I made my own speed tape using a Sony TC-K850ES (wish I didn't sell it) which is quartz locked, direct drive but I also did have the Sony speed tape. If I remember right with the Sony tape it played at 2998 and held very steady. So I know my speed tapes are good as it also read very steady. I used nos late 80's Sony HF 60min tape. I'm pretty sure the Sony test tape was a 60min tape in a high quality shell similar to a Sony UX-Pro shell. Also when setting speed play the tape from the middle section to the tape.
I think dividing W&F REC->PB by 2 in comparison to only PB is not correct, because the overlaying W&F pattern REC and PB can result in both adding and reducing the value, more reducing, but a bit adding, too. Thus the correct value ist SQR(2), that means it is 71% of the REC-PB value.
DrCassette: Using thee tone test tape recorder on direct drive deck have a lot of sense to measure speed on other deck (specially if that drive is cristal oscillator controlled), however using that to measure wow and flutter not. It simpler to just generate the tone and record on the deck perform the measurement and divided the results by 2, as you did on the first deck. Recording that on another media (CD) do not have sense too. You can just use your phone with tone generator app (you can even find website to do that). The precision is pretty high as the cristal clock is very stable on the phone. On the other note. Watching your channel for several years. Truly appreciate what you do.
I don't like using the phone as a replacement for proper test equipment, as it might induce interference into the device under test. Also the phone is what I use to record my videos, so when I'm making a TH-cam video, the phone is not available for anything else.
I did some speed calibration cassettes myself as well, on the Revox B215, which as the Akai, has a quartz locked DD flywheels (with two separate motors for the two flywheels, compared to the belt-drive of the 2nd flywheel in the Akai). It's fine for calibrating any low- or mid end cassette deck, and it's better than those no-name calibration tapes off eBay, but it's not proper "bezugsband" territory either.
I wonder how they made the proper reference cassettes. I guess recording happened on some special open reel deck and the tape was then fed into a cassette case.
@@DrCassette I believe that it is done on Digital loop bin duplicator, where signal is recorded directly on tape (no tape shell, digital source,) . The recording speed could be up to 100 time faster, any wow and flutter is divided by speed reduction factor.
Exactly. A friend of mine bought a Studer A80R QC, which had a 1/8” transport and heads and it was used for quality control purposes of mass duplicated tapes. You’d put the entire spool of recorded tape on the machine and do quality control things with it :) Then it would go to the next machine, which would fill the empty “C0” shells. His plan was to modify this A80 for producing proper reference tapes. I wish I had some of these calibration cassettes, but I only have a 38,1cm/s open reel calibration tape made by BASF, which I use to check and align my Studer B67 and Otari MX55.
Enjoyable video DC. I wonder, if a new tape format was going to be 'invented', what kind of tape deck would we see today - a new reel to reel, or a new cassette deck? Personally, I believe that if Philips knew their 'cassette' was going to 'take off' like it did all those years ago, would they have made the cassette a bit bigger? - longer tape, broader tracks too.
The only way I am thinking that one could speed calibrate a deck without the use of a calibrated cassette is by having a loop cassette with spliced tape at an exact length. Using the splice mark as a reference it is possibile to determine how much the tape has traveled.
I wonder how good duplication plants are if the test tone cassettes where duplicated there. I’ve seen footage of these plants and they all seem to be very “high speed” at duplicating the tapes. I.e. they are focused mostly on quick, high volume production.
Its true. I used to buy test tapes from Panasonic and most seemed OK. However I think if you make your own you often get better results than the ones you pay for. I bought a tone generator from Teac which is much more useful.
When switching to source, you get the signal that's coming from the CD Player, and that is a perfectly constant 3150 Hz as CD Players don't have wow&flutter. The Cassette Checker is calibrated to display zero when the input is a constant 3150 Hz. So it does indeed display precisely zero when the cassette deck is switched to source.
Isn't wow&flutter an (unwanted) form of FM-modulation, the testtone being the modulated wave or like the "carrier" in RF? Think it would be possible to make a articifial testtone by FM modulation. Nice Akai deck, got the GX52 with the same direct drive as this, mine is only single capstan though.
