Tascam 388 typical frequency response/head condition?

7

7upPartridge

New member
Hello friends,

I'm looking at a Tascam 388 to purchase & I did a crude test with some tones to hopefully get some idea of head condition...

Channels averaged about 2vu lower at 10k than they did at 1k. And they averaged about 4vu lower at 15k (than they did at 1k). I know a 388 isn't exactly known for its high fidelity...so maybe this is typical for this machine? Keep in mind it hasn't been de-magged or calibrated. Obviously this isn't a perfect test, I'm just using what I can...is this info helpful at all?

Anyway I'm interested in any and all suggestions. Thanks a bunch!
 
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I think that sounds about normal. There is also some variance you'll get on flattening frequency response with calibration.

@ 7.5ips the frequency response drops off pretty steeply @(above) 16kHz, inherent in the design.

The frequency response can't really* be flattened*, but more accurately to say it balances the peaks and dips within spec over the frequency range.

I've found during calibration if I EQ on 12.5kHz it seems to give the best balance of response over the entire range of frequencies.

If you look at the Jack Endino site, you'll see graphed out that analog tape/head frequency response is *anything but *flat.

There's a former Tascam lead analog tech/svc mgr on this board, maybe he will hop on and give a more definitive answer.

:spank::eek:;)
 
I would also add that the results of your experiment may be consistent with overbias. If the 388 you tested was biased for 457 and you were using LPR35 for your test there will be an HF impact due to overbiasing of the LPR35.
 
7upPartridge said:
Hello friends,

I'm looking at a Tascam 388 to purchase & I did a crude test with some tones to hopefully get some idea of head condition...

Channels averaged about 2vu lower at 10k than they did at 1k. And they averaged about 4vu lower at 15k (than they did at 1k). I know a 388 isn't exactly known for its high fidelity...so maybe this is typical for this machine? Keep in mind it hasn't been de-magged or calibrated. Obviously this isn't a perfect test, I'm just using what I can...is this info helpful at all?

Anyway I'm interested in any and all suggestions. Thanks a bunch!
Click to expand...

How did you measure the freqs? Did you start with 1 kHz @ 0VU and did 1kHz come back at the same level you recorded?

That’s a sharp drop for the 388 even though technically speaking you measure the freq response @ -20 dB with 400 Hz @ zero. It could be a number of things… mechanical calibration, electronic calibration, head wear, and type of tape used. When asking questions like this its helpful to list the type of tape you’re using and whether that tape was new and sealed or used when you got it. It could be bad tape or it could be the machine is not optimized for that tape.

With a steady tone, a properly functioning VU meter on the 388 will match an external dB meter. One VU will equal one dB. Tascam specs are generally conservative. Specs are listed as 30 Hz to 16 kHz +/- 3dB. But it can do a little better than that when optimized to a specific tape.
 
Thanks for the helpful responses everyone, I did the same test on a machine I'm used to using, and had similar results, so I decided to go for it.

I'm aware that there are a million factors at play & I appreciate everyone chiming in despite the crudity of my 'tests'.

For what it's worth, Beck, yeah I recorded all tones at 0, and compared their playback...1k played back about 1-2vu lower, then 10k was another 1-2vu below that, etc etc. Definitely doubt the machine was optimized for the tape I was using (LPR35), not much info on the history or if/when it was ever serviced. I'll calibrate & set up for LPR35 and we'll see what happens!
 
7upPartridge said:
For what it's worth, Beck, yeah I recorded all tones at 0, and compared their playback...1k played back about 1-2vu lower, then 10k was another 1-2vu below that, etc etc. Definitely doubt the machine was optimized for the tape I was using (LPR35), not much info on the history or if/when it was ever serviced. I'll calibrate & set up for LPR35 and we'll see what happens!
Click to expand...

Yeah, that points to a calibration problem. The machine should be setup so that a 1kHz tone recorded @ 0VU should playback at exactly 0VU. If the repro is already a couple dB down then you're not getting the most out of the tape.
 
The 388 by virtue of having 8 tracks on .25" tape pretty much tops out @ 16K.Above that crosstalk becomes excessive.There are adjustments in the manual to minimize the crosstalk-you have to remove the bottom metal panel to get at them.A complete recal.needed.Having the tape tensions correct can be critical-especially play back tension.Too low and you can lose proper head/tape contact,which will affect high freq. response.It may not show up when you are doing the playback alignment but is compounded when recording and playing back.
 
Thanks again for the responses, sorry for the really late reply, but a happy ending, I did buy it, had a local tech calibrate & set tension, and it works like a dream I love it
 
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