AMB Laboratories DIY Audio

[jtostenr]

So I go to turn on the S22 this evening and the E24 decides it's not going to stay powered on. I didn't make any changes, so I'm not sure why it would just stop working. Everything gets power (even the button LED) as long as I hold the button in. Once I let go, everything loses power (except for S25 ofc, which is not using the E24).

Edit: I checked the output of the LM7812 and it is 12V as expected. Next I will see what happens if I connect a resistor in place of the SSR.

Any ideas?

Jeff

[amb]

You're using a solid state relay. SSR's require a certain amount of load current to work properly. If your σ22 is not connected to any load (i.e., the amp boards), then that's why.

[jtostenr]

It seemed to work fine yesterday....not sure why it wouldn't work now. I'll hook up a board and try it out.

[jtostenr]

I hooked up all 4 B22 boards and still no dice. I guess I will stop buy RS and pick up a resistor to put in place of the relay to verify the E24 is working.

Not sure if it matters, but I populated all the parts required to use the thermal breakers, but I have not included them yet. So I have the appropriate pins shorted as directed on the website. Should I bother pulling these extra parts out? I wouldn't think it mattered since initially, everything worked fine.

[amb]

I hooked up all 4 B22 boards and still no dice. I guess I will stop buy RS and pick up a resistor to put in place of the relay to verify the E24 is working.

Just measure the DC voltage across the RLY+ and RLY- terminals on the ε24. You should get ~12V when the power is supposed to be "on", and close to 0V when "off".

Not sure if it matters, but I populated all the parts required to use the thermal breakers, but I have not included them yet. So I have the appropriate pins shorted as directed on the website. Should I bother pulling these extra parts out? I wouldn't think it mattered since initially, everything worked fine.

No, you don't need to remove all those parts. Simply jumpering across J2C should be enough.

[jtostenr]

ok, I measured about 0V and 12V on the terminals of the relay coming from RLY+ and RLY-. Maybe once every ten tries or so, it will actually work and stay on. I found that if I push the button too many times in a short period of time though, the light won't come on anymore. Once I wait a few seconds and push the button again, the light will come on.

I hate intermittent issues like this. I thought maybe there was a bad connection or something, but I couldn't find anything. I think I am going to order the Bulgin switch most people use just so I can rule out any bad (or wrong type) switch issue.

Edit: Here are the specs for the switch I am using (MP0045/1D2/012/BL) http://www.bulgin.co.uk/Products/Switch ... Switch.pdf
Do you see any reason why this switch wouldn't work with the E24?

[amb]

ok, I measured about 0V and 12V on the terminals of the relay coming from RLY+ and RLY-. Maybe once every ten tries or so, it will actually work and stay on. I found that if I push the button too many times in a short period of time though, the light won't come on anymore. Once I wait a few seconds and push the button again, the light will come on.

There is a time-interval within which repeated button presses would not work. This is by design, to prevent switch contact "bounce" from causing problems.

You said that you "measured about 0V and 12V on the terminals of the relay coming from RLY+ and RLY-". Does it reliably go to 12V when it's supposed to be "on" and drop to 0V when "off"? Is there any case where there is 12V across RLY+ and RLY- but the amp does not turn on? That would suggest that the ε24 is working but the solid-state relay isn't getting triggered.

Edit: Here are the specs for the switch I am using (MP0045/1D2/012/BL) http://www.bulgin.co.uk/Products/Switch ... Switch.pdf
Do you see any reason why this switch wouldn't work with the E24?

No problem with that switch... I am using the same switch on my new preamp.

[jtostenr]

You said that you "measured about 0V and 12V on the terminals of the relay coming from RLY+ and RLY-". Does it reliably go to 12V when it's supposed to be "on" and drop to 0V when "off"? Is there any case where there is 12V across RLY+ and RLY- but the amp does not turn on? That would suggest that the ε24 is working but the solid-state relay isn't getting triggered.

Usually, when i push the button, it will act as a momentary switch and the RLY terminals will go to 12V for a split second. If I push and hold the switch (but not push too far) it will stay at 12V. It seems strange to me that by pushing the button further in it turns off.

[amb]

Usually, when i push the button, it will act as a momentary switch and the RLY terminals will go to 12V for a split second. If I push and hold the switch (but not push too far) it will stay at 12V. It seems strange to me that by pushing the button further in it turns off.

I haven't actually tested it yet, but by feel, this switch seems to have two "steps" as you press it. It'd be interesting to see what those translate to in terms of electrical connectivity, because the switch has both normally-open and normally-closed contacts. Which terminals of the switch are you using to wire up to the ε24?

[jtostenr]

I used the NO contacts like the website said to do. I can pull the switch out tonight and see exactly what it does depending on how far you push the button. Before I initially installed it, I did do a quick check to make sure it was functional, but that was it.