Tascam 388 Track 1 and 8 weak muddy playback

[bmacca88]

Hello all!

This is my first post here. I joined today because of the excellent info when fixing my Tascam 388.

Everything is working great except this on tape playback:

Track 1 - VERY WEAK, muddy sound (lots of tape shed after a few plays
Track 2 - Stronger, but still a little weak
Track 3 - Normal
Track 4 - Normal
Track 5 - Normal
Track 6 - Normal
Track 7 - Weaker , but still usable
Track 8 - NOTHING

After a few plays, I look at the heads (which were cleaned before playback), and there is a TON of either tape shed or oxide (or something) on tracks 1 and 8 on both tape heads. Even when I clean it again and try and record, it is still very weak on Channel 1, and very very low signal on Channel 8.

Please help! If anyone can get in touch with @sweetbeats please let them know about this thread!

Thank you!

Ben

 

[sweetbeats]

What kind of tape are you using?

 

[bmacca88]

@sweetbeats Thank you so much for your reply. I am using new ATR Master tape.
I found a thread where you mentioned rewinding and fast forwarding a few times and that pretty much did the trick.
But why??
Any and all answers needed. Thank you for your time and look forward to your reply.

 

[sweetbeats]

Here’s my guess:

I’m assuming there is a wear path established on the tape path, right? Like on the record/play head you can gently feel a ridge at the top and bottom of the tape path on the face of the head with your fingernail?

If I’m correct, and I suspect I am, I’m probably also correct that path was worn by Ampex/Quantegy tape. Ampex/Quantegy tape slitting equipment wasn’t as accurate as other manufacturers’ equipment, so in order to ensure that their tape was never wider than the standard they slit their tape slightly more narrow than the standard. This is not the case with other manufacturers including ATR. So what happens when you run tape through a wear path worn by tape that was slightly more narrow? Edge shed and lift. It takes almost no debris or lift on a 1/4” 8-track tape track to severely or completely diminish playback or record signal. Your tape path is an edge shed factory with pretty much any tape besides Ampex/Quantegy tape. Sometimes if the wear path is very shallow, you can fast wind the tape with the lifters defeated and help establish something of a new wear path, but expect to potentially damage the tape, have cleanup to do afterward, and this only works if the wear path is barely getting started.

 

[bmacca88]

Gotcha.
So should I stick to Ampex and Quantegy tape? Or is it ok continue to wear a new path with the ATR tape?
What I can say is each time I rewound or fast forwarded, there was less and less tape shed.

 

[sweetbeats]

I really can’t advise on whether you should “wear a new tape path” because I have no idea how deep your tape path is already. Like, it could take a long time to do that.

And you don’t want to use Ampex tape because the 457 that the machine was designed to use is all sticky by this point.

The only real solution, if I’m right about your problem, is to have the head relapped. And if possible to have relief slots cut so you never have to deal with this again.

you are likely getting less shed because the tape edges and oxide are getting shaved off. So…if that is working, then just go with that. But, depending on how deep your wear path is, what may be going on is the tape getting worn to the path, not the other way around.

Can you put up some good pics of your record/play head? Is the situation resolving with running the tape in the path at fast wind with the lifters defeated?

 

[bmacca88]

@sweetbeats yes, it is resolved after running the tape path in FF and Rewind with the lifters defeated (tape directly on heads). There was less and less shed each run thru, ultimately bring back my tracks 1 and 8 to fully clear sounding!

I guess my question now, will i have to do this every time I use a new reel of ATR tape??

Here are some pics of the tape heads and path.

 

[bmacca88]

@sweetbeats yes, it is resolved after running the tape path in FF and Rewind with the lifters defeated (tape directly on heads). There was less and less shed each run thru, ultimately bring back my tracks 1 and 8 to fully clear sounding!

I guess my question now, will i have to do this every time I use a new reel of ATR tape??

Here are some pics of the tape heads and path.

View attachment 111248View attachment 111251View attachment 111254View attachment 111257

 

[sweetbeats]

Well it’s hard to tell what the wear path looks like on the record/play head from the pics. You included more pics of the erase head than the record/play head. From what I can see it looks like nominal wear but I’m not really sure. A picture looking across the laminations with better light, like with a flashlight shining on the face of the head and then the head laying more flat so I’m looking across the wear path like looking across a valley so I can see the relief of the wear path is what I’m looking for. I’m not saying you have to go to that trouble, I’m just letting you know what I’m looking for.

As far as whether you’ll need to do this every time? I have no idea. You’ll know if you’ll have to keep doing it the next time you put a fresh reel of tape on. We don’t know if it’s working better because the wear path is relieved, or the tape is now worn at the edges. If you have a fresh reel you could put it on and see, and if you are back to square one you’ll know it’s the tape that’s getting worn. It’s safe to say over time this will get better, but how long it will take us anybody’s guess. OR maybe you put that fresh reel on and it’s much better. Again, a relap is the only way to properly fix the problem, and I highly encourage relief slots be cut if you have that done.

