No Record Playback using Tascam 48 & M-1516

hithere123

New member
Hey everyone,

Thanks so much for all of your help thus far on my analog recording journey. I have been recording ITB for so long that I know many of my questions are rudimentary.

I have been scanning both manuals to see what obvious step I must be missing, and trying to wrap my head around the slightly confusing Dual Master section.

So here are my efforts to record audio on to Track 1.

The 48 = REC - On (Red Light Blinking)
OUTPUT SELECT = SYNC

The 1516 = XLR Microphone into Channel 1 Preamp. Tape Button below Trim Knob is out.
Signal Reaches Channel 1 VU Meter on 48 with either D OUT or 1/L 2/R Buttons In. *If 48 OUTPUT SELECT is on INPUT, 1/L 2/R will also move Channel VU’s other than Track 1
Channel 1 Fader at Unity

I then press Play & Record activating Record mode on the 48, the Red Light goes solid and signal continues to register on 48 Meter while in Record Mode.

I rewind the take and get nothing back.

I have switched to REPRO, taken the track off Record Mode, and switched SYNC & INPUT Button for Track one back and forth.

If I then Press the Tape In below the Trim Knob, and try to Monitor off of 1/L 2/R nothing.

Also if I leave the D Out button on when I do this, I pin the meters of Track 1, and if I am using the Dual Monitor Section to Monitor that Channel a very loud buzz erupts from the headphones. Is that Normal, a Feedback Loop maybe? Definitely not a sound you want through your monitor speakers.

I must be missing something very simple.
 
You're going to think I'm crazy for asking this, but have you cleaned the heads? I mean really cleaned them? I ask because I had a nearly identical situation on a TSR8 I had just gotten. Everything looked like it should work. The meters were going. Nothing played back. The heads "looked" good. I cleaned them, and about an inch of crap came off the erase head. Since then, it's worked fine.
 
I then press Play & Record activating Record mode on the 48, the Red Light goes solid and signal continues to register on 48 Meter while in Record Mode.

I rewind the take and get nothing back.

I have switched to REPRO, taken the track off Record Mode, and switched SYNC & INPUT Button for Track one back and forth.


Forget the mixer for a moment.
When you switch to Play...do you still see a signal on the 48 meter?

If you do, then it means something was recorded.
So then how are you routing the signal back out from the 48 to the mixer?

By the way...what part of the country (world?) are you in?
 
Forget the mixer for a moment.
When you switch to Play...do you still see a signal on the 48 meter?

If you do, then it means something was recorded.
So then how are you routing the signal back out from the 48 to the mixer?

By the way...what part of the country (world?) are you in?

When I switch to play I do not see a signal on the 48 Meter.

So it seems that nothing was recorded to the 48 at all.

I am in the Philadelphia area.

Also the heads are clean, but I am getting some cleaning supplies for the heads delivered this week.
 
Post a close up pic of the heads under good light.

We can verify they are clean. There can be a layer of schmutz on them that looks like clean but is not.

Try the other tracks like you did and as Miroslav asked just see if there is activity on the meter after recording. Don’t worry about the mixer for now.
 
I am in the Philadelphia area.

Do you want a Tascam M3500 console...for free?
It would only cost you the 5 hour roundtrip to come get it. :)
I'm up in the lower Hudson Valley of NY...near Middletown, NY.

I'm not kidding.
I've been wanting to find a home for it rather than toss it. Selling it is not going to get me much...and not many people are looking for this type of console anymore, which is perfect for a home/project setup...because most home/project studios have gone ITB/DAW.
The bigger, commercial studios would go for something much more high-end...but don't mistake this for a crap console, it's actually quite decent.
The 3500 sold for about $8k with the extended meter bridge back in 1990.
I switch to a Trident 4 years ago...and the 3500 has been sitting here...but the time has come for me to get rid of it...I need to clean out a lot of leftover stuff.

Anyway...I don't know you from Adam...so you're the perfect person to give it away to.
Someone who is looking to get into analog stuff, and who would appreciate the extra effort to do so.

