What does one have over the other? Ie... The RH750 has a tuner where the BH does not. I'm trying to get other's perspective.
The BH has a tuner. The primary difference between the BH and RH is that the RH employs TCE’s Active Power Management (APM). APM is an integrated design that, in basic terms, uses adaptive and dynamic aspects of compression and limiting in a way that’s intended to add response like that of a tube power amp to class-D power. APM is the signature basis of the RH’s design and it is also (IMHO) generally misunderstood and the basis of the forum scuttlebutt on the power ratings of the RH heads. The BH is designed with an intention toward a “modern” default sound and does not use APM. Some of the features of the RH are available in the BH as TonePrints.
Beyond that and in terms of features, the differences are the following:
BH - Tuner is always-on BEADGC (two-color LED) on head
RH - Tuner is always-on chromatic with display on head and optional pedal. When muted, the head display changes from indicating tune up or down to displaying fine granularity (pedal always displays fine granularity)
BH - 4-band EQ with “dynamic” midpoints (midpoints changed based on boosting or cutting the band)
RH - 4-band EQ with semi-parametric control
BH - Mute on face switch (mute at pedal)
RH - Mute on face button (mute at pedal)
Unique Features
BH - Two Toneprint banks (selectable, non-simultaneous)
RH - SpecraComp variable compression, TweeterTone (on 750) variable HF boost, TubeTone variable tube emulation/drive, Three preset memory saves (each saves ALL settings except master)
Preference for sound, is highly subjective, but in my own direct comparison, I had some preference for the sound of the RH. For me, the other features push it over the edge. Additionally, its sounds is more shapable. Here’s some notes from that comparison
TCE BH550 vs RH750 | TalkBass.com