Hello,
my LM1875 chipamp kit - a stereo integrated am with alps pot and a 160va 2x18v transformer, and the 2x1500µf stock cap on psu board - produce a strong plock when I turn it off ; any input about this trouble ? I solder on the snubber parts, which is not necessary with the 2x1500µf configuration, is this the cause of my problem ?
my LM1875 chipamp kit - a stereo integrated am with alps pot and a 160va 2x18v transformer, and the 2x1500µf stock cap on psu board - produce a strong plock when I turn it off ; any input about this trouble ? I solder on the snubber parts, which is not necessary with the 2x1500µf configuration, is this the cause of my problem ?
I don't think the 1875 has a mute function.
You might have to fit a relay switched output to the speaker terminals.
This can double up as an delayed switch on to give time for the other parts in the system to reach a quiet state and can also be used as a speaker protection relay in the unlikely event of speaker damaging faults developing.
You might have to fit a relay switched output to the speaker terminals.
This can double up as an delayed switch on to give time for the other parts in the system to reach a quiet state and can also be used as a speaker protection relay in the unlikely event of speaker damaging faults developing.
Hey guys, I've been reading through the threads and I've got the amp 1875 here ready to power up but I'm confused as to how to wire up the transformer. I'm using the 18v version of this transformer http://www.jaycar.com.au/products_uploaded/MT2086 - Modified.pdf Now the PSU board has AC1, AC1 with bar, AC2 and AC2 with bar, now I understand AC1 is secondary 1 and AC2 is secondary 2 but I don't know what the bar represents I thought maybe it was essentially the neutral/ground/0v wire, but then AC1 bar goes into the same trace as AC2 no bar. So I would end up with my 0v wire from the first secondary going into the same trace as the 15v wire from the second secondary which just didn't make sense to me.
Help!
Thanks
Luke
Help!
Thanks
Luke
So it doesn't matter which wire goes where as long as the polarity is the same going into both the AC1 and AC2 spots and my polarity out right at the other end of the PS.
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So the ouputs on my Toroid are as such, and I should be able to wire the PS as I've tried to show.
````___`````___
AC1 AC1 AC2 AC2
0 - - 15v 0 - - 15v
Yel - RED Wht - Pur
Does that make sense, is that going to be correct?
I guess my confusion is around the fact that the Red 15v and Wht 0v are going into the same trace and I guess in my mind I'm used to dealing with DC it's like trying to connect a Ground/negative and Power/positive onto the same terminal. I think I'm just over thinking the whole process.
````___`````___
AC1 AC1 AC2 AC2
0 - - 15v 0 - - 15v
Yel - RED Wht - Pur
Does that make sense, is that going to be correct?
I guess my confusion is around the fact that the Red 15v and Wht 0v are going into the same trace and I guess in my mind I'm used to dealing with DC it's like trying to connect a Ground/negative and Power/positive onto the same terminal. I think I'm just over thinking the whole process.
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use the light bulb tester and you will not damage anything if you wire it wrong.
It will also allow you to measure some voltages so you can confirm it is correct or needs to be altered.
A transformer can be badly damaged if the twin primaries get phase reversed and/or the twin secondaries get phase reversed. The light bulb prevents damage in all 3 cases.
It will also allow you to measure some voltages so you can confirm it is correct or needs to be altered.
A transformer can be badly damaged if the twin primaries get phase reversed and/or the twin secondaries get phase reversed. The light bulb prevents damage in all 3 cases.
You are correct. The LM1875 only uses a single bridge rectifier, vs the LM3886 which uses a dual bridge rectifier setup.
--
Brian
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