Hi all,
I'm trying to get 2.1 output from my Sony TV which has a mini-jack as a line out. I've been using 2 Kef eggs, powered off a TPA3132 amp. That's worked well, but is very boomy with any low frequency signals.
So I just bought a used Kef 30B sub, so I could input the line signal from the TV into the sub high level inputs and use the high level outputs to route high frequency signals to the Kef eggs via the TPA3132.
When I tried it, I got a terrible hum. I tried different RCA cables to no effect. Then I used my phone as the source and the hum vanished, so it's definitely to do with the TV, but there was no hum with the sub not in the chain.
Does anyone know what's going on and if there's anything I can do about it?
Thanks.
I'm trying to get 2.1 output from my Sony TV which has a mini-jack as a line out. I've been using 2 Kef eggs, powered off a TPA3132 amp. That's worked well, but is very boomy with any low frequency signals.
So I just bought a used Kef 30B sub, so I could input the line signal from the TV into the sub high level inputs and use the high level outputs to route high frequency signals to the Kef eggs via the TPA3132.
When I tried it, I got a terrible hum. I tried different RCA cables to no effect. Then I used my phone as the source and the hum vanished, so it's definitely to do with the TV, but there was no hum with the sub not in the chain.
Does anyone know what's going on and if there's anything I can do about it?
Thanks.
For a simple but relatively expensive fix (2nd hand may be allot cheaper) you can buy a Jenson SUB-1RR (ISO-MAX), this fixed my small him with all of my pro amps that I have in my HT system and I was so impressed I thought there was magic inside!
You can try different power points, run a piece of wire from tv-amp as an earth or even remove an earth pin on the power plug if they have one but 9 times out of ten it will be there for good like my system. You could try buying cheap hum destroyers but it's a set frequency that is generally interfering so if they don't work the SUB-1RR is the best bet.
Good luck though as I've had it both in my car and my home theatre and there is nothing worse...
You can try different power points, run a piece of wire from tv-amp as an earth or even remove an earth pin on the power plug if they have one but 9 times out of ten it will be there for good like my system. You could try buying cheap hum destroyers but it's a set frequency that is generally interfering so if they don't work the SUB-1RR is the best bet.
Good luck though as I've had it both in my car and my home theatre and there is nothing worse...
Thanks bjc, but that's out of my price range (I'm currently out of work).
I don't really want to disconnect any safety earth pins as, well, it will make everything unsafe!
I did try a different power socket, but it made no difference (probably as the only ones within reach are on the same circuit).
I don't really want to disconnect any safety earth pins as, well, it will make everything unsafe!
I did try a different power socket, but it made no difference (probably as the only ones within reach are on the same circuit).
The joys of unbalanced signal lines.
If you remove the earth in your 13A plugtop and fit a 3A fuse and two 1N5401 diodes back to back (in parallel) and a 100R resistor across the pair in series with the earth wire and earth pin, that will remove the current source and with the diodes back to back and clamp any potential earth faults to 0.7V maximum.
If you remove the earth in your 13A plugtop and fit a 3A fuse and two 1N5401 diodes back to back (in parallel) and a 100R resistor across the pair in series with the earth wire and earth pin, that will remove the current source and with the diodes back to back and clamp any potential earth faults to 0.7V maximum.
Should be somewhere near your electricity meter. Looks like a circuit breaker, but will have two current ratings, one big (63A or whatever) and one small (30mA is common). The small one is the maximum difference between live and neutral before it shuts everything down.
For example, if you grab a live wire, you might pass 100mA to ground, which would be 100mA going out on live that isn't coming back on neutral. The RCB would open and save your life.
Chris
For example, if you grab a live wire, you might pass 100mA to ground, which would be 100mA going out on live that isn't coming back on neutral. The RCB would open and save your life.
Chris
No. We have had a new meter fitted, but the consumer unit is the same one we've had for forty years or so. Just fuse wire fuses.
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