Cool. I didn’t make this request, but my amp was somewhat of a custom job being built as a power amp with no volume control. After multiple conversations about my use case and needs (headphones, speakers, preamp, powered subwoofer), he proposed building it the way he did.
And yes, Justin is super responsive and helpful. 
mine was bought used at 1 month old and was
Made at the first of the year too. Maybe I need to peek inside and make sure both inputs have the input transformer. I could of sworn he told me they did but as always with time I begin to second guess myself.
Cool. A variance in sonics, noise floor, and ground loop effects could also indicate.
Is it a night and day difference between your inputs? Do you ever use the input without the input transformer?
I need to compare the inputs tonight for shits and giggles. I have not heard a difference between the inputs so they must be on both. Unless it is a subtle change.
I was talking to Donald at DNA and he was talking about how he likes less in the circuitry stream and not to worry about an input transformer in the Stratus. I’m very interested in different peoples approach. I wonder why one amp builder embraces them while another stays clear?
The sonic difference is slight, sometimes not audible. Where there are noise and ground loop issues, without input transformer is easier to manage.
I do prefer the sonics with input transformer, and use it regularly (notwithstanding the additional potential noise and ground loop management).
At first, I wondered how can I tell if the input transformer is in the signal path. Mine allows me to do so.
Based on my discussions with Donald, I believe he features an input transformer in the Stellaris to accommodate balanced inputs only/primarily.
It’s nice to have builders with different philosophies/approaches/designs/ears/tuning. Something for everyone.
The circuit in the DNA amps doesn’t need a balanced input, doesnt improve anything based on how the topology is laid out., at least to my understanding. They are present on the Stellaris as an option only because he can do it as transparently as possible with expensive high end custom transformers. There’s an explanation on his website about why he doesnt run balanced inputs.
What I’m bringing up has less to do about using input transformers for balanced and more about A&S using it on their single ended inputs and DNA not using it on their single ended inputs. I’m sure they both have a reason why they like or dislike the IT’s. Maybe it doesn’t work well in DNA amps where it does in A&S amps? I’m purely interested in why that is and not about whether one is right or wrong.
A fun experiment would be to get the input transformer adapter box and use it with a DNA amp and see if it changes the sound for the better? I used to have the adapter box but sold it when I bought my mogwai although I did use it with my leeloo prototype-ish amp and the input T’s definitely tightened up the some instruments. I do still think it was subtle and if I heard one on Monday and the other on Tuesday it might be hard to pick them out but since I was able to A/B within seconds I could easily hear a difference for the better hence the reason why I asked Donald if I could add that to my Stratus and got a basic No.
I think it might just come down to customer expectations. Justin might feel it makes his amps more accessible while Donald is sticking with his design philosophy. Neither is wrong.
I totally agree. I’m sure they have perfectly sound reasons for doing so as they are the creators. I don’t know shit when it comes to them and I’m sure whether they use them or not is helping them attain their own building goals.
I’m still very interested in trying that adapter with a DNA amp. I think it was an excellent choice for Justin to add it into his amps. I read somewhere that he had let people compare the two at a convention and most of the people preferred the input transformer. Seems to me a great choice to use it and try it out in real-time with customers.
After I get my Stratus I will definitely be making one of those adapter boxes with balanced and unbalanced taps. Will let you know what I think then…
What does an input transformer do? In the context of this conversation.
For A&S builds, I understand that Justin uses them to help with separation, layering, bass articulation, and graininess for digital sources.
I believe he touches on this in @MRHifiReviews’s Nautilus video.
when I first got my Kenzie OG the signal was too “hot” from the DAC and I was only getting up to 9-10 o’clock on the volume. Justin suggested the transformer should also attenuate that signal a little. I may have mis-understood. By the time I bought a transformer used I had sold the OG and ordered the Ovation, which has one built in. @jthvac may be able to help I think he uses one with his OG.
It seemed to help tighten up all the instruments
It definitely added separation. I noticed it immediately when I put it in. Just an overall improvement in sound.
More plankton @PaisleyUnderground 
Got a mogwai SE on order
This mite sound a stupid question but are the 3 outputs on the front right side all for headphones?
I am mostly going to be using planars and heard that the 8ohm tap will be the best but I do plan on eventually getting some zmf headphones in the future so would I be better getting the 300ohm tap replaced to a 100ohm?
what benefit will having a 300ohm tap have over the 100ohm? more bass?
headphones i own are arya, lcd xc hd 600
I think it will depend on your personal taste. When I bought my ampsandsound Nautilus (which has both 100 and 300), I was curious to try my Verite on the 300 ohm output, since my ZMF Pendant “only” had 100 ohms.
With rock music like Tool’s Fear Inoculum, I found it exhilarating. The rhythm appeared to be heightened, with drums locked in, and guitars were thick and weighty. Rock music was very aggressive. I absolutely loved it… until I didn’t. By the end of the day, I found it too overwhelming and went back to the smoother, more liquid-sounding 100 ohm output, and have used the 100 ever since. But YMMV.
Yes.
When I ordered my Mogwai SE in December, I was told that I couldn’t change 300 to 100, which I requested. I mainly use 32 and 8 for dynamics and planars and the 300 gets minimal use due to noise floor and too aggressive of a presentation.
If you like Jazz try the 300 tap for ZMF’s!!
95% of the time I use the middle tap with my ZMF’s though.
I am definitely in the honeymoon phase where I am loving the 300ohm tap.
When I am doing critical listening, the difference is that there is way more texture to the bass especially when paired with the rca 6l6gc power tubes. The difference is less noticeable with the stock tubes.
I also find 300ohm pulls forward the micro details in the recording (things like background vocals, harmonies, high hats, etc) and it’s like I am listening to tracks for the first time. That “hear a track like listening for the first time” magic is a bit less present on the 32ohm tap, but the sound is still fantastic and more liquid like others are saying.
I think genre to @Earmuffs point is important to consider as well. Jazz, Blues, Rap, Electronic (think James Blake) sound amazing on 300ohm because they are less intense. But I could totally see heavy metal or related genres being way too fatiguing.
All in all, I think 300ohm is a pretty fun option even if you only listen to it from time to time. And the 32ohm is more than sufficient for the ZMFs to my ears otherwise.
@PaisleyUnderground how would you say 32 compares to 100 for ZMFs on the Nautilus?
With the VC, the 300 ohm tap is often unlistenable due to noise, regardless of the tubes used. It’s interesting how others have success - lucky them.
Generally, for the ZMF VC, I use the 32 for instrumental, and the 8 for vocals where vocals on the 32 can be too shouty and inappropriately placed among the instruments (and 300 when I have no regard for noise and want the driver to be fully unleashed and my world to be rocked while on stage). Choosing the lower impedance results in the amp exerting more control of the headphone driver, which can tighten the bass and attenuate sonic properties. Whether that is favorable depends on the listener’s desired presentation (and varies by system, apparently, given the inconsistency of 300 results/usage by various listeners).