Ten Things You Probably Didn’t Know About Portastudio Recording

Tascam Four Track Level Meters

Most people with a major interest in tape recording will probably know a fair bit about Portastudios. But whatever your experience in this field, I bet there’s at least one thing in this collection of obscure facts that you didn’t know about the world of Tascam four-track tape machines…


It’s fairly well known that Portastudio manufacturers TEAC strongly recommended high bias Type II cassettes for use in their Tascam machines, which were rigidly pre-set for Type II operation. But it’s perhaps less well known that they actually recommended specific TDK and Maxell tapes by name. TEAC also, rather strangely, recommended that users pick one quality brand of tape and stick solely to it. Justification was given for why users should avoid poor quality cassettes (and C120s with very flimsy tape), but no reasoning was provided as to why users should not be free to continue experimenting with a range of high quality brands.


The Pitch control on Portastudios speeded or slowed the travel of the tape so that the pitch of the music could be matched to the tuning of the instrument being recorded. But since faster tape travel gave higher recording quality, wily users would record their ‘sharpest’ non-retunable instrument first, with the Pitch set to maximum for the highest tape speed. They’d then reduce the tape speed to accommodate any ‘flatter’ instruments, returning the setting to maximum pitch (and thus fastest tape travel, optimum quality) for the final mix.

Four Track


The DBX noise reduction used by Tascam Portastudios as an alternative to Dolby (some other brands of home multitracker used actual Dolby), could be corrupted by extreme low frequencies present in the live sound. These ‘subsonic’ frequencies could not be recorded, and were therefore absent from the playback, disrupting the DBX’s ‘mirror image’-dependent process of compression and expansion. For some models of Tascam four-track, users subject to problems with ‘sub’ frequencies were advised by the manufacturer to place a high-pass filter at the record input and electronically filter out extreme lows before the DBX picked them up.


Bouncing (the practice of mixing three recorded tracks down onto the remaining one, to free up space for more instruments) by nature rendered the mixed portion of the recording monaural, and lost the stereo image. However, some home recordists cheated their way round this by bouncing to their stereo mastering tape deck rather than the available mono Portastudio track.

The stereo mix on the outboard deck was then played back to record on the first two tracks of the Portastudio along with one live instrument, adding a full, four-track stereo mix to the Portastudio, with room still for two more tracks.

Whilst technically, this added an extra stage of sound degradation to the process, compensations could be built in, which actually facilitated a higher fidelity result than the standard bouncing process. Compensations included the fact that a good stereo mastering deck inherently recorded and played back at much better quality than the average Portastudio, the fact that higher grades of tape could be used in a standard deck (including very high quality metal Type IV), the typical existence of multiple Dolby noise reduction options on a standard deck, and the fact that equalisation could be employed between the mastering deck and Portastudio to restore or even pre-empt frequency loss.



Despite incorporating dbx noise reduction and generally insisting on high bias tapes, Portastudio recordings were still prone to noticeable tape hiss. Part of the problem was that a typical Portastudio’s treble response did not rival that of a good stereo deck. Therefore, the higher frequencies in the hiss were not as well masked by the recording’s own highs, and there was not much scope for rolling off treble at the mastering stage, because the recording would be rendered too dull.

Cheats could negotiate round this by placing a graphic equalizer on the live input to their Portastudio and over-emphasising certain treble components of the sounds being recorded. The overbright treble was then cut back at the mixing stage, taking the worst of the high frequency hiss with it.


TEAC warned users not to talk to anyone when carrying out the degaussing (head demagnetisation) process, such were the consequences of a lapse in concentration!


In addition to its conventional use, the Timecode sync feature on a Portastudio could be utilised as a means of ‘humanising’ computer-sequenced MIDI recordings on-the-fly. Typically, the tempo of digitally sequenced recordings was rigid, and set by the computer. But real musicians, led from the back by a drummer, would vary the tempo subtly throughout a track. Some rock tracks, in particular, speeded up as they progressed, and as the musicians’ adrenaline flowed.

This human trait was very difficult to simulate by adding numerical and calculated fluctuations to a computer’s tempo track. However, if a digital timecode was recorded to a Portastudio, and tempo control was passed from the computer to the external source of the tape, the Portastudio’s Pitch control could be used to fluctuate the tape speed, and thus the track’s tempo, in a very organic and human fashion. The tape was never heard – it functioned purely as a hands on, analogue tempo control for the MIDI sequence, complete with random mechanical (and highly human) micro-fluctuations.

Tascam Porta 05 HS


The qualitative issues associated with all amateur home multi-trackers meant that the sparkle of a professional recording could be evasive. However, with some sounds, the human ear is much more sensitive to qualitative degradation than with others. Electric guitars, for example, can be quite heavily degraded without causing that much concern, but the ear is particularly sensitive to degradation in drum kit sounds, which incorporate prominent and critical high frequency elements.

Therefore, minimising the degradation in drum sounds, whilst making the compromises with instruments like guitar and bass, was the key to creating professional sounding recordings in these limited circumstances.

With sequenced drums, the standard move was to keep the beatbox off the four track tape altogether and run it live via MIDI timecode – even during the final mastering. Only the less sensitive instruments went onto the tape.

With real drums and a band, the best option was usually to record a live stereo mix of the whole group onto tracks 1 and 2, then use tracks 3 and 4 to embellish the recording with overdubs. Even though, after recording tracks 1 and 2, the instruments’ relative levels could not be tweaked, the stereo image of the drums, and the lack of a need to degrade the cymbals’ high frequencies with a bounce, was much more valuable than the ability to tweak the levels. The attention to mixing was paid before the recording, rather than after.


Portastudios often featured a double speed record/play capability to increase record quality. And because Portastudios recorded on both sides of a tape at once (that was how they got four separate tracks from an ordinary stereo cassette), it was commonly cited that a C60 gave just 15 minutes of record time. However, it was much less commonly cited that, on a more positive note, a Portastudio could erase two sides of unwanted material from a cassette four times as quickly as a standard stereo deck. With the Pitch control set to max, even faster erasure was possible. With some Portastudios, you could erase a full C30 cassette in less than 7 minutes.


TEAC warned that if you record a Black Sabbath album onto tracks 3 and 4 of a Portastudio, then play Side 2 of the cassette in a standard stereo deck, the backwards playback may summon the spirit of the Devil and destroy the entire hi-fi… Oh okay then, that’s not true, but Ten Things You Didn’t Know sounded so much better than Nine…