He lists some prices on his site, but the way it usually works is you send the head stack, he quotes, and if you agree he removes and laps the heads, re-installs them and then does a laser alignment.
Bad heads can be replaced.
I have not yet done it. I almost purchased a set of SAKI heads but decided to wait a bit.
Bad heads can be replaced.
I have not yet done it. I almost purchased a set of SAKI heads but decided to wait a bit.
There is an English service too I now see. Prices look fair: Head Relapping Services - Summertone UK
The ATR-700 machines were Ampex-branded, Teac-made machines. The ATR-100, 102, 104 were definitely NOT made by Teac; they were Ampex-designed (in Redwood City), Ampex-made (in Colorado Springs, later some in Mexico). The 100 series are a completely different animal, totally designed to be the best professional analog tape deck ever made.
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Good to know..
Head lapping isn't difficult. We did this at the shop. The only real issue was with an older head that might be worn out. When you lapped those you might see the gaps suddenly begin to widen. So all your work was for nothing. Or, the client would put the head into service only to wear through in 6 months or so. They tend to be unhappy, but what can you do beyond telling them that their old head might be done very soon?
I would highly recommend the kit. If you are down near the bottom of the flats cut into the head, it's pretty much over for that head. I imagine the inductance would be changing too. Never took the time to measure this between a new head and worn out one.
-Chris
I would highly recommend the kit. If you are down near the bottom of the flats cut into the head, it's pretty much over for that head. I imagine the inductance would be changing too. Never took the time to measure this between a new head and worn out one.
-Chris
If you sent a headstack to JRF, they would measure the inductance and give you an estimated percentage of life left. This could be done before lapping too, so if it was only 10-20%, they'd tell you so you could forego the expense and just get new heads. Made sense for JRF to do this since they saw so many headstacks, but I guess if you have some datapoints and some sort of impedance bridge or meter, you could do this at home too.
Hi Monte,
We just looked at the depth of the cuts at each end of the head stack. We didn't see enough of the various brands of heads more than the few we did warranty work for.. So Tascam/Teac and Studer/Revox mostly.
Hi Kevin,
I wasn't aware they stopped making the kits available. Too bad. That makes lapping heads a dying art.
-Chris
We just looked at the depth of the cuts at each end of the head stack. We didn't see enough of the various brands of heads more than the few we did warranty work for.. So Tascam/Teac and Studer/Revox mostly.
Hi Kevin,
I wasn't aware they stopped making the kits available. Too bad. That makes lapping heads a dying art.
-Chris
I did not compare otari with akai sound (recording/playback) quality-wise. Otari just by the fact of being two track, 15ips deck sounds better than any 4 track 7.5 ips home deck. I simply investigated parts availability and potential problems in domestic use. I have also added that in making these choices I'm not entirely logical.
As a matter of fact I consider digital sources such as DVD audio, SACD and even some well recorded CDs as offering superior sound quality to analog sources used in domestic environment. I like tape decks for quite different reasons. Partly nostalgic as in my life I also happened to work in the music industry for some time and analog recordings of analogue sources (classical instruments) made on 1-2inch tapes on professional studio decks sound really great and actually in my subjective opinion sound better than digital recordings of the same analogue source.
In the end we deal here with 40 years old equipment which has its mechanical ailments or sooner or later will have. I have to add that I have two akai gx decks, teac x1000r and pioneer rt-909 for non-logical reasons and only akai decks have pristine heads until today and can record an playback the same highest frequencies as they did when new. Of course if one runs out of luck ferrite gap chipping may alter all that.
cheers,
Hi janusz,
Be prepared to replace the capstan motor in he X-1000R. Inside they used capacitors across the coils (I think). They are tantalum and as the motor goes backwards, it will reverse bias those capacitors. Guess what happens? At some point the capstan motor will smoke. Opening the motor, you'll see a ring of solder spray that came off the connections to he capacitors.
If you are very lucky, this already happened and the motor has been replaced. The replacement motors did not have this problem.
