Mx50se and mur860g

[Mcass]

Hi guys so I built my mur860g rectifier board question is this I’m new to building amp kits I have Mx50se x2 built ready to go i have a toroidal transformer putting out 38x2 when I put power . 38x2 to my mur860g rectifier board power supply I’m getting 52x2 dc which is to much for my Mx50se’s question is is it supposed to increase my voltage?? And if so I guess I have to now get anew toroidal probably like 30x2 would this fix the problem or could I have screwed up some how on my build?? Thank u for any input in advance...

 

[rayma]

i have a toroidal transformer putting out 38x2 when I put power . 38x2 to my mur860g
rectifier board power supply I’m getting 52x2 dc which is to much for my Mx50se’s

The 38VAC is AC rms (average) voltage, and the rectified 52VDC is from the peak input voltage.
Then 38VAC x sqrt(2) = 38VAC x 1.414 = 53.7Vpeak. Then you subtract the diode drops (1.2V)
and get the 52VDC. Sounds like you need a lower voltage transformer.

What DC voltages do you want, and what is the power supply circuit?

 

[Mcass]

So I would like to have about 35 to 40 V DC

 

[rayma]

So I would like to have about 35 to 40 V DC

Here are some standard transformer secondary voltages.
Your DC voltage would be a volt or two less due to diode drops.
Remember that your line voltage could vary up to +/- 10% also.
18 x 1.414 = 25.5
22 x 1.414 = 31.1
25 x 1.414 = 35.5
30 x 1.414 = 42.4

 

[Mcass]

Yes thank u very much I just ordered 25x2 I’m getting excited When I learn how to post pics I will show you how my amp is looking Thank you again for your input

 

[rayma]

Yes thank u very much I just ordered 25x2 I’m getting excited When I learn how to
post pics I will show you how my amp is looking Thank you again for your input

Do you have a DVM, scope, and generator for testing?

 

[Mcass]

No I don’t and really don’t know how to test things that good... voltage and continuity is about all I know . But very willing to learn . I am a electrician but trade that’s what I do. I’ve started building amps as a hobby and I am amazed by it .

 

[rayma]

No I don’t and really don’t know how to test things that good... voltage and continuity
is about all I know . But very willing to learn . I am a electrician but trade that’s what I do.
I’ve started building amps as a hobby and I am amazed by it .

Then you'll have to be very slow, careful, and methodical.
However, you'll almost certainly still need a passable digital voltmeter.

Can you post the schematics of what you are currently building?

 

[Mcass]

So what I am building it is called the MX 50 SE it is all over the Internet you can find the schematics on them I am basically buying modules and circuits putting them together and then wiring them as I am showed to do and it has been very Successful thus far but if you could check the schematics and see if there is something I have missed let me know I will let you know everything that I have

 

[rayma]

I will let you know everything that I have

Can you post the links here? Thanks.

 

[phase]

I was looking at a rectifier board on evilbay that has what are described as mur860, however, the picture doesn’t exactly match the data sheet examples. I was going to get one just for the board, and use other diodes. Seemed a fair deal for $3.99.

Isn’t that mx50se a clone of the blameless amp from Doug Self?