This is a pair of completed pc boards (opamp multi-purpose) that are configured for use as direct boxes. The sockets are empty as I have not yet decided what opamp chip to use. I may experiment with several different parts before putting the boxes into regular use in the studio.
If you have purchased the Opamp Multi-Purpose pcb, you should check the construction page again since I have changed a few values on some of the projects. The link was emailed to you after you bought the board.
I have just built one of these and used a NE5534 and changed R1 to 4K7 and R2 to 47K and it suodns great but what I would like to know, is there a way of cutting the highs by changing any of the components rather than having to add a tone control? Cheers.
Tom,
Add a capacitor in the C3 position. A 1000pF will set the highs to roll off at about 16kHz.
If you use a larger value capacitor, then the corner frequency will move down. A 2200pF capacitor sets it at about 7.2kHz.
You can try a few values and test by listening to see what you like.
regards, Jack