It's a 24 channel console...with another 24 possible on mixdown...so more than enough for your 48...and maybe enough to make you want to get something more than the 48...a nice 16-track deck. ;)

I have some spare parts for it, and the full manual.
I want to see this go to a good home where it will get some use.
It hasn't been powered up in 4 years...and has spent that time in storage...so yeah, might need some TLC and contact cleaning...but it all work perfectly when I used it last.

Anyway...I was getting ready to offer it up for free in the local musician classifieds...but it's yours if you want it.
It's my way of paying forward...and there might even been a couple of extra things I end up including.
You wouldn't need to come get it immediately...but like in the next few weeks I'll be ready to start my big spring cleaning project, and that's when I'm going to want to say goodbye to it.

Think about it and let me know. It would fit in the back of an SUV if the seats go down...and I would help getting it loaded...so you don't even need to bring anyone to help. Two people can carry it easy enough.

This isn't a picture of mine...but basically, this is the console...mine is the same.

csxfsix06f92atbeqytc.jpg
 
Miroslav,

That is beyond generous and I will surely PM you about it soon. Also congrats on the Trident, used to track through them at a studio I worked out of a lot!

So here are some pictures of the heads.

They are definitely dirtier than I thought, and I know it is because I only had an old baked Ampeg 456 Reel that to came with the machine to demo it. That was my first experience with sticky shed, and I can see how quickly it gunked the clean heads up. My new reel of ATR just arrived yesterday.

Getting isopropyl alcohol during the pandemic has been difficult, I have been waiting on a bottle I ordered for 2 weeks now. I do have some American Recorder Cleaning Fluid arriving this Thursday.

I went through and tried to record on tracks 1-8.

Track 7 seemed to retain a little bit of signal, and Track 8 came back perfectly. The rest, nothing.

IMG_0437.JPGIMG_1362.jpg
 
You can go to the hardware store and get denatured alcohol. Make sure it is virgin and not reprocessed. It should say in the detail on the back. Denatured alcohol is as good or better than 91% iso alcohol.

Use high quality cotton makeup remover pads, the kind that look quilted, to clean the heads, lifters and guides. That will work better than cotton swabs.

Then use your new tape and retry your test, tracks 1-8 and report back the results.

If you can record at all then it is not a problem with the bias oscillator...that was my first thought. Once the tape path is truly clean and you are using new tape then we can get a baseline for what is working and what is not, and if the problems are stable we can start swapping amp cards around to see if the problem follows the card to further narrow down the problem source, and if the problem isn’t stable and “moves around” it is usually related to faulty relays.

All of this we need to methodically take step by step. Okay?

Start with a good and proper cleaning using the proper supplies and then retry your record testing across all tracks using new tape and report back.
 
Ok, the good news is cleaning the heads totally fixed my the recording issue on the 48.

The bad news is I came across some other problems. FYI I am using two RCA to RCA snakes to connect the 1516 & 48

1. The RCA 48 Output seems to not be functioning on track 1 & 7. I took me a while to figure out why I couldn't get playback of my recordings, though the meters on the 48 had received what was tracked. When I tested both outputs with a RCA - 1/4 cable into my Apogee Duet Interface, they both outputted no sound, with a low static hiss. When I did the same with the other track number RCA Outputs, the recordings played back fine into my DAW.

I then switched to using track 1 & 7 with the 48 XLR Output to my recording interface, and it worked just fine.

Solution = Fix the 2 RCA outputs, or have to purchase an entire RCA-XLR snake?

2. Track 6 of the 1516 is not working correctly. I can get barely any signal output from the XLR or Line In unless I push the PFL button. The OL Meter on the channel does work, so it is getting signal. When I push the PFL button it sounds like dust or some cleaning needs to be done.

Because of these two issues, I am currently down track 1, 6, and 7.

With all that being said, I did a quick demo last night, and was very pleased with the sound and performance of the 48!

PS is there any way to avoid the horribly loud noise that erupts from your monitors, when you mistakenly have a channel on the 1516 with the D OUT & Tape In button engaged at the same time?
 
