To check the Opamp circuit. Without any audio. Pin 3 should be around 2.5 V because of the two 1k resistors that divide the 5V power in half. If not that the resistors are not installed correctly or do not make contact. The Opamp should be in balance to amplify an analog signal, which means that pin 2 needs to be 2.5 V too. The Opams just ampllifies the slightest difference between pin 2 and 3. If the voltage on pin 2 is higher than pin 3 the output is low. Id the voltage on pin 2 is lower than pin 3 then the output is high. If the output is between 0 and 5 volt the that is only possible if the voltage op pin 2 is about the same as the voltage on pin 3. If in balance the voltage on pin 2 shall be 2.5 V as well. Since pin 2 only gets DC from pin 1 also pin 1 needs to be 2.5 V. I think your output was 5 V which cannot be okay. If the output is 5 V then the voltage on in 2 is also 5 V but if the voltage on pin 2 is above the voltage of pin 3 then the output should be 0 and not 5. So it either does not have the feedback via the resistor or the voltage on pin 3 is not 2.5 V. Once these voltages are okay any signal will attempt to raise or lower the voltage on pin 2 and the output with go the other way to compensate and keep pin 2 at 2.5 V. so you will measure almost no signal on pin 2 because the output cancels out the input signal on pin 2. But in doing so the output now has the same signal as the input but with reversed polarity. The amount of feedback is the potentiometer, when set to 1k the amplification is 1x. The amplification is the ratio between the input resistor (1k) and the feedback resistor, for example if the feedback resistance is 2k then the amplfication is 2k/1k = 2 times. This is because the output has to have double the voltage of the input to keep the voltage on pin 2 unchanged (because the opamp keeps the pin 2 voltage to be the same as the pin 3 voltage until it clips to either max or minimum output voltage). Now you also see why the + op the cap needs to be on the Opams side, that pin has 2.5V while this input signal averages to 0. So the Opamp side has the higher voltage.
I still use various trackers to this day, mostly for demos before going into the studio. Great to see they are still used and loved. And I love the 66º North t-shirt! When I lived in London I’d go to Iceland fairly regularly and would always stock up on the 66º North stuff. I think the manufacturer of the sampler has sanded off the information on the IC so it can’t easily be duplicated.
If a chip has been buffed off, you might try a bit of gentian violet on a cotton swab. It might help "raise" the part number enough to read it at least partially under magnification. Swab down with IPA afterward.
Gosh that old sampler is a poor build. No prevention from cable rotation. Learns us all to always take a peek before plugging in. As you said the strobe got torn down when plugged to the new sampler curcuit my backflash into the analog days says us you could have connected two outputs against each other. Either the chips are really not what they should or you caught a wrong pin number. Also I'm a bit surprised the A/D chip digital outputs go towards the port connector without any driver curcuitry, like transistor gates for each line or a driver IC altogether. But I can't be sure. It doesn't matter the whole thing is not working yet, the video is greatly entertaining and encouraging us all to take up similar project. Speaking of... I got my XUM1541 working and it was a software thing only. While it worked on a 1541 first day with a line like: d64copy.exe 8 image.D64 I need to use some partially undocumented arguments for my FNX1591 (being a correct 1581 clone): imgcopy.exe --drive-type=1581 --no-warp -ts2 9 image.D81 Swap the drive digit against the .d64/.d81 name to copy to other way around. This only should there one day be an Arctic episode on how to connect a retro drive rebuild to a modern day PC. ;)
You use a mono jack on a modern cassette player. I'm almost sure they used a stereo socket on the cassette player and shorted left and right. They do this so you can use stereo headphones and not only have sound in the left ear. Your mono jack will short the right channel to ground and with that short the complete signal. So you will have no audio input at all this way, this will never work. Use a stereo jack with left and right shorted on a player like this.
Really nice! I had a good friend who could use the Trackers even blindfolded. Brings back some good memories!
Thanks!
Hi Tommy! I can't believe Norway came in last in Eurovision! I thought the song was fantastic! Cheers from Canada!
Hi! I guess it did not appeal to most others. Personally I did not like it. The second place in the Norwegian final was much better :)
To check the Opamp circuit. Without any audio.
Pin 3 should be around 2.5 V because of the two 1k resistors that divide the 5V power in half. If not that the resistors are not installed correctly or do not make contact.
