Uploaded January 2026 | Updated September 2026, 2 weeks ago

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Thanks to Fosi Audio for sending the GR70 for review!

Buy from Amazon (affiliate link): amzn.to/49rmF0Y
Buy from Fosi Audio: fosiaudio.com/products/gr70-tube-headphone-amp

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Test Gear...

All music was digital and either lossless/hi-rez FLAC or DSD played locally, or in the case of FLAC also streamed from Qobuz, all through Roon.

Chain 1...

FiiO SR11 (youtu.be/YuagbK8p0FA) into Fosi ZH3 (review coming!) into GR70

Chain 2...

Chord 2Go+2Yu (youtu.be/S3O7JNOJIqI) into Ferrum WANDLA GSE (review coming!) into Ferrum Oor (youtu.be/xUsRyoBPdyk) then single-ended preout into GR70

Chain 3...

FiiO SR11 into Schiit Mimir (youtu.be/JnT_3HpAHt0) into GR70 - GR70's preout also went into Ferrum Oor from this chain.

Compared Amp...

Apos Gremlin: youtu.be/EgKvSKdKwlE

Headphones Used...

HEDD D1: youtu.be/VEMQwuZDVBs
HiFiMan Ananda Unveiled (review coming!)
Massdrop + Sennheiser HD6XX: youtu.be/02Um5rMNYS8

PSVane Horizon Tubes...
My Review: youtu.be/IpSNBwgNkOE
Amazon Link (affiliate link): amzn.to/456tGTH

Timestamps...

00:00 Intro, Pricing, Disclaimer
02:21 Shameless Self Promotion
02:48 About the GR70
06:19 Build, Features, Specs, Ergonomics
15:43 Test Gear & Sound
27:51 Comparison with Apos Gremlin