How to connect a Tascam DX-4D to TEAC A-3440, help!

[fellwinter]

Hi all, I was starting to get some help on this when the Tascam forum went offline.

So my situation, I have a Teac A-3440 4 track, and a recently aquired Tascam DX-4D..

My problem, I have no idea how to properly connect it up!

I have tried numerous ways, and they either result in, no audio when enabling dbx, to very faint all high-end audio (kinda like when you pull a headphone jack halfway out type of sound).

Are the LED's on the dbx unit supposed to light up when dbx is enabled? They turn on when I first turn the unit on, then go off after a few seconds, some sort of power up test I would guess. The power light stays on..

I connected up the control cable to the 4-track, and have tried numerous ways to connect the two units and my mixer together, with limited luck.

As soon as i enable dbx, no sound or very limited sound like I described above there.

It's starting to drive me a little crazy, I didn't get a manual with the Dx-4d, but I have the manual for the TEAC, unfortuantly it shows how to connect up the RX-9 unit and not the dx-4d (the dx-4d I have read is a more reliable unit).

So I am attaching some photos of what I am babbling about here, and any help/wireing diagrams scanned in would be awesome!

Thank you.

Photos of what I am talking about:


Teac Shot 1

Teac Shot 2

Teac Shot 3

Teac Shot 4

[Herm]

I posted a way to hook up your unit on tascam but as you know they are gone and I already deleted the pics I had so lets try this again.

First put the jumpers back in the dbx connectors on your 3440.
Then connect the number one output of your recorder to the number one decode input on the dbx unit. Then connect the number one input of your recorder to the number one encode output of the dbx unit .
Then you will plug the output of your mixer to the plain input on the dbx unit, thats on the first 4 set of rca,s on the dbx.
Then connect the output of the number one of the first four of the rca, s to the tape input of your mixer.

Ignore the dbx rca connectors on your recorder and put the jumpers back in.

[Herm]

Now this is just the hook up for one channel.

The pic shows how to hook up the dbx unit.
Now your mixer will hook into the 4th set of inputs and outputs of the dbx unit.
Remember your mixer only hooks up to your dbx unit now and your recorder is hook to the dbx unit only also.

[fellwinter]

Its perfectly clear, and thanks for responding again! I did as your diagram shows, but still the same thing.

I start an audio source through the mixer, can see the levels moving on the 4 track.

As soon as I unpress the dbx switch on the front (to enable dbx) nothing, the level drops to zero, there is no sound, and the LED does not light for that channel on the dx-4d... I press the button in (bypass), and I can see/hear the audio again..

I try hitting record thinking that its the record/playback that starts up the control signal for the unit.. but no luck..

[fellwinter]

Should the LED's turn on when the unit is decoding/encoding?

[Herm]

Im going to hook my dbx unit up this after noon and see what happens.
Could you maybe post another pic and let us see how you have it wired now?
And maybe just hook up one channel so there is not so many wires running around in the pic.
Thanks

[Herm]

I tried my dbx unit with one of my 22-4,s today and the lights only went off when I pushed bypass. I even disconnected the signal cable and some channle inputs and nothing happend that shouldnt have.
I dont know what to tell you now cept just maybe you got a bad unit
Hang in there we will get it figured out some how.
Also where are you located at?

[fellwinter]

Hi, I am starting to think it might be a bad unit too.

What happens when you first power on the unit, do all 4 lights come on, stay on for a few seconds, then turn off?

I am about 20 hours away by car, im on the east coast of Canada, in New Brunswick.

[Chris Shaeffer]

On my DX-4D's the dbx lights only come on if the channel is engaged- and they stay on until I disengage them. If the are disengaged when I power them on only the power led lights.

-Chris

[Herm]

I just checked and the unit lights come on and stay on even with the recorder off and with the control cable disconnected.
You might want to try that and see what happens with the control cable disconnected see if the same thing happens.
One other thing are you sure you are getting the plug all of the way in cause it can appear to be in far enough but needs to be plugged in till the flat part of the plug is level with the back plate of the recorder.
Another thing are you using a mixer or the mic inputs on the front of the machine? cause its not going to work with those mic inputs on the teac. And things are not going to sound right through the headphone amp on the machine also.

[fellwinter]

Ok my results:

DX-4D by itself, only power chord connected to the wall.

Power on, and only the power led lights up. Power it off and the 4 dbx lights blink quickly once as the unit powers down.

Then, I connect the control cable upto the 4-track, but leave the 4 track powered off. Turn on the DX-4D, and same result.

I then power on the 4-Track, then power on the DX-4D, now all 4 dbx lights turn on, and stay on for about 10 seconds and then all turn off at once.

I also noticed that when the led's power off after 10 seconds, there is a little 'click' sound that comes from inside the 4-track...

[SteveMac]

Where did you get the DBX unit? My suggestion is to check the little silver tab in the back of the unit to see if its been taken off at some point. I think there is a jumper in there because I have one that acts similar if a second one is not plugged into it. This might sound confusing but it might have been used with another unit and if the other is not hooked up it wont work right unless another unit is plugged into it or a jumper is in place. I may be way off course but one the DBX units I have, the one without the silver tab on there wont turn on unless the the tape deck is on with the other DBX unit plugged into it. It does the same thing yours does, the lights turn on for a second then shut off.

