I received my RS-B755 about 2 weeks ago. Panasonic label. I must say I'm impressed. 70 euro including shipping was a sweet deal in fully functional condition. I'm not going to do your upgrades. Thanks for your video.
"injecting", recording and playing back whatever frequency will of course always give you the exact same frequency when real-time monitoring on a 3-head deck... or when recording and playing back on the same deck for that matter
Congrats for fixing this ! I replaced the same gear on my 727 (the red one, think it came from poland). After a while it started to move up the shaft, so i putted some screw lock on the top.
It will always be 3000 when recording and play back tone on same deck. If you put proper speed tape in, it will be 3015, which is normal for quartz lock deck. They play slightly fast from the factory. If you record 3khz tape on this deck and use that tape to calibrate another deck, it will be 15hz off.
Just to add a bit to what Mr. Sidiropoulos wrote, the 1.4 times number can be correct, but not universally. It can also be higher, correct, or due to the phenomenon of complimentary error, even lower. Consider it similar to phase cancellation but in the mechanical realm. Although every W&F meter I've ever seen has the ability to generate a signal, the results of using it in this way are meant to give a reasonable expectation of meeting the NAB standard (which is a comparatively high .2%), not so much for accurately testing the actual flutter numbers. That needs to be done with a dedicated flutter tape in a high quality shell as he stated. At very minimum, record the test tone at the beginning, middle, and end of the tape, then measure the flutter on playback for some generally beneficial data. If you wish to be further surprised, do it a number of times over a period of days, temperatures, and relative humidifies :)
Finally got the time to check the Technics speed tape on the DR-M3. The M3 is still running exactly 1Hz slow, and confirms the Technics tape is slower than it should be. It also gave me better W&F results than my FYA reference tape. Not that it means too much while said tape is giving me the wrong frequency, but I'm starting to think the Technics is actually running at least as well as the machine that recorded the FYA tape does (TC-K555ESJ). It's running better than next week's direct drive unit as well, but I'll let that video speak for itself. It was shot before this one went live so I didn't have these comments to learn from at the time.
@@Oklawolf 1Hz slow isn't even close to any kind of concern, I'd say you did a good job on both to get them so close. I would think the Technics would be a little fast but all depends where the FYA tape was recorded. I don't have one of those so can't check. I did buy one from someone or other a while back just to keep mine from wearing out, but I should have just stuck with my own homebrews, they are much more consistent. Looking forward to the next one.
Hi, one comment if I may. When you record a 3kHz tone to a deck and play it back on the same deck, it will show you a false correct speed reading because you are recording and playing at the speed of that deck. Whatever that speed is. And if you monitor directly during recording, you will get a perfect speed reading because you are eliminating any speed fluctuation the deck might be having between runs. The w&f reading you get by recording and playing back on the same deck will be approximately 1.4 times the reading you would be getting by using a reference flutter tape. For example, if you record and playback the 3kHz tone and get a 0,056 reading, it means actually 0,04 that you would be getting if you were measuring using a tape with a residual flutter of less than 0,04%.
Checking a quartz locked deck with a tape from a quartz locked deck won’t help. You could make your calibration tapes stating to set any deck from that tape to 3015.
Hi, perfecious here. I Did the PDF summary with all the mods. I thoroughly enjoyed the video. The sound demo from Robin Hood, one of my all time favorite films, really brings back some memories. :) However, I would like to apologize and issue a slight correction regarding the modifications when using the amorphous head mentioned in the PDF. *This is only if the head is changed, so in the case in the video, it doesn't apply, but it's important to mention non the less.* The CB 36001 is a half amorphous head, with only the playback head being amorphous, and the recording head is hard permalloy, very similar to the original. That means that the modifications listed on the recording side should not be made. The CB 36001 should work correctly with the original configuration. The head Alex most likely used for these modifications, is most likely designated "H2374-4105", which is used in decks like the TEAC V-3010. I need to confirm that though. It's also a head with a left guide, which is what should be used in the technics decks anyway. The CB 36001 is a head with a right guide, so I would not recommend using it in these decks, because it has some issues with phase between the rec and play heads, due to horizontal offset. I will update the PDF's with this information to correct the errors. . . . There is also another important thing that is not mentioned in the PDF (which I will correct). If the OP-AMP is changed, it is recommended to change the signal path capacitors to bipolar, with my recommendation being to use the Nichicon UES. In fact, recapping the entire signal path with them is highly recommended by me, this deck greatly benefits sonically with that. That also includes the 2x 470uF caps in the PB EQ (C9 & C10). I've also discovered that the LM833N or the MC33078 op-amps sound amazing in the Phase Correct stage, so if you want to thinker with the deck a little bit more, I recommend to try them. They are DIP8 package though, so you would need to make a DIY adapter. 0.1uF Bypass caps across the supply pins (4 & 8) are also a must as always. The NJM2114 is fine, but it's a bit more cold and flat sounding comparatively. Still decent though. Also, the big local filtering caps 1000uF 10v (C620, C621, C618, C619, C610, C611), which are 6x in total, also play a huge role in the sound. I liked Panasonic FR best in those positions, but you can keep things consistent with the Rubycon's, I haven't heard them though, so I can't comment on them. The other local filtering caps you can leave the Puresims in, although I did recap them with Nichicon Fine Golds on my 755.
