Tascam 22 - Low freq. bump questions

leddy

leddy

Well-known member
Hey folks. So my Tascam 22 has been functioning perfect. All is good.

*Except*

The low frequency bump is pretty substantial, which requires me to do a significant amount of mixing while I'm monitoring from tape. Not a deal killer, but it creates a lot of unnecessary passes on my tape, head wear, etc.

So, are there other tapes that would not have such a bump (I'm using LPR35 @ 15ips)? Do I need to explore adjusting the bias? Is this my payback for buying a more entry-level machine?

As always, I appreciate the help! :)
 
leddy, can you better define a "substantial" head bump? You may just be experiencing the normal spec of the machine. what are you mixing through? Different tape is not going to change the head bump, but how you utilize the tape may. Have you done a calibration recently? What facilities does the 22 have for eq calibration? Can you tell us the frequency response curve of your deck? Even a rough plot...reference 0dB at 1kHz, and then the relative level at 100Hz and 10kHz even might be revealing. Add 40 or 60Hz, maybe 500Hz and 16kHz to tell a bit more...

Sorry that may not be much help, but with a little more info it might give some direction.
 
sweetbeats said:
leddy, can you better define a "substantial" head bump? You may just be experiencing the normal spec of the machine. what are you mixing through? Different tape is not going to change the head bump, but how you utilize the tape may. Have you done a calibration recently? What facilities does the 22 have for eq calibration? Can you tell us the frequency response curve of your deck? Even a rough plot...reference 0dB at 1kHz, and then the relative level at 100Hz and 10kHz even might be revealing. Add 40 or 60Hz, maybe 500Hz and 16kHz to tell a bit more...

Sorry that may not be much help, but with a little more info it might give some direction.
Click to expand...

Thanks. I'll plot that out tonight and report back.
 
Ok I just did it now.

Here's what I got:

1000 @ 0

40 +3.5
60 +3.5
80 +2.5
100 +2.5
200 + 1.5
300 + .5
500 0

5k 0
10k -.5
 
Leddy...that is a healthy head bump...:eek:

Wow...

But that's from a tone generator to your LPR35 tape, and then looking at the levels coming off tape right?

  1. Do you have an alignment tape?
  2. Has the deck been calibrated recently?
  3. If it has been calibrated recently, or if you otherwise know the following, what level standard was it calibrated for (i.e. 185, 250, 320 nanowebers/meter etc.?
  4. Do you know what kinds of calibration trim controls you have on the 22 (i.e. I know on my 58 there are hi and low eq response trimmers)?
  5. When was the last time you demagged with a good demag unit?
  6. Is the tape path clean?
  7. What is the wear condition of your heads (i.e. flat spots, trapezoidal wear patterns on the heads)?
  8. If you playback a 10kHz tone and apply slight back-pressure to the supply reel (like with one finger on the edge, just to put a little gentle drag on it), do you see the output level of the 10kHz tone increase?
  9. Is this a new sudden problem, or has it always been that way or gradually worsened over time?

Sorry for all the questions, but if you can answer each of them it will help me help you a bunch. ;)

Bullets 5~8 are really dealing with the possibility that you aren't wrangling with a low frequency head bump, but rather a high frequency rolloff due to a worn, soiled, magnetized or maladjusted tape path that is presenting as an increased low-end response but is actually causing a decreased high-end response.

Anybody else with a 22 that can help leddy out with this?
 
Also, sorry if my questions seem basic...you have clearly been around for awhile...I always like to start from a "is there gas in the tank" approach and go from there. I have had the good fortune of respected others pointing out to me that the tank is indeed empty. :D:D

Do you have a manual for the 22, and if so what does it say about the proper frequency reponse that should be expected?

Also, BTW, I understand the 22 to be a fine deck. Let go of the "entry-level" hype. It is well-made with potential for great recordings.

Lastly, you are correct that a bias adjustment may be an issue as well, right inline with my thought of the issue being not a low-end hump, but a high-end rolloff.
 
I am doing my best to live life with no ego. Feel free to ask me if I have the thing plugged in. :)

Yes, I recorded the tones from Wavelab in my PC and played them back, noting the differences.