[fellwinter]

I think you maybe onto somthing, I checked the back of the unit (we're talking about the cascade connector, right?) if so, it still had the original foil sticker over it saying: (please read manual before removing). So I removed it, and all I saw in there was a 6 pin plug socket, and no jumpers if jumpers are supposed to be there. If they are, which pins are jumpered?

[SteveMac]

Originally Posted by fellwinter

I think you maybe onto somthing, I checked the back of the unit (we're talking about the cascade connector, right?) if so, it still had the original foil sticker over it saying: (please read manual before removing). So I removed it, and all I saw in there was a 6 pin plug socket, and no jumpers if jumpers are supposed to be there. If they are, which pins are jumpered?

That's what we have to figure out. Mine came with that lable off and works only if the other is plugged in with the tape deck powered on. There is something about it. Is it possible the silver tab acts as the jumper and it wasn't in place ? ? It must say something about it in the manual. Unfortunately I dont have the manual either. Someone here has the manual.

[fellwinter]

Ok, here are a couple of shots of the back of the unit, and the foil sticker I removed:


http://cotw.no-ip.org/Teac/p1010116.jpg

http://cotw.no-ip.org/Teac/p1010117.jpg

[SteveMac]

Originally Posted by fellwinter

Ok, here are a couple of shots of the back of the unit, and the foil sticker I removed:


http://cotw.no-ip.org/Teac/p1010116.jpg

http://cotw.no-ip.org/Teac/p1010117.jpg

I can only suggest trying to make a connection between those two metal pieces coming down from the top and the bottom. It's just a guess. Maybe that sticker being metallic was supposed to be acting like a bridge and wasn't. If it works like a normal unit it should power on with all the lights when standing alone. Like I said it's only a guess if not then maybe someone with a manual can tell you what it says.

[fellwinter]

Yeah unfortuantly they are not metal pieces but plastic posts for the plug to plug into. The foil sticker was only covering the hole and not making any electrical connections.

Herm, you mentioned in an older thread about connecting jumpers 123 to 456, care to tell me more about that.. I've started playing with jumpers in the cascade plug and different things are happening now...

So I think I just have to jumper them the right way.

Do you have the manual there?

[Herm]

It doesnt make any differance there are no jumper that are suppose to go in there. I will have to look up the manual and see what I can find. But I do remember there are only two of those connection that do anything. But right now Im not sure which ones they are.
Do you have your mixer hooked up to the dbx unit?

[fellwinter]

Yeah, I connected everything up like you said, I can hear music fine through the returns back to the mixer, as soon as I hit the dbx enable button there is no sound at all, press bypass and I can hear sound again. The led over the dbx button(s) never lights up.

[fellwinter]

Once my battery charges in the digital cam, i will take a couple quick movies of all that I have been describing, maybe it will help.. I am determined to make this work, I think the DX-4D does work, just somthing I am missing.

[The Ghost of FM]

Originally Posted by fellwinter

Hi, I am starting to think it might be a bad unit too.

Sadly, I think it is a defective unit.

How you described the dbx channel lights coming on for no longer then 10 seconds indicated problems. Probably on a component level on a board inside the unit.

Did you purchase this used off of a stranger? Did they give you any indication that there was a problem with it or did they pull the old, "I'm selling this for a buddy and don't know shit". routine?

Besides anything else, I don't believe the DX-D4 was designed to interface with the 3440. The control signal connectors are different, no?

Do you have the manual for the 3440? If so, which dbx NR unit does it specify as the correct one to mate with it?

Sorry for all the headaches.

Cheers!

[fellwinter]

Hey, well I bought it off eBay, and yes to your , "I'm selling this for a buddy and don't know shit"

In any case the control cable from the DX-4D connected perfectly into the back of the A-3440..

I do have the manual and service manual for the A-3440, the manual shows the RX-9 being the mated unit, but I've been told that that unit is rare and was prone to failures..

The thing I don't get is, is this, when the lights on the dx-4d turn off, I hear a 'click' from the A-3440, like a relay turning off.

I did a bit more playing around, and found this..

I hit record on the A-3440, stop, then play, and the lights come back on the dx-4d for another ten seconds, then turn off...

*sigh* lol

[The Ghost of FM]

Unless you've really screwed up the connection paths and have somehow created a loop that is forcing the deck to mute and protect itself, (which I don't believe it has that capability as a feature), I'll maintain that the dbx unit is in need of qualified service.

Cheers!

[fellwinter]

Well, I think you are right.. I will add this, the unit is from Europe.. Yes, I do have a pro voltage converter, 120/240V 300W, since the unit is only 10W its more then enough.

I am starting to wonder if perhaps the relay circuit in the A-3440 maybe faulty?

I wish one of you were near enough to cross test this equipment with!

Ghost, its like the unit powers up fine, sees the A-3440 connection, then the A-3440 shuts it off, its really bizzare..

I will post a couple videos of this tomorrow.

[Herm]

There is an Export model of the dx-4d and there is a plug inside of it next to the transformer.
In the directions it says Make sure and unplug it from the wall first!

1. Remove the top cover of the unit by removing the screws on each side.

2. locate the voltage selector plug near the transformer inside the unit.

3 pull out the plug and reinsert it so that the desired voltage appears in the cut out window of the plug.

This could be the problem with your unit.