@Irv - thanks for the feedback !  Yes - it had not escaped me that our 50Hz mains hum can be present (the "studio" is reasonably electrically-quiet).   In other situations ( I sometimes record in the living room or front porch ) I'll often see 50, 100, 150 Hz (fairly low, admittedly) peaks if I'm driven to investigate something... (but that's not what the left-most peak is - if I get hum, it is bang on the 50, 100, 150 and immeasurable at 200 and beyond) 

The idea of using the mute is interesting.... That had never occurred to me....  I have a couple (rarely used) kicking around somewhere.....

Awesome, I'll give that a quick try before I transfer the octaves to the EV !

Good idea, thanks Irv !   

@Irv - sure - here you go -

G - 1.21mm

D - 0.81mm

A - 0.65mm

E - 0.69mm  (yup, repeated measurement on both A and E shows the E marginally thicker)

They are the D'Addario Helicore Octaves - they say (and my comment in red) - "Helicore violin strings are crafted with a multi-stranded steel core, resulting in optimal playability while producing a clear, warm tone. The smaller string diameter provides quick bow response (perhaps so, but they could mean that as being relative to "other" octave strings - I find the G and D noticeably slower to respond than I had expected). Premium quality materials combined with skilled workmanship produces strings known for excellent pitch stability and longevity. (can't argue with that!) "

@Irv and others - right - finally have the octave strings on the EV, and the result is pretty much what I had hoped for, with the G2 fundamental now making a proper appearance in the spectrum. Note that in this trace, there is equalization applied, basically a (very steep) roll-off from 2500Hz onwards (after all, that gives us a whole 25 harmonics to the fundamental which is just below 100 Hz.....  ).     Without the EQ the harmonics continued in a decreasing manner to around 15KHz - and - it sounded like a chainsaw !   Also, the filter envelope is just "flat" until the drop-off point - so a more realistic profile would have been to tailor it so the drop-off wasn't as steep, and perhaps starting at 500 Hz - but that's all "studio work" when you're aiming for a particular sound-profile....

Below - the open G2 on the EV, what it sounded like as a sample, and, for fun, an impromptu shot at Moonlight Shadow by Mike Oldfield (played on the D and A strings, but you can just hear that low G resonating in places...)

Other than the bandpass/EQ on the audio, there is no other post processing, no echo, no reverb, that's what she sounds like with octaves....

@Irv - Audacity is pretty much a "down in the dirt" tool ( I mean that in an extremely nice way, I like tools like that, that really address the problem-space ).   As well as the basic program, there are all sorts of handy plug-ins and add-ons.   As a piece of free software, developed and released under the GNU GPL licensing terms, it's one of the best, and best-supported out there.

Unlike specific "music editors" with their (sometimes) easy to use GUI - Audacity pulls no punches - you just gotta get used to it - BUT - there is a HUGE amount of reference material on-line - and you won't go far wrong using this as you launch-point - https://www.audacityteam.org/h.....mentation/

Another (related and to some extent duplicate) source is the specific wiki - (not Wikipedia) https://wiki.audacityteam.org/....._Home_Page

My own use is relatively specific (signal analyses using FFT), and although I've used it for years, I probably am aware of only a fraction of its capabilities.   If you have any specific questions, don't hesitate - but I'm sure you'll figure it out

As regards the 1/6 cello strings - I suspect they would work (although - obviously - the instrument would be strung/tuned from a 5th down to the normal octaves).   When I say they would "work" they would work as poorly as they did on my acoustic (in fact probably worse on the low C with an even lower body response to the fundamental and 2nd harmonics on the low string).   Put them on an EV with a pizeo pickup under the bridge - I guess they would rock !  No idea about the linear mass of such strings, and what their bow-response would be - but I can't see it being far away from the violin octaves...

Aye, good point @Irv  - I had considered planetary pegs (probably just because other folks were using them, and being inquisitive, had it half-in-mind to try them.  I have no issues with normal pegs - so - I ended up saving the cash and spending it on something else - errrr - like Octave strings??? LOL)

So - I had never seen such a thing (the string mounted fine tuner - but of course, it makes sense for certain situations.... although, as you say, in this scenario it would surely unbalance things, particularly on the string it was fitted on)   

Ahhh, octaves/short cellos on a modified HITH viola - yeah - that could well be interesting.

Awesome @Fiddlerman!  ( LOL at "Gibbles"  !  Haha - I know who you mean !)   Yup, I'll bet it was fun !