Yeah, I'm not trying to downgrade the m920. I've done some listening on it and although I own the HA-1, I think Grace makes some wonderful products and anyone who buys the m920 will be satisfied. I just didn't like the comment about the m920 being superior in every way. As you mention, it is an audiophile/pro crossover product, which explains the TRS and some of the other features. My understanding is that to enable HT bypass on the m920, the line output for a given source has to be set to a gain of 90. This doesn't seem as convenient or user friendly as the HA-1's HT bypass. The menus and navigation for the m920 certainly seem more convoluted than the HA-1. I can also see some instances where the pairing of the HA-1 with balanced headphones would be superior to a pairing with the m920. I also have found with my TV's functionality that the BT connection on the HA-1 is beneficial for connecting the TV when I'm not using a secondary source (i.e. aTV). I don't have Amazon on my aTV (as it doesn't exist), but I can connect my TV over BT and watch 4K Amazon content while still having the aTV feed as a source to the HA-1 if I want - or use the optical from my bedroom DAC for listening across rooms. For some consumers at a slightly lower price point the HA-1 might be a better fit with quite a bit of feature parity. I don't think either product would be unsatisfying if you're upgrading from a <$500 DAC.
For sure, you make fair points.
There are jumpers inside the unit that allow you to set the single-ended line-out for true bypass. This is a hardware bypass and all functions that involve volume attenuation such as volume control, balance, offset, etc. for the line out will be disabled. This is what I use, as my line out gets split and goes to a NAD D 3020 for my speakers, and a Woo Audio WA7, which is my primary headphone amp. Both of these amps have preamps and volume attenuators, so I don't need a second one in the signal chain for my amps.
For the balanced outputs, yes, there is no true bypass. As I said, the best way to do it would be to set the L2 output to go to unity gain when the unit is powered on. This isn't a true bypass, and the volume attenuator will probably still affect the signal a bit, but it should be quite minor.
The HT bypass for the HA-1 makes sense, and while I wouldn't mind a better implementation of it on the m920 (mainly to have it available on the balanced outputs as well), I understand why they did it this way. In a surround sound studio environment, you're not going to be using weird split setups with different amps and what not. You want uniformity, so you're going to be using matching equipment and a surround sound monitor controller, such as Grace's m906. The same goes for Bluetooth. It's handy to have for sure these days (my D 3020 has it, and I use it once in a while), but it's a completely useless feature for studio use, where you need everything performing at its best, so it makes more sense to put on something like an AES input instead.
The menu on the m920 does take a bit of memorization, but most of the settings in it (and there are a lot) are the kind you generally set and forget. Those that I sometimes play with I just memorized from use.
But yeah, I agree that for many audiophiles, the HA-1 will be more appealing, and that's completely fair. It's a great unit with a really nice feature set, and fair price. The m920 has a great amp, but I would not be surprised if the HA-1 readily beats it (I have barely had any time with the HA-1 myself). My guess is that the m920 will have the superior DAC, and the HA-1 the superior amp, but this is only a guess.
