@support_aodyo Excellent insight and info ... Thanks!!

Pedro Eustache posted his Sylphyo settings on the Respiro forum ... it's from a while ago, but some may find it of interest ...

https://www.imoxplus.com/site/index.php/forum/tips-tricks/34-pedro-eustache-s-sylphyo-settings

From what I understand, the impedance (Ohm rating) of the headphones is very important for volume. There is an inverse relationship: more impedance (higher Ohm rating) = lower volume. However, more impedance also means better quality sound (for reasons of electrical engineering beyond my understanding).

Most "on the road" earbuds and "consumer" headphones seem to be low impedance, because the sound sources (MP3 players, smartphones, etc) don't have enough current to drive high-impedance headphones to sufficient volume.

The Sennheiser HD 201 of @Fanch35 is rated at 24 ohms ... in the "low impedance" category ... and should be quite loud.

The Ultrasone Pro 900 of @David-Lazzi is rated at 40 ohms, so they should be quieter (maybe twice?) and would require a higher volume setting to get the same level in the ear.

The Presonus HD7 and HD9 are rated at 32 and 40 ohms.

My personal preference are the line of Beyerdynamic headphones. They are ultra-comfortable (for me), have replaceable earpads, and come is a variety of configurations and impedance ratings. My preference is for closed-cell (closed-back) headphones, because I often do overdubs and don't want the sound of the track to bleed into my microphone. (However, that issue is now moot with the Syplhyo!)

I use the DT-770s in the 80 ohm and 250 ohm varieties. On the 250 ohm headphones, about 80-100% volume on the Sylphyo is right for me on Flute Phy # 30.

One concern for me: the strength and durability of the 1/8" headphone connector (and its neighbors, the on-off switch and USB port). My headphones have a spiral-wound chord and do put possibly heavy side-loads on the connector. If anything happens to the connectors in that area, I think it would be a big repair!

@support_aodyo The Factor Reset worked!! I can now store settings and they persist through a power cycle.

Thankfully, I wrote down the myriad settings I have adjusted ...

Thank you SO MUCH for your help!!

@support_aodyo Updating the Sylphyo to the v1.4.8b10 firmware seems to have no effect (although I do see a little "BC" symbol with a wave over it in the lower right of the display, with something that looks like a speaker to the right). I have not updated the firmware on the Link.

BTW this v1.4.8b10 does not have my Native flute fingering updates - the 6 additional fingerings from 25Feb21 ...

@support_aodyo It is only changes that I make. My setup as it existed before this issue began happing have not been affected.

The affected setup changes include Quick Changes made to the three parameters (Base pitch, Sound, and primary MIDI channel) as well as any changes made using the full menu.

My Sylphyo currently has firmware v1.4.8b4. I have the installer for v1.4.8b10, but hesitate to run it because whatever issue is causing the loss of settings might cause havoc during a firmware upgrade.

Have you heard of this happing before?

Not sure what could make this happen ... but ...

Any changes I make to settings on my Sylphyo are lost if I power the Sylphyo down and up with the power switch near the foot of the instrument.

Any advice??

Thanks Maxence ... yes, I've got that ... but the "3" in "C3" could mean (as I've found out recently) many different things depending on the octave numbering you use. The Sylphyo (from my examining the MIDI stream it puts out) puts out MIDI hex 3C = decimal 60 for "C3" which is Middle C. That's the same standard that Kontakt, Apple Logic, Cubase, Steinberg, and Yamaha keyboards use.

However, the ISO standard that is used by Korg, Roland, and most of the piano tuning and composing world (and also the Native flute world) use "C4" for Middle C. That's why I was always off by an octave before I understood these issues.

Cakewalk Sonar actually uses C5 for Middle C, which is really confusing!

The manual mentions C3 in a number of places, but never mentions that the Sylphyo uses C3 = Middle C (the Apple and Yamaha standard) rather than the ISO C4=Middle C standard (or Sonar which uses C5!).

This was actually a head-scratcher for a few minutes, until I saw the MIDI stream and realized C3 was producing MIDI note 60.

Hello @jcfitn ! ... interesting idea ...

If I understand your intent, I think that is achievable without modifying the Sylphyo. I use Cantabile to route the Sylphyo MIDI stream to many different places (software and hardware). It is designed to split the MIDI stream to may routes that go to many targets, and also apply complex filtering (curves, minimum, maximum and many more possibilities). There is a free version of Cantabile which has quite a lot of features ...

Alternately, the Sylphyo can transmit CC messages from the breath sensor on up to 3 MIDI CC channels simultaneously.