Thx for this video. I have a TC399 as well and as as soon as the machine gets warm it starts to distort and the record and playback levels start to shift. I also had the caps in mind, but now I will start with those transistors replacing them with the 2SC1815 you mentioned. Hope this will fix it, the machine works great mechanically
Glad you found this useful. Hopefully it will save you some time. I thought it a little peculiar as so many times electrolytic capacitors are at fault. The amp is not easy to get at the components so you will need some patience. Good luck.
I had mine apart just recently to clean the record switches. They were giving some noise at the beginning of a recording. I removed the black bracket at the back that has the line cord and record playback jacks. That will make working on the circuit board a lot easier. I wish I had have realized that when I changed the transistors on the amplifier board a couple of years ago.
Larry....I've learned alot from your video...many thx...I have one too....your video inspires us to fix them up....Many Thanks!!! (PS where did you order the 100 piece bag of transistors?)
I’ll have to check and see where I got the transistors. It was 5 years ago now. I noticed another problem with the deck that you may want to look out for. I noticed it was playing older tapes I had slower. I was able to determine it was slow by 3% since I had created an alignment tape when I bought it new somewhere around 1980. I went over everything to see if it could be the idler slipping or the pause lever dragging and I determined that the motor was just running slow. I even replace the motor capacitor and there was no change. My solution which is still working was to wrap the flywheel (on the 7 1/2 speed) with two layers of electrical tape very carefully minimizing any sort of seam. It works fine but is a bit noisier than before. I guess a new pulley would be best but the reality is it doesn’t get used that much.
I checked Digikey and the 2SC1815 is &1.33 in single unit quantities. I also checked Ali Express and you can get 100 for just over a dollar and a couple of dollars for delivery.
Replacing the electrolytic capacitors is a bit of an internet chatroom thing, it is surpising how many caps are fine, even 40-50 year later! As I rule though, I do tend to replace them! At least that way, we can be sure. I also measure the new ones, and replace them after measuring them as 'matched pair'. For example: say L-Ch and R-Ch need 10uF caps, I randomly select 1/2 dozen and measure, then pair-off those that are very similar in value, they may be 9.1 uF each, and so these go into circuit. Sincere regards.
I have one of these reel to reel recorders. I should get it going again. I used to run and buy for a company called Teletape and we specialised in tape recorders of all kinds. I generally found the TDK and Maxell fine. I still have many tapes and although I have not played them for a couple of years the tapes still seem fine. We stocked many brands of tape ranging from Scotch, 3M, Ampex, BASF, EMI, TDK, Maxell and probably some I haver forgotten. On Japanese machines we found that BASF and the Japanese tapes worked best.
I used many different brands of tape too over the years. Even Concert Tape from Radio Shack. I only noticed recently that the oxide seems to come off the TDK and Maxel tapes. The old Ampex tapes that I'm pretty sure were used by Radio stations back in the day, seem to have stood up really well. The trade off is a slightly higher noise floor but otherwise they are quite good.
Almost bought this exact model off of Ebay until I questioned the seller and found out that "full service" meant he only replaced the counter belt, oiled the capstan and sprayed deoxit on the controls. Said the caps weren't leaking and the main belts "looked good" so there was no reason to replace them. I wished him luck with his auction and continued searching. I eventually found a seller on Ebay from Belgium with a beautiful Akai GX that really was fully serviced including every belt and cap replaced with new ones, thorough cleaning and all moving parts greased. The only catch is the machine runs on 220v so I need a voltage transformer to run it here in the US.
I had the same problem on a TC-377, a full recap of audio, power source, and motor cap and the problem was gone. No need special caps, only a decent brand, and the same capacitance numbers, voltage equal or superior.
Thanks for the wonderful video and I am wondering how do you remove the Pause/Lock button (on the far left) in order to get the faceplate out? do you just yank it out? unscrew it or ??? mine is kinda stuck and i don't want to break it.
That’s a good question. The pause lever has a knob that is threaded. The trick is that it’s a reverse thread. It should come off if you screw it clockwise. The reverse thread will keep it from undoing during normal operation I suppose.