No alignment tape.

I have no idea if it was calibrated recently. I did take it to a local tech who said it was operating nicely. I trusted that meant it was not needed. I asked him about demagnetizing the heads and he said it was not needed. Again, I trusted him - but I know he had some prejudice against the machine. He said these were toys compared to what he normally works on.
Nice guy, though. I'd still go back to him.

I do not know what the calibration controls would be.

I do keep the heads clean. They have an even wear pattern, and are in decent shape by my own judgement and that of the tech.

Putting drag on the reel playing a 10k tone makes the output decrease.

The deck has performed this way since I got it.

I do have a manual, and it says +/- 3db accross the range, so I guess it's not really out of spec by much.

Now here's some new info:
I have another Tascam 22. I bought it from the tech who fixed this one. It was on a shelf and he only wanted $40 for it. We checked it out to make sure everything worked. I have yet to use it - I was keeping it as a spare. I will pull it out and perform the same tests and report back.

:)
 
I am doing my best to live life with no ego. Feel free to ask me if I have the thing plugged in.
Click to expand...

Right on!

No alignment tape.
Click to expand...

Okay. The problem with doing your tests using tones recorded onto tape and played back is that the response curve will be influenced by the record electronics on the 22-2, as well as the D/A converter and amplifier characteristics of your soundcard, rather than just reproducing from a tape made with a known/flat response. There is a cumulative effect. Does that make sense?

I do not know what the calibration controls would be.
Click to expand...

Okay. No prob. We can go there if needed, but not yet. You'd need the calibration tape first too anyway, which, if you got the short tape, would not cost too much for your deck.

I do keep the heads clean. They have an even wear pattern, and are in decent shape by my own judgement and that of the tech.
Click to expand...

Any possibility that you could post up a picture of your heads? Worth a thousand words. ;)

Putting drag on the reel playing a 10k tone makes the output decrease.
Click to expand...

And you're applying the drag to the supply reel right?

I do have a manual, and it says +/- 3db accross the range, so I guess it's not really out of spec by much.
Click to expand...

And what is the frequency range specified for that response range? Does your manual have the maintenance section?

I did take it to a local tech who said it was operating nicely. I trusted that meant it was not needed.
Click to expand...

May have been speaking mechanically.

I asked him about demagnetizing the heads and he said it was not needed. Again, I trusted him - but I know he had some prejudice against the machine. He said these were toys compared to what he normally works on.
Nice guy, though. I'd still go back to him.
Click to expand...

May have been a nice guy, but IMHO he's doing you somewhat of a disservice if he indicates demagging is not necessary/needed. Unless he was able to measure the gauss on the heads he has no idea how magnetized they are. That could be a significant contributor. Who knows when it was done last and it can indeed have a serious effect on the high frequency response of an atr. I suggest you get a demag unit. A good one like the Han-D-Mag (it is worth it), not the $10 toys that are on eBay all over the place. I'm speaking from direct experience. Now, I think I am justified in calling those "toys", because they are not capable of getting the job done. Your 22-2 however is capable of getting plenty done and I take respectful exception to the tech referring to your 22-2 as a toy. I don't care if he spends all day working on Studer or ampex 1/2" 1/2 track decks...respect the deck and the user...no sense in him putting you in the place he feels you are. My 2p. ;)
 
sweetbeats said:
Okay. The problem with doing your tests using tones recorded onto tape and played back is that the response curve will be influenced by the record electronics on the 22-2, as well as the D/A converter and amplifier characteristics of your soundcard, rather than just reproducing from a tape made with a known/flat response. There is a cumulative effect. Does that make sense?
Click to expand...

Makes perfect sense. I need a test tape or at least a different test tone generator. I will hunt down a test tape. I'm actually in the market for new converters as well, but I will still get a tape first.

sweetbeats said:
Any possibility that you could post up a picture of your heads? Worth a thousand words. ;)
Click to expand...

I'll see what I can do.

sweetbeats said:
And you're applying the drag to the supply reel right?
Click to expand...

