MulattoKid
New Member
Hello everyone!
Disclaimer: this is my first week of properly diving into all of this, so bear with me
Some years ago I bought a Schiit stack: Modi 2 Uber + Magni 3 (while I'm new here I've noticed Schiit not always getting the best mentions here, but anyway...bought is bought...for now at least). I've used this stack to drive a few different headphones without ever giving it much thought.
However, last week I received my pair of custom-fit JH7 IEMs! I was so excited to try them out, but I could hear a lot of noise when using them with the stack. When connecting them to my Mac M1 Air there was no audible noise. I was a bit puzzled...
Back on my desktop and Schiit stack, I had my volume in Windows turned quite low. I therefore had turned the volume knob on the AMP up quite high. After doing some reading I read that it's better for audio quality to turn the volume in Windows all the way up to avoid Windows' mixer adjusting the amplitude in the signal it sends out. So, I did that, and then naturally had to turn the volume knob on the AMP down. The noise was no longer audible in the volume-knob-range I use the AMP in, so in a way all was good.
But, being who I am I started trying to understand what caused the noise. I disconnected the AMP from the DAC, plugged in my IEMs, and turned the volumne knob up. I could again hear the same noise. The more I cranked up the amplifier, the louder the noise became. This tells me that it's the AMP that's introducing most of the nosie I heard originally. So, onto the specs
JH7 IEM:
Thanks, Daniel
Disclaimer: this is my first week of properly diving into all of this, so bear with me
Some years ago I bought a Schiit stack: Modi 2 Uber + Magni 3 (while I'm new here I've noticed Schiit not always getting the best mentions here, but anyway...bought is bought...for now at least). I've used this stack to drive a few different headphones without ever giving it much thought.
However, last week I received my pair of custom-fit JH7 IEMs! I was so excited to try them out, but I could hear a lot of noise when using them with the stack. When connecting them to my Mac M1 Air there was no audible noise. I was a bit puzzled...
Back on my desktop and Schiit stack, I had my volume in Windows turned quite low. I therefore had turned the volume knob on the AMP up quite high. After doing some reading I read that it's better for audio quality to turn the volume in Windows all the way up to avoid Windows' mixer adjusting the amplitude in the signal it sends out. So, I did that, and then naturally had to turn the volume knob on the AMP down. The noise was no longer audible in the volume-knob-range I use the AMP in, so in a way all was good.
But, being who I am I started trying to understand what caused the noise. I disconnected the AMP from the DAC, plugged in my IEMs, and turned the volumne knob up. I could again hear the same noise. The more I cranked up the amplifier, the louder the noise became. This tells me that it's the AMP that's introducing most of the nosie I heard originally. So, onto the specs
JH7 IEM:
- Input sensitivity: 124dB @ 1mW
- Impedance: 17 Ohm
- Maximum Power, 16 ohms: 3W RMS per channel
- THD: Less than 0.001%, 20Hz-20KHz, at 1V RMS, less than 0.02% at 5V RMS into 32 ohms
- SNR: Greater than 108db, unweighted, referenced to 1V RMS
- Output Impedance: Less than 0.3 ohms at either gain
- Input Impedance: 25k ohms
- Gain: 1.4 (3db) or 7 (17db), selectable via rear switch
- I've set the AMP to low gain - that's good for my situation, as I'm in no need of extra amplification
- The Magni's input impedance is quite high, so there should be a big voltage drop and little actual current flowing from the DAC into the AMP - that's good AFAIK
- The Magni's output impedance is low, so there should only be a small voltage drop and most of the output current will flow to the IEMs - that's good AFAIK
- The Magni's THD and SNR seem reasonable to me compared to what I've seen for other AMPs
- The JH7's have relatively low impedance (17 Ohm), so the voltage drop will be relatively small
- The JH7's sensitivity is pretty high (124dB @ 1mW), so as I understand it: less power is needed to create loud sounds
Thanks, Daniel