Just my 10 cents worth for anyone unsure .... I have replaced many signal transistors with 100% success. An easy tip is to look at the collector pin and see what kind of RL ('load') resistor it is connected to. As a general guide, if RL > 33KΩ, then you can replace the said NPN transistor with a Fairchild KSC1845-FTA or similar. We can estimate the maximum Ic (collector current) if we imagine the transistor is in a saturated state, typicall Vce ~ 0.2v (or less), and the max Ic current is approximately Vcc/(all the resistors added) mA. The KSC1845 series has a max Ic rating of 0.050 amps, so Q102 above can be replaced with a 1845 series transistor. They also bias 'earlier' at the Vbe junction - the ideal very small signal, low noise transistor! For Q101 and Q103 a KSC1815-GR or similar fits the bill nicely! Hope you deck is working well! ;o)
The deck is still working well however I did discover that the speed was actually running slow and I unfortunately didn’t document this repair. More recent recordings were fine but when I listened to some recordings from 40 years ago I noticed the deck was running slow. An original test tape I had made with an 800 hz tone confirmed the deck was slow by 3%. I replaced the ACmotor run capacitor and verified idler, belts and everything were all good. No change in speed. In various forums I read that induction motors can slow naturally with time. My fix was to increase the size of the pulley on 3 3/4 and 7 1/2 to compensate. Of course getting a pulley made is the real solution but 2 layers of carefully wound black tape is working for now.
@@larryh8072 Hi Larry. Glad the tape deck is working - good idea, until it gets sticky! Personally, I would not touch the pulleys - although I have thought of this myself, and glad I didn't capitulate to the idea! ;o) Just some general thoughts - (1) To know which speed is correct (to within, say ±1.0%, or even ±1.5%) you'll need a true reference tape - not easy to source? (2) If belts are used to drive the capstan, then the thickness of the belt *does* alter gear ratios - something I've discovered. As much as ±5% from my experience, but that's from 1970s (induction motor driven) cassette decks, a similar figure will apply to R2R I'm sure? (3) Also check the motor bearings, although to be fair it would take some friction to slow it down by 3% IMO. Are they sealed? I bought some recently, they can be got easily. Thanks for your reply. PS: I try not to take much notice of forums, a lot of folk just spread the same gossip, information, and unintentional disinformation. ;o)
Well I spent an entire day on the speed issue and true I didn’t have a reference tape but I did have a tape that I made the day I bought the deck new with an 800 hz tone and 12 kHz for head alignment. In comparison to theat tape the deck was running 3% slow. The belts for this deck are actually just “O” rings that I sized and purchased at a local fastener supplier. So the thickness is not really an issue. And as far as the motor goes, yes, it was disassembled and meticulously cleaned and lubricated. This finally led me to the fact that the motor was simply running slow. I was quite honestly going to just leave it because the deck really gets very little use. In the end I decided to tackle it as I had some live recordings from the early 80’s that I had not digitized yet. I was pretty happy with the drive pulley taping that I did. The tricky part is to have a seam that is virtually seamless to get the lowest running noise. I did quite well on the 7 1/2 speed and not quite as good on the 3 3/4 speed. I quite agree with your comment on the forums but after an entire day I came to the conclusion that the motor was simply running slow. I made another tape once the speed was corrected and I now play that tape and check the speed occasionally to see if there is any drift. So far no change! I’ll likely do a video of that the next time I have the deck apart. I’m sure there will be more repairs in the future.
