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SMSL SH-9 THX Headphone Amplifier Review

bongo_bong

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Hi!

I have the SU-9 DAC and a NC122MP amp with XLR and I wonder if I could use this SH-9 as a preamp in between via the headphone out? And if so would there be any drawbacks?
I don't really need a headphone amp but would probably use it with headphones occasionally. I would on the other hand lika a RCA input for my turntable and still be able to control the volume with a remote (and I think this matching pair would look good together).
Are there any other solutions for RCA input and remote volume?
Would an analog-to-digital converter from the phono stage to the optical input on the DAC work?

Appreciate any help! I am certainly no expert.
 

THIBAULT

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Hi,
Can we use the same remote control to drive the SMSL SH-9 and the SU 9.
Regards.
 

alexrus

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Hey @amirm great review! Did you measured channel crosstalk for this amp? I am wondering if it much worse compared to fully balanced designs
 

Pritaudio

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use it for a year and then throw it away, because it won’t be fixable out of warranty.
 

BenF

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It's pretty much a standard THX AAA 888 reference design which has to prove its long-term reliability yet as it's pretty new. But why would it fail after only one year? If it's a halfway well executed design with reliable and proven components it will survive some dozen years.
 

Pritaudio

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It is only warranties for 1 year, with shipping too.
who is going to fix it after that.
plus smsl have a worse record than topping and other such Chinese.
 

dmac6419

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It is only warranties for 1 year, with shipping too.
who is going to fix it after that.
plus smsl have a worse record than topping and other such Chinese.
There's nothing wrong with a 1 year warranty,at least it has a warranty.
 

manishex

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Can someone measure out the Input impedance? I'm having the same issue as the a90 where the signal is being attenuated. I sold the a90 and got this because it states 47kohm input impedance but from testing, it doesn't seem to be the case...
 

Hemi-Demon

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Can someone measure out the Input impedance? I'm having the same issue as the a90 where the signal is being attenuated. I sold the a90 and got this because it states 47kohm input impedance but from testing, it doesn't seem to be the case...

What dac are you using that may be creating this repetitive attenuation issue? If both the A90 and the SH9 are causing you issues, seems that something else in your daisy chain is the issue. Even attenuated, either amp should be able to power any headphone on the market.

Do you have another amp that seems to work well with your existing dac? Maybe try a tube amp? What headphones are you using?
 

manishex

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What dac are you using that may be creating this repetitive attenuation issue? If both the A90 and the SH9 are causing you issues, seems that something else in your daisy chain is the issue. Even attenuated, either amp should be able to power any headphone on the market.

Do you have another amp that seems to work well with your existing dac? Maybe try a tube amp? What headphones are you using?

I'm using the musician pegasus r2r, it's spec'd the same as the Denafrips dacs at 625ohms unbalanced out. The sh-9 sounds much better with the gustard a22 and sda-6 adv whilst my burson amps are unaffected when comparing the dacs as they have a 37kohm impedance.

I'm using the harder to drive lcd-4 (people have reported they're 9db less efficient than what audeze stated?) and I'm happily using volume 83 with my CDT and 86 with my music server on the normal dacs, but my favourite is the pegasus and it's forcing me to use 99 volume which is just shy of what I want which forces me into high gain where the sound is less focused, blurry, thin and less cohesive.

If I had known the sh-9 wasn't really 47kohm impedance as stated, I wouldn't have got it. I thought since the M400 has a similarly high impedance and that this is the unbalanced version of the sp400, It would work. It's a shame because this amp is amazingly neutral, I never feel it's warm or bright, thin or thick, it just is whilst pushing out tons of detail and speed.
 
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Veri

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It's never a good idea to use a headphone output as a pre-amp. In a pinch it might work, but it's not something you should plan your set-up around. Get an amp with proper pre outputs, like the Topping A90 or cheaper alternatives.
 

Hemi-Demon

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I'm using the musician pegasus r2r, it's spec'd the same as the Denafrips dacs at 625ohms unbalanced out. The sh-9 sounds much better with the gustard a22 and sda-6 adv whilst my burson amps are unaffected when comparing the dacs as they have a 37kohm impedance.

I'm using the harder to drive lcd-4 (people have reported they're 9db less efficient than what audeze stated?) and I'm happily using volume 83 with my CDT and 86 with my music server on the normal dacs, but my favourite is the pegasus and it's forcing me to use 99 volume which is just shy of what I want which forces me into high gain where the sound is less focused, blurry, thin and less cohesive.

If I had known the sh-9 wasn't really 47kohm impedance as stated, I wouldn't have got it. I thought since the M400 has a similarly high impedance and that this is the unbalanced version of the sp400, It would work. It's a shame because this amp is amazingly neutral, I never feel it's warm or bright, thin or thick, it just is whilst pushing out tons of detail and speed.

Had a feeling you were running a R2R dac. Why not run a tube amp? Seems odd to run R2R and then match it too something like the SH9. Few recommendations; monoprice liquid platinum balanced only (low price), auris Ha2 (mid to high) and Felix Elise (high). Sleeper recommendation if you like SS, is the Geshelli Erish. It will match better than the SH9 to your pegasus. It doesnt have the rated power, but its current based design will scale better with your LCD4, imo. Its only $200 and you can return it easy in the US, if you don't like.it.
 

bongo_bong

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It's never a good idea to use a headphone output as a pre-amp. In a pinch it might work, but it's not something you should plan your set-up around. Get an amp with proper pre outputs, like the Topping A90 or cheaper alternatives.
Thanks for the reply! I would also like to know the reason to why that is - besides from the relative inconvenience, what is the difference between using headphone output and preout XLR?
 

Veri

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Thanks for the reply! I would also like to know the reason to why that is - besides from the relative inconvenience, what is the difference between using headphone output and preout XLR?
Headphone output is not designed to be fed to another upstream device but rather as the "final" link. The chances of creating a ground loop from the headphone out is relatively high, so if you already have it all you can try it of course and see if you run into any issues, but to buy something specifically to try this would be a bad idea. Would be pretty annoying just to have it not working well.

I've seen people do this with some luck though, so that's not to say it won't ever work...
https://www.audiosciencereview.com/...s-atom-headphone-amp.5262/page-98#post-437237
https://www.aliexpress.com/item/32871666622.html

To add, pre-out XLR has a dedicated ground wire on both cable which will cancel out the common mode noise, chance of ground loop hum is just about zero in this scenario ;) to sum up, it's all about noise. Once you have a low-level hum picked up in your chain, it's a terrible thing to get rid of.
 
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