Are you using MDS-36 tape?

 

[bmacca88]

@sweetbeats, just tested tracks 1 and 8 with ATR test tape at 1khz on playback. track 1 is fine, but a little lower than the others. track 8 Vu is jumping up and down, sounding like a slow tremolo on the 1k tone. When i push the tape closer to the head, it evens the modulation out.

head relapping or tension issue?

also, this is the tape i have been using:

Master Tape

ATR Master Tape provides for high-output, low-noise recording with an industry-standard bias compatibility. Our advanced preparation and coating techniques produce a consistent, high quality product that meets the needs of professional recording studios and hi-fidelity enthusiasts alike. Tape...

nashvillerecordingsupply.com

And this is the test tape i am using:

7" MRL Reference Tape - 1/4" — ATR Magnetics

1/4” 7” MRL Reference Tapes - 15 IPS or 7.5 IPS - IN STOCK - NAB equalization - 7.5ips 112 nWb/m - 15ips 355 nWb/m (+6) - 4-Tone (1k, 10k, 16k, 50 Hz) Short Version - If you have any questions or concerns regarding calibration tapes, please look at our training manual on our website.

www.atrtape.com

 

[flyingace]

Hey, @bmacca88 Welcome to the forum! And thanks @sweetbeats for getting involved, I know you know your stuff on 388s!

I purchased my 388 a few months ago and while waiting to get my studio set up, then delays due to a bad builder, lumber costs, etc. I have put off fully testing my 388. I’m glad I saw your post today and I had time to test mine. I’m only having the weak or low levels via LINE input on tracks 1 & 2, all the other tracks are good. But it was the same slow tremolo kind of effect. I’m using ATR MDS-36 tape, new reel.

I did a thorough cleaning and degaussing the heads, capstan, tape path. Playback was significantly better on all, so I know it was dirty and likely magnetized. But I’m still getting low signal via LINE on 1 & 2. Via MIC, no problems though. Sweetbeats, think it’s something deeper? Capacitors on those channels? Weak solder joints on LINE input?

Thanks all. (I hope you don’t mind, not trying to hijack your thread)

 

[TimOD]

There's always computers and DAWS and tape emulation plugins, but I guess there's the sheer joy of fiddling with tape machines.

 

[sweetbeats]

@sweetbeats, just tested tracks 1 and 8 with ATR test tape at 1khz on playback. track 1 is fine, but a little lower than the others. track 8 Vu is jumping up and down, sounding like a slow tremolo on the 1k tone. When i push the tape closer to the head, it evens the modulation out.

head relapping or tension issue?

also, this is the tape i have been using:

Master Tape

ATR Master Tape provides for high-output, low-noise recording with an industry-standard bias compatibility. Our advanced preparation and coating techniques produce a consistent, high quality product that meets the needs of professional recording studios and hi-fidelity enthusiasts alike. Tape...

nashvillerecordingsupply.com

And this is the test tape i am using:

7" MRL Reference Tape - 1/4" — ATR Magnetics

1/4” 7” MRL Reference Tapes - 15 IPS or 7.5 IPS - IN STOCK - NAB equalization - 7.5ips 112 nWb/m - 15ips 355 nWb/m (+6) - 4-Tone (1k, 10k, 16k, 50 Hz) Short Version - If you have any questions or concerns regarding calibration tapes, please look at our training manual on our website.

www.atrtape.com

So that is not necessarily the tape I would use. How are you setting the bias for that tape? It’s also significantly thicker than the 1mil class tape the transport is designed for. I’d be using LPR35 or MDS-35 or if you can find Quantegy 457 use that. I suspect the tape is curling in the tape path and you are abating that by applying some pressure, but I don’t know for sure. If you can find some non sticky 457 you can test my theory. Be careful running your test tape if it isn’t made from Quantegy tape stock.

 

[sweetbeats]

Hey, @bmacca88 Welcome to the forum! And thanks @sweetbeats for getting involved, I know you know your stuff on 388s!

I purchased my 388 a few months ago and while waiting to get my studio set up, then delays due to a bad builder, lumber costs, etc. I have put off fully testing my 388. I’m glad I saw your post today and I had time to test mine. I’m only having the weak or low levels via LINE input on tracks 1 & 2, all the other tracks are good. But it was the same slow tremolo kind of effect. I’m using ATR MDS-36 tape, new reel.

I did a thorough cleaning and degaussing the heads, capstan, tape path. Playback was significantly better on all, so I know it was dirty and likely magnetized. But I’m still getting low signal via LINE on 1 & 2. Via MIC, no problems though. Sweetbeats, think it’s something deeper? Capacitors on those channels? Weak solder joints on LINE input?

Thanks all. (I hope you don’t mind, not trying to hijack your thread)

But you ARE hijacking the thread lol.

