EHX - Small Clone - Difference in schematic !?
Gentlemen, I have the following question.
On the internet I see a difference in the schematics of the small clone.
I am talking about the Tonepad schematic and the original EHX schematic.
With the version of Tonepad, pin 2 of ic1 is connected via a network of 6k8 and a 10nF to 4.5V.
On the original version, this network is not connected to 4.5V but to GND!?!
Which of the two is right ?!
On the internet I see a difference in the schematics of the small clone.
I am talking about the Tonepad schematic and the original EHX schematic.
With the version of Tonepad, pin 2 of ic1 is connected via a network of 6k8 and a 10nF to 4.5V.
On the original version, this network is not connected to 4.5V but to GND!?!
Which of the two is right ?!
- mictester
- Old Solderhand
Information
It's part of the gain setting for the op-amp. The gain is determined by the feedback resistance divided by the resistance to ground (or half rail - both are at AC ground) plus 1 (not that this will be significant). The capacitor gives frequency dependent gain, as the impedance of the capacitor reduces as the frequency rises - this will give (effectively) treble boost. The output stage has a corresponding treble cut network, to give an overall flat response, but the signal to noise ratio is improved, since most of the noise is at high frequency..... It's a simple and cheap noise reduction circuit.
"Why is it humming?" "Because it doesn't know the words!"