Speed calibration of a cassette deck

Basic principle of setting correct speed on a compact cassette deck from Akai.
Ignore all references to a signal generator, I mean to say frequency counter.

[@midwestguy42]

I once serviced a Pioneer dual cassette deck that had an inaccurate playback speed. There was no spool adjustment on the motor, but rather on the main pc board. Two ports on the board to control the two motors for both tape drives. An additional 2 ports were for adjusting the high speed dubbing mode. I just enjoy working on these long obsolete cassette decks during the day!

[@oldhamegg]

The anticipation of getting to 1 khz was as suspenseful as all the fight scenes in the last Thor movie.

[@dangaAgadanga]

It worked!!! I first tuned the Pioneer deck by ear using a familiar song. After that test, I set up my phone with an app that generates and analyses frequencies and recorded onto tape through a trusty Technics tape deck. Played back tape on the Pioneer and I’m quite pleased to say I ear-tuning was only offset by a few hertz or so. Very surprised by the amount of flutter by both decks. Both rapidly hovered between 3002 to 3010. Nonetheless, I’m very pleased I came across this video.

[@youtuuba]

I am glad that you finally zoomed in close to your frequency counter; you kept saying that you were connecting the tape output to your 'signal generator'..... same kind of verbal glitch happens to me when I narrate my videos..... my brain is thinking 'A', and the cognitive part delegates to the other part that runs my mouth, but it says 'B', and the cognitive part is thinking about the next bit and does not notice the error.

[@SoddingaboutSi]

youtuuba Yes I meant to correct this error . Hope it was of use?

[@wilfredheggart647]

my panasonoic or nothing and you in a silver barcelte

[@SchuchDesigns]

The adjustment tolerance on most of these machines was 0.5% so it was actually already within spec.

[@321reh]

A Very Important Adjustment in a Tape Deck//Thank you Simon!!!!

[@1975Loeven]

Great video, thanks. I do it a similar way myself, but i have no fancy meter, only a smartphone app doing pretty much the same thing. Also works just fine. Always nice to see a fellow cassette deck lover in action :-)

[@SoddingaboutSi]

Yes, the frequency counter is just part of the workshop infantry, Another method is to use two decks with two copies of the same frequency and play the known good deck while adjusting the second. If you listen to them both you can tune for zero beat.

[@1975Loeven]

I need a workshop like that too :-) Back in the days i used to match with another deck like you mention, or rely on my ears on a well known recorded tape but a proper meter is the best after all.

[@SoddingaboutSi]

Thanks Richard, Akai were great tape players.

[@Watcher3223]

I sort of had to improvise a way to calibrate speed on a cassette deck. On a deck I know to be at the right speed, I record a 1 kHz tone onto a good cassette. On a deck I'm calibrating, I use an instrument tuner, such as my Korg TM-40, instead of a frequency counter. More or less, I get the same result this way. Though it may not be quite as precise as a frequency counter, it should be more than adequate for a regular consumer deck while not breaking the bank, resulting in an adjustment that should fall well within the margin of error that may be indicated in the deck's service manual.

[@MikeG-fo1lb]

I love your chilled presentation

[@WhoAteEarth]

instructive and, with ease, not very difficult. i was looking for instructions on this because i also own a nice Reel to Reel, and with the ability to change speeds on that i had that thought that the same could be done with cassettes to similar effect. faster speeds giving better quality, slow speeds the opposite. definitely going to give this idea a try and see what happens!

[@VproAudio]

Hi Thanks for this beautiful video I finally understood how to adjust the engine!! I have another problem during the recording phase, when I arm the recorder the input sound disappears or is very distorted, is there an explanation for this? Thank you so much

[@chylogurti]

Great vid. Do you turn clockwise to speed up please? Can contact cleaner be squirted into the motor pot hole? Thanks

[@zoundsic]

if you got another tape deck you trust the speed of you can record a tone from a keyboard checking it with a pitch tuner, then adjust the wrong speed tape motor to match that or you can buy a test tone tape and do similar. You also used to be able to get a casette that strobed so you could do it visually

[@spannerworks1]

Hi Simon Great and many bits that look the same as my Akai open reel tape deck which I just love. My DD Technics tape deck is just great and sounds fantastic. Warm regards Richard

[@ydonl]

I'm struggling to think of a speed regulation mechanism that could live in a motor and involve an adjustment pot, and still be very accurate... was there any kind of actual feedback in a control loop? Or did we just sort of take our chances that the load on the motor was pretty consistent? I'm aghast! :)

[@HDXFH]

I use a spectrum abalyzer app that reads the frequency like an actual counter Works great

[@dangaAgadanga]

I was nearly gonna destroy a top-end Pioneer model and find a new motor - all I needed to do was this! Gonna try it later. I'll have to generate my own test-tone from a mobile phone app, to record from a decent Technics deck. Haven't got the luxury of a reference deck.