@@larryh8072 Hope you don't mind me replying again, and apologies if you know some of this anyway. ;o) I've just been looking at the service manual for your TC-399. And it appears that the capstan is driven by a belt. My suggestion is to - identify that belt, take it out and measure its cross sectional dimensions. If it's a square belt - find other belts with both smaller and larger cross sectional dimensions. Eg: if it was 1.8mm x 1.8mm, then purchase a 2mm x 2mm, and a 1.6mm x 1.6mm etc. Of course the overall diameter must be the same. If it's a rounded cross sectional belt, then try the same variability of size. Sony do make provisions for 'tweaking' the speed on this machine in the service manual - there are 7 different motor pulleys available for both 50Hz (UK), and 60Hz (US) mains frequencies. However, you may find these difficult to source which is why I'm suggesting tweaking the drive-to-capstan belt effective widths. If you are still uncertain, remember in the maths that 'connects' the speed, there is a gear ratio, and we may define the most salient part as D1/D2. Adding a belt to the pulley does alter the *effective* diameters of the pulleys D1, and D2. And if we were to reduce (or increase) the effective values of D1 and D2 by some constant, say ±0.1mm, ±0.2mm etc, the ratio does not remain the same. {Except when D1=D2, then no change.} It really is worth a try if you can't source new motor pulleys.
All good advice. Anyone reading this thread should check a few things before resorting to pulley or belt changes. Check the idler pulley surface and ensure it isn’t slipping, pause lever belt tensioning is correct, motor run capacitor value is in tolerance and of course verify the motor bearings are lubricated. Basically rule out all of the other variables before condemning the motor itself.
At around 2.30 you mention voltages being way off. I have my TC-399 on the bench now and I’m tracing voltages following the schematic . How way off is too much? A lot of the voltages I’m measuring are 1 to 3 volts off what it says in the schematic. Is that too much? Also I’m having difficulty removing the boards to get at them for replacing components - any tips? Thanks for the video :-)
The voltages were off about 4 or 5 volts. That was a good clue that they were bad. If I ever go back in I think I will replace them all with the 2sc1815. Anyway I share your pain in working on those boards. I didn't remove them and it was quite a pain replacing components. The deck is still working great so there is no need to go back in right now. If you are chasing bad transistors you might want to use cold spray to see which ones are bad.
Thx for this video. I have a TC399 as well and as as soon as the machine gets warm it starts to distort and the record and playback levels start to shift. I also had the caps in mind, but now I will start with those transistors replacing them with the 2SC1815 you mentioned. Hope this will fix it, the machine works great mechanically
Glad you found this useful. Hopefully it will save you some time. I thought it a little peculiar as so many times electrolytic capacitors are at fault. The amp is not easy to get at the components so you will need some patience. Good luck.
@@larryhuff3383 I did swap the transistors today and now it works really nice now. Thx for the heads up!
I had mine apart just recently to clean the record switches. They were giving some noise at the beginning of a recording. I removed the black bracket at the back that has the line cord and record playback jacks. That will make working on the circuit board a lot easier. I wish I had have realized that when I changed the transistors on the amplifier board a couple of years ago.
I had to give a like for the Cinema Show test!!😀
I thought it was worth the risk of a copyright strike. Its a go to for me when audio testing.
Larry....I've learned alot from your video...many thx...I have one too....your video inspires us to fix them up....Many Thanks!!! (PS where did you order the 100 piece bag of transistors?)
I’ll have to check and see where I got the transistors. It was 5 years ago now.
I noticed another problem with the deck that you may want to look out for. I noticed it was playing older tapes I had slower. I was able to determine it was slow by 3% since I had created an alignment tape when I bought it new somewhere around 1980.
I went over everything to see if it could be the idler slipping or the pause lever dragging and I determined that the motor was just running slow. I even replace the motor capacitor and there was no change.
My solution which is still working was to wrap the flywheel (on the 7 1/2 speed) with two layers of electrical tape very carefully minimizing any sort of seam. It works fine but is a bit noisier than before. I guess a new pulley would be best but the reality is it doesn’t get used that much.
I checked Digikey and the 2SC1815 is &1.33 in single
unit quantities. I also checked Ali Express and you can get 100 for just over a dollar and a couple of dollars for delivery.
Hi, can you please tell me how to remove the lever on the left hand side next to the tape speed? I really need To get this off!
The puss control knob is threaded but it’s a reverse thread. So turn it clockwise to undo it.
Pause control.
