"is the head dead yet?" Does this look bad or not?
- Thread starter Kahoona
- Start date
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- akai 202d-ss head wear
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Kahoona
Super Member
One of the front channels does not play when run forward unless the power is flicked on and off a number of times. It will then play for a short while. It is not the power switch. I have deoxed the other switches including the internal ones. Oddly enough it plays both channels when in reverse.I have low volume and static like over-driven levels when recording and playing back in stereo using a CD player as a source even though the meters are reading sufficient volume. I also have low volume when recording and then playing back in all four channels when in Quad mode. It doesn't record in reverse so I would have to flip the tape to check the side 2 head gaps for Stereo. Since the record head is separate I guess it could be either or both. I should have put a better shot of the record head here.
These things make me think that I am in for troubleshooting on the boards and parts replacement. These things are at least one level over my head especially since I haven't been able to afford an oscilloscope as yet. Since these aren't worth much I would be doing the work for the experience. No point in doing this if the head is worn. In that case I would be better to wait for a better one to learn on.
If you want to seriously chase down the issues with the deck, at the very least you will need the oscilloscope and a fluke type tester. The head is obviously worn but the symptoms indicate the boards need a full diagnosis, recap and possibly a full rebuild of the circuit. You should open the deck up and see if the boards are removable, take a few pictures and post them here. Also you may fine something obvious.
By the way that is a very nice deck if you have use for the 4 track configuration or dont mind flipping a 1/4 track tape over. Worth your time investigate the problems, most of which will be in the boards and power supply.
By the way that is a very nice deck if you have use for the 4 track configuration or dont mind flipping a 1/4 track tape over. Worth your time investigate the problems, most of which will be in the boards and power supply.
Kahoona
Super Member
Thanks. I have a nice Tripplett. I have rebuilt a few things and recapped others, I have the case and front plates off and will post more pics. The boards are removable in a loose sense of the word. All connections look to be soldered so it will take some doing to get them out. I'll take another look. I can't see the component side of the boards till I can get them out. I would love to have an oscilloscope and am keeping an eye out for a good but locally. Not much wiggle room in the budget though. With the heads worn and lacking the 'scope it might be best to move on for now. I'll take a closer look tomorrow.
elnaldo
Lunatic Member
I think I reach to see a gap on the 2 lower tracks, specially the 3rd track from top to bottom. I see a "dent" on the bottom edge.
If I can see a gap with the naked eye and a blurry pict, I'd say they are gone...
I'd take another pict, better focused. Set your camera to macro, make sure the focus is right, and use the highest resolution you have. You can crop and zoom on the part later. It's better a sharper pict from a longer distance than a close up out of focus.
You can send your better pict to JRF magnetics (no affiliation) asking for a relap quote, they will tell you if they are still usable.
If I can see a gap with the naked eye and a blurry pict, I'd say they are gone...
I'd take another pict, better focused. Set your camera to macro, make sure the focus is right, and use the highest resolution you have. You can crop and zoom on the part later. It's better a sharper pict from a longer distance than a close up out of focus.
You can send your better pict to JRF magnetics (no affiliation) asking for a relap quote, they will tell you if they are still usable.
KentTeffeteller
Gimpus Stereophilus!
This head may be relappable, but it is very worn.
Kahoona
Super Member
I do appreciate all of the help here. It has been worth the education it gave me and the experience of tearing it down. I have learned some basic things and I will still pull it apart to see what I can see but at this point there is no point in doing the electronic work and buying a head for a low value machine anyway. I do believe it is time to move on. I really do need to find a 'scope though.
Thanks.
Thanks.
elnaldo
Lunatic Member
I've used a PC based oscilloscope for a while, it was very useful. I've downloaded "Visual Analyzer", and built a probe with a capacitor to block any DC. There are some threads at AK about this.
It won't work for Radio Freqs, but for audio and troubleshooting was very useful, you can see clipped or distorted waves, out of phase signals (azimuth in a tape). It measures THD too. You can't measure DC levels, or DC coupled signals, since the capacitor will filter the DC component.
It won't work for Radio Freqs, but for audio and troubleshooting was very useful, you can see clipped or distorted waves, out of phase signals (azimuth in a tape). It measures THD too. You can't measure DC levels, or DC coupled signals, since the capacitor will filter the DC component.
Kahoona
Super Member
Very interesting. Thank you. I am going to do that. I'll dig around for those threads and download a program. I could use that to check the DA-A10DC
JURB
Super Member
You probably should actually test the performance of the unit before ditching it. That head IS worn but there are a few factors to that.
The head is a round thing usually, pretty much toroidal, with a slit cut. It depends on how they cut the slit. If it gets wider much as you dig down into it then the gap is affected greatly. However if the cut is pretty much even, the gap could be just fine.
If the thing basically works and you make a test recoding, it should sound virtually the same as the original in 7½ IPS. Some decks are as good as a good cassette at 3¾ IPS so you might hear some difference there. It would be nice to have a generator to see how high it can play back. the gap of the record head is not as critical and in fact is wider than the playback, so it probably records fine.
Most likely, if it is not too too bad, you can recalibrate the playback EQ to get good sound, though the S/N will not be as good as original. How bad it is depends. some of them were rated like 48 dB which seems to suck but then back then alot of things "met or exceeded" their specs.
You should probably clean up a bunch of switches etc. because they are probably the immediate problem. You might wind up with a usable deck, but really, with that playback head I would not do a full restore on it. Just fix it and maybe get some use out of it. Maybe have some fuin editing tapes...
The head is a round thing usually, pretty much toroidal, with a slit cut. It depends on how they cut the slit. If it gets wider much as you dig down into it then the gap is affected greatly. However if the cut is pretty much even, the gap could be just fine.
If the thing basically works and you make a test recoding, it should sound virtually the same as the original in 7½ IPS. Some decks are as good as a good cassette at 3¾ IPS so you might hear some difference there. It would be nice to have a generator to see how high it can play back. the gap of the record head is not as critical and in fact is wider than the playback, so it probably records fine.
Most likely, if it is not too too bad, you can recalibrate the playback EQ to get good sound, though the S/N will not be as good as original. How bad it is depends. some of them were rated like 48 dB which seems to suck but then back then alot of things "met or exceeded" their specs.
You should probably clean up a bunch of switches etc. because they are probably the immediate problem. You might wind up with a usable deck, but really, with that playback head I would not do a full restore on it. Just fix it and maybe get some use out of it. Maybe have some fuin editing tapes...