Varispeed mod for tape echo

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7upPartridge
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Varispeed mod for tape echo

Post by 7upPartridge » Wed Jul 23, 2014 6:01 pm

I tried some searching without much luck. I've been doing tape echoes with 2-trk machines for a while, but I'm usually limited to 1 or 2 speeds (+/- the limited varispeed on a 388). I'd like to build a varispeed control onto a 2-trk for more flexible echo time...could anyone direct me to a thread with some info on this? Or do you have any suggestions? I'm not a total novice, but I'm also no expert...is this a heavy duty undertaking? The good news is 2-trks are borderline worthless on Craigslist so I can probably afford to screw up a couple...

Thanks!

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Darlington Pair
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Re: Varispeed mod for tape echo

Post by Darlington Pair » Thu Jul 24, 2014 6:03 am

7upPartridge wrote:I tried some searching without much luck. I've been doing tape echoes with 2-trk machines for a while, but I'm usually limited to 1 or 2 speeds (+/- the limited varispeed on a 388). I'd like to build a varispeed control onto a 2-trk for more flexible echo time...could anyone direct me to a thread with some info on this? Or do you have any suggestions? I'm not a total novice, but I'm also no expert...is this a heavy duty undertaking? The good news is 2-trks are borderline worthless on Craigslist so I can probably afford to screw up a couple...

Thanks!
If the motors are AC then all you need is a rheostat to control the speed, not a big deal. If the motors are DC, like in a space echo, then it's a little more complicated and needs to be controlled with PWM.

Of course there are decks like the Roberts/Akai stuff that have two speed settings and then a sleeve that goes over the capstan to provide two more speeds. Still a bit limiting, but don't need heavy modification.

7upPartridge
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great point!

Post by 7upPartridge » Thu Jul 24, 2014 11:11 am

wow..a capstan sleeve, a larger capstan circumference would effectively speed up the machine, right? can't believe that never occurred to me...my primary concern here is speeding the tape rather than slowing, I'm going for ADT type speed and that's what my machines are always too slow for

themagicmanmdt
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Post by themagicmanmdt » Sun Jul 27, 2014 3:50 pm

i'd think you'd be better off doing a dremel-mod and just being able to move the playback head ala an echoplex...

re-tach-ing a capstan will help, but it will most likely show it's limitations of what the capstan will take (or give) within boundaries (or being unreliable/burning out).

a slidey playback head brings more of the fun!

IMO
we are the village green
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*chief tech and R&D shaman at shadow hills industries*

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Darlington Pair
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Post by Darlington Pair » Mon Jul 28, 2014 6:26 am

themagicmanmdt wrote:i'd think you'd be better off doing a dremel-mod and just being able to move the playback head ala an echoplex...

re-tach-ing a capstan will help, but it will most likely show it's limitations of what the capstan will take (or give) within boundaries (or being unreliable/burning out).

a slidey playback head brings more of the fun!

IMO
A moving head would be super awesome if you're mechanically inclined enough to make it happen!

7upPartridge
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Moving playback head

Post by 7upPartridge » Mon Jul 28, 2014 3:17 pm

Man, that's another great idea...I'm probably not mechanically inclined enough to make a movable playback head, but then again, I have some old machines that I'm not afraid to try a little caveman engineering on. Thanks everyone!

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