Himage DVR-4010 TBC quality
 

This is a quick test to see if this DVR works in pass through mode. The test involves an ION VCR2PC with a tape in still frame. The result through the Ion was noisy, with flagging and jumping. The same signal put through the Himage at the same time (and captured simultaneously by another capture device), was quite stable but had a noise band in one field. I'd say that it's definitely working as a TBC.

Sorry for the low quality, the ION will preview but not capture in VirtualDub. I can only play with graphedit or install the original software. I may make a better comparison sometime.

Himage DVR 4010 teardown

ES6128F - ESS Vibrator single chip DVD player, very common in the era
PCM1802 - ADC (for recording sound)
PCM1606 - DAC, 6 channel (for sound playback)
ESS 7010F - MPEG2 Encoder (digitizes video then sends to disk), does film and scene change detection
ES7110S ? - could be TV encoder (converts digital video to analog output)

One thing I still haven't found is the video decoder chip, it's driving me nuts!

A lot of cheap chips are decoder + encoder.
ESS is definitely a cheap chip.

The test was done in NTSC