Thread: Teac 80-8

We're gonna need more info to do anything else but guess, because it could be any number of problems.

It may be something as simple as a meter calibration.

It could be as involved as checking bias and alignment.

You also didn't mention if the meter was hot or shy playing back, and you didn't mention if there was an audio level boost or drop.

The more info provide, the more we can help.

Does it sound correct, meaning that it could be just a metering problem? Is it the same on all channels? Do the meters show the correct envelope of amplitude but simply at a greater or lesser level on playback, or is there a sticking-point above which the meters will not go?

A few things you can do to help us help you more:

Is it just one track, several tracks, odd tracks, even tracks or all tracks?

print a 1k test tone to the track(s) effected, record at 0db

playback, and check to see how far the meter(s) is off, either + or -

listen for an audible difference in the volume... is it playing back softer or louder?

listen for tonal differences... is the top end attenuated, muffled, etc.

are you using new tape?

are you noticing drop outs in recorded material?

is the db change consistent? Does it always happen and if it does is it always to the same degree?

Originally Posted by DonnyAir

A few things you can do to help us help you more:

Is it just one track, several tracks, odd tracks, even tracks or all tracks?

print a 1k test tone to the track(s) effected, record at 0db

playback, and check to see how far the meter(s) is off, either + or -

listen for an audible difference in the volume... is it playing back softer or louder?

listen for tonal differences... is the top end attenuated, muffled, etc.

are you using new tape?

are you noticing drop outs in recorded material?


is the db change consistent? Does it always happen and if it does is it always to the same degree?

I have recently had the Teac serviced, so I wasnt expecting stuff like this. The Ampex 456 I have isnt the "sticky shed" type either. As far as I can tell , there are no dropouts.
Also, where do I come by a 1k test tone?

You didn't mention what problems you had the deck serviced for... was it something specific like the issue you are having now? Was it just general maintenance?

If these metering issues weren't happening before the servicing, I'd certainly get it back to the service tech who did the work.

As far as your original post, You still haven't answered all the questions.

Test tones - you can either pick up a tone generator ( they are relatively cheap) ...or, I'd find it hard to believe that you couldn't find a simple 1 k test tone on youtube.

In any regard, again, the more info you can provide the more we can help you.

That's a nice machine and it's built pretty much like a tank. Though a machine of that vintage will start to have electronics issues with the drying up of electrolytic capacitors. This machine is from the 1980s. The electrolytic capacitors are very similar to rechargeable batteries and they have a finite lifespan just like rechargeable batteries do.

For those of us that enjoy this vintage stuff, it brings along with it, the need for technical knowledge so as to be able to maintain this old stuff. Much of the highly coveted recording equipment at major studios is of this vintage and earlier. But for proper and reliable studio operations, many hundreds of electrolytic capacitors have to be replaced, first and foremost as it is usually responsible for much of the electronic issues such as you've described without describing much LOL.

You say you don't have any sticky tape of 456? But I think you do. It might not be as severe as it is for other similar vintage recording tape? But we know otherwise. It's beginning to shed. And that shedding may only be apparent when it gathers in the gap of the head and clogs a single channel. And that will cause gross record and playback level variations along with poor frequency response. And it's no easy task swabbing the head down with 91% isopropyl alcohol. It's good to take a lot more Q-tips and heavy handed swabbing. It's hard to remove that which has glued itself into the gap. And this could be happening on either record or playback heads if not both. It frequently rears its ugly face more on the edge tracks such as 1 & 8. Where after some regular use, edge damage also occurs even without the shedding problem. And because this has very narrow track widths, compared to a professional deck, it makes the problem all the more worse. So you can only use the tape over and over again, so many times. Of course we never did that with clients. It was always fresh tape for clients. You would never rerecord over any tape, for clients. You wanted your tape to be as virginal as possible. So maybe you're just wearing your role of 456 out? Fleetwood Mac actually had that problem on the Rumors album. They ran their 24 track, 2 inch tape to the point of wearing it out. It then had to be transferred to a second 24 track machine onto a fresh roll of 2 inch tape. Making that 24 track master, now a second-generation down, less high frequency response and more noise.

I thought that album had a pleasant but somewhat diminutive mushy sound quality to it? I didn't know why it should sound that way until I found out many years later what had happened to them. Suffice it to say, I've never worn out any recording tape ever before myself. So in other words, they rewound and played it back obviously, more than 1000 times. And for a single album. Tape lasts a long time. But it doesn't last forever certainly not in professional release condition. And Boston's first album, in 1976, was tracked to a Scully, 1 inch 12 track. That was later taken to Westlake's studio in LA where it was then transferred to 2 inch 24 track. The drums were erased and replaced with new drum tracks recorded at Westlake, LA. So that held up a little better because the guitar tracks and the vocal tracks, didn't suffers greatly from ever being worn out, physically on the tape. And those don't have transient attacks that are more noticeable when they wear out and wipe off over time the little iron oxide particles.

Adjustment trim controls within the guts of this machine do have a tendency to get an accumulation of airborne particulate based pollution. This gathers on the trimmer adjustments and they go intermittent. And then they will go to all or nothing without being in between where you want them LOL. And when it comes to analog tape, if your playback is not calibrated to a standard reference laboratory made calibration reference tape, all bets are off. And those ain't cheap. Probably will cost you almost as much to obtain as is the worth and resale value of your 80-8?

