Those resistance readings are a tad inconsistent. The reading on the master bed (with 2 speakers) should in theory be about half the reading for the upstairs landing.
I make the difference 4, is that something that would cause concern? Well your numbers on the post were master bed 181.5, upstairs landing .359, so a difference of 181.2!. It is intriguing- always dicey using DC for transformer impedance but some consistency would be reassuring.
I know there are issues with metering transformers using DC. I'm really intrigued by the reading on 1-4, they look too high for a transformer and too low for 8 ohm speakers. Your original amp wanted a minimum system impedance of about 50 ohms (which sounds right- at 50 ohms the total current would be 2 amps).
What could likely be causing these readings? Dunno
Just had another look at the pic of the speaker- can you remember what wires are in which hole in the terminal block? The BLUE coming in should connect to BLACK speaker, the BROWN coming in should connect to RED or YELLOW (speaker). From that pic it looks as if the RED and YELLOW might be connected to BROWN, which wouldn't be good.
I’ve just had another look at that speaker and the wires are correct thankfully. Good, as long as red OR yellow are connected then that's not the problem
We still haven't got to the bottom of why you've lost 2 amplifiers- you might want to try some current measurements (using the AMPS setting on your new meter). The lightbulb will act as quite a useful fuse but will also reduce the overall useful system output (since it'll be converting a good chunk of your audio signal into light and heat).
Im sorry but would you mind explaining this and the below process for me. As I do not understand what I need to do. I suspect the impedance on your system is lower than the amplifier requires, causing the circuit to be carrying more current than the amp is rated for. Those meter readings you've done tell me there are no short circuits between the volume controls and the loudspeakers but the inconsistent readings are troubling. The light bulb (in series with the system) will guarantee that the total system impedance exceeds the minimum required and thus limits the current to below what the amp is rated for. It will make the system quieter though since it will be converting up to 100 watts into light and heat (instead of into sound).
Have you measured the resistance presented to the amplifier yet? I don't think you'll get a realistic number but it should be greater than zero. You could also try some tone and volt experiments. With amplifier powered up but NOT connected to speakers, find a test tone on your replay device, play it, adjust input controls etc til the amp appears to be doing something and check the voltage at the 100v terminals (on the back of the amp) (Reason for tone= you should get a fairly constant voltage).
OK, you have working amplifier- excellent. We'll skip voltage and go for current measuring instead
- Have a look at the instructions (with your meter) for measuring current (you usually need to swap the LIVE probe from V/ohms hole to the 10A hole).
- Switch the amplifier off
- Disconnect the '100v' output from the amplifier (brown cable(s))
- Connect the COM (black) probe to the 100v output on the amplifier
- Connect the 10A (red) probe to the brown speaker cable(s)
- Switch the amplifier back on
- Find a test tone on Spotify or in any half decent audio program- play it through your speakers at a audible but not deafening level
- See how much current is running
- Turn the level of your test tone up till the speakers are delivering what you reckon is the loudest you'll ever want the things
- See how much current is running
With your setup you should be running at 1 amp maximum (you've only got 10 speakers at 6W apiece). If it is a bit higher don't worry. If it is a lot higher there's still a problem, wire the 100w light bulb in series with the speakers and repeat the above tests.
Many thanks as always,
Devs.
P.S just going back to the non functioning volume control that I moved into the kitchen. Should I be seeking to replace this? Am I likely to have blown it?
Attached is how it is currently wired and what I believe is correct? Previously I have the last two wires swapped around. My question is.. Have I damaged this volume control and need to replace or is it still wired incorrectly?
