Changing Schiit Gain Resistors

Discussion in 'Advice Threads' started by oreo1, Apr 12, 2021.

  1. oreo1

    oreo1 Rando

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    Hello,first time poster here. As the title says,I would like to know if I could increade the gain of my Magni from its high setting of approx. 15db to around 30db.The reason for this is I run my television audio out which has a max. output volyage of .375 Vrms thru my Magni and into one of my Diy power amps.I have just been able to get a new Vfet Diy power amp that puts out 10W per channel and the way my setup is now I won't be able to get that.I have experience soldering smd and have an electronics knowledge.I believe its a matter of changing 1 resistor value per channel.Has anyone done anything like this? I will not be hooking this up to anything other than my present setup so i'll not be overdriving it.I realize people are concerned about liability but any advice would be taken as a suggestion.
     
  2. Armaegis

    Armaegis Friend

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    Hey it's a fellow Winnipegger!

    Normally I'd advise just sticking another cheap preamp with gain into the chain, or presumably adding a dac with higher output taking the hdmi or optical audio from the tv (are you currently drawing from the headphone jack? that's going to be awful noisy)

    If you understand the circuitry, then you gotta find the feedback resistor, read the value, remove it, then get a replacement that's roughly x5 higher. This is under the gross assumption that there's no other compensation or filter or whatever attached to that feedback loop and assuming the whole thing works like a simple opamp gain... which it probably isn't because why would Schiit do anything normal? But hey crack it open and try to trace the circuit diagram.

    If you do find it, it might be easier to verify that it does affect gain by parallel'ing the same resistor value on top of it and see if it drops your gain. Y'know, before you start irrevocably removing the original parts.
     
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    Last edited: Apr 12, 2021
  3. Cspirou

    Cspirou They call me Sparky

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    Ah, so you managed to win the VFET raffle. Lucky!

    The Magni 2U is basically a mini speaker amp and does have a feedback resistor. Tracing the resistor shouldn't be too hard since there is a gain switch and you can pinpoint which two resistors are getting switched.

    The problem is whether the circuit is fine outside the stock gain. It might be unstable and oscillate or lead to other performance issues.

    I do think you'd be better off with a DAC. My current TV has no RCA audio output but it does have an optical SPDIF. I use a FiiO d03k to get audio and it has an output of 1.6V. Should also be higher quality then your TV too

    https://fiio.com/productinfo/379441.html
     
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