Thanks for stopping by, and for your efforts in making the PDF! I was originally planning to do just that with the UES parts - I think I have them all on hand. I just wanted to see how those Purism caps sounded first, is all. I was only in the process of discovering how much I like those Panasonic FRs at the time I did this - I'm going all-in on those now. I've got a full complement of FRs coming in for my first import from Japan for 2024 as I type this. Only one capacitor in the PSU of that machine won't be an FR, and it's the big one I couldn't find an FR for. I went Chemi-Con KZN for that one.
@@Oklawolf That's actually a good plan, checking the sound with the original caps first. That way, the 755 will impress you a second time. :) BTW, keep an eye on the W&F after some time passes. I had some bad experience with FIA rollers for these decks. Initially, the performance was decent at 0.045% WRMS (worse than the original roller at 0.0280%, so if it's not in a bad shape, I recommend the original roller), but after a few months something happened where all 3 rollers degraded in some way, and the W&F jumped to 0.1% on average - terrible. And that is not a case with just a single deck, I had them installed in 1 RS-B555, the RS-B755 and a RS-B965 - all degraded similarly in performance. Now this could be just bad batch and my luck, and thus an isolated case, but I have to mention it. Basically, just check the W&F periodically, to make sure W&F is still good. Right now, it seems excellent. Hopefully it will stay that way. Good thing is, you can remove the roller arm from the front, without needing to disassemble the deck again. :) Cheers, and happy taping! - Chris
That reminds me, the M245X from last week got its recap now using the UES parts in almost the entire signal path. UKLs in the DBX circuit and other places needing low leakage, FRs in the power supply. I should get that video done, because that deck sounds like it had a decent leveling up on playback alone. I figured I would do the polar to bipolar experiment there first because it needed new capacitors much more urgently than this one.
IMO black face decks just don't do it for me😄 Nice deck and all. We had a Technics receiver and turntable with Jensen speakers for one of our bedrooms growing up. Always remember waiting for that little click when you'd hit the power button.
factory specs are 0,05 w&f and you get that so what you expect? you can’t do better them factory in mechanism much unfortunately, you can do electronics mods but when it comes to mechanism is not so much possible. anyway, many decks with double capstans witch to have this w&f results especially as they all are old ones.ps, when it comes to those brakes you can use any rubber with same size. what i did i bought a cable with same diameter and i use this cable shild as a replacement for those brakes and it works very well.
Very nice and informative video. I am owner of the RS B765, which is identical. Currently looking to replace the smd capacitors on the DD motor. What capacitors have you used on it?
I've finally replaced all the electrolytic capacitors on mine including the gears and ofc performed some modifications as well. I gotta say you got lucky having most of the capacitors replaced by it's previous owner because the original PXS ones was really bad, they could dry out over time and fail. Thanks for the modifications part, I've kinda followed you in the modifications.Edit: I forgot to mention the leaf switches could fail at some point and need to be replaced.
Yeah I'm happy with this one considering it had a lot of damage when I got it. I would say my Aiwa XK-007 and Carver TD-1700 are doing best for belt drive. Both are around 0.06%.
I received my RS-B755 about 2 weeks ago. Panasonic label. I must say I'm impressed. 70 euro including shipping was a sweet deal in fully functional condition. I'm not going to do your upgrades. Thanks for your video.
Oh the joys of electronics repair! Got it done anyway 🎉
"injecting", recording and playing back whatever frequency will of course always give you the exact same frequency when real-time monitoring on a 3-head deck... or when recording and playing back on the same deck for that matter
Wow great deck
Congrats for fixing this !