There’s no point in conjecturing why you are getting a lower level with your line inputs on channels 1 & 2. Bad capacitors in the audio path don’t typically manifest as diminished signal level. Neither do bad solder joints, at least not if the diminished level is consistent. Is it? Does it change as the unit heats up? Does it crackle at all?

You exercise the source select switches at all, or exercise the insert points?

 

[bmacca88]

@sweetbeats would this tape work better?

Recording The Masters LPR35 (Long Play Version of SM911 1/4

Long play standard bias pro audio tape compatible with low speed recording. Recording the Masters LPR35 (long play version of the SM911 formulation) is backcoated to provide a magnetic tape with low print-through, high level frequency uniformity and wide dynamic range for your reel to reel...

nashvillerecordingsupply.com

@flyingace not at all hijacking! I am so thankful for all the info I’ve found on this site. At the very least maybe something on this thread has helped you. @sweetbeats is the most knowledgeable

 

[sweetbeats]

@sweetbeats would this tape work better?

Recording The Masters LPR35 (Long Play Version of SM911 1/4

Long play standard bias pro audio tape compatible with low speed recording. Recording the Masters LPR35 (long play version of the SM911 formulation) is backcoated to provide a magnetic tape with low print-through, high level frequency uniformity and wide dynamic range for your reel to reel...

nashvillerecordingsupply.com

@flyingace not at all hijacking! I am so thankful for all the info I’ve found on this site. At the very least maybe something on this thread has helped you. @sweetbeats is the most knowledgeable

Forum thread hijacking is in the domain of the original poster. I was out of line. If it’s not hijacking to you it’s not hijacking.

Yes LPR35 whether BASF, RMGI or RTM branded or whatever is much better suited for the 388.

 

[flyingace]

Now that we have the hijacking dilemma solved ?… Would using LPR35 or MDS-36 require re-biasing and how would one be able to tell if it did?

I’m going to exercise all the switches and pots on my console to see if it helps my issues. I DID notice that it seemed to really like to get warmed up before performing well. I’ll do some more testing and see how it goes. Thanks for your continued and awesome advice @sweetbeats!

 

[sweetbeats]

Now that we have the hijacking dilemma solved ?… Would using LPR35 or MDS-36 require re-biasing and how would one be able to tell if it did?

I’m going to exercise all the switches and pots on my console to see if it helps my issues. I DID notice that it seemed to really like to get warmed up before performing well. I’ll do some more testing and see how it goes. Thanks for your continued and awesome advice @sweetbeats!

The way Teac designed the bias setup instructions for the 388 are really jacked up. Bias is a high frequency signal that gets applied to tape by the erase head during recording…the signal excites the tape oxide preparing it to receive audio signal. Proper bias level helps to maximize high frequency response and minimize distortion. You with me so far? The amount of bias signal to apply, the level of the bias signal, varies by brand and type of tape. It can even vary from batch to batch of the same brand and type of tape. So you bet your boots you should be setting bias if you’re switching between LPR35 and MDS-36…but Teac gave us no guidance in the 388 manual for how much bias to apply. They gave us a flat level to set at the output of the bias amps and it’s based on using Ampex/Quantegy 457. I spoke directly with analog tech staff at Teac in Montebello CA years ago before Teac dissolved that department and was warned the bias requirement for LPR35 was very different than 457. MDS-36 didn’t even exist at the time. So I set about determining correct bias level for my BASF LPR35 tape using the LF modulation “bias rocks” method. IIRC I determined 110mV was the number but I think this is all documented somewhere in my “Tascam 388 Story…” thread. With any tape one would ideally set the bias using some method that provides some feedback of the results of the bias level. Overbias method, LF modulation, etc.

 

[flyingace]

Thanks @sweetbeats I thought I'd looked all over for info on the 388, and did not discover your "story" on the 388. That's one of the reasons I made the post about being crazy buying one that you were so kind to help me on. I have the thread open now and will read it in entirety before asking any more questions, as I'm sure you covered a lot, just like you did in the "M-520 Story". Thank you again for your documentation and willingness to share your experience!

 

[bmacca88]

So that is not necessarily the tape I would use. How are you setting the bias for that tape? It’s also significantly thicker than the 1mil class tape the transport is designed for. I’d be using LPR35 or MDS-35 or if you can find Quantegy 457 use that. I suspect the tape is curling in the tape path and you are abating that by applying some pressure, but I don’t know for sure. If you can find some non sticky 457 you can test my theory. Be careful running your test tape if it isn’t made from Quantegy tape stock.

I set the each tracks' playback level on the MRL test tape to be reading 0dB on each VU meter with the 1k tone. Then, I recorded a 1k tone (using protools tone generator, sending at -18dB into each PGM Buss in channels one at a time) on my blank ATR tape and set each tracks' recording level to match as close to the playback volume as possible. The lowest I could get everything on the recording level was about +3 dB.

I am a greenhorn with all this. Not even sure if I did it correctly but it sounds pretty good to me and is not clipping going in or on playback like it was.