Buzzing Cassette Deck

MR_MU53NDO · 4 Sep 2013 at 21:06

Yes... i know... the technology isn't exactly modern but anyway, i am trying to record some cassettes, and so i've connected an RCA to 3.5mm jack to my cassette deck IN and connected the jack to the headphone OUT in my PC. however, as soon as i click record on the cassette deck, i get a loud buzzing sound from the speakers connected to the deck. when i play back the tape, there's a faint sound of the song (in poor quality), but it is drowned out by the buzzing. is the cable broken, or is it the deck.

Some info:

> Technics Double Cassette Deck RS-TR255
> On-board sound for Asus Gryphon motherboard

Kei · 4 Sep 2013 at 21:20

Potentially a ground loop. Does the cassette deck have an earth or is it double insulated? (check the mains plug)

MR_MU53NDO · 4 Sep 2013 at 21:42

Kei said:
Potentially a ground loop. Does the cassette deck have an earth or is it double insulated? (check the mains plug)

you see, i'm not too knowledgeable in this area, so i can describe the socket connecting power cord to cassette deck (don't know if that helps) its a 2 pin one (obviously the 'plug that goes into the wall' has three pins, on of which is the earthing pin). it works on tape to tape recording, but not from PC

MR_MU53NDO · 4 Sep 2013 at 21:46

just an update: it's not my PC. tried it on another one (using sound card) and problem persists. Also, it starts buzzing when i turn on the record function on deck 2

Kei · 4 Sep 2013 at 21:54

If the connection at the tape deck is two pin figure of 8 shape, then it's unlikely to be a ground loop as the tape deck is double insulated and has no physical connection to earth. Have you got any other external sources you can try using the same cable? (like a phone or mp3 player, battery power ideally as this will eliminate a ground loop) If the noise is still present then i'd suspect the cable or the input connections. if the noise disappears, then i'd suspect a ground loop and try an inline isolation transformer.

EDIT: Since your new post, it suggests that it's a problem with the deck. Try wiggling the connection at the back and seeing how that affects it. The unit is 23-25 years old so there is a high chance that some capacitors inside have degraded and are no longer performing as intended. The electrolyte in them dries out over time which causes their values to change and their resistance to increase, eventually they will give up working altogether but that usually takes a good 40 years with regular use. The enemy here is lack of use as unused capacitors age faster than those used at sub 50 degree temperatures. (i.e. if the deck has been stored in the loft for a few years, it's probably not faired well)

MR_MU53NDO · 4 Sep 2013 at 22:36

Kei said:
If the connection at the tape deck is two pin figure of 8 shape, then it's unlikely to be a ground loop as the tape deck is double insulated and has no physical connection to earth. Have you got any other external sources you can try using the same cable? (like a phone or mp3 player, battery power ideally as this will eliminate a ground loop) If the noise is still present then i'd suspect the cable or the input connections. if the noise disappears, then i'd suspect a ground loop and try an inline isolation transformer.

EDIT: Since your new post, it suggests that it's a problem with the deck. Try wiggling the connection at the back and seeing how that affects it. The unit is 23-25 years old so there is a high chance that some capacitors inside have degraded and are no longer performing as intended. The electrolyte in them dries out over time which causes their values to change and their resistance to increase, eventually they will give up working altogether but that usually takes a good 40 years with regular use. The enemy here is lack of use as unused capacitors age faster than those used at sub 50 degree temperatures. (i.e. if the deck has been stored in the loft for a few years, it's probably not faired well)

Yep. Tried it with my iPod, less fuzzing but same problem. You're right about the connector with respects to the the shape. I don't know the condition of the deck, as I bought it off eBay recently as working for an astonishing £3.99... So it's not that much of a loss if it doesn't work that well. Playback is still great for its age though!

I'll get back probably tomorrow after I've consulted the IT technicians at school (one of them used to sell these machines). Ill try and do what you suggested and post the results. Thanks for the help.

MR_MU53NDO · 4 Sep 2013 at 22:53

Update again: I've got it to work. I wiggled the RCA plugs at the back and plugged my iPod in. If I act as the earth wire (put my hand on the deck) it works perfectly (ish). As soon as I touch the iPod though, the buzzing will occur until I let go. Just to mention, the deck is plugged into a multi plug thing (one of those plastic things with 4 sockets on it). Does that affect it? Also, does Ot affect it that my monitor (metal frame) is on top of it, and computer next to it? It says in the manual that any receiver/tuner can cause noise in playback and recording (it's only happening in recording from PC though)

Kei · 5 Sep 2013 at 12:03

Definitely a grounding issue and the noise you describe sounds like mains hum. Try insulating the cassette deck from anything touching it. You could try changing which mains socket it gets power from, but IME that doesn't tend to change anything.

If you record with no input cable connected do you still get any noise? See if touching the metal case of the deck affects it and see if isolating the deck from the monitor affects it. (with no input connected still)

Is the deck connected to an amplifier for playback?

MR_MU53NDO · 5 Sep 2013 at 19:47

Kei said:
Definitely a grounding issue and the noise you describe sounds like mains hum. Try insulating the cassette deck from anything touching it. You could try changing which mains socket it gets power from, but IME that doesn't tend to change anything.

If you record with no input cable connected do you still get any noise? See if touching the metal case of the deck affects it and see if isolating the deck from the monitor affects it. (with no input connected still)

Is the deck connected to an amplifier for playback?

tried that. and it works now! thanks for that tip. i still think the cable's a bit iffy; i have to wiggle the 3.5mm end in the PC headphone jack to get sound without fuzz, but once it's positioned correctly, it'll work absolutely fine.

Thanks again. Now let the cassette factory begin production