opl3 with +/-5V

MIDIbox FM
1

hello,

you say “The TL074s can be alternatively powered from +/-5V to +/-18V.”

So, is it possible to make an OPL3 Module with +/-5V instead of +/12V?

If yes, what modifications should i do to the OPL3 Module?

thanks!

2

Hi,

there are no modifications required for +/- 5V, the TL074 works fine in this voltage range.

Best Regards, Thorsten.

3

Thanks,

Congratulations for your work!

4

Hi.

I may be way out of line here, but from my experience, opamps such as the TL074 work much better with higher supply rails.

You can absolutely use +/-5V rails, but be aware the noise and distortion figures may be compromised.

Good luck!

Matt

5

On a related note, anyone knows of a _small_  =+12/center/-12 transfo with enough amperage to drive the three opamp, that

would FIT inside a 1U rack???  Ive got two of them from different manufacturers, but they are way too big (one is 2A and the other 1A)

Cheers

6

I was lazy (read as: sick of perfboarding), so I picked up this kit: http://www.rpelectronics.com/English/Content/Items/CK342.asp

And the recommended transformer:

http://www.rpelectronics.com/English/Content/Items/640-1803.asp

IIRC it’s short enough to fit in a 1U rack, but I would have to go home and measure it to make sure (it’s sitting in a drawer right now, waiting for me to have more free time).  This is only going to be enough juice to handle the +/-12V easily, but possibly not the +5V if you’re using a backlit LCD.  And as always, remember to use fuses, etc.

7

I was lazy (read as: sick of perfboarding), so I picked up this kit: http://www.rpelectronics.com/English/Content/Items/CK342.asp

And the recommended transformer:

http://www.rpelectronics.com/English/Content/Items/640-1803.asp

IIRC it’s short enough to fit in a 1U rack, but I would have to go home and measure it to make sure (it’s sitting in a drawer right now, waiting for me to have more free time).  This is only going to be enough juice to handle the +/-12V easily, but possibly not the +5V if you’re using a backlit LCD.  And as always, remember to use fuses, etc.

Wow, if i had known, i would have bought this pre made kit too!

Id be currious on the dimensions of the transformator, ill wait for the results.

Im using a separate transfo for the normal MB operations.

8

IIRC it’s short enough to fit in a 1U rack, but I would have to go home and measure it to make sure (it’s sitting in a drawer right now, waiting for me to have more free time).  This is only going to be enough juice to handle the +/-12V easily, but possibly not the +5V if you’re using a backlit LCD.  And as always, remember to use fuses, etc.

Well, it’s a pleasantly small transformer, smaller than I remembered.  36mm tall, that is about 1.4" high, which should still give you enough clearance to put it into a 1U rack case.

9

Well, it’s a pleasantly small transformer, smaller than I remembered.  36mm tall, that is about 1.4" high, which should still give you enough clearance to put it into a 1U rack case.

What about the 12VCT / 300mA Transformer from that same dealer:

http://www.rpelectronics.com/English/Content/Items/640-1203.asp

12VCT should be enough to drive a 7912 and a 7812? and wouldn’t generate as much heat as the

18VCT.. in any case ill order both of them and report.

Thanks again for the dimensions!