Excellent video. Mine has this same problem. Reading the comments I think most do. I was so happy the day I realized you could buy a DivMMC. Not because of this issue but I used to get so frustrated trying to load games from tape and having them fail over and over.
The problem is poor layout of the tape deck PCB. It can actually be quietened down a lot by some fairly simple mods, involving an extra capacitor, and cutting/rerouting some ground tracks with wire
Would be worth scoping the power supply when it's under load. I wouldn't be surprised if the smoothing cap in the PSU is on its way out. That's definitely 50hz hum that you can hear. I'd be interested to know if it's always present. If it is, it's almost certainly coming from the power supply;
Chances are I filmed that shot using the bench supply with is most definitely cheap and noisy and would have exaggerated the issue, which is good for demonstration purposes at least!
Excellent mod! That relay maybe flush it on the board with double sided tape. If one day you have to replace it if it's glued on the board you may damage the board.
Very Nice indeed. I have an Issue 1 Grey +2 with the 377 tape board. Presumably I can just follow the attachment points for the motor and ULA wire and do the same? I am also going to install an external ear port for PlayZX / TZXDuino - this denoising won't affect that as it doesn't need the motor to be activated to input a signal?
Blimey. I keep buying old broken computers off EBay for some reason. I`ve got a 128k 2 coming Saturday lol. I got an Amstrad cpc 464 at the weekend that needs new ram. I was thinking of making a copper U shaped piece to un solder the 16 pin chips that attaches to a 6mm soldering iron. See how it goes. :)
nice solution, one thing i have done in the past is to increase the resistor from tape to sound output jack/scart so it reduces tape audio but does not effect signal to ULA (think R80 from 10k to 270k) obvious draw back that the loading sound is quieter or some people may see it as an advantage ?
Interesting video, I wasn't aware of this problem with Grey Spectrum's. I'm not sure, but a lot of relays have a diode connected across to them to stop back emf? As I say I'm no expert and it may not be need here, be interested to hear what you think.
Thank you. You can see on the datasheet that this model includes an internal protection diode, this is why there is a polarity indicator on the coil pins. Good question!
Well, here comes the criticism; That's not a Reed Relay, it is just a SPST regular relay. A Reed Relay is magnet activated by proximity to the magnet, there are no coils in it that requires power. And secondly, see that diode in the data sheet of the relay? You need that there. The release of the coil winding causes a high voltage discharge that can kill sensitive electronic components, placing a diode (in reverse polarity) across the coil pins of the relay shunts that discharge. Very important, use a 1N4007 there, it can take up to 7000 Volts, which is just adequate, yes that discharge can get that high.
Ah it's such a shame I don't have a time machine to send this video back to me in 1986.
Excellent video. Mine has this same problem. Reading the comments I think most do. I was so happy the day I realized you could buy a DivMMC. Not because of this issue but I used to get so frustrated trying to load games from tape and having them fail over and over.
Hey thanks, just ordered a relay as I just bought a grey spectrum with this very problem.
Excellent! Let us know how you get on.
The problem is poor layout of the tape deck PCB. It can actually be quietened down a lot by some fairly simple mods, involving an extra capacitor, and cutting/rerouting some ground tracks with wire
A good topic for another video
@@HappyLittleDiodes I have pictures and everything ;)
Would be worth scoping the power supply when it's under load. I wouldn't be surprised if the smoothing cap in the PSU is on its way out. That's definitely 50hz hum that you can hear. I'd be interested to know if it's always present. If it is, it's almost certainly coming from the power supply;
Chances are I filmed that shot using the bench supply with is most definitely cheap and noisy and would have exaggerated the issue, which is good for demonstration purposes at least!
Excellent mod! That relay maybe flush it on the board with double sided tape. If one day you have to replace it if it's glued on the board you may damage the board.
Good tip. Fortunately I used gorilla glue which is about as sticky as Colgate
Very Nice indeed. I have an Issue 1 Grey +2 with the 377 tape board. Presumably I can just follow the attachment points for the motor and ULA wire and do the same? I am also going to install an external ear port for PlayZX / TZXDuino - this denoising won't affect that as it doesn't need the motor to be activated to input a signal?
I don't see why not. And yes you should be fine with the external socket 😉
Blimey. I keep buying old broken computers off EBay for some reason. I`ve got a 128k 2 coming Saturday lol. I got an Amstrad cpc 464 at the weekend that needs new ram. I was thinking of making a copper U shaped piece to un solder the 16 pin chips that attaches to a 6mm soldering iron. See how it goes. :)
I've seen that done before! Good luck, are they surface mount?
nice solution, one thing i have done in the past is to increase the resistor from tape to sound output jack/scart so it reduces tape audio but does not effect signal to ULA (think R80 from 10k to 270k) obvious draw back that the loading sound is quieter or some people may see it as an advantage ?
Interesting video, I wasn't aware of this problem with Grey Spectrum's.
I'm not sure, but a lot of relays have a diode connected across to them to stop back emf?
As I say I'm no expert and it may not be need here, be interested to hear what you think.
Thank you. You can see on the datasheet that this model includes an internal protection diode, this is why there is a polarity indicator on the coil pins. Good question!
@@HappyLittleDiodes I missed that bit on the video, must of been dunking some cookies in my coffee......that's my excuse!
Hello how much would you charge to fix this problem on my grey +2 spectrum?
Hi John, send me an email please. happylittlediodes@gmail.com
👍
Well, here comes the criticism; That's not a Reed Relay, it is just a SPST regular relay. A Reed Relay is magnet activated by proximity to the magnet, there are no coils in it that requires power. And secondly, see that diode in the data sheet of the relay? You need that there. The release of the coil winding causes a high voltage discharge that can kill sensitive electronic components, placing a diode (in reverse polarity) across the coil pins of the relay shunts that discharge. Very important, use a 1N4007 there, it can take up to 7000 Volts, which is just adequate, yes that discharge can get that high.
Hi Bora. Appreciate the comment, but check out the datasheet, this is a reed relay with an internal protection diode.