I am amateur and just have serviced the same one. FF and FWD were week not only because the motor but two reels themselves needed to be dismantled to parts to clean up and lubricate too. Many thanks for your demonstration video, without this I couldn’t make it myself +++++
I have many decks but missing this one from Hitachi. I heard good things about Lo-D decks and thank you for the inside look. It has a different transport than the other decks and the design looks very original to Hitachi.
Nice videos! :) I've always been somewhat interested in how the auto-calibrations are implemented by various manufacturers (in decks that I've never seen such as this one), maybe you will consider including a segment where you play back the portion of the tape being recorded during the (auto) calibration process. I'm sure you won't get any copyright matches from TH-cam :P Cheers!
@@hifirulezzz Yes I know you do :) What I meant was what the auto-calibration test tones sound like. Most of the decks mute the line while processing. Like in this vid (played back afterwards): th-cam.com/video/6r5V-WTYa-w/w-d-xo.html
@@mihaischitcu1917 they all mostly the same tones of 2, 3 or 4 frequencies with different levels, it limited to the CPU programming and should not affect results. The issue is within measurement precision. As tape levels may fluctuate. And ADC were slow or non existent at that days. For example Nakamichi 1000zxl used DAC and OpAmp in comparator mode to check levels.
@@hifirulezzz The Kenwwod deck from the clip I sent you uses such a comparator arrangement too, and it only "measures" the Right channel (the L&R channels are locked together, always receiving the same amount of correction). Others (like Technics on their last 3 head decks) use a much more sophisticated implementation and have much finer control - 64 steps for bias, however they only take 6 measurements as a binary search algorithm is employed. And they adjust the L&R channels completely independent of each other. I know in principle they all work in the same way but the actual implementation makes a big difference - those are the details I was curious about, and you can tell a lot just by listening the test sequence.
nice long educational video, thank you
I am amateur and just have serviced the same one. FF and FWD were week not only because the motor but two reels themselves needed to be dismantled to parts to clean up and lubricate too. Many thanks for your demonstration video, without this I couldn’t make it myself +++++
Nice work man
This man is a wizard.
🫡
I have many decks but missing this one from Hitachi. I heard good things about Lo-D decks and thank you for the inside look. It has a different transport than the other decks and the design looks very original to Hitachi.
Nice videos! :)
I've always been somewhat interested in how the auto-calibrations are implemented by various manufacturers (in decks that I've never seen such as this one), maybe you will consider including a segment where you play back the portion of the tape being recorded during the (auto) calibration process. I'm sure you won't get any copyright matches from TH-cam :P Cheers!
Stay tuned to my channel. I always do audio test.
@@hifirulezzz Yes I know you do :) What I meant was what the auto-calibration test tones sound like. Most of the decks mute the line while processing. Like in this vid (played back afterwards): th-cam.com/video/6r5V-WTYa-w/w-d-xo.html
@@mihaischitcu1917 they all mostly the same tones of 2, 3 or 4 frequencies with different levels, it limited to the CPU programming and should not affect results. The issue is within measurement precision. As tape levels may fluctuate. And ADC were slow or non existent at that days. For example Nakamichi 1000zxl used DAC and OpAmp in comparator mode to check levels.
@@hifirulezzz The Kenwwod deck from the clip I sent you uses such a comparator arrangement too, and it only "measures" the Right channel (the L&R channels are locked together, always receiving the same amount of correction). Others (like Technics on their last 3 head decks) use a much more sophisticated implementation and have much finer control - 64 steps for bias, however they only take 6 measurements as a binary search algorithm is employed. And they adjust the L&R channels completely independent of each other. I know in principle they all work in the same way but the actual implementation makes a big difference - those are the details I was curious about, and you can tell a lot just by listening the test sequence.
@@mihaischitcu1917 I do not need to record - I may tell you by looking into schematics how many steps it can have :)
Victor dd 77 không đưa đầu từ lên tới băng