SL1200 at 78rpm
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#1 SL1200 at 78rpm
If this is discussed elsewhere, please point me in that direction, otherwise...
I have searched the 'net for ages looking for a mod to the Technics SL1200 to give it 78rpm facility.
I KNOW that Kevin of KABUSA sells the upgrade at $175 (see here:
http://www.kabusa.com/frameset.htm?/
for details)
BUT
I don't want to spend $175 plus shipping and wait weeks for turnaround. Does ANYONE know:
(1) either what mod KABUSA uses, or
(2) any other mod that can be applied by a competent electronics enthusiast?
(Incidentally I have great respect for Kevin, he has helped me with a number of things in the past.)
I promise to share the mods with everyone if you share it with me
I have searched the 'net for ages looking for a mod to the Technics SL1200 to give it 78rpm facility.
I KNOW that Kevin of KABUSA sells the upgrade at $175 (see here:
http://www.kabusa.com/frameset.htm?/
for details)
BUT
I don't want to spend $175 plus shipping and wait weeks for turnaround. Does ANYONE know:
(1) either what mod KABUSA uses, or
(2) any other mod that can be applied by a competent electronics enthusiast?
(Incidentally I have great respect for Kevin, he has helped me with a number of things in the past.)
I promise to share the mods with everyone if you share it with me
Last edited by RussellS on Thu Jan 10, 2013 3:18 pm, edited 1 time in total.
I either do, or I don't. There is no 'try'.
- Dave Cawley
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#2
"if it measures well and sounds good, it is good : "if it measures badly and sounds bad it is bad" : "if it measures badly and sounds good, it could be improved" : "if it measures well but sounds bad it is bad"
- Dave Cawley
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#4
That can be done, but it's expensive, unless you ditch 33/45 and just have 16 and 78 ?
Dave
Dave
"if it measures well and sounds good, it is good : "if it measures badly and sounds bad it is bad" : "if it measures badly and sounds good, it could be improved" : "if it measures well but sounds bad it is bad"
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#5
Thanks Dave.
I'll wait a bit and see if anyone else has ideas. No need to reinvent any wheels.
But, I'm not just waiting. As something of an electronics fundi myself, I am looking at the circuits and frequency dividers to see if I can do it using my own initiative. If I succeed, this thread will be the first to know.
I'll wait a bit and see if anyone else has ideas. No need to reinvent any wheels.
But, I'm not just waiting. As something of an electronics fundi myself, I am looking at the circuits and frequency dividers to see if I can do it using my own initiative. If I succeed, this thread will be the first to know.
I either do, or I don't. There is no 'try'.
- Dave Cawley
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#6
The way to do it, and the way the MK4 works; is to simply switch in new crystals, it's that simple! OK you have to have them made or use a DDS from eBay ?
Don't be afraid that I'm a manufacturer, I'll talk technical to any good person!
Dave
Don't be afraid that I'm a manufacturer, I'll talk technical to any good person!
Dave
"if it measures well and sounds good, it is good : "if it measures badly and sounds bad it is bad" : "if it measures badly and sounds good, it could be improved" : "if it measures well but sounds bad it is bad"
#7
Very interesting because i'm looking at this mod myself at the moment to my MKII.
I have what I think is the right crystal so as proof of concept I fitted it to the deck (switching crystals can come later) , but it wasn't happy - the turntable bounced back and forth, strobe not working and the start/stop made no difference. I assume the crystal is not oscillating, anything else needed to make it work?
I have what I think is the right crystal so as proof of concept I fitted it to the deck (switching crystals can come later) , but it wasn't happy - the turntable bounced back and forth, strobe not working and the start/stop made no difference. I assume the crystal is not oscillating, anything else needed to make it work?
- Dave Cawley
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#8
No, just change the crystal. Make sure it's a fundamental.
Oh ! the pitch needs to be switched off so the green light lights.
Regards
Dave
Oh ! the pitch needs to be switched off so the green light lights.
Regards
Dave
"if it measures well and sounds good, it is good : "if it measures badly and sounds bad it is bad" : "if it measures badly and sounds good, it could be improved" : "if it measures well but sounds bad it is bad"
- Dave Cawley
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#11
.
The crystal is obvious when you take a peek and the frequency is 78.26/45 times the frequency of the original one.
Regards
Dave
The crystal is obvious when you take a peek and the frequency is 78.26/45 times the frequency of the original one.
Regards
Dave
"if it measures well and sounds good, it is good : "if it measures badly and sounds bad it is bad" : "if it measures badly and sounds good, it could be improved" : "if it measures well but sounds bad it is bad"
#12
It's X201 in on the PCB.RussellS wrote:Where is the crystal?
The original is 4.19328Mhz. The MK4 is using a 9.844Mhz (for 78rpm) so it must be using that in conjunction with the 33rpm setting. 9.8304Mhz crystal is readily available which is what I was trying and near enough for this experiment.
#15
Well further investigation reveals a perfect waveform with the original crystal but nothing whatsoever with the new crystal.
So either all my new crystals are faulty or the components in the SL1200's oscillator circuit are not suitable for them. Without a schematic for the AN6680 control chip its the realm of guesswork here.
So either all my new crystals are faulty or the components in the SL1200's oscillator circuit are not suitable for them. Without a schematic for the AN6680 control chip its the realm of guesswork here.