS is at 1700 hours, what if there is a tape that needs even more BIAS than those chrome tapes I've tested now.

What tape you guys are using for adjusting a BIAS? Normal, chrome, some specific brand/model/year?

Not that I can't ask the same Phoenix member and my dear friend, but if someone already helped you by spending a lot of time to solve your problems, it doesn't mean that you should bother that person every time you're wondering something.

 

[Elite-ist]

If you are set on using blanks that are at the extreme of your external bias settings - when calibrating - then you have to be prepared to make calibration adjustments internally.

Nando.

 

[Alex SE]

If you are set on using blanks that are at the extreme of your external bias settings - when calibrating - then you have to be prepared to make calibration adjustments internally.

Nando.

And that's exactly where I don't want to go

I was curious it there are some tapes that are more "in the middle" and better for BIAS adjustment.

As an amateur, I have so far learned myself that ferric tapes are more flat and needs less bias, while chrome needs more bias. Didn't tested metal tapes.

Here is a plot of BASF FE tape. I'm not reaching 20kHz but 16-17kHz is OK I guess. Shame that 965 don't have EQ adjustments

-20db signal

 

[Elite-ist]

Which deck are you using? I'm sure your operating manual would have listed the brands of tapes it was compatible with. That means keeping to the same vintage of cassette as the year of the deck.

Nando.

 

[Alex SE]

The one I'm talking about is RS-B965 which is I believe from '90. or '91.
I think somebody wrote somewhere that Technics and some other Japanese decks are adjusted with TDK tapes. How good was TDK tapes from that era is something else. I wasn't even thinking about that you said "... as the year of the deck".
Have tested TDK D from 90's and a plot is more or less the same as that FE.

This is FE I have used and this is D.

 

[George S.]

The Phase Linear deck service manual lists three Pioneer and one Sony blank tapes needed to perform a complete calibration of the recording section.
I won't be using those specific blanks.
I'll use the cheap, used 80's TDK tapes I pick up locally, and internally calibrate the deck to those four types, and try to stay with those types.
For the odd tape, if the Microscan won't calibrate the deck to it, no problem. I'll manually calibrate it using the external controls on the face plate.

 

[mr_rye89]

I had to put a new bias pot (the external one) on my Nak BX-300. Before I replaced it I could bias TDK D (1990s), TDK SA (any vintage), Maxell XLII (any?), Sony Metal XR (2000s) just fine but any true CrO2 tape wouldn't bias correctly. I should also try a few more tapes I had touble with (80s TDK D, Fuji DR)

TL;DR is your bias pot broken?

 

[Elite-ist]

So, stick with the 1992-1997 TDK SA. Don't use the TDK SA-X as you will most likely be out of range for your external calibration process.

Image courtesy of vintagecassette.com



Or try the 1990-1991 TDK SA:




Nando.

 

[BlazeES]

Not quite sure about this advice to use specific 'vintage' years of tapes tied closely to the date-of-mfg for a deck. Most quality decks that are well designed & internally calibrated to-spec should have plenty of Bias adjustment range for Type I and Type II's - spanning the early 80's, right on through to the demise of the compact cassette era. (not talking about pure Chrome here).

And the other reference above, about true CrO2 formulations... those will always be finicky to dial in on many, if not most, decks from circa 1986/87 and onward.
Sorta of a crap-shoot and I would be highly suspicious of any deck being able to perform up-to-snuff with a range of other tapes if in fact a true Chrome lands towards the middle of the Bias adjustment range - for a particular deck post-dating - say - 1984.

 

[Elite-ist]

The only problem is you will pay a pretty penny for 80's vintage NOS cassettes. I, recently, found the 2001-2003 TDK CD Power to be an excellent tape to record to... and inexpensive, to boot.




Nando.

 

[BlazeES]

I am also not convinced that certain tapes are unobtainable at decent or even low pricing. Sure, there are these 'forces' that drive up the cost of the more "classic" NOS specimens and create a perception that EVERYTHING is stupid expensive anymore - but at least here in the States - patience is still rewarded with good finds - for new & lightly used NOS.

All these years later (since that era a lot of us were discussing this hobby in the mid-to-late 2000's) I've managed to continue to score relatively inexpensive NOS specimens. The hunt takes more tenacity, more than ever certainly, but there are still people unloading blanks - not knowing what they have and/or just wanting to sell vs. throwing away what they've found in their living spaces or storage lockers.

Luck of the draw; timing; due diligence - are all key factors - but persistence of the hunt is the most important part. It's sort of no different than finding a nice deck.

 

[Elite-ist]

Yes, there are deals still surfacing. A couple of days ago I received 15 NOS cassettes for $100 CAD or just over $6.50 each. This was through a FB Marketplace ad and sometimes FB is where the best deals can be found because as you say there are people unloading blanks for reasonable prices.

I bought all the tapes shown, except for the Memorex and Fuji tapes.

Seller's pictures:





Nando.

 

[J!m]

Those late “CD power” tapes are SA inside a crappy shell.

And through my testing, I’ve shown amazing consistency in SA from 1983 until the bitter blue welded shell end. Take the tape out of a blue shell and pop it into a vintage shell and there is no difference.

And, by the 90’s pretty much every manufacturer had settled on the SA as the type-II standard. Nakamichi of course only ever endorsed their tapes (not sure who made them) and often the metal tape for calibration might not be MA but type II was pretty solid.