I replaced the same gear on my 727 (the red one, think it came from poland). After a while it started to move up the shaft, so i putted some screw lock on the top.
It will always be 3000 when recording and play back tone on same deck. If you put proper speed tape in, it will be 3015, which is normal for quartz lock deck. They play slightly fast from the factory. If you record 3khz tape on this deck and use that tape to calibrate another deck, it will be 15hz off.
Just to add a bit to what Mr. Sidiropoulos wrote, the 1.4 times number can be correct, but not universally. It can also be higher, correct, or due to the phenomenon of complimentary error, even lower. Consider it similar to phase cancellation but in the mechanical realm. Although every W&F meter I've ever seen has the ability to generate a signal, the results of using it in this way are meant to give a reasonable expectation of meeting the NAB standard (which is a comparatively high .2%), not so much for accurately testing the actual flutter numbers. That needs to be done with a dedicated flutter tape in a high quality shell as he stated. At very minimum, record the test tone at the beginning, middle, and end of the tape, then measure the flutter on playback for some generally beneficial data. If you wish to be further surprised, do it a number of times over a period of days, temperatures, and relative humidifies :)
Very helpful, thanks.
Finally got the time to check the Technics speed tape on the DR-M3. The M3 is still running exactly 1Hz slow, and confirms the Technics tape is slower than it should be. It also gave me better W&F results than my FYA reference tape. Not that it means too much while said tape is giving me the wrong frequency, but I'm starting to think the Technics is actually running at least as well as the machine that recorded the FYA tape does (TC-K555ESJ). It's running better than next week's direct drive unit as well, but I'll let that video speak for itself. It was shot before this one went live so I didn't have these comments to learn from at the time.
@@Oklawolf 1Hz slow isn't even close to any kind of concern, I'd say you did a good job on both to get them so close. I would think the Technics would be a little fast but all depends where the FYA tape was recorded. I don't have one of those so can't check. I did buy one from someone or other a while back just to keep mine from wearing out, but I should have just stuck with my own homebrews, they are much more consistent. Looking forward to the next one.
Hi, one comment if I may. When you record a 3kHz tone to a deck and play it back on the same deck, it will show you a false correct speed reading because you are recording and playing at the speed of that deck. Whatever that speed is. And if you monitor directly during recording, you will get a perfect speed reading because you are eliminating any speed fluctuation the deck might be having between runs. The w&f reading you get by recording and playing back on the same deck will be approximately 1.4 times the reading you would be getting by using a reference flutter tape. For example, if you record and playback the 3kHz tone and get a 0,056 reading, it means actually 0,04 that you would be getting if you were measuring using a tape with a residual flutter of less than 0,04%.
Interesting. I'll have to try the tape this deck made on the other quartz lock machine I just finished restoring sometime.
Checking a quartz locked deck with a tape from a quartz locked deck won’t help. You could make your calibration tapes stating to set any deck from that tape to 3015.
Hi, perfecious here. I Did the PDF summary with all the mods. I thoroughly enjoyed the video. The sound demo from Robin Hood, one of my all time favorite films, really brings back some memories. :)
However, I would like to apologize and issue a slight correction regarding the modifications when using the amorphous head mentioned in the PDF. *This is only if the head is changed, so in the case in the video, it doesn't apply, but it's important to mention non the less.*
The CB 36001 is a half amorphous head, with only the playback head being amorphous, and the recording head is hard permalloy, very similar to the original. That means that the modifications listed on the recording side should not be made. The CB 36001 should work correctly with the original configuration.
The head Alex most likely used for these modifications, is most likely designated "H2374-4105", which is used in decks like the TEAC V-3010. I need to confirm that though. It's also a head with a left guide, which is what should be used in the technics decks anyway. The CB 36001 is a head with a right guide, so I would not recommend using it in these decks, because it has some issues with phase between the rec and play heads, due to horizontal offset. I will update the PDF's with this information to correct the errors.
. . .
There is also another important thing that is not mentioned in the PDF (which I will correct). If the OP-AMP is changed, it is recommended to change the signal path capacitors to bipolar, with my recommendation being to use the Nichicon UES. In fact, recapping the entire signal path with them is highly recommended by me, this deck greatly benefits sonically with that. That also includes the 2x 470uF caps in the PB EQ (C9 & C10). I've also discovered that the LM833N or the MC33078 op-amps sound amazing in the Phase Correct stage, so if you want to thinker with the deck a little bit more, I recommend to try them. They are DIP8 package though, so you would need to make a DIY adapter. 0.1uF Bypass caps across the supply pins (4 & 8) are also a must as always. The NJM2114 is fine, but it's a bit more cold and flat sounding comparatively. Still decent though.
