A while back, I was watching a YouTube video where new cassette machines were being tested in various ways. The individual performing the tests noted that the cassette speed on a lot of these new devices were a little fast. There seemed to be a trend with this being typical of all reviews concerning the tape speed of most new cassette decks manufactured today.
This got me thinking about cassette speed calibration in general. I am very strict on the speed of my cassettes being accurate. So, I got to thinking about why it might be that the new cassette decks being sold today are generally running a little fast. There are so many things that can affect the correct speed adjustment of a cassette mechanism. Tape stretch and drag, deck lubrication (or lack thereof), belt and/or the motor itself just to name a few. I also do not trust these generic calibration cassettes that are sold on eBay, recorded using a recently "calibrated" deck. I can't begin to tell you how many calibration cassette tapes that were made on another machine that simply dialed my deck to the deck that made the recording, but not to a factory recorded cassette.
The reason I think some of these machines are a little fast, might be due to lower quality belt(s) and/or lubricants used. I say this because I have noticed that I can calibrate a machine and dial it in perfectly after a belt replacement, only to notice that it is playing faster after a while and needs a follow up adjustment. This becomes more annoying on something like the M70. A complete disassembly is needed to adjust it's speed unless you have the Victor M70 or the M75 where you can get by with the pitch adjustment knob on the front. A good quality belt is less susceptible to stretching, but I still have had to go back and slow them down after a bit of playback.
So, my guess is that the new cassette decks may have been calibrated, but after a bit of use, the belt and/or mech loosens up a bit and causes them to run fast. I guess it could always be because they are turning them out quickly and don't do a thorough job or using low quality components. But again, I have had to go back and adjust machines after a new belt due to slowly increasing in speed. A few of them had NOS quality belts installed made by PRB. I guess you could argue that even though the PRB belts are new, they are still old. That could also cause them to stretch more when they are installed and used. All mechanical devices will have more drag before they have been run-in. Parts tend to wear in to one another over time and the resistance goes down. Maybe that could be it also.
When it comes to belts, I have learned that there are so many other factors other than overall size. Some cassette decks need a belt that is made from a different type of compound to increase elasticity but without adding tension. Most of these belts are needed in decks where a pulley needs to shift back and forth for FF or Rewind applications and the belt needs to expand and contract to make up for the distance of travel without adding more tension.
Anything I am missing here? Do you feel I am on the right path overall as to why a new machine would be slightly fast or an older machine speeding up after a while after a new belt once calibrated?
This got me thinking about cassette speed calibration in general. I am very strict on the speed of my cassettes being accurate. So, I got to thinking about why it might be that the new cassette decks being sold today are generally running a little fast. There are so many things that can affect the correct speed adjustment of a cassette mechanism. Tape stretch and drag, deck lubrication (or lack thereof), belt and/or the motor itself just to name a few. I also do not trust these generic calibration cassettes that are sold on eBay, recorded using a recently "calibrated" deck. I can't begin to tell you how many calibration cassette tapes that were made on another machine that simply dialed my deck to the deck that made the recording, but not to a factory recorded cassette.
The reason I think some of these machines are a little fast, might be due to lower quality belt(s) and/or lubricants used. I say this because I have noticed that I can calibrate a machine and dial it in perfectly after a belt replacement, only to notice that it is playing faster after a while and needs a follow up adjustment. This becomes more annoying on something like the M70. A complete disassembly is needed to adjust it's speed unless you have the Victor M70 or the M75 where you can get by with the pitch adjustment knob on the front. A good quality belt is less susceptible to stretching, but I still have had to go back and slow them down after a bit of playback.
So, my guess is that the new cassette decks may have been calibrated, but after a bit of use, the belt and/or mech loosens up a bit and causes them to run fast. I guess it could always be because they are turning them out quickly and don't do a thorough job or using low quality components. But again, I have had to go back and adjust machines after a new belt due to slowly increasing in speed. A few of them had NOS quality belts installed made by PRB. I guess you could argue that even though the PRB belts are new, they are still old. That could also cause them to stretch more when they are installed and used. All mechanical devices will have more drag before they have been run-in. Parts tend to wear in to one another over time and the resistance goes down. Maybe that could be it also.
When it comes to belts, I have learned that there are so many other factors other than overall size. Some cassette decks need a belt that is made from a different type of compound to increase elasticity but without adding tension. Most of these belts are needed in decks where a pulley needs to shift back and forth for FF or Rewind applications and the belt needs to expand and contract to make up for the distance of travel without adding more tension.
Anything I am missing here? Do you feel I am on the right path overall as to why a new machine would be slightly fast or an older machine speeding up after a while after a new belt once calibrated?