MFOS mixer headphone amp problem

lexvortex · Joined: May 14, 2008 Posts: 155 Location: Toronto

Hi,

I built the MFOS mixer a while ago and really like it, but the headphone amp is really noisy and it picks up signals from my other modules in the cabinet, like the clicking from my ADSR when it is set for a fast attack and decay or the frequency modulation from my JH freq shifter, this happens even if the modules are not being used. I don't have a problem with the regular stereo outputs.

Is there a better IC or maybe something I can do to minimize the cross talk and reduce the noise?

Thanks,
Dave

druish · Joined: Jun 23, 2009 Posts: 91 Location: New Paltz NY

Shielded cables and better power supply decoupling or use separate PS.

L-1 · Posted: Thu Jul 14, 2011 12:11 am Post subject:

I have finished this mixer now. I used shielded cables. But headphones amp is very noisy too. This problem have solution or better to build another amp?

Gaetano_AU · Joined: Oct 08, 2011 Posts: 64 Location: Australia

I had the same problem. Just use *** 35v Tantulum Caps *** and NOT Electrolytics.

C75 & C76 - 10uF 35v Tantalum caps, AND

C55 & C61 - 1uF 35v Tantalum caps for the best results.

The amp can then cleanly run a small set of speakers like an ARP 2600!

08_Speakers.jpg

Description:

Filesize:

836.58 KB

Viewed:

143 Time(s)

This image has been reduced to fit the page. Click on it to enlarge.