My thoughts about the BP-18…
For context, I have the following as part of my main hifi, plus two other full systems and a few headphone-only setups…
Bryston BP-17
Bryston BDP-2
Bryston BOT-1
Bryston BHA-1
Bryston 7B3 (x2)
Bryston Middle-T (passive)
There are a couple of pieces that I’d like to add from the Bryston lineup, but the system performs very well as it is and gets a lot of use.
BP-18 aesthetics:
I’d appreciate the visual indication of volume, either through a single
pinpoint LED on the volume knob, or with a ring of pinpoint LEDs around the volume knob. I have a Shanling A2.1 integrated amplifier that has the latter, and it’s quite successful. I’ve attached a poor phone-quality photo - it’s better looking in real life (no LED flare, etc.), as it’s functionally useful without being blinding at night (it’s in the bedroom.)

Having user-settable illumination levels, with the option for full-dark, and auto-dark after a defined interval would be great. It’d also be appreciated if the volume LED could optionally be left on (at a preferred illumination level) while the others were dimmed or off entirely. Probably separate illumination control of the volume LED(s) would be best.
The front panel of the BP-18 is very busy, and I’d prefer to see it cleaned up. I prefer a minimalistic aesthetic, while providing all the useful feedback a user needs. I’d like to see fewer rows of buttons & LEDs. Two rows, one for input selection, and one for other functions, grouped sensibly, to the right of the display, matched aesthetically to existing current gear (e.g. BP-17, BCD-3, BDA-3.) The display of sampling rate etc. could then be accommodated in the space to the left of the volume knob, using the “classic” layout as found on the BDA-3, optionally with smaller (pinpoint) LEDs. Choice of LED colour should respect existing Bryston conventions (ideally user selectable) and I’d prefer volume indication to use a distinctive colour - e.g. red for volume, with green for source/function indication.
I’m open to associating the mute button and power with the volume control, but not fully convinced. I’d need to see a revised layout, ideally with a higher quality photo to make a final assessment. It might make sense to have mute and bypass buttons/indicators be the ones associated with volume, and separate the power function. LEDs for mute & bypass (or power) might look better if they were beside the label (on the "outside" relative to the knob) and not between the label and the volume LEDs.
I don’t care for the detail around the headphone jack - there again I’d prefer a clean jack with minimal involvement of the front panel. I’d pair it with a visually similar IR sensor and pair them symmetrically below the display (cf the BP-17.)
I’d relocate the BP-18 PRE-AMPLIFIER silkscreen, as it’s awkward where it’s currently placed and initially looks to be associated with the headphone jack, but offset improperly. It might end up over the sampling rate LED group to the left of the volume knob.
BP-18 Functions & Implementation:
I think you’ve chosen an excellent combination of inputs, allowing you to leverage development for your other platforms (good engineering practice!) and maintain a high degree of versatility while offering the benefits of internal coupling (avoids interconnect costs and “issues”), and reduced cost due to the single chassis and power supply savings. I would prefer having more than a single USB input - can an external USB hub be used to allow multiple storage devices, without compromise?
Is there provision for internal storage - i.e. spinning HD or SSD?
I am slightly wary that the Pi may prove to be the limiting factor (in real or perceived terms), and it’d be great (if feasible) if the BP-18 could be offered with the equivalent of the BDA-3’s (or it’s successor’s) capabilities as an option. The rest of the BP-18 appears to be class-leading, and while the Pi allows for reasonable-cost implementation, it isn’t necessarily an ideal solution for large collections. I’m quite willing to be wrong about this though.

The modularity is welcome, assuming it’s the basis for reasonable user selection of capabilities or meaningful upgrades.
The outputs being only XLR is a bit troubling, as it reduces perceived versatility. While it may be possible to adapt to RCA/unbalanced passively, the output level may be restrictive depending upon the amplifier(s) used. It shouldn’t be assumed that a Bryston amplifier will always follow, much as that might be the ideal case. Having one set of outputs at a user-selectable fixed/variable level would be appreciated. That allow for connection to a BHA-1 in order to accommodate “balanced” headphones, electrostatics, etc. I’m presuming the BHA-1 will still outperform the BP-18 headphone output (at least in power), though the comment about the BP-18 headphone drive quality is encouraging. Inclusion of a tape/processing loop is probably asking too much!
The inclusion of Bypass and Invert functions is an excellent choice - again considering versatility and marketability/perception.
The lack of a digital output is, perhaps, slightly unfortunate, and I presume it’s because there’s no ADC for the analogue inputs, as well as the quality of the inbuilt DAC that it’s deemed to be unnecessary. Perhaps a USB connection could allow for output from digital sources? Considering this is an analogue preamp with inbuilt DAC and streamer, this seems very minor to me.
Inclusion of WiFi & Bluetooth, even if it’s an external dongle (potentially preferable, due to upgradability to accommodate evolving standards) would be very worthwhile. WiFi & Bluetooth capability should allow for reception of signals (e.g. streamed from a phone or tablet) and transmission (to wireless headphones or speakers) using the latest quality WiFi & Bluetooth standards.
I’m curious about the perceived audio performance compared to the BP-26 and the BP-17. It’s been mentioned that the spatial presentation between those two is different, and they do have somewhat different character - we’re not quite at the “wire with gain” stage yet. How would you compare the BP-18? It being fully balanced throughout will be something of a selling point, though the actual impact on objective performance will depend on the implementation. There is a certain “camp” that elevates objective performance using the suite of traditional measurements above all else, and in amplifiers that often comes down to bringing noise and distortion down to almost immeasurably low levels, which is indicative of engineering effort, but may go beyond what’s actually meaningful when listening to music.
While I am tentatively in the group that believes that there’s limited benefit of digital replay at very high bitrates, and any benefit is typically substantially outweighed by the recording and mastering processes (which include aesthetic choices as well as technical concerns), the market does respond to the inclusion of very high bitrate playback as an indicator of quality, so it’s vital that any digital piece accommodates the perceived markers of quality. Note that I acknowledge the actual merit of recording and processing audio at higher bitrates in the professional realm, to avoid compromising the end result when released at “sensible” bitrates. I say this as someone that has extensive former experience recording professionally, as well as being an active consumer of recorded and live music.
On the whole, the BP-18 looks like an excellent addition to the lineup, and while I’m unlikely to purchase one, given that I’m already well down the road with quality separates and I need more analogue inputs (at least in my main system) I hope it entices more people to join the Bryston family, and enjoy the highest quality reproduction of music - which is presumably why we’re all here…

Regards,
Syncytial.