Also, the big local filtering caps 1000uF 10v (C620, C621, C618, C619, C610, C611), which are 6x in total, also play a huge role in the sound. I liked Panasonic FR best in those positions, but you can keep things consistent with the Rubycon's, I haven't heard them though, so I can't comment on them. The other local filtering caps you can leave the Puresims in, although I did recap them with Nichicon Fine Golds on my 755.
Thanks for stopping by, and for your efforts in making the PDF! I was originally planning to do just that with the UES parts - I think I have them all on hand. I just wanted to see how those Purism caps sounded first, is all. I was only in the process of discovering how much I like those Panasonic FRs at the time I did this - I'm going all-in on those now. I've got a full complement of FRs coming in for my first import from Japan for 2024 as I type this. Only one capacitor in the PSU of that machine won't be an FR, and it's the big one I couldn't find an FR for. I went Chemi-Con KZN for that one.
@@Oklawolf That's actually a good plan, checking the sound with the original caps first. That way, the 755 will impress you a second time. :)
BTW, keep an eye on the W&F after some time passes. I had some bad experience with FIA rollers for these decks. Initially, the performance was decent at 0.045% WRMS (worse than the original roller at 0.0280%, so if it's not in a bad shape, I recommend the original roller), but after a few months something happened where all 3 rollers degraded in some way, and the W&F jumped to 0.1% on average - terrible. And that is not a case with just a single deck, I had them installed in 1 RS-B555, the RS-B755 and a RS-B965 - all degraded similarly in performance. Now this could be just bad batch and my luck, and thus an isolated case, but I have to mention it. Basically, just check the W&F periodically, to make sure W&F is still good. Right now, it seems excellent. Hopefully it will stay that way. Good thing is, you can remove the roller arm from the front, without needing to disassemble the deck again. :)
Cheers, and happy taping!
- Chris
That reminds me, the M245X from last week got its recap now using the UES parts in almost the entire signal path. UKLs in the DBX circuit and other places needing low leakage, FRs in the power supply. I should get that video done, because that deck sounds like it had a decent leveling up on playback alone. I figured I would do the polar to bipolar experiment there first because it needed new capacitors much more urgently than this one.
IMO black face decks just don't do it for me😄
Nice deck and all. We had a Technics receiver and turntable with Jensen speakers for one of our bedrooms growing up.
Always remember waiting for that little click when you'd hit the power button.
factory specs are 0,05 w&f and you get that so what you expect? you can’t do better them factory in mechanism much unfortunately, you can do electronics mods but when it comes to mechanism is not so much possible. anyway, many decks with double capstans witch to have this w&f results especially as they all are old ones.ps, when it comes to those brakes you can use any rubber with same size. what i did i bought a cable with same diameter and i use this cable shild as a replacement for those brakes and it works very well.
Very nice and informative video. I am owner of the RS B765, which is identical. Currently looking to replace the smd capacitors on the DD motor. What capacitors have you used on it?
Two 10uF 16V polarized, three 4.7uF 25V bipolar. They don't need to be anything special.
@@Oklawolf Thanks!
I've finally replaced all the electrolytic capacitors on mine including the gears and ofc performed some modifications as well. I gotta say you got lucky having most of the capacitors replaced by it's previous owner because the original PXS ones was really bad, they could dry out over time and fail. Thanks for the modifications part, I've kinda followed you in the modifications.Edit: I forgot to mention the leaf switches could fail at some point and need to be replaced.
Also how did you got the power transformer off the actual board, I had a really hard time with it attached on.
hi.could you tell me were you got the replacement gear from
as mine has developed the same fault thankyou
great channel by the way
I got it from eBay.
@@Oklawolf
item number or seller please as cant find any parts for my model listed
thankyou
Seller is appleof666sodom - I used his parts again in the Philips DCC machine.
hi, i think the result of 0,06 is amazing perfekt -wow-. What belt driven models are doing best?
Yeah I'm happy with this one considering it had a lot of damage when I got it. I would say my Aiwa XK-007 and Carver TD-1700 are doing best for belt drive. Both are around 0.06%.