Indeed W&F could be seen as frequency modulation, but then you would have to find a generator that allows you to set the carrier frequency as low as 3150 Hz, I don't think many generators would allow for that as this frequency is far, far away from RF. But it is an interesting thought, that the Cassette Checker employs something similar to an FM demodulator to measure W&F.
@@DrCassette Any abritrary function generator can do that, like the FY6800 or FY6900. Even the cheaper generators can do that. I used that method to test my Ferrograph RTS2 and it worked perfectly.
Do you still have the installer for the wow and flutter software you use and could you please send it to me? I think it was removed from the website...
DrCassette: Did you herd about the PWM recording on audio tape, some time digital audio. It was use in high speed duplicators for prerecorded tapes. I wonder if regular deck can be converted to use that methods. From what i read tape recorded with that methods have very low noise.
@@DrCassette I need to correct my self look like it was PCM , not PWM,. PCM have more sense as it kind of look like AC biass signal. The recording methods was advertise as "digalog". Some prerecorded cassettes have that label. Some people reported that some of the prerecorded cassettes could have up to 10 dB higher signal recorded with out distortion. I wonder why they never introduce that to to high end decks. Possible explanation is that recording industry that hold that patent, do not like to give better quality recording to customers to copy CDs , as it was case with DAT. Wonder if that can be revive by modifying some tape recorder.
You have a great opinion on the AKAI GX-75, but I think it is heavily overrated. It has a direct drive transport, but it is not Quartz locked which is not very different from a good quality motor + belt drive. The tape path is a nightmare to align and in my experience azimuth changes after stop and restart. The electronics is nothing exceptional, I wasn't blown away by how it recorded or played back. It' built like a tank, it's very heavy and it appears to be "professional", but compared to a Revox it is nowhere near. As for test tapes, this fellow (www.ant-audio.co.uk/index.php?cat=post&qry=alignment_tapes) sells alignment tapes made with a high quality standard. He uses a modified Revox.
DrCassette I wish i had a Revox! I only tried it at a friend’s home, but it is way too expensive for a cassette deck. I had the Akai some years ago, but after tinkering for over two months I sold it out of desperation. I now have a more consumer Aiwa you reviewed some years ago and you were not impressed with. In the end it all boils down to personal experience
Do you mean the Aiwa AD-F910? I think I may have been a bit too critical on that. As for the Akai GX-75, the mechanism in mine is absolutely rock solid. The one big problem I have with it is the implementation of the Dolby circuits. Any cassettes recorded with Dolby B lack brilliance, and Dolby C recorded cassettes don't sound right either. I often end up playing Dolby recorded cassettes without Dolby, but then there tends to be too much brilliance. If there is no Dolby involved, the deck sounds very good.
@@DrCassette That sounds like a wrong playback gain setting. I did that too in my tinkering and according to the spec of the Dolby IC (HA12090NT) when playing back a tape recorded with a 400 Hz tone at Dolby Level you should get ~500 mV (493 mV to be precise) on the RCA outputs. With the playback gain set to correct level, at least Dolby B sounds ok. Dolby C also requires a very accurate playback EQ setting (tones at 400 Hz and 8 or 10 kHz must have same amplitude). My Akai had random W&F problems and even after changing both pinch rollers it still had problems. I had to realign the head, but I was never too satisfied with the result; the procedure specified in the service manual is not exactly effective: you have to swipe the head with you finger so that it become greasy, then after playing a tape, verify which portion of the head got wiped by the tape (I'm not kidding). Very very complicated tape path. Also when in rest position, the springs pushing the pinch rollers against the capstan are in compressed state; with time they lose strength and tape might slip due to insufficient pinch roller pressure.
![Megan Thee Stallion - Neva Play (feat. RM) [Official Video]](http://i.ytimg.com/vi/TpYTyAaTRts/mqdefault.jpg)
In case the video chapters don't work for you, there are time stamps to the chapters available in the video description.
New DrCassette videos are like treat to viewers like me :D
very well explained. And using the same deck for record and playback testing is rather ingenious.
I love that Akai deck
Learned a boat-load of information that's always been vague to me. Great video!
Thank you :)
I made my own speed tape using a Sony TC-K850ES (wish I didn't sell it) which is quartz locked, direct drive but I also did have the Sony speed tape. If I remember right with the Sony tape it played at 2998 and held very steady. So I know my speed tapes are good as it also read very steady. I used nos late 80's Sony HF 60min tape. I'm pretty sure the Sony test tape was a 60min tape in a high quality shell similar to a Sony UX-Pro shell. Also when setting speed play the tape from the middle section to the tape.
