I'd be interested in one of these transformers, if you have any left, and if Don doesn't take the last one (he gets priority). Thanks.
JP thank you for the pics. A birdie by the name of Dave told me you might have one. I would very much like to buy your US V toroidal if you have one for sale. PM me or post it here. Just need to know how to pay you. I'll send you my address via this thread. You will need it for the chip any way.
Thank you.
And thank you hirscwi for your kindness and etiquette. Appreciated.
R,
Don
Thank you.
And thank you hirscwi for your kindness and etiquette. Appreciated.
R,
Don
I can start a new thread but thought I'd start here.
Went through calibration procedure on my SP-10k2a. Got everything in spec except the RS current setting which is supposed to be 0 V but I can't get it below 0.162 V - it jumps up if I keep turning the pot. It appears to be running ok, no vibrations and strobe looks good at all speeds. Not sure if this is any cause for concern?
I did find a typo in the service manual. It said to measure this between Test CN2 terminals 2 and 4 but you actually have to measure it between 3 and 4 - I discovered this when checking continuity between Test CN2 pins and IC201 terminals 6 and 8.
Thanks
Kevin Looker
Went through calibration procedure on my SP-10k2a. Got everything in spec except the RS current setting which is supposed to be 0 V but I can't get it below 0.162 V - it jumps up if I keep turning the pot. It appears to be running ok, no vibrations and strobe looks good at all speeds. Not sure if this is any cause for concern?
I did find a typo in the service manual. It said to measure this between Test CN2 terminals 2 and 4 but you actually have to measure it between 3 and 4 - I discovered this when checking continuity between Test CN2 pins and IC201 terminals 6 and 8.
Thanks
Kevin Looker
This really need to be in the SP-10 thread here https://www.diyaudio.com/community/threads/the-incredible-technics-sp-10-thread.261735/
I've re-posted in the SP-10 thread. Only posted here becasue someone said the mk2a was closer to the 3 than the mk2 and there was a previous post here about the RS current measurement.
Thanks
Thanks
This maybe the last time I see this one. First in for 100V to 240V transformer conversion. A few years later the JP Chip, and now the LED digits sorted and also the hinge modification. It's going to be collected by a chauffeur tomorrow. Oh BTW he kept his headshell and cartridge at his home, this is a spare AT-33EV that's none too shabby.
I did the cap replacement of all the electrolytics. Seemed to go well. Then went on to the measurements and adjustments.
Seemed to go well in the beginning although quite the learning curve the first time around. Certainly couldn't have done it without the blog help of JP and Dave so thank you for significant contributions. Especially with Vs and Rs but throughout..
Unfortunately things went really bad when I checked Vcc on ICs 201,202 and 203. IC203 has 0.00V at pin 5 vs ground.
Checked and re checked it. Voltage at IC206 is exactly 12.0V with nothing visible on the board. All the pin voltages are crap for both stop and start. All negative something. Can't get anything meaningful on the scope. I looked around and couldn't find any source for an AN660. I need suggestions.
I have no Idea If I buggered the IC myself or if it came that way. The table runs perfectly smoothly at all three speeds and the "strobe" lights are steady and hang on very well if I try and drag it down with my finger. I only ran it briefly before the recap but it appeared to run the same then. Actually amazes me how well it runs considering.
I have recapped two MK2's in their entirety and set them to spec and they run perfectly.
This is clearly a different animal but I am essentially a novice at electrical engineering and IC's.
Maybe TMI but wanted to give some background.
Thank you for any help or advice.
Don
Seemed to go well in the beginning although quite the learning curve the first time around. Certainly couldn't have done it without the blog help of JP and Dave so thank you for significant contributions. Especially with Vs and Rs but throughout..
Unfortunately things went really bad when I checked Vcc on ICs 201,202 and 203. IC203 has 0.00V at pin 5 vs ground.
Checked and re checked it. Voltage at IC206 is exactly 12.0V with nothing visible on the board. All the pin voltages are crap for both stop and start. All negative something. Can't get anything meaningful on the scope. I looked around and couldn't find any source for an AN660. I need suggestions.
I have no Idea If I buggered the IC myself or if it came that way. The table runs perfectly smoothly at all three speeds and the "strobe" lights are steady and hang on very well if I try and drag it down with my finger. I only ran it briefly before the recap but it appeared to run the same then. Actually amazes me how well it runs considering.
I have recapped two MK2's in their entirety and set them to spec and they run perfectly.
This is clearly a different animal but I am essentially a novice at electrical engineering and IC's.
Maybe TMI but wanted to give some background.
Thank you for any help or advice.
Don
@JP, @Dave Cawley
Thanks for steering me in the right direction. I flipped the board over and everything measured correctly. I finished the checklist and all is good. Appreciate the help.
Now its on to the turntable.
Don
Thanks for steering me in the right direction. I flipped the board over and everything measured correctly. I finished the checklist and all is good. Appreciate the help.
Now its on to the turntable.
Don
Greetings all,
I've had a Mk3 sitting in my shop for a while now. A home purchase, remodeling, and move kept me from getting it up and running. It worked when I bought it but I didn't want to use it till it had been restored and adjusted. It's time to put it to work...
I have been following this thread for a while and have just re-read it. Great information. Thanks especially to Dave and JP for their expertise.