[@SoddingaboutSi]

Chris Tsangari That should work fine. Good luck.

[@wheatonna]

I watched this hoping for an answer to two questions: 1 Is it a philips screwdriver or a flat-head? 2 Which way do you turn the screw to increase the speed?

[@robcol66]

Brilliant! Thanks for this.

[@bobjerome1205]

hi you were going on about the tape it's sp tape in side you can't get it any more. all cass have the lp tape in them now. i got the last of the lp 1/8 pancakes from the usa for my tascam 238 units. yes alot of tape player are all over the place on the playing speed i have to do this to reel to reel units

[@Bevoin1970]

You realise your like "Superman" to me don't you?..lol - Brilliant stuff yet again. I do hope all this old hi-fi becomes desirable again one day, I shall have good reason to dust off my Pioneer stack system, circa 1983 and bring it down from up in the loft. :-))

[@robertmattison1282]

What cassette deck has a PLL circuit and operations are direct direct. Thanks. Personal Note, I hit a key by accident so I am re-posting my question here. Thank you.

[@SoddingaboutSi]

Cheers Bevion might do the azimuth alignment next.

[@robertmattison1282]

posted 2013 Great Video. Question, your claim that the play back speed is off. One wonders is the the speed of this cassette deck is the speed set at the Factory. Also if the factory does set the speed dead on, can you explain how the motor speed change. This is a very nice vintage audio cassette deck. With good looks. Thank you for your time.

[@1975Loeven]

I believe the speed slightly change over the years due to mechanical wear in material and the belt may also differ in quality after a replacement. i may stand corrected though.

[@robertmattison1282]

Would an average person not a critical listener be able notice the slight change. Thank you for answer me back.

[@1975Loeven]

i can only use my ears as a reference but sometimes i can notice a small speed change, usually on songs i listen very much to. When using a test tone like this it's a good way to make sure if the speed is wrong

[@robertmattison1282]

Thanks for your replies. You must have great headphones and speakers. Please continue to make video's. R.

[@1975Loeven]

i'm not the guy who did this video but thanks anyway :-) I'm fiddling with the same kind of stuff though, it's fun to keep the decks alive

[@pqpmoscon]

could you please show the bias calibration for this tape? for a two head deck, could one adjust the bias by measuring the sent ac-voltage?

[@esenel92]

Was there something like a metal cover on the back of the motor originally?

[@JamesE707]

Nice circuit board layout. Unlike the Aiwa AD-F770 which is a mess.

[@ValleryRastr]

Please tell. What i need to rotatate in my akai gxc-36. Where is controller? (Sorry for my English)

[@damiemlindzay2187]

Exellent video....i have a question. ...i have a 1970s jvc but the power on off button wont stay on..any advice. .can they be fixed...cheers from belfast

[@SoddingaboutSi]

Most likely the catch has broken the plastic ramp on the switch.

[@damiemlindzay2187]

@@SoddingaboutSi ..thanks. .are they fixable

[@SoddingaboutSi]

Not usually. A replacement might be easier to find if you compare it to one online.

[@damiemlindzay2187]

@@SoddingaboutSi ..cheers...at the minute i have jammed a cocktail stick in to keep it on....what are those switches called?...thanks .

[@giuseppelavecchia775]

Un buon lavoro,taratura precisa.

[@SoddingaboutSi]

Grazie!

[@codebeat4192]

Very smart!

[@MatrixAlphaCWX]

When you record mixtapes on this. Does it actually record the dolby onto the tape. Or is dolby only for playback on this machine and not in a car.