Sounds like it’s time to pull the backplane off the 48 and reflow the solder joints of the PCB-mount RCA jacks...it’s not the best design. The 58 was even more fragile. But that’s where I would start is assume the solder joints need re-flowed. If you are getting signal at the XLR jacks you know it’s not a problem with the line amps that drive those outputs. The XLR output jacks get their signal from the same place as the RCA jacks, so it’s something in between where those branch and the jacks themselves and there’s not much of anything in between to go wrong except the solder joints of the jacks themselves...not an uncommon problem.

As far as channel 6 on the M-1516, I would start by exercising the INSERT jack for channel 6. Those jacks are horizontal and prone to get crud in them...they have normaling contacts in them so that when nothing is connected signal passes through from the input amps to the channel, and then when you insert an insert cable the contacts are broken so the signal goes out to and comes back from your effects processor. Those contacts can get corroded. So take a TS or TRS cable and carefully but rapidly plug and unplug. If you have some contact cleaner all the better...squirt some in there while you exercise the jack. You can also test to see if what I’m suggesting is the problem is really the problem by plugging in an insert cable, and then connecting the SEND and RETURN plugs together using a female TS barrel connector...or just hook up your outboard processor to the INSERT jack and see if signal flows.

On your “PS” question you are going to have to be a little less mysterious...what kind of sound are you hearing? Feedback? A crunch? When does it happen? And please provide some greater detail as to what is connected to the Direct out and tape in jacks...short answer? Don’t make the mistake of pressing those two buttons at the same time. It might be more than your ears that get damaged.

Glad you got the 48 working as far as recording and reproducing on all tracks.
 
Testing of a deck is done with known good cables on a bench with a common sine wave generator. That way the deck is the only thing known or unknown in this set up. Trying to do repairs in a studio with all kinds of other variable can drive you crazy as it gets all too much more complicated. I have fixed many 48 decks and one thing I will warn you about on those audio cards that I can across recently were things called 220uF 16V Marcon capacitors. Now when I see Marcon caps out they come in favor of better grade 105* C Panasonics or Nichicon or even the new Wurth caps that are Red. New filter caps where these are will keep your deck going more reliably. Of course there are the mute relays that I have to change often and I put them into sockets. Then the last thing I cam across one time was the oscillator amp block that was dead for a channel- these are hard to find but in my case they can be repaired. The output cap on the module was shorted .0033uFd I think was the value and I changed it with a higher grade film cap the module then worked and that channel was recording again.

Yes, too many people jump over the head cleaning task to head for more expensive parts- cleaning is something that has to be done often and the new comers from digital will never understand that but tape to head contact is very critical and is why I polish heads with Nu Finish Car polish and get a improved tape to head contacts and better consistent level.

I am also an enemy of 10V caps so I change them out upon site with 16V caps. They are known for shorting as well. Now Marcon is joining that group. Black lead transistors should also be included.
 
Alright,

Long post ahead.

So I am in the midst of a move and finally got back to trying to get this rig up and running.

Unfortunately, it seems like the problems I found a fix for, led to more problems.

Let’s start out with

1. The screeching noise.

Here is a video of using RCA - RCA cables between the Board and 48. When I having D Out & Tape In depressed on a channel strip, this is the loud shrill noise that emits & channel needle pins. This only happens when 48 & 1516 are connected, both In & Out, as well as the 48 Track is Armed to Record.

Screech on Vimeo

*Track 1 & 7 do not do this, read on


2. The 48 Outputs

Rather than open up the back of the machine during this busy time, since it was only two of the RCA outputs ( 1 & 7 ) that were being finicky, I would order some simple Unbalanced XLR-RCA cables.

I went from XLR on the 48 Output to RCA Tape IN on the 1516 & RCA from the 48 Input to RCA Output on the board.

Not only did it work perfectly recording and playing back from the machine, but with the mix of the cables, I could not reproduce the screeching sound found when using only RCA - RCA cables depressing the Tape In & D Out buttons on a channel.

I figured I would try this phenomenon on other channels. Yet suddenly… none of my XLR Outputs BESIDES 1 & 7 were working…

As it stands now on the 48

Only the XLR Outputs 1 & 7 work
Only the RCA Outputs 2,3,4,5,6, and 8 work

What are the chances of that?


3. Channel 6 on the 1516

I think you were onto something with the Insert jack Sweetbeats. Plugging in and out seemed to get a little extra signal coming into the meters & onto the tape.