First up was to replace the electrolytics. There were 7 or 8 of these that had corroded legs. I've restored a bunch of 60s and 70s electronics in the past 20 years but I've never seen so many corroded cap legs in the same unit. Wonder what's the cause?
With regards to the caps, recently JP mentioned that C251 should be a bipolar electrolytic. In my unit, C251 was polar. Also it shows as polar on the schematic in the service manual I have. What am I missing?
With regards to the adjustments. First and foremost I don't plan to tackle the Offset voltage. It's clearly beyond my skill and patience level. I've been advised that it likely doesn't need adjustment so I'm steering clear. My understanding of the adjustment for VS, RS, and Synch position is that the service manual is not correct. I believe I have gleaned the following from this thread:
VS: measured between VS and 0V and should be 2.1V with the platter spinning (VR201 is the adjustment trimmer). VS is pin 13 on AN660 (pin 3 on CN206) and 0V is pin 5 on CN206
RS: measured between AI and VO and set to 0v with the platter spinning (VR206 is the adjustment trimmer). AI is pin 6 on AN660 (pin 2 of CN206) and VO is pin 8 on AN660 (pin 1 of CN206)
Synchronizing position is measured between ST2 and 0V with the platter running. ST2 is pin 2 on AN660 (pin 4 of CN206) and 0V is pin 5 of CN206.
My understanding is that the service manual is correct for setting Middle Voltage.
I would greatly appreciate it if someone could confirm my understanding of the corrections to the service manual procedures.
Many thanks.
I've had a Mk3 sitting in my shop for a while now. A home purchase, remodeling, and move kept me from getting it up and running. It worked when I bought it but I didn't want to use it till it had been restored and adjusted. It's time to put it to work...
I have been following this thread for a while and have just re-read it. Great information. Thanks especially to Dave and JP for their expertise.
First up was to replace the electrolytics. There were 7 or 8 of these that had corroded legs. I've restored a bunch of 60s and 70s electronics in the past 20 years but I've never seen so many corroded cap legs in the same unit. Wonder what's the cause?
With regards to the caps, recently JP mentioned that C251 should be a bipolar electrolytic. In my unit, C251 was polar. Also it shows as polar on the schematic in the service manual I have. What am I missing?
With regards to the adjustments. First and foremost I don't plan to tackle the Offset voltage. It's clearly beyond my skill and patience level. I've been advised that it likely doesn't need adjustment so I'm steering clear. My understanding of the adjustment for VS, RS, and Synch position is that the service manual is not correct. I believe I have gleaned the following from this thread:
VS: measured between VS and 0V and should be 2.1V with the platter spinning (VR201 is the adjustment trimmer). VS is pin 13 on AN660 (pin 3 on CN206) and 0V is pin 5 on CN206
RS: measured between AI and VO and set to 0v with the platter spinning (VR206 is the adjustment trimmer). AI is pin 6 on AN660 (pin 2 of CN206) and VO is pin 8 on AN660 (pin 1 of CN206)
Synchronizing position is measured between ST2 and 0V with the platter running. ST2 is pin 2 on AN660 (pin 4 of CN206) and 0V is pin 5 of CN206.
My understanding is that the service manual is correct for setting Middle Voltage.
I would greatly appreciate it if someone could confirm my understanding of the corrections to the service manual procedures.
Many thanks.
I followed the above procedure and everything seems to be adjusted accordingly. The table performs properly and I'm excited to put it into use. I already have the plinth made. I used a layered core with steel for added weight. The exterior is covered with 1" Bocote (one of the densest woods available commercially).
I would note for others that follow, that there is (of course) an interplay between these adjustments. I recommend making a connector for CN206 and CN102 to avoid potential shorts. Also I recommend monitoring VS, RS, Middle Voltage and Synch positioning simultaneously. This made it a lot easier for me to get everything adjusted. I also suggest downloading both copies of the service manual from VinylEngine. Each has its own benefits in terms of sections with good clarity. Of course the original written manual would be optimal but apparently it's more scarce than the Mk3 itself.
Thanks again to Dave and JP for the information in this thread! Cheers.
I would note for others that follow, that there is (of course) an interplay between these adjustments. I recommend making a connector for CN206 and CN102 to avoid potential shorts. Also I recommend monitoring VS, RS, Middle Voltage and Synch positioning simultaneously. This made it a lot easier for me to get everything adjusted. I also suggest downloading both copies of the service manual from VinylEngine. Each has its own benefits in terms of sections with good clarity. Of course the original written manual would be optimal but apparently it's more scarce than the Mk3 itself.
Thanks again to Dave and JP for the information in this thread! Cheers.
The Kaneta Design SP10 referred to recently went quite well for a debut.
Speed Control proved adequate enough not to be commented on by a SP10 time served EE.
The Tonearm Swap took a extended period to achieve, but once in use nothing was detected amiss as an audible elaluation.
The Kaneta is now housed in Panzerholz,.
I like to think the impression made was quite enlightening, if the merits of adding P'holz were to be immediatly made available.
Speed Control proved adequate enough not to be commented on by a SP10 time served EE.
The Tonearm Swap took a extended period to achieve, but once in use nothing was detected amiss as an audible elaluation.
The Kaneta is now housed in Panzerholz,.
I like to think the impression made was quite enlightening, if the merits of adding P'holz were to be immediatly made available.