—ChiFi Guru—

Your guide in the world of Chinese HiFi

Fosi Audio TB10D (Upgraded)vsOldchen (Laochen) EL34-B

A detailed side-by-side comparison of the Fosi Audio TB10D (Upgraded) and Oldchen (Laochen) EL34-B — two popular amplifiers in the Chinese HiFi space.

Specifications

Spec
Fosi Audio TB10D (Upgraded)
Oldchen (Laochen) EL34-B
Class
D
A
Chipset
TI TPA3255
—
Power
2 × 300W (Max) / ~100W Clean @ 4Ω
10W x 2
Inputs
RCA
—
Features
Bass and Treble Tone Controls
—
Topology
—
Single Ended Triode (SET)
Tubes
—
EL34 x2, 6N9P x2, 5U4G x1
Wiring
—
Point-to-Point (Hardwired)
Remote Control
✗
✗
Tube Stage
✗
✓

Price (estimated)

Price
~$70
~$170
Difference
~$100.00 cheaper (Fosi Audio TB10D (Upgraded))

Things to Know

Fosi Audio TB10D (Upgraded)

  • ⚠Volume control is logarithmic but very sensitive; gets loud at the 9 o'clock position.
  • ⚠Tone controls lack a center detent, making it hard to know when you are truly 'flat'.
  • ⚠DC input spark is common when plugging in the power supply (connect to amp first, then wall).

Oldchen (Laochen) EL34-B

  • ⚠The '5U4G' rectifier is often wired in hybrid mode with silicon diodes, which purists dislike.
  • ⚠Transformers run very hot, suggesting they are pushed near their saturation limits.
  • ⚠Stock Chinese EL34 tubes can sound harsh compared to budget re-issues like Mullard or JJ.

* As an affiliate, we may earn a small commission from qualifying purchases — at no extra cost to you.