Replacing the electrolytic capacitors is a bit of an internet chatroom thing, it is surpising how many caps are fine, even 40-50 year later! As I rule though, I do tend to replace them! At least that way, we can be sure. I also measure the new ones, and replace them after measuring them as 'matched pair'. For example: say L-Ch and R-Ch need 10uF caps, I randomly select 1/2 dozen and measure, then pair-off those that are very similar in value, they may be 9.1 uF each, and so these go into circuit.
Sincere regards.
I have one of these reel to reel recorders. I should get it going again.
I used to run and buy for a company called Teletape and we specialised in tape recorders of all kinds. I generally found the TDK and Maxell fine.
I still have many tapes and although I have not played them for a couple of years the tapes still seem fine. We stocked many brands of tape ranging from Scotch, 3M, Ampex, BASF, EMI, TDK, Maxell and probably some I haver forgotten. On Japanese machines we found that BASF and the Japanese tapes worked best.
I used many different brands of tape too over the years. Even Concert Tape from Radio Shack. I only noticed recently that the oxide seems to come off the TDK and Maxel tapes. The old Ampex tapes that I'm pretty sure were used by Radio stations back in the day, seem to have stood up really well. The trade off is a slightly higher noise floor but otherwise they are quite good.
Almost bought this exact model off of Ebay until I questioned the seller and found out that "full service" meant he only replaced the counter belt, oiled the capstan and sprayed deoxit on the controls. Said the caps weren't leaking and the main belts "looked good" so there was no reason to replace them. I wished him luck with his auction and continued searching. I eventually found a seller on Ebay from Belgium with a beautiful Akai GX that really was fully serviced including every belt and cap replaced with new ones, thorough cleaning and all moving parts greased. The only catch is the machine runs on 220v so I need a voltage transformer to run it here in the US.
I had the same problem on a TC-377, a full recap of audio, power source, and motor cap and the problem was gone. No need special caps, only a decent brand, and the same capacitance numbers, voltage equal or superior.
Thanks for the wonderful video and I am wondering how do you remove the Pause/Lock button (on the far left) in order to get the faceplate out? do you just yank it out? unscrew it or ??? mine is kinda stuck and i don't want to break it.
That’s a good question. The pause lever has a knob that is threaded. The trick is that it’s a reverse thread. It should come off if you screw it clockwise. The reverse thread will keep it from undoing during normal operation I suppose.
@@larryhuff3383 thank you so much! Got it out. :)
This button is a screw, easy to remove if it is not stuck.
Just my 10 cents worth for anyone unsure .... I have replaced many signal transistors with 100% success. An easy tip is to look at the collector pin and see what kind of RL ('load') resistor it is connected to. As a general guide, if RL > 33KΩ, then you can replace the said NPN transistor with a Fairchild KSC1845-FTA or similar. We can estimate the maximum Ic (collector current) if we imagine the transistor is in a saturated state, typicall Vce ~ 0.2v (or less), and the max Ic current is approximately Vcc/(all the resistors added) mA. The KSC1845 series has a max Ic rating of 0.050 amps, so Q102 above can be replaced with a 1845 series transistor. They also bias 'earlier' at the Vbe junction - the ideal very small signal, low noise transistor!
For Q101 and Q103 a KSC1815-GR or similar fits the bill nicely!
Hope you deck is working well! ;o)
The deck is still working well however I did discover that the speed was actually running slow and I unfortunately didn’t document this repair.
More recent recordings were fine but when I listened to some recordings from 40 years ago I noticed the deck was running slow. An original test tape I had made with an 800 hz tone confirmed the deck was slow by 3%.
I replaced the ACmotor run capacitor and verified idler, belts and everything were all good. No change in speed.
In various forums I read that induction motors can slow naturally with time. My fix was to increase the size of the pulley on 3 3/4 and 7 1/2 to compensate. Of course getting a pulley made is the real solution but 2 layers of carefully wound black tape is working for now.
@@larryh8072
Hi Larry.
Glad the tape deck is working - good idea, until it gets sticky! Personally, I would not touch the pulleys - although I have thought of this myself, and glad I didn't capitulate to the idea! ;o)
Just some general thoughts -
(1) To know which speed is correct (to within, say ±1.0%, or even ±1.5%) you'll need a true reference tape - not easy to source?
