Installing a headphone jack with volume control in MB6582

MIDIbox SID
1

  1. Is it safe to connect headphones directly to the mixed output pin on the baseboard of the MB6582, or should I connect some headphone driver?

  2. How can I install a volume control to the headphone jack? Is a normal potentiometer in series (or parallel?) good enough, and if so, what value would be reasonable? I don’t need to make it louder, but lower.

2

The installed BC547 transistor on the MBSID is not meant as an amplifier, rather a protection for the SIDs - thus the output can only be considered a “line” out. 

 

But, as for many line out devices, the output levels were high enough for small normal “ipod” headphones for me.

If you intend to use larger headphones with bigger “drivers”, I´d strongly recommend to use a headphone amp (which usually also offers volume control). You can reduce volume levels by using a stereo logarithmic potentiometer, of e.g. 10k, 50k, or 100k value.

 

Many greets,

Peter

3

Cool! I want to drive my big phones, so I guess I’d better getting a good driver then. Any suggestions? Thanks!

4

DIYing them can save a lot of bucks for good quality:

http://www.head-fi.org/t/537398/list-of-diy-headphone-amplifiers

 

There you´ll find the full spectrum from solid state, hybrids, tube-driven and portable ones :smile:

 

I´ve read good things about the CMOY portable one, it can also be used to properly drive your bigger sized quality phones when you are on road/plane with a tiny mp3 player/phone.

It is driven by 4560 opamps, uses two 9v batteries for a bipolar supply with lots of headroom and fits into a metal tin box :slight_smile:

http://en.wikipedia.org/wiki/CMoy