I think dividing W&F REC->PB by 2 in comparison to only PB is not correct, because the overlaying W&F pattern REC and PB can result in both adding and reducing the value, more reducing, but a bit adding, too. Thus the correct value ist SQR(2), that means it is 71% of the REC-PB value.
DrCassette: Using thee tone test tape recorder on direct drive deck have a lot of sense to measure speed on other deck (specially if that drive is cristal oscillator controlled), however using that to measure wow and flutter not. It simpler to just generate the tone and record on the deck perform the measurement and divided the results by 2, as you did on the first deck. Recording that on another media (CD) do not have sense too. You can just use your phone with tone generator app (you can even find website to do that). The precision is pretty high as the cristal clock is very stable on the phone.
On the other note. Watching your channel for several years. Truly appreciate what you do.
I don't like using the phone as a replacement for proper test equipment, as it might induce interference into the device under test. Also the phone is what I use to record my videos, so when I'm making a TH-cam video, the phone is not available for anything else.
I did some speed calibration cassettes myself as well, on the Revox B215, which as the Akai, has a quartz locked DD flywheels (with two separate motors for the two flywheels, compared to the belt-drive of the 2nd flywheel in the Akai). It's fine for calibrating any low- or mid end cassette deck, and it's better than those no-name calibration tapes off eBay, but it's not proper "bezugsband" territory either.
I wonder how they made the proper reference cassettes. I guess recording happened on some special open reel deck and the tape was then fed into a cassette case.
@@DrCassette I believe that it is done on Digital loop bin duplicator, where signal is recorded directly on tape (no tape shell, digital source,) . The recording speed could be up to 100 time faster, any wow and flutter is divided by speed reduction factor.
Exactly. A friend of mine bought a Studer A80R QC, which had a 1/8” transport and heads and it was used for quality control purposes of mass duplicated tapes. You’d put the entire spool of recorded tape on the machine and do quality control things with it :) Then it would go to the next machine, which would fill the empty “C0” shells. His plan was to modify this A80 for producing proper reference tapes. I wish I had some of these calibration cassettes, but I only have a 38,1cm/s open reel calibration tape made by BASF, which I use to check and align my Studer B67 and Otari MX55.
@@DrCassette ANT audio test tapes ... he is located close to you I think
Website link
www.ant-audio.co.uk/index.php?cat=post&qry=alignment_tapes
Good repair job as always
Thank you :)
Luv these videos, i luv cassettes!
Enjoyable video DC.
I wonder, if a new tape format was going to be 'invented', what kind of tape deck would we see today - a new reel to reel, or a new cassette deck? Personally, I believe that if Philips knew their 'cassette' was going to 'take off' like it did all those years ago, would they have made the cassette a bit bigger? - longer tape, broader tracks too.
The only way I am thinking that one could speed calibrate a deck without the use of a calibrated cassette is by having a loop cassette with spliced tape at an exact length. Using the splice mark as a reference it is possibile to determine how much the tape has traveled.
I wonder how good duplication plants are if the test tone cassettes where duplicated there. I’ve seen footage of these plants and they all seem to be very “high speed” at duplicating the tapes. I.e. they are focused mostly on quick, high volume production.
wow I have that ONKYO Cd player bought it new about 30 years ago and still using it.
I found this Onkyo CD player in the e-waste back in 2009. It needed a lot of cleaning, but it has worked fine ever since.
Its true.
I used to buy test tapes from Panasonic and most seemed OK. However I think if you make your own you often get better results than the ones you pay for.
I bought a tone generator from Teac which is much more useful.
Excellent
Perfect
Did you check the W&F when the deck was switched to source? It would be curious to know how close it goes to zero. I'll bet it's still not perfect.
When switching to source, you get the signal that's coming from the CD Player, and that is a perfectly constant 3150 Hz as CD Players don't have wow&flutter. The Cassette Checker is calibrated to display zero when the input is a constant 3150 Hz. So it does indeed display precisely zero when the cassette deck is switched to source.
Isn't wow&flutter an (unwanted) form of FM-modulation, the testtone being the modulated wave or like the "carrier" in RF? Think it would be possible to make a articifial testtone by FM modulation.