(2) If belts are used to drive the capstan, then the thickness of the belt *does* alter gear ratios - something I've discovered. As much as ±5% from my experience, but that's from 1970s (induction motor driven) cassette decks, a similar figure will apply to R2R I'm sure?
(3) Also check the motor bearings, although to be fair it would take some friction to slow it down by 3% IMO. Are they sealed? I bought some recently, they can be got easily.
Thanks for your reply.
PS: I try not to take much notice of forums, a lot of folk just spread the same gossip, information, and unintentional disinformation. ;o)
Well I spent an entire day on the speed issue and true I didn’t have a reference tape but I did have a tape that I made the day I bought the deck new with an 800 hz tone and 12 kHz for head alignment. In comparison to theat tape the deck was running 3% slow.
The belts for this deck are actually just “O” rings that I sized and purchased at a local fastener supplier. So the thickness is not really an issue.
And as far as the motor goes, yes, it was disassembled and meticulously cleaned and lubricated.
This finally led me to the fact that the motor was simply running slow. I was quite honestly going to just leave it because the deck really gets very little use. In the end I decided to tackle it as I had some live recordings from the early 80’s that I had not digitized yet.
I was pretty happy with the drive pulley taping that I did. The tricky part is to have a seam that is virtually seamless to get the lowest running noise. I did quite well on the 7 1/2 speed and not quite as good on the 3 3/4 speed.
I quite agree with your comment on the forums but after an entire day I came to the conclusion that the motor was simply running slow. I made another tape once the speed was corrected and I now play that tape and check the speed occasionally to see if there is any drift. So far no change!
I’ll likely do a video of that the next time I have the deck apart. I’m sure there will be more repairs in the future.
@@larryh8072
Hope you don't mind me replying again, and apologies if you know some of this anyway. ;o)
I've just been looking at the service manual for your TC-399. And it appears that the capstan is driven by a belt. My suggestion is to - identify that belt, take it out and measure its cross sectional dimensions. If it's a square belt - find other belts with both smaller and larger cross sectional dimensions. Eg: if it was 1.8mm x 1.8mm, then purchase a 2mm x 2mm, and a 1.6mm x 1.6mm etc. Of course the overall diameter must be the same. If it's a rounded cross sectional belt, then try the same variability of size.
Sony do make provisions for 'tweaking' the speed on this machine in the service manual - there are 7 different motor pulleys available for both 50Hz (UK), and 60Hz (US) mains frequencies. However, you may find these difficult to source which is why I'm suggesting tweaking the drive-to-capstan belt effective widths.
If you are still uncertain, remember in the maths that 'connects' the speed, there is a gear ratio, and we may define the most salient part as D1/D2. Adding a belt to the pulley does alter the *effective* diameters of the pulleys D1, and D2. And if we were to reduce (or increase) the effective values of D1 and D2 by some constant, say ±0.1mm, ±0.2mm etc, the ratio does not remain the same. {Except when D1=D2, then no change.}
It really is worth a try if you can't source new motor pulleys.
All good advice. Anyone reading this thread should check a few things before resorting to pulley or belt changes. Check the idler pulley surface and ensure it isn’t slipping, pause lever belt tensioning is correct, motor run capacitor value is in tolerance and of course verify the motor bearings are lubricated.
Basically rule out all of the other variables before condemning the motor itself.
At around 2.30 you mention voltages being way off. I have my TC-399 on the bench now and I’m tracing voltages following the schematic . How way off is too much? A lot of the voltages I’m measuring are 1 to 3 volts off what it says in the schematic. Is that too much? Also I’m having difficulty removing the boards to get at them for replacing components - any tips? Thanks for the video :-)
The voltages were off about 4 or 5 volts. That was a good clue that they were bad. If I ever go back in I think I will replace them all with the 2sc1815.
Anyway I share your pain in working on those boards. I didn't remove them and it was quite a pain replacing components.
The deck is still working great so there is no need to go back in right now.
If you are chasing bad transistors you might want to use cold spray to see which ones are bad.
Larry H Thank you so much for your reply.