Tapes at wrong speed

[Grubhead]

Years ago I bought a second hand tape cassette recorder and used it for taping off the radio. It was in operation for quite some time when I discovered, after playing back a pre-recorded cassette. that it worked at the wrong speed. I looked inside the machine and found that the motor had been replaced with one that worked off the wrong voltage. I don't recall seeing any speed controller on the motor or in the circuit, so it was a fixed speed. It wasn't a well known make either. I think it was called "Wye" or something like it. There wasn't anything wrong with the motor it just recorded everything at a slower speed than a normal cassette.
So I have a stack of tapes that I need to transfer over to digital. So I am wondering if there are makes of tape machines that it is easy to adjust the speed of them to get these old tapes playing back right? Ideally with easy access. Just take the top cover off.
It would have to be a common machine that I could find second hand. I wouldn't want to break the warranty agreement by messing with a new one.
I suspect also that the head wasn't aligned right either on the old model. So I would need to adjust the head too.
Incidently the old deck failed completely when the nylon plastic lugs broke off on both sides that held the cassette cradle and door.
I currently have a tape deck, but the motor speed control is hard to get at and the deck uses none typical belts that are expensive to replace. And is currently acting up, it has problems rewinding tapes. It does need a new belt

[paulsherwin]

You can correct the speed in software once the tapes are digitised.

[TIMTAPE]

There's a limit to how far the speed/pitch can be varied in software before it degrades the sound. 2% is probably OK but maybe not 20%. Later model cassette deck motors had an electronic speed regulator inside the motor, usually adjusted through a small hole in the motor's back with a suitable small flat blade screwdriver. Care is needed in adjustment.

[emeritus]

If you can put up with mono, the common Philips EL3302 has a readily-accessible preset pot on the printed circuit board for adjusting the speed. Some of their stereo models use a similar arrangement. If necessary, it would be possible to replace the internal preset pot with an external one.

[Ted Kendall]

Many machines have front panel varispeed, notably the Tascam 122, Nakamichi BX300 and Sony WMD6C Pro Walkman, plus other, cheaper types.

[Grubhead]

Originally Posted by paulsherwin

You can correct the speed in software once the tapes are digitised.

Yes I have seen that with 78 rpm played at the lower speeds. I will have to check my recording software to see if it will adjust the tracks speed. I always thought that was just for the 78 rpm records and was just set to increase the speed to a certain level.
Might get away with just replacing the belts on my Technics RS B205 then a save some cash.

[dglcomp]

The Teac/Tascam tape/CD units have speed control for the tape on the front,
i.e. https://www.thomann.de/gb/tascam_202_mkviii.htm
A second hand older model shouldn't be too expensive

[ben]

If you're just digitizing tapes made from the radio, you won't need to worry much about quality loss. Use a standard stereo cassette deck connected to the PC's line in jack.

I use Audacity, which is free software. You can very easily fine-tune the speed.The important thing is to adjust the head alignment to get the clearest sound before starting.

[Gulliver]

WYE electronics....from up Sheffield or Chesterfield way? 70s manufacturer of low end audio equipment. A cassette recorder from WYE would have used off the shelf parts, but ought to have functioned OK.

I do have an early 90s Sanyo "Walkman" which has a speed adjustment screw accessible without opening up the case. Probably at least +/- 10% adjustment. But if you're looking at digitising your cassettes, I have a second vote for Audacity unless you want to buy software.

[emeritus]

The instructor of the step aerobics/body conditioning class that I used to attend, had a self-contained speaker/amplifier/cassette player unit that had a speed control knob that could adjust the speed over a wide range according to the level of exertion required. I don't recall who made it.

[TIMTAPE]

I believe speed change software is better than it used to be but it does things fundamentally differently from analog. Digital is happier with an even numbered speed change like double speed or half speed. Intermediate speed changes work if they're not too large but eventually fidelity is compromised.
For best sound quality with speed or pitch manipulations, higher than normal sample rate recordings are best, as the file can sliced and diced more precisely.

The most difficult task is changing speed and pitch independently but at the same time. With analog this was impossible so any improvement digital offered was welcome.

[ben]

Coomber and Philips made models with a pitch control, but most of those are mono. Also, chances of finding one in full working order without needing at least a new set of belts is slim these days. The portastudio route would give you stereo, but apart form the belt problem is also likely to be expensive, given those units were always specialist, and even today are in some demand.

I'd still stick with software for a case like this.

