Th3Drizzl3
500+ Head-Fier
these didnt sell nearly as well as the cth and lcx so it may be a while before they do a drop again prob after the first drop ships out.
I can confirm that THX-789 indeed sound natural and clean. Plenty power, too. For purists, or people that love very natural sound with no coloration - this one is worth your consideration!Hi All,
Thank you for your interest. We didn't have as many listening samples as we wanted at launch but knew this would be a great amp and loved due to early prototypes and the graphs during development.
I just saw some shots of the amps being built...will get a few off the Pilot Run soon and will send a couple of them out for listening impressions.
We also have some measurement graphs from THX we will post.
I have an earlier build that I keep on my desk. The amp is surprisingly natural-sounding, but not "dry". Dynamic, powerful, and clean.
I think we will re-open the drop next month to sell a few that we will have left from the first production run.
Or, the planning team may open it up for more sales with a later shipping date...please keep an eye out next month!
I hope they do the same for their R2R DAC.I'm pretty sure they didn't put the huge amount of time and money it took to make this amp into it hoping they would only sell the 300ish they have so far. I'd say it's probably about a 99 percent certainty that they will drop it again eventually.
Hi UFO. The 789 has tons of gain and will still go nearly to clipping with a 2 V DAC. What's your DAC/source rms voltage? And do you use TRS or XLR-4 headphone connection?"
This update is for members who joined the drop in March:
Hi everyone,
The Massdrop x THX AAA™ 789 Linear Amplifier is making its way through production! We also have some important updates to share about the gain specifications.
We worked with THX to adjust the gains for the primary use case of the Audiophile community. Previously, the gains were optimized for variance in source output power. Most Audiophiles typically use 2V DAC sources and wish to drive in-ear monitors or hard-to-drive headphones.
With these slight changes there were some updates to the gain specifications, which we have listed below:
General:
Balanced Output:
- Frequency response: + 0.01 dB / - 0.03 dB 20 Hz–20 kHz; + 0.05 dB / - 0.15 dB 10 Hz–50 kHz
- THD: -130 dB, 32 ohms, 1 mW: 0.000032%
- THD: -130 dB, 32 ohms, 100 mW: 0.000032%
- THD: -122 dB, 16 ohms, 1 mW: 0.000080%
- THD: -122 dB, 16 ohms, 100 mW: 0.000080%
- Gain: 0.66x , 2.0x, 6.6x (-4, +6, +16 dB), selectable via front switch"
Damn. The reason I was interested in this amp was the 24db high gain. Going to have to look elsewhere.
Exactly. We added the -10dB gain setting because it's awesome for IEMs. It permits a large usable range from the volume pot and a really low noise floor.The reason I'm interested is the negative gain. It would make my life much easier...
Hi UFO. The 789 has tons of gain and will still go nearly to clipping with a 2 V DAC. What's your DAC/source rms voltage? And do you use TRS or XLR-4 headphone connection?
With the design optimized for 2V inputs, I presume that is singled ended RCA inputs only. Is the design also based on a max balanced XLR input voltage of 4V?
No...
In gain = 0dB or -10dB position, to avoid clipping internally the max inputs are 7Vrms for RCA unbal or XLR bal.
In gain = +10dB position, to avoid clipping internally the max inputs are 2.1Vrms for RCA unbal or XLR bal
The architecture treats inputs differentially regardless of unbal or bal. That's why the max Vin remains the same.
That would make things much more practical indeed. Since dedicated PC soundcard line-outs pump out 2V (let alone the headphone amp outs), I have always had trouble with the volume control. Currently I'm using low gain on my AE-5 and have set the volume to 18% and I still have to lower the volume further a lot with volume pot (without vol pot I'd have to stick with single digit numbers). It would be the same story with line-out + O2 1x gain mode. While Sabre DACs have pretty great digital volume control but still, this is not optimal...Exactly. We added the -10dB gain setting because it's awesome for IEMs. It permits a large usable range from the volume pot and a really low noise floor.