Tascam 244 headphone hiss

frilyd

New member
Greetings from snowy Norway to all you knowledgeable sirs & madams,

I have been lurking on these forums for some years, and have learned a lot that has helped me keep my analogue gear in somewhat good shape. For that, I thank you all.

Now, I have recently acquired a Tascam 244, partly for playing my old 4-track recordings, partly for actually using it to record. According to previous owner, it was used as a mixer (sic) and has been out of use for the last few years.

It seems to be in relatively good condition. The heads have no wear that I can detect, and the interior is relatively clean. Of course, after so many years, both belts are much too slack, and will be replaced. I've already ordered replacements, and useful resources such as Dr. Zee's instructions will make the belt replacement easy.

I listened to a few tapes today before the belts finally said goodbye. All in all, it was a good experience: None of the faders are crackly (a problem I haven't been able to remedy on my Tascam 388), and all audio goes where it's supposed to. There are some pops and crackles in the pan & EQ pots, but I can live with that for now.

My problem is that the headphone outputs are very hissy, even with no signal going to them. This is the "white noise" type of hiss, and it's loud enough that I will have difficulty using the 244 for recording. It's been many years since I touched one of these, but I can't recall them being that noisy - and my hearing certainly isn't better now than it was 20 years ago... But my memory may be failing me, and perhaps the 244 just is this hissy? Any experiences?

I suspect I am looking at an electronics problem here, but I'm in the dark about where to start diagnosing and eventually fixing it. Any input would be most welcome.

I can't repay much in the form of technical advise, but perhaps someone will find some merit in a recording I've done on my Tascam 388. It's a cover of a Steve Miller Band song, done for my mother's 60th birthday :)
 
Hi there,
Sounds like a similar problem I recently had with the Tascam 246. It turned out to be a ground loop problem in the headphone section. I took the unit to an electronics repair man here in Los Angeles and he fixed it for me. I unfortunately can't tell you exactly what was done. Check out the post I started a few months ago for more information.

Best
Brian
 
Thanks, Trovador98! I don't primarily suspect grounding issues, though, because there is no 50Hz (or 60Hz, if we were in the US) hum. The hiss sounds like what you get from speakers when the amplifier is cranked too loud, ie. normal static noise. Turning down monitor buss level or cue level doesn't help.

I haven't tried the track or stereo outputs yet, but will do that later today.
 
I know exactly what yr talking about. I have the same thing on the 244 I bought last summer. When you turn the machine on, does the hiss start suddenly, or doest it fade in?

The reason I ask is because when I turned my 244 on, it would give a 1-2 second fade in of hiss, and the same thing when I powered it down. It would fade out, sounded like out was letting out a breath. It wasn't enough of a problem that I couldn't use it, and the hiss didn't appear on the recordings so I just dealt with it until a friend of min offered to take a look at it. He fixed it by doing something to the DBX noise reduction. He told me exactly what he did but I don't remember what it was he said. If this is what is happening with yours I will ask him to tell me so I can tell you.That way, at least you have some idea of what kind of repair you are looking at. I was in for $50 and a 12-pack, but I have a parts machine so I didn't have to buy any pieces.
 
Hi all,

The headphone hiss is still there, but is not so bad anymore. I can only attribute this to the fact that the machine hadn't been used for several years when I picked it up. Now that it's been powered on a few times, it seems a bit less noisy - but I still think the electronics are to blame for the remaining hiss. It doesn't appear or disappear gradually, it starts once the machine has power.
Also, the background hiss doesn't change much when the monitoring is set to "cue", no matter the level of each track cue. However, the hiss changes noticeably when the monitoring is set to "remix" according to the volume on each channel fader. Channel 3 has a faint ground loop hum at high volumes, while channel 4 has ample amounts of white noise at high volumes :)

I'm attaching a few shots of the 244 for entertainment value. Thanks for your input! Head shots coming up next.

20160306_212341.jpg20160306_202633.jpg
 
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Just a thought, these machines were probably designed for 8ohm headphones, headphones nowadays are any where from 32 and more. Could it be that the headphone amp is running harder to power the headphones? Can you find an old pair of 8ohm phones to try?

Alan.
 
Hi witzendoz,

Headphone impedance is on my list of suspects, but I have reasoned that the impedance must be too low rather than too high. I have a pair of 44 Ohm headphones, and I've seen advice to increase that value:

Fix Headphone Noise

It makes sense, so for good measure I'll try both methods :-)
 
Hi witzendoz,

Headphone impedance is on my list of suspects, but I have reasoned that the impedance must be too low rather than too high. I have a pair of 44 Ohm headphones, and I've seen advice to increase that value:

Fix Headphone Noise

It makes sense, so for good measure I'll try both methods :-)

Usually with power amps as the impedance goes down the power output goes up, so I reason that it may be the same with headphones, 8 ohms gets more power output from the headphone amp then 32 ohms?

Reminds me of a Oz built live mixer we all used in the 1980's, the headphone out was designed for 8ohms, when 30 plus ohms headphones came along everybody plugged them in and of course left them turned up, all of a sudden mid gig a whole load of smoke came out of the mixer and it shut down, the headphone amp circuit board had melted and taken out the power supply regulation as well due to it being on the same circuit board. These things could live through a jug of beer being poured over them but not the wrong impedance headphones :facepalm:

Alan.
 
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