[G6Tanuki]

You can definitely do it 'quite well' in software; a friend digitized a lot of his cassettes by sampling the audio from his dual-deck ghetto-blaster's cassette mechanisms in 'high speed dubbing' mode [which was the standard way people used to do tape-to-tape copies back in the 80s] and then corrected the result in Audacity.

The result was quite good enough for in-car playback or listening on his iPhone while out running.

[TIMTAPE]

Sure but that's an easy example as I mentioned. High speed dub on most cassette decks was usually at double tape speed, requiring only digital playback at half the recorded sample rate. No fudging needed. Actually it would normally be a little trickier as most decks muted the audio with high speed dubbing to avoid the unpleasant sped up shrieking sounds while h.s. dubbing. You'd need to bypass the muting somehow. Also technically the high speed dub could have frequencies above the range of normal hearing.

[G6Tanuki]

The "high speed dubbing" didn't need to run at any particular speed; the ghetto-blasters I recall using this feature just had a single motor to drive both the playback- and record-drives - so the source and destination were by definition always synchronized.

And these days once you've got the content digitised [at whatever speed] re-generation at the required audio-rate is just a matter of software - it's no harder to run at 2:1 or 3.0623:1 or 1.7719:1

"adjust the playback-speed slider to get what sounds best for you".

Just hook an audio-output to your soundcard from the high-speed-dubbing playback head. Equalise [to accomodate Chrome/Dolby-issues] once you've got it digitised.

[wd40addict]

I once had a CD that had clearly been dubbed from an LP running too fast. Luckily it was an American live recording with a bit of 60Hz stage buzz in it. I pulled it into Audacity, did an FFT on the '60Hz', found it was 63 or whatever then speed corrected by that amount. Result was fine - try it!

[TIMTAPE]

Originally Posted by wd40addict

I once had a CD that had clearly been dubbed from an LP running too fast. Luckily it was an American live recording with a bit of 60Hz stage buzz in it. I pulled it into Audacity, did an FFT on the '60Hz', found it was 63 or whatever then speed corrected by that amount. Result was fine - try it!

I have, many times. Actually I prefer to use
a Dehum tool for more precision. I adjust the frequency of the tool for best audible and measurable null of the hum fundamental and harmonics. It can be quite tricky to optimise especially at high Q settings. I note the percentage difference in speeds and time adjust a copy. Yes mains hum on analog recordings (in moderation) can be a great reference for correcting off speed recordings. A slight digression but its a common mistake to try and remove hum from a recording by using a general purpose Denoiser tool.

[TIMTAPE]

E

Originally Posted by G6Tanuki

... Just hook an audio-output to your soundcard from the high-speed-dubbing playback head. Equalise [to accomodate Chrome/Dolby-issues] once you've got it digitised.

If you're happy with that approach, fine. Some of us take a slightly more engineering based approach. I once knew an archive which digitised their thousands of studio tape masters at about 9 times real time speed. Fine as far as it goes but they used a recording sample rate of 44.1 kHz. Playback sample rate: 44.1 kHz divided by 9. "Sounds a bit muffled? Oh well after all they are only old recordings. What else did you expect?"... As for Dolby cassette decoding, let's not go there...

[G6Tanuki]

The OP is after advice on recovering and reworking content from cassettes recorded from broadcast-radio on a secondhand unspecified and probably wrong-speed cheapie recorder using who-knows-what quality cassettes/bias/equalisation and Dolby, not 'studio tape masters'.

So to be honest, "what sounds OK" is to my mind going to be "good enough"!

[TIMTAPE]

Originally Posted by G6Tanuki

The OP is after advice on recovering and reworking content from cassettes recorded from broadcast-radio on a secondhand unspecified and probably wrong-speed cheapie recorder using who-knows-what quality cassettes/bias/equalisation and Dolby, not 'studio tape masters'.

So to be honest, "what sounds OK" is to my mind going to be "good enough"!

The OP said he is prepared to open up a suitable cassette deck and tweak the motor speed to the original recorded speed. For his large number of tapes, this alone will probably save a lot of post processing time. He also wants to tweak the play head for best sound. I know people who digitize tapes in their day job and wouldn't bother about correcting speed at source even if they knew how to do it. As for azimuth and head align to the tape, they wouldnt even know what the word means. If I wasn't fortunate to now have decks with front panel varispeed, I'd be temporarily tweaking the speed internally myself, as I once did. I commend the OP for his wish to do a good job on his own recordings. "What sounds OK" can vary greatly between individuals.