Wishing you luck!
-Chris
Be prepared to replace the capstan motor in he X-1000R. Inside they used capacitors across the coils (I think). They are tantalum and as the motor goes backwards, it will reverse bias those capacitors. Guess what happens? At some point the capstan motor will smoke. Opening the motor, you'll see a ring of solder spray that came off the connections to he capacitors.
If you are very lucky, this already happened and the motor has been replaced. The replacement motors did not have this problem.
Wishing you luck!
-Chris
Thank you, I did not know that. I opened both capstan motors years ago on x1000r and rt-909 (they are the same), cleaned them, lubricated them and fully recapped their circuits. I do not remember if there was some tantalum cap inside any of them or not. Taking out the motor in any of these is not a great problem but installing it again is a bit tormenting because of the belt.
Luckily I have one spare capstan motor. I have to check what's inside. It's a bit time consuming but it's easier on the spare one as I do not have to put it back. So if I find a tantalum there I understand that I have to replace it with a reliable long life eletcrolytic. Tantalums are small, electrolytics a bit bigger. I hope one mini would fit.
cheers,
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Best to avoid auto-reverse machines in general. I would include that advice for cassette decks. The one exception would be the RX-xxx series from Nakamichi as these spin the tape around while the transport continues in the same direction once the flip is done. These can be easily recognized because of the "bay window" where the transport is.
-Chris
-Chris
JRF purchased all of remaining Nortronics stock some years ago when Joe Dundovic decided to retire. Nortronics was gone long before that. (How he came to have so much stock is a long story.) I no longer remember when, but I do remember JD emailing me to inform me he retiring and selling his stock to JRF if I was looking for anything. Joe died a few years ago. This was going on as I was having my own little health problems and I was not really paying attention.
I posted the manual because it details the process, and all of the materials are readily available. You can do the lapping on a sheet of glass. (I think there are even instructions in the manual on how to do it without the handy lap) I don't believe that the handy lap has been available for at least 20 - 25 years.
Hi Kevin,
Yes, and Walmart carries the sand paper up to 2,000 grit I think. You can get the polish else-ware, probably in some hobby shops. You need a 90° block in addition to the glass plate. Also, flat stones are available that will support the glass in a true flat position.
It was just easier to buy the kit.
-Chris
Yes, and Walmart carries the sand paper up to 2,000 grit I think. You can get the polish else-ware, probably in some hobby shops. You need a 90° block in addition to the glass plate. Also, flat stones are available that will support the glass in a true flat position.
It was just easier to buy the kit.
-Chris
After all of the changes made I recalibrated the recording path in the MX-5050MKIII last week-end, to my surprise things were a bit off. I'm wondering if I forgot to do it when I switched to the SAKI head stack?
It sounds a little better, but not a too significant difference. I think I will use my precision volt meter rather than the internal meters and give it another shot at some point. (Keithley 2002)
In particularly it is hard to tell when you have over-biased the tape too much, and a more accurate meter might help me to tell. (They recommend some over-bias, how to tell what is optimum is an open question, and it is more obvious on one channel than the other.)
I will also check playback calibration and if I need to make adjustments I will also perform a recording calibration since it is dependent on proper playback response. (Yes I have cal tapes, but not from MRL)
I like the MX-50N, but I am coming to the conclusion that it really does not handle tape any better than the 5050, perhaps the tension is a bit lower in play, but it's not obvious to me.
Braking performance with 10.5" reels is somewhat better on the 5050 (it has a better braking system), but the supply reel still takes quite a while to stop, but much longer on the 50 than the 5050. The 5050 brakes are adjusted to specification, the 50 I have not checked yet.
I don't think playing fragile acetate backed vintage tapes on either of these machines is a good idea.
Another area of trouble is the ball bearings in the impedance roller and supply reel roller in the MX-50, they really need to be low friction and the NTN 607Z-2 bearings I purchased as replacements do not work well. The counter is badly off on rewind and it is due to bearing drag - improved after a lubrication swap, but not acceptable. Self lubricated ceramic bearings are on the way and I will report how they work once they are here.
