Eddie Current DIY amplifier "Monolith"
Nov 16, 2013 at 3:28 PM Post #166 of 172
 
Thanks!

 
I have to wait for the opamp and the input transformer for ending the amp!
 
shipsupt, do you already compare the monolith with an other amp?
 
Jan 16, 2014 at 6:39 PM Post #168 of 172

 
oops
The household voltage in my place has been always on the high side.
Victim No.1 is one of the diode on the psu. After replacing both of them neither channel is working.
Hooked up with a oscilloscope every channel looks like this with 1k sine wave input.
Did I broken all the OPs?
 
Feb 7, 2014 at 11:29 PM Post #170 of 172
Well, I have to share how I fixed it.
The amp is oscillating, it appears as output wave when turned on, but soon output straight dc keeps increasing until it's 13v(L- L+ R+ R-) to the ground.
As I trace the signal with osocpe probe I realize everytime the probe connect to anything along the signal path feeds into the opamp will zero the dc offset.
Considering the oscope probe as a 1m resistor to the ground I added 4 100k resistors to ground on each signal path before R6 R7 R13 R14. Problem solved.

 
Apr 28, 2014 at 2:38 PM Post #171 of 172
My Monolith is done but when my potentiometer is at 0, I have sound and I have a difference of 1V between my left and right channel. Someone could check the voltage on the headphone output?
 
Dec 7, 2014 at 7:57 AM Post #172 of 172
  I really like it with the HD800.  Very open and dynamic, if just a bit on the bright side.  I've taken to adding just a slight touch of EQ with this set up.  
 
I'm looking forward to getting the Slant I ordered to try it with an orthodynamic.  

 
The Monolith is a little bright with the LCD-3 Fazor so I'm pretty sure it's the same with the HD800... But yes it probably sounds really good with the Sennheiser, with a nice soundstage.
I want to hear it with a LCD2.2 !!!
 
As discussed with Ony, the next step is to try a better PSU. But firstly, time to order an enclosure...
 

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