Affirmative.

sweetbeats said:
And what is the frequency range specified for that response range? Does your manual have the maintenance section?
Click to expand...

40-22kHz +/- 3db @0 VU
35-25kHz +/- 3db @-10 VU

Yes, there is a maintenence section. I'll do some studying.

sweetbeats said:
May have been a nice guy, but IMHO he's doing you somewhat of a disservice if he indicates demagging is not necessary/needed. Unless he was able to measure the gauss on the heads he has no idea how magnetized they are. That could be a significant contributor. Who knows when it was done last and it can indeed have a serious effect on the high frequency response of an atr. I suggest you get a demag unit. A good one like the Han-D-Mag (it is worth it), not the $10 toys that are on eBay all over the place. I'm speaking from direct experience. Now, I think I am justified in calling those "toys", because they are not capable of getting the job done. Your 22-2 however is capable of getting plenty done and I take respectful exception to the tech referring to your 22-2 as a toy. I don't care if he spends all day working on Studer or ampex 1/2" 1/2 track decks...respect the deck and the user...no sense in him putting you in the place he feels you are. My 2p. ;)
Click to expand...

I will also buy a demag unit. A good one.

Looks like I have some homework to do. I'll order the tape and demag unit. I'm going out of town for a few days, so I'll hopefully have these things next week when I'm back. I'll let you know when I'm back at it.

Thanks again for all the great help. :)
 
BTW, Where's the best place to go for the ref. tape, and how do I tell what nWb/m I need?

Sweetbeats, I PM'd you in case you don't check back here before I go.
 
leddy said:
I have no idea if it was calibrated recently. I did take it to a local tech who said it was operating nicely. I trusted that meant it was not needed. I asked him about demagnetizing the heads and he said it was not needed. Again, I trusted him - but I know he had some prejudice against the machine. He said these were toys compared to what he normally works on.

Nice guy, though. I'd still go back to him.
Click to expand...

For what… to talk about the weather? :D ;)

Take it to a tech who cares or better yet learn to calibrate it yourself. These are nice little machines and easy to calibrate once you get the hang of it. The 22-2 is one of the least expensive half-tracks ever made, but is a decent unit, and can be moded to increase performance. In any case a used machine should be calibrated when you get it no matter what it is. The nice tech is wrong on all points. :)
 
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Leddy,

I agree with Beck 100%.

Tim, Do you still have a couple of these yourself?

What is the machine setup for...250 nanowebers/meter? IEC or NAB? I'd like to help leddy select the right cal tape...

BTW, Where's the best place to go for the ref. tape, and how do I tell what nWb/m I need?
Click to expand...

There are a number of places to get the tapes. If you want to make sure you are getting the genuine article and brand new, you can get it from someplace like US Recording Media. If you're not familiar with them, browse around. Kind of one stop shopping for us analog-o-philes...there are other places too, I'm just most familiar with them and am happy with their services. Might be better prices elswhere but not by much. There is also probably a link or links to dealers on the MRL Website. You have probably been there already. :)

Be careful of the temptation to get a used cal tape or even new cal tape on eBay or similar, unless you know the source. I was a rebel and bought a used tape from the 90's from an unknown (at the time) source, but the Seller had 100% feedback so I went for it. I was lucky...months and months later after becoming active on this forum I discovered it was Beck from whom I purchased the tape!! :D He's a great guy...tremendous resource...you probably know that already...what am I saying? I'm the spring checken around here. :D:rolleyes::p

On the nWb/m rating of your deck, there should be, on the specs page in your manual, a line that states what nWb/m the deck is setup for...the reference from which they obtained the performance specs...also the equalization standard (either IEC or NAB). I'm guessing it is 250nWb/m and NAB standard, but check your specs page and if you can't find it on there hopefully Beck or another in-the-know user will post it up.

Makes perfect sense. I need a test tape or at least a different test tone generator.
Click to expand...

Yeah, but keep in mind that even with a different tone generator, like a dedicated external analog generator, you still would be recording tones with the response curve of the record electronics. You've got the idea...to do it right you need the cal tape.

Quote:
Originally Posted by sweetbeats
And you're applying the drag to the supply reel right?

