Hi guys, please go easy as this is my second build and I'm still a bit dyslexic with regards the primary and secondary wiring basics. I'm confident with safe IEC wiring and the on/off switch but lost on the power supply board wire colours.
In the pic attached what colours do I put in 1 2 3 4 on the power board module?
(I've just positioned it like that for ease of viewing)
Thanks in advance for anyone with the knowledge and patience to help.
Also please ignore the two small bottom green circuit boards as these I don't want, so just imagine the pic with the tranny wires all loose.
In the pic attached what colours do I put in 1 2 3 4 on the power board module?
(I've just positioned it like that for ease of viewing)
Thanks in advance for anyone with the knowledge and patience to help.
Also please ignore the two small bottom green circuit boards as these I don't want, so just imagine the pic with the tranny wires all loose.
1 & 2 is one high power winding for one supply rail.
3 & 4 is the other power winding for the other supply rail.
5 & 6 is for the low voltage, low current winding.
Secondary wiring only! The mains primary is not on that board.
3 & 4 is the other power winding for the other supply rail.
5 & 6 is for the low voltage, low current winding.
Secondary wiring only! The mains primary is not on that board.
Thanks for replying! Ignoring 5 & 6 as low current not needed. What colours in the pic go to 1 2 3 4? Looking at the second pic I've attached do any of those need to be twisted together and soldered together and heat shrinked? Thanks for your patience!
Also read this to see the method of identifying windings and phase:
Post #11
https://www.diyaudio.com/community/...noyed-by-stupid-questions.360754/post-6359226
Post #11
https://www.diyaudio.com/community/...noyed-by-stupid-questions.360754/post-6359226
So you need to identify the windings as in the post I linked to. Just substitute the word Red in that post for one of the leads on your transformer and work through the steps to set the phase correctly. The two wires that end up joined together are the ones that go to pins 2 and 3 on your board.
Cheers! The original Rotel wiring (I'm using a Rotel RB-1070 for the chassis and tranny) appears numbered here, you see 1234 white, green, orange, yellow in the pic attached. Following this just leaves a loose red wire and the primary thick red, orange, black wires cable tied together.
I won't be testing the amp until I'm absolutely positive that I've wired it correctly.
I would recommend you run the transformer alone (not connected to anything else) and with a DBT (dim bulb tester) in the primary. When you have the primary wires correct you will see the expected AC voltage as measured from the centre join to each of the two other wires and you will see twice that voltage as measured end to end.
Only when you are happy with that should you think of connecting it all to the board.
(working from pictures is not always easy tbh, circuit diagrams every time 😉)
Only when you are happy with that should you think of connecting it all to the board.
(working from pictures is not always easy tbh, circuit diagrams every time 😉)
We can tell from that (-/+55 volt DC) that the transformer must be 55/1.414 which is 39 volts... I see you just posted... and it shows 40 volts AC. That may be a little higher off load.
The secondary wires are the 3 slightly thicker wires still tied together with the cable tie ( orange , black and red ) connect these thus :-
orange to AC1
black to AC2
red to AC4
AC2 is spare
The primary wires are the group of 7 which were connected to connectors 3 and 4 , connect these thus :-
brown to mains positive
white to mains negative
solder yellow and orange together double insulate and isolate
green , red and blue are spare BUT STILL LIVE WITH MAINS POTENTIAL so individually double insulate and isolate . Dont cut the wires overly short in case I have made a mistake though I have double checked .
Ps the Rotel transformer has 42V secondaries
orange to AC1
black to AC2
red to AC4
AC2 is spare
The primary wires are the group of 7 which were connected to connectors 3 and 4 , connect these thus :-
brown to mains positive
white to mains negative
solder yellow and orange together double insulate and isolate
green , red and blue are spare BUT STILL LIVE WITH MAINS POTENTIAL so individually double insulate and isolate . Dont cut the wires overly short in case I have made a mistake though I have double checked .
Ps the Rotel transformer has 42V secondaries
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Thanks for replying and your help! You helped me with the basics on my first build last year which is still going strong and my main amp.
I seem to struggle with learning and memorising in this area of construction.
I followed your instructions and the amp is all wired up and working perfectly on one channel but the other channel is pulsing the speaker. Pushing the cone outwards in short precise bursts with no music behind it just silence and the pulsing bursts. Can you think what I may have done wrong, the other channel sounds so good! It's really annoying.
I've just fixed the issue, I'm not sure why but a stray blob of solder on one fuse contact appears to have been causing the pulsing. Both channels are running dead silent now and music sounds brilliant! Thanks to everyone who helped me out!