Pots or attenuators - how often are you guys changing volume. I tend to set it and forget it. I donāt have a lot of input variability to the amp I guess.
Also, +1 for the RebelAmp. After 8 months of daily listening, Iām still impressed. The RebelAmp / Topping D70 / DT1990 combo is addictive.
Also, I just looked at the RebelAmp website. It used to come with a power cord and RCA cables. They were pretty cheap, but they were there. Now, they are not included. Be sure to have an extra power cable available if you order one.
It all depends on the number of steps, if there are only 24 steps like in DACT, then this is not enough. But the FLUX has 64 steps, which should provide smoother control. But in such a FLUX tube preamplifier there are already 128 steps, which should be very smooth.
Even 1024 steps would be discrete steps. Depending on execution, but 64 steps should be enough for amplifier applications (assuming 1dB step size).
There are applications when discrete steps are a big no. You could design circuits to give you extremely fine controll, point remains, discrete steps are sometimes not an option.
In case it isnāt obvious, I am an electronics hobbyist and tinkerer.
I looked into ways to adjust volume for an headphone amp I have in planning stage and decided against digital potis for that step reason.
What I may do is link two multi-turn pots together via timing belt.
You can build relay based stepped attenuators with 100ās or thousands of steps relatively compactly.
1024 steps requires 10 relays 65536 would require 16. To me these seem to be a better solution than the mechanical switch based stepped attenuators.
I have one here for a passive-pre I keep meaning to finish with 7 relays and 128 steps.
The other option Iāve seen is using a pair of pots, one for gross adjustment and a second for fine adjustment, but then you have two devices with none linearities and balance issues at the start and end of travel.
FluxLabās implementation is a little sketchy, it has a tiny delay and the low quality pot makes it easy to land in the middle of two volume settings, that makes the volume jump up and down on its own until you move it a little on either direction.
It works ok and has no channel imbalance but itās noisy and if you have closed back headphones it can be clicking non stop and it will take a couple minutes to notice. I have to wait a couple of seconds after adjusting the volume to see if it stays stable.
The rebel amp has a high quality pot that doesnāt have those issues, and I havenāt notice any channel imbalance.
So you can choose precise with quirks or a stable traditional pot that might have some channel imbalance.
I would say itās personal preference, for a shared office the clicking sound is a huge downside, and it gets worse when it starts to click nonstop.
That happens to me and it is annoying, but not a deal breaker for me.
Benchmark has a blog on their website detailing the issues they ran into when implementing a relay controlled attenuator. It doesnāt really help with the Flux (or Rebel) amp but itās useful information for the future when researching amps with relays. Zeos mentioned a similar issue to whatās described here with the Schiit Ragnarok, for example.
https://benchmarkmedia.com/blogs/application_notes/benchmarks-256-step-relay-controlled-attenuator
Anyone know if there is going to be any discernible difference between the thx and the rebel?
There is, for sure.
Can the RebelAmp power 600ohm DT 880s?
Not at one watt per channel.
Hi. Welcome to HFGF. The Rebelamp should handle the 880 just fine.
A lot of people here run their DT880 600 ohms with a 1 watt per channel Liquid Spark, too. So 1 watt per channel is plenty (my Atom and my Liquid Spark both run my T50RPs just fine, too, and most of the time when the volume is at 50% itās too much ā and these planars are demanding).
Also 1 watt of Class A is probably the equivalent of two watts of Class Dā¦ because my ~270mA Class A amp can 100% power my T50RPs at 2/3 volume more or less.
I had both and rebel had no issue to drive them. Asgard has 3wpc and in my opinion rebel did it better.
Important to note, not all amplifiers āscaleā exactly linear with output impedance. That depends on topology, if it has a feedback network, etc. Itās sad the Rebel Amp has no ratings besides 32Ohms, so I guess we only have the experience of others to count on.
Heard this a lot around, and it never quite clicked for me. As far as I understand, Class shouldnāt change output power rating necessarily, more about the efficiency and linearity. Maybe Class A has a less aggressive slope for distortion. Or maybe itās related to a more dampened time domain response, I donāt knowā¦ 
how does RebelAmp compare to the 789?
Yeah lol I donāt get it either!
I have both. When I initially received the RebelAmp my first impression was that the bass was more filled out, similar texture but more of it. Iāve been using the RebelAmp for a few months now and I recently tried the 789 again. On some tracks it can be kind of offensive especially in the treble. I found myself thinking āowā on some pop tracks. I think the RebelAmp retains most of the resolution of the 789 but just smooths everything out. Iāve been tapping my toes a lot with this amp and I think itās a good value at 500. The build quality imo is far superior to that of the 789 as well. The potentiometer is a lot smoother and the switches are nice compared to the mushy buttons of the 789.
As someone said recently, āYou canāt measure foot tappingā 
