Modifying a Tascam Porta07 to output 4 discrete tracks?

[0degreesk]

Hi, my name is Robbie and I'm new to this site. I posted a similar thread in the Tascam forum, but I think it's probably better placed in here.

I have a Tascam Porta07 cassette 4-track. It only has the ability to output a stereo signal, so there's no way for me to archive my old recordings to digital by recording all 4-tracks simultaneously.

I'm wondering if it would be possible to rewire the machine to achieve this?

My thought is to somehow modify it so that Tracks 1 & 2 feed the Line Out output and Tracks 3 & 4 feed the Monitor Out output.

My goal would be to output the tracks raw: same relative levels, no EQ, no effects, etc.

I have two units, so I'm not worried about losing one like this.

Any thoughts?

Thanks.

 

[ashcat_lt]

This link has the easy answer. Basically you send track 1 and 2 hard panned opposite each other to the main out, track 3 via cue to the monitor out, and track 4 always comes out the sync hole.

It is definitely possible to actually rewire the thing like you asked, but without a schematic all you can do is poke around and trial and error.

Edit - Actually, I'd be willing to bet that the signal from each track of the tape is available at its respective line/off/tape switch. Find out which lug it's on (audio probe might help) and run a wire to the jack where you want it. Hopefully it would already have whatever gain it needs to be a useful line level by this point, else you'd have to hack in a simple amplifier.

 

[0degreesk]

Thanks for the reply, Ashcat.

I actually found that page after posting here and I went home to try it out myself, but it didn't work.

I grabbed my manual when I was home as well and I've attached the schematic.

You'll see that the L and R busses are fed to the Cue buss right before being sent to the Monitor Out and then finally to the Line Out.

Unfortunately, when I tried what the person described on that page, I was in-fact hearing tracks 1 and 2 in the monitor.

I haven't broken open the machine, yet, but I'm assuming it's all going to be on a circuit board.

Hopefully, I can just cut the conductors leading from the L and R busses to the Cue buss and achieve what I'm going for, because it would do what I want it to do.

Ideally, I could do this in a way that I could switch on and off, but I'll take simply cutting it permanently for now.

 

[drtechno]

well I think an easy way would be to tap off the tape return that is a direct line. they are -10db line stages.
If the channels are like the porta studio one, then you need to take your signal and capacitor couple it off of the top of the input fader (you shouldn't have to connect it to the wiper. because you should be able to digitize a -10 line signal w/o using this attenuator if you discover that you need to connect it to the wiper you can do that afterwards). connect like a 22uf @16V cap positive(+) lead to the input fader your unbalanced tape out is the negative lead of this cap and the dc power ground (of couse there should be a lot of places to get the ground inside. with the unit unplugged from the wall and powered off, use an ohm meter and ohm pin 1 of your mic xlr to find the grounds)

of course you might try to find a portastudio one. they had tape outs
I attached a schematic of the porta studio one. I don't have one for a seven.

 

[famous beagle]

Well, this isn't doing exactly what you want to do, but, if it sounds the same in the end, then ... ?

I had a similar problem when I wanted to transfer some tracks from my Tascam 414 to my DAW for further processing. It didn't have tape outs, so I just did this:

1) Transfer tracks 1 and 2 panned hard L and R over to tracks 1 and 2 on the DAW
2) Transfer tracks 3 and 4 panned hard L and R over to tracks 3 and 4 on the DAW
3) Use time stretching to line them up. I simply aligned the first note of tracks 3 and 4 with that of 1 and 2 and then squashed them until the last note lined up with 1 and 2. After doing that, the first note will have moved a tiny bit out most likely, so you realign it and then realign the end.

Shampoo, rinse, and repeat until they are lined up. The whole process took me about 15 minutes, and that included transferring the tracks from the 414.

You can hear the result here. If you can hear phasing/sync issues between the tracks, you have better ears than I do. I couldn't hear a difference at all when I listened to the tracks from the DAW compared to the tracks from the 414.

 

[Lt. Bob]

Well, this isn't doing exactly what you want to do, but, if it sounds the same in the end, then ... ?

I had a similar problem when I wanted to transfer some tracks from my Tascam 414 to my DAW for further processing. It didn't have tape outs, so I just did this:

1) Transfer tracks 1 and 2 panned hard L and R over to tracks 1 and 2 on the DAW
2) Transfer tracks 3 and 4 panned hard L and R over to tracks 3 and 4 on the DAW
3) Use time stretching to line them up. I simply aligned the first note of tracks 3 and 4 with that of 1 and 2 and then squashed them until the last note lined up with 1 and 2. After doing that, the first note will have moved a tiny bit out most likely, so you realign it and then realign the end.

Shampoo, rinse, and repeat until they are lined up. The whole process took me about 15 minutes, and that included transferring the tracks from the 414.

You can hear the result here. If you can hear phasing/sync issues between the tracks, you have better ears than I do. I couldn't hear a difference at all when I listened to the tracks from the DAW compared to the tracks from the 414.

^^^^^^ this ^^^^^^^^^

Simply export them two tracks at a time into the DAW and then align them