Affirmative.
Click to expand...

Hmm...seems I've seen that on my 58 before. Just make sure the pressure you are applying is very light. My guess is you are fine. If the VU's deflect higher with increased back-pressure it means that the tape is not contacting the head(s) well enough in normal operation which will have a measurable effect on the high-end response among other areas of the spectrum. If the meters deflect down just for a moment when you first apply increased back-pressure that is normal...it is just the tension mechanism catching up with the change. If they do that and then pop back to where they were, all is good. If they drop and and then pop to a higher reading than they were under normal operation then the "wrap" or tape to head contact is not strong enough and the heads have to be physically adjusted. If the signal is not getting stronger with increased back-pressure, I believe all is good and I'd keep the tools off the head-mounting screws. :D

40-22kHz +/- 3db @0 VU
35-25kHz +/- 3db @-10 VU
Click to expand...

Toy my...as I was saying earlier, those are not toy specs. Ksounds has been putting up some great stuff done on a 424 mkII...or check out stuff Dave (A Reel Person) has done on his cassette 4-trackers...246 and 244 I believe. Neither are using fancy schmancy stuff...even the mics (though I recall Ksounds is using a Rode NT3) aren't big $$$ gear...Dave is using some sleeper Tascam condensors from two decades ago I think...but they are both getting GREAT sounds...beautiful recordings...its mic placement, careful mastering, the room and the artistic content. On paper your 22-2 smokes a cassette 4-track. It outspecs the 3340S I used to have which made the most unbelievable recordings of my electric bass I have ever been able to attain thus far (hoping for similar results out of my 58)...the tech you used, and I'm not questioning you...is speaking a bit snobbish.

Man I was looking at 22-2's online...they go for CHEAP! I even saw a 22-4 for just over $100 that looked great. That's crazy...and with the 7" reels on the 1mil tape, media is very affordable and yet the tape path looks like a 32. Seems like a great option.

What are you using for A/D/A and do you have an analog mixer?
 
Beck said:
For what… to talk about the weather? :D ;)
Click to expand...

I hear you. :D

sweetbeats said:
What is the machine setup for...250 nanowebers/meter? IEC or NAB?
Click to expand...

The manual states NAB. Are the nanowebers/meter listed by the distortion specs? If so, it states:

1.0% @ 0 VU, 1000Hz, 185 nWb/m
3.0% @ +10db, 1000Hz, 585 nWb/m

That is the only reference to nWb/m I can find in the specs.

sweetbeats said:
Yeah, but keep in mind that even with a different tone generator, like a dedicated external analog generator, you still would be recording tones with the response curve of the record electronics. You've got the idea...to do it right you need the cal tape.


Hmm...seems I've seen that on my 58 before. Just make sure the pressure you are applying is very light. My guess is you are fine. If the VU's deflect higher with increased back-pressure it means that the tape is not contacting the head(s) well enough in normal operation which will have a measurable effect on the high-end response among other areas of the spectrum. If the meters deflect down just for a moment when you first apply increased back-pressure that is normal...it is just the tension mechanism catching up with the change. If they do that and then pop back to where they were, all is good. If they drop and and then pop to a higher reading than they were under normal operation then the "wrap" or tape to head contact is not strong enough and the heads have to be physically adjusted. If the signal is not getting stronger with increased back-pressure, I believe all is good and I'd keep the tools off the head-mounting screws. :D

Toy my...as I was saying earlier, those are not toy specs. Ksounds has been putting up some great stuff done on a 424 mkII...or check out stuff Dave (A Reel Person) has done on his cassette 4-trackers...246 and 244 I believe. Neither are using fancy schmancy stuff...even the mics (though I recall Ksounds is using a Rode NT3) aren't big $$$ gear...Dave is using some sleeper Tascam condensors from two decades ago I think...but they are both getting GREAT sounds...beautiful recordings...its mic placement, careful mastering, the room and the artistic content. On paper your 22-2 smokes a cassette 4-track. It outspecs the 3340S I used to have which made the most unbelievable recordings of my electric bass I have ever been able to attain thus far (hoping for similar results out of my 58)...the tech you used, and I'm not questioning you...is speaking a bit snobbish.