I am going to start the overhaul on the MX-50N II in December, it's the nicest deck I own.
After that I need to decide what decks are for the long haul and which I will sell or pass along to others. I can't store all of these long term, and I think 2 would be sufficient to my needs.
It sounds a little better, but not a too significant difference. I think I will use my precision volt meter rather than the internal meters and give it another shot at some point. (Keithley 2002)
In particularly it is hard to tell when you have over-biased the tape too much, and a more accurate meter might help me to tell. (They recommend some over-bias, how to tell what is optimum is an open question, and it is more obvious on one channel than the other.)
I will also check playback calibration and if I need to make adjustments I will also perform a recording calibration since it is dependent on proper playback response. (Yes I have cal tapes, but not from MRL)
I like the MX-50N, but I am coming to the conclusion that it really does not handle tape any better than the 5050, perhaps the tension is a bit lower in play, but it's not obvious to me.
Braking performance with 10.5" reels is somewhat better on the 5050 (it has a better braking system), but the supply reel still takes quite a while to stop, but much longer on the 50 than the 5050. The 5050 brakes are adjusted to specification, the 50 I have not checked yet.
I don't think playing fragile acetate backed vintage tapes on either of these machines is a good idea.
Another area of trouble is the ball bearings in the impedance roller and supply reel roller in the MX-50, they really need to be low friction and the NTN 607Z-2 bearings I purchased as replacements do not work well. The counter is badly off on rewind and it is due to bearing drag - improved after a lubrication swap, but not acceptable. Self lubricated ceramic bearings are on the way and I will report how they work once they are here.
I am going to start the overhaul on the MX-50N II in December, it's the nicest deck I own.
After that I need to decide what decks are for the long haul and which I will sell or pass along to others. I can't store all of these long term, and I think 2 would be sufficient to my needs.
Setting the bias on a tape recorder can be a tricky thing, and often it ends up being a trade-off of optimizing various parameters. Usually a manufacturer will recommend a certain amount of overbias at a specific frequency; i.e., "3 db over bias @ 10 KHz". This is usually because it's easy to do and gives reasonable results certainly in the neighborhood of the ideal setting. Probably the best way is to observe the results of various settings on a audio-band spectrum analyzer and set for minimum THD; but this is neither practical nor expedient, especially when aligning a 24-track machine!! Another method I saw used in high-end recording studios was to take a low-frequency test signal (say, a 200 Hz sine wave), send it to the tape machine; put the signal through the mixing console on a phase-flipped channel and mix it with the return of the tape machine channel and adjust the bias for maximum cancellation. This usually produced a setting with a very narrow, easily observed notch as opposed to the broad area result of overbiasing to a specific meter reading.
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Hello Kevin,
I am following with great interest your fascinating thread from the very beginning.
Today by chance found an article about the restoration of an Otari MX55 and also a link to a Facebook photo album of the same process.
So I thought you might find it interesting. And not only you but anyone following this discussion.
Here are the links:
Otari MX55 – Improvement & Modifications | LAB2104
Lab2104 @Technical University of Plovdiv - Photos | Facebook
Keep up the good work.
Best
Stan
I am following with great interest your fascinating thread from the very beginning.
Today by chance found an article about the restoration of an Otari MX55 and also a link to a Facebook photo album of the same process.
So I thought you might find it interesting. And not only you but anyone following this discussion.
Here are the links:
Otari MX55 – Improvement & Modifications | LAB2104
Lab2104 @Technical University of Plovdiv - Photos | Facebook
Keep up the good work.
Best
Stan
Thanks for the links! Interesting stuff; but at first glance, I do have to disagree with his choice of opamps---he selects precision opamps OPA827 ($10.80) and OPA211 ($7.23). I think these are pretty much spec-matched by the newest FET opamp--the OPA1656, and it's only $2.94.