Akai GX-280D-SS Tape Recorder (for CassetteMaster)

[MrBassdude5]

what song is that? sounds good

[CameramanLink]

@MrBassdude5 It's a homemade song with GarageBand.

[jrcstudios]

I dismantled one of these that had a bad motor and poor cosmetic condition (missing panels, etc) Let me know if you need parts..

[CameramanLink]

@jrcstudios Thanks. Everything on this one seems to be in good cosmetic and mechanical condition. The only thing wrong with it is something in the record circuitry, or the head itself.

[CassetteMaster]

It seemed to sound pretty good to me. Was it weak crackling sound?

[CameramanLink]

@CassetteMaster For some reason it doesn't come through very well on YouTube even with direct audio. I just listened to the tape while it was recording (the monitor switch lets you hear the tape as it's recorded), and sounds like the kick drum and snare are garbled, almost like they're too strong but they don't register too strong on the meter. Reducing record level only makes it quiet, but there still is distortion.

[CassetteMaster]

@CameramanLink Maybe the bias needs adjustment. Also did you try recording on different tapes?

[CameramanLink]

@CassetteMaster I was thinking the bias too. Are there different bias oscillators for each channel or is there a main one? I just recorded on a different tape and the sound quality did seem improved. I'm still having some distortion with the drums (not alone but in the music). I'll keep trying different things. Thanks for the ideas.

[CassetteMaster]

@CameramanLink Maybe for each channel, maybe not. You'd have to see the boards and there should be trimmers for adjusting the bias.

[CameramanLink]

@CassetteMaster Thanks! Bias is needed for increasing the upper end of the frequency response, correct? I just did a test recording with a sub-sonic (about 40Hz) tone followed by cymbals. This caused the cymbals and guitar to sound distorted for a couple seconds after the huge bass pulse. Is this normal for tape recorders? This could explain the distortion from the kick drum, which goes sub-sonic. I'll try to make a recording for YouTube.

[AllAmericanFiveRadio]

1974/5 it still may need new electrolytic caps. Nice video. Hope you do some videos about all the stuff you have built and explain why, how long it took to build, and how much you dislike transistors.

[CameramanLink]

@AllAmericanFiveRadio Oh no! How am I going to remember where they all go? (no writing at all on PCBs) This recorder, fortunately, is built with modules and the circuit boards unplug from sockets like in a computer.

Wait, didn't I just do a bunch of videos about all the stuff I've built? I don't think I can remember how long it took me to build them, but I remember why for most :) I could make a cassette recording and have my tape player "discuss" them in a "talking" video.

[AllAmericanFiveRadio]

@CameramanLink

You forgot about transistors. Another thing to try is to unplug the modules and clean the contacts. I hope you consider building my one transistor FM transmitter, with the mod. I have had reports of three miles which means good coverage for over a mile.

[CameramanLink]

@AllAmericanFiveRadio Ah the dreaded transistors! I don't hate them like I used to, I just don't use them much. If I hated them I wouldn't be using this Akai tape machine. As for the modules, I did just that. They went in nice and smoothly after the cleaning. When I get a craving for another short electronics project I'll try the transmitter, but keep reminding me so I don't forget. I still haven't gotten around to my octal AA5.

[wattmeter]

Have you tried demagnetizing the record head?

[CameramanLink]

@wattmeter No, I haven't tried that. What could I use to do it? Now that you mention it, it does sound like there is residual magnetization in the head.

[wattmeter]

@CameramanLink I think a dedicated head demag tool would be best, but perhaps a soldering gun...they emit a strong alternating magnetic field that I know can be used to degauss a cathode ray tube shadow mask, so it might work on a tape head. I expect you would have to remove the head from the chassis to achieve a good result.

[CameramanLink]

@wattmeter I'll give the demagnetizer a try. I think I have some coils I might be able to pass some AC though to produce a strong field.

[CameramanLink]

@wattmeter I tried a diy demag tool (coil with an iron core from a grab bag of coils from RadioShack). I hooked this up to a 12V transformer and it seemed reasonably strong when put against metal (the vibrations were loud and I could feel it easily). I went over metal parts and heads, and now the problem seems reduced. Both channels sound the same now. Thanks for the suggestion!

[wattmeter]

@CameramanLink Awesome! So glad it worked for you.