It seems to me the real culprit is the Fader on Channel 6. If I move it and put just the right amount of pressure on it, the proper signal comes in and out fuzzily. Definitely needs to be cleaned somehow. I need to order contact cleaner

Strangely, when plugged into the 48, this fader also interacted with the Tape In channel causing a loud noise when touched and moved. That was a first… video below

Fader on Vimeo


Sure hope I can get this sorted soon. The little I got to do on the machine sounded great, and seems otherwise be running smoothly.

Again thanks so much for the help.
 
Record each track, one at a time, completely bypassing your mixer (plug in a single RCA from your iPhone playing music or something), and monitor from a headphone amp or something more simple, one output at a time. That sound sounds like an adjacent track is overloading in sync or something (not familiar with that machine, but familiar with that sound).
 
Hmm, I would not know how to address an adjacent track overloading sync.

Wonder if the screeching could somehow be related to a problem with the outputs.

I suppose the next step is going to be to open the back up and see if the solder joints need to be reflowed as Sweetbeats suggested.

Hopefully it isn't something to do with the Line Amp, since now all the XLR outs besides 1 & 7 are not operational.
 
1. The screeching noise.

Here is a video of using RCA - RCA cables between the Board and 48. When I having D Out & Tape In depressed on a channel strip, this is the loud shrill noise that emits & channel needle pins. This only happens when 48 & 1516 are connected, both In & Out, as well as the 48 Track is Armed to Record.

Walk through this with me. You have a mixer channel direct out connected to a tape machine input. Then you arm that tape machine track to record. When you do that the input of that track is present at the corresponding tape machine output...it does this so you can monitor the source you are going to record and set levels and such. You have that tape machine output connected to the tape input on the same channel that has the direct out connected to that tape machine input right? So you just setup a feedback loop. Mixer channel signal goes out to tape machine, that signal passes through the tape machine when you arm the corresponding track, and the same signal returns to the same mixer channel at the TAPE IN jack which goes where? Yes...the direct out jack...and around and around we go...meters peg, ears get covered, and sometimes opamps fry. The squeal sound also goes away when you lower the channel fader right? Because that's what feeds the direct out jack. You are not supposed to monitor your tape outputs using the same channels that are feeding the tape inputs. You have to use separate mixer channels or a monitor mixer or something to do that...looking at the M-1516, this is why they included the TAPE IN jacks as one of the sources for the DUAL buss. So, when tracking and overdubbing, do NOT source the TAPE IN jack as the source for the mixer channel. Set the DUAL source on that channel to TAPE IN, set the level and pan controls to taste, and then in the master section raise the level on the DUAL MASTER rotary control and then on the far right of the mixer in the monitor select switchrack latch the DUAL button, and this will allow you to monitor any or all TAPE IN jacks as an independent stereo cue mix without sending any of those signals back out to the tape machine causing a feedback loop.

2. The 48 Outputs

Rather than open up the back of the machine during this busy time, since it was only two of the RCA outputs ( 1 & 7 ) that were being finicky, I would order some simple Unbalanced XLR-RCA cables.

I went from XLR on the 48 Output to RCA Tape IN on the 1516 & RCA from the 48 Input to RCA Output on the board.

Not only did it work perfectly recording and playing back from the machine, but with the mix of the cables, I could not reproduce the screeching sound found when using only RCA - RCA cables depressing the Tape In & D Out buttons on a channel.

I can't explain this. I would need to see how you actually had things setup at the time. But the facts remain as presented above, it is not intended that you feed a direct output on a channel strip with an input that comes from the same device the direct output feeds. This creates a feedback loop or risk of it if you forget what you are doing and arm the tape track and **skreeeeeee**. There are lots of ways to screw up on most mixers and create this problem. You have to understand your console and how signal flows and know how to avoid it. It won't do it for you (not saying you are saying it should, just underscoring that it happens sometimes because it *can*, and you have to be aware of that and actively avoid it with your setup and operation).

I figured I would try this phenomenon on other channels. Yet suddenly… none of my XLR Outputs BESIDES 1 & 7 were working…

As it stands now on the 48

Only the XLR Outputs 1 & 7 work
Only the RCA Outputs 2,3,4,5,6, and 8 work

What are the chances of that?