And where it could be, that your heads are beginning to not only wear out but have developed grooves in the pathway of the tape? This is because heads have to be made from soft ferrous metals to be efficient. Which means they wear out easily and within a couple of thousand hours of use. And I think a machine of that age might likely be suffering from that? Luckily, sometimes this can be remedied preventing the need for replacement. And you literally take the heads off and grind them down, on a mirror with a piece of Emory cloth of varying grits, dry, not wet. And that's called re-lapping re-contouring the heads. They were designed for that. You can get away with doing that two or three times at least.

It's the grooves the tape wears into the heads that actually ends up damaging the edges of the tape. This provides poor response, it especially is noticeable in the high frequencies. That along with a wobbly continuous sound coming from the edge tracks. Once that happens, the tape is effectively destroyed. It'll never track properly again. And tape ain't cheap. It never has been. People complain about spending $150 for a 2 TB disk drive, that can hold a week's worth of continuous recording of 24 tracks without ever filling it up. 2 inch 24 track tape was $150 for 30 minutes of record time. 15 minutes if you wanted better quality at the higher speed. And so if you wanted to release an album of material how much would you need to spend on tape? And that usually exceeded the budget of the local bands. So they didn't have multiple takes they could simply composite together. They had one tape and you couldn't even get a whole album of material on one tape. So you would spend a minimum of $300 on tape just for one album. And where you couldn't spend more than $300 on studio time for the tracking and $300 for the mixing time. And that's what it cost most local bands just to release their vanity albums.

You haven't even indicated in your dearth of information where in the world you might be? You can get a/build a oscillator with parts from and available from Radio Shaft here in the US. Otherwise, the local music stores that carry musical instruments, recording stuff equipment will either have them or can order them. Sometimes many consoles and mixers have been built in. It's essential in our work. But you'll also need 10 kHz and 100 Hz at the very least. So generally, you purchase a test bench, sine wave generator. You might even want a function generator that can deliver square Waves to look at on your oscilloscope? Much I think is a little bit beyond your scope LOL? If you had a scope? It's not in your bathroom. And it's not on your tripod in your backyard, tilted up. Nor is it connected to your rifle. You're looking at it, right now. See? And you're also looking at your sine wave and square wave oscillator. What I was describing earlier is what we did before we had computers. Even shareware audio software frequently has the ability to generate different types of audio oscillations. Sine waves, square waves, triangle waves, sawtooth waves, modulated waves, sweep frequencies. And then Bobby Moog got this great idea! But he had problems concentrating with that dog always ARPing, next door.

You should also know that TE-AC rubber pinch rollers also like any other machine, dry up. And when they do, it can cause tape to skew up and down on the heads so as to cause gross mis-tracking. So there is a myriad of possibilities of what could be wrong? Perhaps the holdback tape tension has sagged due to the aging of the reeling motors? And that will cause mistracking and poor head to tape contact making for less than adequate results?

And you might possibly be using dbx noise reduction which will cause a twofold deterioration overall from a poorly adjusted and maintained, recorder. Making things four times as bad as they should be.

So if you need technical assistance, it has to be more than " mommy I boo-booed ".
Mx. Remy Ann David

My understanding of this problem with the Ampex 456 and even some reports of the Quantegy 456 was one of sticky/shed no matter what the storage was like. even some 499 which was supposed to have a different binder than 456 or the BASF. The way its been explained to me was the EPA (government intrusive a---holes) would not let a particular type of chemical be used in the binder formula for certain tapes being manufactured during this time (late 80's-90's) and it has resulted in this gummy problem for ALL 456 formula based tape. An industry unto itself has been created just for replacing all the viable recordings made on this product onto better and unaffected product.

I know this because I currently am restoring masters I made back in the day on 456. (I'M not doing it per se....having it done) The baking has begun! Long live the baking! I have a few 16track 1" multis to go also.Gotta finish up those projects that never got done due to all kinds of stuff.....

Actually Dave, the problem began back in the 1970s. Almost immediately after the EPA was founded. I don't think that 206/406 stock has suffered as much as the 226/227/250 Scotch and Ampex 456 on. But hey, the same thing happened to Agfa and that was in Germany. Same crap with the tape. The only place it wasn't happening was in Japan. Just try to find some 1/2 inch-2 inch tape in Japan LOL. 1/4 inch no problem. Maxell good. Sony good. No flat black back coating on those.

The flat black back coating was also carbon-based. It sheds also. It was found to add stiffness to the tape providing more consistent packing and travel across the heads. It was a stability factor. But that too spewed junk forth onto your heads that gathered upon the iron oxide side. These more environmentally friendly binders a.k.a. glue, were a urethane base. And it did go through rigorous torture tests that all of the tape manufacturers performed. We were told it would last 100 years. It didn't last 10. And that's theory vs. practice. It's sad that these PhD's screwed up as bad as they did LOL. They all screwed up. On both sides of the pond. From the greatest generation to the Third Reich... And all of us baby boomers have to clean up after our parents now. LOL. My mother couldn't even get me to clean my bedroom. And while my recordings will all be clean... my bedroom is still a mess.

Sometimes things don't change over time LOL.
Mx. Remy Ann David