For sure, any deck you plan to keep should be internally calibrated for the tape you prefer. Many MANY decks have a single cal point with the others referencing that one point. The D5 is like this. The Panasonic boom box I have was fixed bias but ESL installed a trim pot so it does type 1 and 2 rather than 1 and 4 only. (Had to pus the Metal tape in the early 80’s)

 

[J!m]

Actually the 122 Mk. III is a single cal point referenced. The Mk. I and Mk. II both had three discrete cal points.

 

[Elite-ist]

Those late “CD power” tapes are SA inside a crappy shell.

And through my testing, I’ve shown amazing consistency in SA from 1983 until the bitter blue welded shell end. Take the tape out of a blue shell and pop it into a vintage shell and there is no difference.

And, by the 90’s pretty much every manufacturer had settled on the SA as the type-II standard. Nakamichi of course only ever endorsed their tapes (not sure who made them) and often the metal tape for calibration might not be MA but type II was pretty solid.

For sure, any deck you plan to keep should be internally calibrated for the tape you prefer. Many MANY decks have a single cal point with the others referencing that one point. The D5 is like this. The Panasonic boom box I have was fixed bias but ESL installed a trim pot so it does type 1 and 2 rather than 1 and 4 only. (Had to pus the Metal tape in the early 80’s)

Actually, it has been shown the TDK CD Power is close - if not equal - to TDK SA-X. It's likely the TDK SA-X offcuts ended up being spooled as TDK CD Power.

Nando.

 

[vince666]

can you try if, on external bias knob, you have enough range to calibrate a "black magnetite" version of the maxell XLII-S?
That's one of the type2 tapes which want the highest bias setting i've experienced so far.
So, if you can do those, also with fine bias knob close to the max, then you will be able to calibrate any other type2 out there.
Otherwise, you'd need to raise the bias a bit from the internal pots.

PS: on the aforementioned XLII-S, some treble boost is to be expected, even when biased right.

 

[J!m]

I never realized there was a difference in CDing 2 and CD Power. I thought they were the same tape!

I don’t like CDing 2. That’s a case where i’d just get an MA if they had those CDing only for type 2.

 

[El Magnifico]

Nakamichi tapes were TDK, but allegedly it were taken from the middle of the pancake to have better "quality", as they said. Even though Maxell were the hghest domestic selling tape back then, almost every brand of cassette deck manufacturers used TDK as their reference.

 

[Alex SE]

XLII-S is one of my favs but didn't tested yet to record one on my newly adjusted decks. Good that you Vince pointed that XLII-S one is one of those which needs more bias.

Generally, is it so that all chrome tapes need more bias than normal ones?
How about a metal tapes, are they closer to ferric or chrome?

BTW Vincent was the one who guided me thru bias calibration when I was running out of nerves. Solution was simple (for him), I was using wrong tapes and wrong frequency

One of the most important things I was wrong about is that a deck can be biased so that almost every tape will sound as good as a source and that was totally wrong. Just because some tapes are boosting LF and other HF, non of them have 100% flat response. (Thanx Vince)

What I think is funny is, when cassette decks was up to date back in the 80s, no one was talking about opening decks and making mods or adjustments, neither where a tape was made. It was like a buy a deck you like (and can afford), buy a tapes you like, it was mostly TDK D and SA and Maxell UR and XLII, calibrate (if your deck have that function) and record. That's it. No one, at least in my surrounding was talking about FR and such a thing and I was the only one using Dolby C . I mean, there was just a basic discussions, more about music itself than about technical details about a decks and tapes. And yes, many people bought decks because of how they look or what the seller said and a tapes because it was some specific brand or type.
Today, decks and tapes are no longer produced and it seems that both are more appreciated than 30-40 years ago. And we know much more than we knew in that time. Again, at least for my part.

 

[vince666]

thanks for your nice words, Alex.

about biasing, i prefer to bias while checking mid-low freq MOL and output.
The actual recorded frequency reponse is also influenced by REC EQ too.

about type2 needing more bias than type1 and metals even more... yes, it's this way and the bias difference is just big, it's a substantial difference.
Anyways, the bias setting (both for internal pots and external knob) is automatically set to a different range while the deck detects normal, chrome or metal cassette.
In general, when the deck detects any of the different tapr types, a few things automatically go to the actual range for the detected tape type... i mean bias range, REC gain/sensitivity range, REC EQ and, on the playback side, the PB EQ (120us or 70us).

So, you need to only check if you need more bias from internal pots for XLII-S or you can do them with your actual internal settings.
Of course, if you change the internal bias setting, it will influence the fine bias knob for all tape types.
But your actual reference check is to tune it in order to properly bias type2 and type4 with highest bias requirements and you are OK.
No need to worry a lot about type1 setting because all type1 tapes (excluding the very old ones before the end of the 70s which you probably will never use on that deck) have bias points which are relatively close... so, also a smaller portion of your external bias fine knob (even if not well centered around the zero) is enough to bias them all.

and even more in general, you might check any of the blanks tape models you actually own and take note about their fine bias setting and, then, you can see if you can do them all or you need to touch the internal pots and how.
This way, you can make a well informed choiche just about your own blank tapes (which is what i did here myself).