The Opamp should be in balance to amplify an analog signal, which means that pin 2 needs to be 2.5 V too. The Opams just ampllifies the slightest difference between pin 2 and 3. If the voltage on pin 2 is higher than pin 3 the output is low. Id the voltage on pin 2 is lower than pin 3 then the output is high. If the output is between 0 and 5 volt the that is only possible if the voltage op pin 2 is about the same as the voltage on pin 3. If in balance the voltage on pin 2 shall be 2.5 V as well.
Since pin 2 only gets DC from pin 1 also pin 1 needs to be 2.5 V.
I think your output was 5 V which cannot be okay. If the output is 5 V then the voltage on in 2 is also 5 V but if the voltage on pin 2 is above the voltage of pin 3 then the output should be 0 and not 5. So it either does not have the feedback via the resistor or the voltage on pin 3 is not 2.5 V.
Once these voltages are okay any signal will attempt to raise or lower the voltage on pin 2 and the output with go the other way to compensate and keep pin 2 at 2.5 V. so you will measure almost no signal on pin 2 because the output cancels out the input signal on pin 2. But in doing so the output now has the same signal as the input but with reversed polarity.
The amount of feedback is the potentiometer, when set to 1k the amplification is 1x. The amplification is the ratio between the input resistor (1k) and the feedback resistor, for example if the feedback resistance is 2k then the amplfication is 2k/1k = 2 times. This is because the output has to have double the voltage of the input to keep the voltage on pin 2 unchanged (because the opamp keeps the pin 2 voltage to be the same as the pin 3 voltage until it clips to either max or minimum output voltage).
Now you also see why the + op the cap needs to be on the Opams side, that pin has 2.5V while this input signal averages to 0. So the Opamp side has the higher voltage.
Thanks for the info. I'll check it out
I still use various trackers to this day, mostly for demos before going into the studio. Great to see they are still used and loved. And I love the 66º North t-shirt! When I lived in London I’d go to Iceland fairly regularly and would always stock up on the 66º North stuff. I think the manufacturer of the sampler has sanded off the information on the IC so it can’t easily be duplicated.
If a chip has been buffed off, you might try a bit of gentian violet on a cotton swab. It might help "raise" the part number enough to read it at least partially under magnification. Swab down with IPA afterward.
Thanks for sharing!
Nice job Tommy! Every job dosent work out.
You got that right! Thanks!
The chips have been sanded down. This is a typical method to prevent replication!
Yep exactly. The cost of parts to build a sampler was about $5 back in the day. Sanding the chips down stopped many people from building their own.
Ok, thank you :)
Gosh that old sampler is a poor build. No prevention from cable rotation. Learns us all to always take a peek before plugging in.
As you said the strobe got torn down when plugged to the new sampler curcuit my backflash into the analog days says us you could have connected two outputs against each other. Either the chips are really not what they should or you caught a wrong pin number. Also I'm a bit surprised the A/D chip digital outputs go towards the port connector without any driver curcuitry, like transistor gates for each line or a driver IC altogether. But I can't be sure.
It doesn't matter the whole thing is not working yet, the video is greatly entertaining and encouraging us all to take up similar project. Speaking of... I got my XUM1541 working and it was a software thing only. While it worked on a 1541 first day with a line like:
d64copy.exe 8 image.D64
I need to use some partially undocumented arguments for my FNX1591 (being a correct 1581 clone):
imgcopy.exe --drive-type=1581 --no-warp -ts2 9 image.D81
Swap the drive digit against the .d64/.d81 name to copy to other way around. This only should there one day be an Arctic episode on how to connect a retro drive rebuild to a modern day PC. ;)
Thanks for the info :)
Nice video ❤
Thanks 🤗
I have the DSS8+. Currently its not working on my A600. Not sure if its because of Workbench 2.0
nice video my love❤❤
Our old friend the broken flat ribbon cable?🤨
How much did (or would if you got it free) that 1581 case cost.
Not sure, I got more parts than I needed. I guess around 80 USD
You use a mono jack on a modern cassette player. I'm almost sure they used a stereo socket on the cassette player and shorted left and right. They do this so you can use stereo headphones and not only have sound in the left ear. Your mono jack will short the right channel to ground and with that short the complete signal. So you will have no audio input at all this way, this will never work. Use a stereo jack with left and right shorted on a player like this.
Thanks!