Man I was looking at 22-2's online...they go for CHEAP! I even saw a 22-4 for just over $100 that looked great. That's crazy...and with the 7" reels on the 1mil tape, media is very affordable and yet the tape path looks like a 32. Seems like a great option.

What are you using for A/D/A and do you have an analog mixer?
Click to expand...

So, yes I will locate the right tape. Beck, do you still sell them? PM me.

I'll try the supply real pressure again.

I'm afraid to say that I track digital at the moment :o. I only do location recording (my own jazz gigs). I used to use cassette, but I usually need more than four tracks. I use two sync'd Edirol R44's now (just sold my HD24). I mix to the Tascam 22. I have a Yamaha mixing board, but I do not like it. I mix in Cubase for now until I come accross some better outboard gear.

My ADDA is modest (Delta 44), but frankly, I've sent mixes to tape, then back in to the PC from the tape and A-B'd them and the difference is almost negligable. The tape makes a huge difference in the euphonic nature of my mixes, but the extra trip through the converters does not seem to be a big deal. I am planning to upgrade to Lynx converters, but I am skeptical that it will make a big difference. I'm open minded to the idea that my ears may not be hearing a bigger difference. We'll see.

I have put good money into mics. I've got a nice collection of Beyers - MC930's, several ribbons, some Sound Room matched Oktavas, Avenson omnis, several good dynamics (RE20, M88).

I am looking forward to doing direct to 2-track recordings with the Tascam in the near future. I am also looking for an 8-track machine, but I don't have a dedicated live room yet. I only have a single, smaller (but well-treated) room for mixing after I capture a live gig.
 
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You should clean the heads demagnetize the heads and the tape transport parts before you spend any more time on this - just to be sure that isn't the problem.



AK
 
Thinking about it, if 1000Hz @ 0 VU = 185 nWb/m, it would seem logical that I need a 185 nWb/m tape, no?

I found a Teac model number in the manual (YTT-1044 for 15 ips), but does not give the spec, and a google search turnes up nothing. Zilch. Squat.

The MRL price list gives three options for 185 nWb/m. +1, +3 and the other is +6. I assume that depends on the tape you plan to use? If so, I assume again that LPR35 is around +3 or maybe +6? Here: http://www.jrfmagnetics.com/mrltapes.html

I am I grasping this stuff?

I will demag the heads before adjusting anything.
 
Thinking about it, if 1000Hz @ 0 VU = 185 nWb/m, it would seem logical that I need a 185 nWb/m tape, no?

I found a Teac model number in the manual (YTT-1044 for 15 ips), but does not give the spec, and a google search turnes up nothing. Zilch. Squat.

The MRL price list gives three options for 185 nWb/m. +1, +3 and the other is +6. I assume that depends on the tape you plan to use? If so, I assume again that LPR35 is around +3 or maybe +6? Here: http://www.jrfmagnetics.com/mrltapes.html

I am I grasping this stuff?

I will demag the heads before adjusting anything.
Click to expand...

Leddy, its like this...the electronics on a tape deck are setup to reference 0VU at a certain level of fluxivity of the tape. Read this thread. It will help...I hope. :o

My manuals for my 48 and 58 have a line "Record Level Calibration" in the specs.

I'm thinking now that the 22 might be setup at the 185 standard, if the distortion is 1% at 0...but somebody else is going to have to confirm that here. I don't want to lead you astray. Or just call Tascam Support. In fact, better yet, just call MRL. Those folks would know exactly what you need for the 22.

I think LPR35 is a +6 tape, which means it it can handle signal that is +6 over 185nWb/m at 3% distortion...that's what the +3, +6, +9 derivations mean.

Getting the cal tape that matches the record level calibration standar of your deck is convenient, but not necessary...
 
Well I ordered a tape and a demag unit from JFR. They suggested the 250 nWb/m tape.

It will probably take a couple of weeks to get, though.
 
250 is the standard level for all the Tascam decks I have dealt with - I've never worked with a 22 though.


AK
 
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