Possibly really good if your feedback issues blew a bunch of opamps. I would do exactly what [MENTION=80733]lonewhitefly[/MENTION] suggested. Take the console out of the chain for now, test each track one at a time on the tape machine using a simple source device and simple monitoring solution, use the same simple setup for each track and, again, just do one track at a time. Use the same known good cables for each track's test, and test all 16 inputs and all 16 outputs (8 RCA + 8 XLR). Make a chart or something to keep track of the results. Report back. This will tell us what is working and what is not, and then we can dig further into the tape machine depending on the results. Once that's squared up we can then do the same type of testing process on the mixing console, one channel at a time to sort out what might roached there if anything. THEN we can marry the two together and try it again. But please, if something doesn't seem right, avoid the temptation to just plow ahead and (figuratively) bang on it with a hammer to see if THAT works. I'm telling you from painful personal experience that's a bad idea. Here are some of the fun things I've experienced by rushing ahead without a plan or the right equipment/resources/support...these all happened at different times...yes...I'm a slow learner...:

Stuff exploding
Big sparks flying
Bad smelling smoke
Electrical shock
*Completely* roached my mint-condition Tascam 58 well beyond my ability to repair it.


3. Channel 6 on the 1516

I think you were onto something with the Insert jack Sweetbeats. Plugging in and out seemed to get a little extra signal coming into the meters & onto the tape.

It seems to me the real culprit is the Fader on Channel 6. If I move it and put just the right amount of pressure on it, the proper signal comes in and out fuzzily. Definitely needs to be cleaned somehow. I need to order contact cleaner

DeoxIT F5 is what you want for that fader type, but you can jet it in there all day and it won't likely fix the issue unless you can actually get the crud OUT...who knows what was spilled in there. So, the right way to do this, assuming the faders are the low-profile ALPS faders commonly found in a number of 70s, 80s and 90s Teac mixers, is to disassemble the fader and clean it, and also carefully reposition the fader wiper according to the instructions in this video here:

YouTube

The trick with the M-1500 series is I *think* the faders may be mounted directly to the channel cards rather than mounting to the chassis and being physically separate from the card, which complicates things...you have to desolder the fader from the channel card first before you can disassemble the fader. This is the kind of thing I was talking about much earlier when we were talking about how the M-1500 mixers have a lot of useful features and they aren't "bad", but as you get into the mid to late 80s and into the 90s Teac prosumer products had more plastic, and other design features centered around cutting manufacturing costs, but made them less durable, and harder to service. Every company did this...not singling out Teac per se. And Teac generally did a good job at passing some of those savings on to the customer with lower prices than other companies. I personally would take an M-300 console over an M-1500 any day for this and other reasons, but you've got that M-1516 for now, and its a neat mixer that can nicely serve the needs of your setup...has way more routing features and flexible input/output faculties than ANYTHING you will find in that bracket today or for the last couple of decades and beyond, really, so let's love on it and figure out what's going on...great bang for the buck...I've always, for some reason, wanted to lay hands on an M-1508 and fiddle around with it.

Strangely, when plugged into the 48, this fader also interacted with the Tape In channel causing a loud noise when touched and moved. That was a first… video below

Fader on Vimeo

Hopefully you understand now you are creating a feedback loop in your video just like we talked about in point #1 above, only the janky fader is saving your ears and your gear from certain destruction. You'll have to open the mixer up and take a look at the fader. Hopefully its not mounted to the channel card but I'd bet money it is. But it is either extremely dirty inside, is broken, needs the wiper re-positioned, or all of the above. You can also look for compromised wiring/connections (if the fader is not mounted to the channel card), or bad solder joints. I think I would start by opening the case up, sending some signal through that fader and gently manipulating the fader body to see if it is a bad solder joint or something before tearing into it...and looking for general trauma or damage first also. Somebody could have dropped something down onto that fader knob and broken something.
 
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Had some time this morning to take the console out of the equation and test the 48 by itself.

RCA Inputs = All Functioning
XLR Inputs = All Functioning

RCA Outputs = 1 & 7 Non Functioning
XLR Outputs = ONLY 1 & 7 Functioning

All Non Functioning Outputs buzz & have faint playback from recorded track when gain is cranked.

