While building the (amazing) O2 objective amp and dac I did some measurements before powering up the unit. This is strongly advised by the guides because it allows me to detect problems and mistakes before adding power, thus hopefully preventing costly burnouts or worse, explosions.
Unfortunately most of the measurements I made were way off from the ones listed in the guides. Here is what I measured:
R1&R2 476 instead of 100-220
R5 191k instead of 100k
R15/18/10/11 240 instead of 1
R16/22 1.55k instead of 1.3k
R7/14/3/20 500 instead of 100-300
(all values are in Ohms)
The measurement device I use is a somewhat expensive voltcraft digital multimeter with a high sampling rate. My suspicion is that this specific MultiMeter is outputting amps while measuring ohms without allowing the amps to drain out before doing another sample. That could result in a higher ohms measurement due to capacitance in the circuit. Unfortunately I did not have a different (digital) MM available to do any measurements with. After checking and triplechecking the placement of the components and the soldering joints I decided to try the unit.
And it works beautifully!
I compared it to all the amplifiers and dacs I have and for its cheap price it could only be matched by equipment 4 times its price or above. I find that to be very good value for money.
I hope this post helps if ever you build your own O2.
Unfortunately most of the measurements I made were way off from the ones listed in the guides. Here is what I measured:
R1&R2 476 instead of 100-220
R5 191k instead of 100k
R15/18/10/11 240 instead of 1
R16/22 1.55k instead of 1.3k
R7/14/3/20 500 instead of 100-300
(all values are in Ohms)
The measurement device I use is a somewhat expensive voltcraft digital multimeter with a high sampling rate. My suspicion is that this specific MultiMeter is outputting amps while measuring ohms without allowing the amps to drain out before doing another sample. That could result in a higher ohms measurement due to capacitance in the circuit. Unfortunately I did not have a different (digital) MM available to do any measurements with. After checking and triplechecking the placement of the components and the soldering joints I decided to try the unit.
And it works beautifully!
I compared it to all the amplifiers and dacs I have and for its cheap price it could only be matched by equipment 4 times its price or above. I find that to be very good value for money.
I hope this post helps if ever you build your own O2.