[@SoddingaboutSi]

When you use Dolby, you have to record with the Dolby system of choice onto the tape. Dolby will give a dull and sometimes pumping sound when played back on a tape that did not have Dolby recorded on it.

[@matthewkando305]

I can’t for the life of me figure out how to adjust this thing. There’s this thick layer of foam over the hole that seemingly makes it impossible to know if I’m even adjusting anything

[@nopochoclos]

Any way to calibrating without expensive hardware? like sound card on PC or something?

[@Burritosuupreme]

nopochoclos i use the PanoTuner app on my iPhone. It’s meant as a guitar tuner but it displays the frequency and does a good enough job for me.

[@nopochoclos]

@@Burritosuupreme Thanks for that information!!!

[@edwardjames9361]

I've recently bought a 70s Crown music centre off eBay. It was advertised as fully working but when it arrived the tape was running slow. Prerecorded tapes play slow, but tapes that are recorded off the record deck and played back are running at normal speed. I'm not an expert, I have no experience repairing tape decks, I'm at a loss as to what's wrong with it??

[@SoddingaboutSi]

The machine is running slow if the pre recorded tapes are plying show. It could be a belt slipping or motor problem.

[@edwardjames9361]

Simon Spiers Just I'm confused as to why it's playing at normal speed when you play back from the record player? If it's a mechanical problem why is it playing at normal speed, it should be like that with both. I think it's something more serious like a circuit problem

[@SoddingaboutSi]

Recordings recorded on the deck that runs slow ill sound normal as the speed is the same as you recorded it (slow)

[@edwardjames9361]

why is that? should it be at slow speed because you are recording it a slow speed?

[@SoddingaboutSi]

Can you confirm. When you record on this deck and play that recording back on this deck the speed is correct? When you play a tape recorded on another machine back on this deck it is slow? If that is the case when you record on this deck at a lower speed and then play back at that same speed, the recording will sound correct because there is no difference in speed.

[@WL-vw4qx]

I changed the pinch rollers and belts with new ones on my Sony TC-WE835S. The 10 minutes 3kHz test cassette I bought does not have constant frequency. It started at around 300xHz then gradually reduced to 296xHz in about 5-6 minutes then went back up to 297xHz in the last 2 minutes. The difference is about 40Hz. It that normal? Should I calibrate in the first 3 minutes or wait until after 6 minutes? Thanks.

[@SoddingaboutSi]

That is not likely to be the tape. Sounds like a motor servo problem.

[@WL-vw4qx]

@@SoddingaboutSi Thanks. Is there anything I can do? I have some electronic knowledge.

[@SoddingaboutSi]

@@WL-vw4qx you need to check the rpm on the motor really. Are the belts tight? Check the test tape on another cassette deck will confirm.

[@WL-vw4qx]

@@SoddingaboutSi The belts were changed about 3 years ago. I ran the test tape on both decks and both directions. They all presented the same problem. The frequency was high in the beginning then gradually reduced. The differences are 2xHz, 3xHz, and 4xHz in 4 tests. The worst is on deck A side A. Unfortunately I don't have an equipment to check motor rpm. If the belts are loose, could the speed be slow in the beginning or fluctuate all the way?

[@SoddingaboutSi]

@@WL-vw4qx If you tried the tape on two machines and get the same frequency shift, yes the tape is faulty. You need better tape,

[@Synthematix]

you can use a multimeter with HZ setting to do this job cant you?

[@RakeshKumar26026]

🙏

[@brentfisher902]

It's just like the Microsoft Certificate of Authenticity...how do you know it's real? Do the send another certificate of authenticy to prove it's real? And how do you know that's real? I would suggest digitizing some pre-recorded cassettes in short sections and uploading them to a site like AudioTag.info and twiddling the speed until it recognizes the song (artist/title). It's quite intolerant of wrong speed and provided you aren't too far off (and the digitizer is calibrated to WWV using MMSSTV) you can get the tape speed that gets the most songs recognized on different tapes.

[@SoddingaboutSi]

I have a lot of Junk you mean?

[@GisellePadilla-jt6qh]

AKAI

[@theohilton1276]

u sound like jonathan creek .. do you live in a windmill? a giant cassette reel windmill

[@theohilton1276]

errrrrmazing :)

[@wilfredheggart647]

cop mazing

[@rockermarco]

Wanna hear the most annoying sound in the world?