Nice Akai deck, got the GX52 with the same direct drive as this, mine is only single capstan though.
Indeed W&F could be seen as frequency modulation, but then you would have to find a generator that allows you to set the carrier frequency as low as 3150 Hz, I don't think many generators would allow for that as this frequency is far, far away from RF. But it is an interesting thought, that the Cassette Checker employs something similar to an FM demodulator to measure W&F.
@@DrCassette Any abritrary function generator can do that, like the FY6800 or FY6900. Even the cheaper generators can do that. I used that method to test my Ferrograph RTS2 and it worked perfectly.
Do you still have the installer for the wow and flutter software you use and could you please send it to me?
I think it was removed from the website...
Download still works fine for me on the ant-audio website. It's the first result when you google WFGUI.
Thanks for the answer, maybe the website was offline the day I checked it
DrCassette: Did you herd about the PWM recording on audio tape, some time digital audio. It was use in high speed duplicators for prerecorded tapes. I wonder if regular deck can be converted to use that methods. From what i read tape recorded with that methods have very low noise.
I think I have heard about that somewhere but I don't remember any details.
@@DrCassette I need to correct my self look like it was PCM , not PWM,. PCM have more sense as it kind of look like AC biass signal. The recording methods was advertise as "digalog". Some prerecorded cassettes have that label. Some people reported that some of the prerecorded cassettes could have up to 10 dB higher signal recorded with out distortion. I wonder why they never introduce that to to high end decks. Possible explanation is that recording industry that hold that patent, do not like to give better quality recording to customers to copy CDs , as it was case with DAT.
Wonder if that can be revive by modifying some tape recorder.
You have a great opinion on the AKAI GX-75, but I think it is heavily overrated. It has a direct drive transport, but it is not Quartz locked which is not very different from a good quality motor + belt drive. The tape path is a nightmare to align and in my experience azimuth changes after stop and restart. The electronics is nothing exceptional, I wasn't blown away by how it recorded or played back. It' built like a tank, it's very heavy and it appears to be "professional", but compared to a Revox it is nowhere near.
As for test tapes, this fellow (www.ant-audio.co.uk/index.php?cat=post&qry=alignment_tapes) sells alignment tapes made with a high quality standard. He uses a modified Revox.
Love it or hate it, the Akai GX-75 is the best cassette deck I have in my collection. And I assume you don't want to send me a free Revox? ;)
@@DrCassette A drawback to the Revox B215 (at least) is that there is no manual override for recording bias.
DrCassette I wish i had a Revox! I only tried it at a friend’s home, but it is way too expensive for a cassette deck. I had the Akai some years ago, but after tinkering for over two months I sold it out of desperation. I now have a more consumer Aiwa you reviewed some years ago and you were not impressed with. In the end it all boils down to personal experience
Do you mean the Aiwa AD-F910? I think I may have been a bit too critical on that. As for the Akai GX-75, the mechanism in mine is absolutely rock solid. The one big problem I have with it is the implementation of the Dolby circuits. Any cassettes recorded with Dolby B lack brilliance, and Dolby C recorded cassettes don't sound right either. I often end up playing Dolby recorded cassettes without Dolby, but then there tends to be too much brilliance. If there is no Dolby involved, the deck sounds very good.
@@DrCassette That sounds like a wrong playback gain setting. I did that too in my tinkering and according to the spec of the Dolby IC (HA12090NT) when playing back a tape recorded with a 400 Hz tone at Dolby Level you should get ~500 mV (493 mV to be precise) on the RCA outputs. With the playback gain set to correct level, at least Dolby B sounds ok. Dolby C also requires a very accurate playback EQ setting (tones at 400 Hz and 8 or 10 kHz must have same amplitude).
My Akai had random W&F problems and even after changing both pinch rollers it still had problems. I had to realign the head, but I was never too satisfied with the result; the procedure specified in the service manual is not exactly effective: you have to swipe the head with you finger so that it become greasy, then after playing a tape, verify which portion of the head got wiped by the tape (I'm not kidding). Very very complicated tape path. Also when in rest position, the springs pushing the pinch rollers against the capstan are in compressed state; with time they lose strength and tape might slip due to insufficient pinch roller pressure.