Video example (Please excuse the morning birds from outside)

48 Output Buzz on Vimeo

I have not yet taken the back off of the 48 to reflow solder yet as Sweetbeats initially suggested.

Feeling very foolish about the Feedback Loop. I had some inkling that is what it was, but I really hope that I didn’t damage any opamps. As a DAW guy I am learning every day first hand with this rig in things I have only read about. I don’t know how expensive / difficult of a fix that would be and hope I didn’t majorly screw anything up already.

I’ll get back to checking channel 6 on the 1516 later when I have some more time.

I am much more concerned with the 48 functioning properly right now, as that was the much bigger investment.

Again, all this help you all have offered has been invaluable. Especially when I don’t have access to a tech during the quarantine. Would be lost without it.
 
Hey, happy you’re finding assistance here. It’s part of why it exists.

Here is my hunch:

RCA outputs 1 & 7 have compromised connectivity...in other words bad solder joints or need connections exercised...IIRC (it’s been a decade or so since I’ve laid eyeballs or digits on a 48) the RCA jacks themselves are soldered directly to a jack PCB on the backplane, or possible individual jack PCBs for each pair of input/output jacks. That PCB or those individual PCBs have connectorized wires going back to the motherboard. So you can take the back panel off in order to wiggle/manipulate connections and the jack PCB(s) to test for intermittency. Like I said, it’s very likely to be something like that with the RCA outputs because if it was further upstream and a problem with the output line amps then you wouldn’t have anything on XLR outputs 1 & 7 either. So my hunch is you take the back apart, manipulate things and you’ll find you either need to exercise the connectors or heat up your soldering iron.

As far as my hunch on the XLR outputs 2, 3, 4, 5, 6 & 8? Unfortunately that sounds like blown opamps. I’ll have to refresh my memory as to where all these guts are mounted, but the line output driver that feeds the RCA output jacks and the inputs to the balance amp for the XLR jacks is on the record/play amp cards. I suspect we are all good there. But then there is a separate balance amp for each XLR input and output and I believe those are all on one board. Teac did a nice job from a service standpoint with how they put the 48 together...I’ll need to crack open the manual and look but I think it’s not too terrible a job to get to those balance amps. And then your options are to:

1. get out some diagnostic tools and trace and diagnose the issue and execute the repair
2. Shotgun the opamps blindly and hope that works (i.e. just go with the hunch and replace those output opamps and see if that fixes the issue)
3. Pull the balance amp board and take it to or send it to somebody to diagnose and repair.

The parts will be cheap.

Bottom line, it can be repaired. Through hole components are still readily available. There is nothing fancy or unobtanium in those balance amp circuits. So it can be fixed.

You check out the RCA jacks when you can and report back your findings.

I’ll pull up the manual when I can and refresh my memory as to the balance amp, where/how it’s mounted and the circuit design.

If you fix the RCA jacks then you can record. The XLR jacks are superfluous to your setup. You probably want them fixed, but there is no reason you can’t operate the machine even if every single XLR input and output was roached.

[EDIT]

Okay well it looks like the line output (RCA) driver AND the balance amp for each channel reside on each record/play amp card...this is actually a better design. You can swap amp cards to see if the problem follows the card or not, and this will narrow down where the problem or problems reside. Swap amp cards 1 & 2. I betcha the RCA output 1 still doesn’t work, RCA output 2 still works, XLR output 1 now doesn’t work, but XLR output 2 *does* work. Try it.

The balance amp is a pretty neat high headroom design with a discrete transistor output stage and an NJM2043 opamp input stage. The 2043 was a high output high slew rate upgrade to the 4558. It looks like it’s end-of-life but still pretty readily available...Mouser still has some stock...less than $10 to replace all of that balance amp input stage on all cards if needed, and beyond that Teac chose to use a standard DIP8 package and the 4558/2043 are dual JFET opamps with a pretty standard pinout; a lot of options there for replacement if that’s what’s needed and you couldn’t find the 2043. Likewise if it’s the transistors that’s the problem those parts can be sourced...likely same-same parts or suitable equivalents.
 
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