So, it seems that the only difference between the brand new Sirin and the good ol’ Minitaur is the note range in the high direction. That’s on paper however.
Are there any of you guys who have both? Do they differ on a sonic aspect or anything else?
I’m also interested to hear if there are differences in the bass registers.
I’ve found that the oscillators are slightly different. I’ve just compared the two in this video - https://youtu.be/3wNQjv_nRk0
Long story short, the Square wave in the Sirin sounds more similar to the Sub 37 sub oscillator (albeit more vibey), whereas to my ears the Minitaur has more of a Moog Rogue flavour in the Square (which I prefer). The saw wave is basically the same from what I’m hearing. maybe slight less bass/more top, but honestly you’d have a hard time hearing the differences once you’re actually using it in a patch.
Both are great, I’m finally selling my Minitaur and Rogue!
I’ve got two Sirins coming in the mail wednesday. Ill let you guys know what I think but my ears take a while to process the differences. I am a huge fan of this new synth from Moog. I’ve got a good feeling about it and its sound. Been wishing the Minitaur went into the upper ranges for a long time now. This is going to be great.
I think the MIritaur is one of Moogs best sounding synths and that growl will be very nice up in the upper octaves IMO. Now I will have two mother 32’s a Minitaur and a Sirin for my drone section.
I do have a question though. Are the Mother 32’s control voltages compatible with Sirin? Can I use the Mother 32’s keyboard to activate notes on the SIrin via patch cables?
Seems like I’m the only disappointed Minitaur owner.
I assume this couldn’t be done via firmware update. I’d love to see a hardware update option for the Minitaur if that’s what would be necessary.
I’m also curious why they didn’t add a power button/switch. I had to leave the screws out of my rack so I could unplug my Minitaur.
There are differences in the bass registers of the Minitaur and Sirin (Minitaur goes lower, way too low).
Sirin is hard locked to MIDI note 16 (about 20 Hz, 1 octave bellow a 4 string bass). Minitaur can go as low as MIDI note 4 (10.3 Hz) and stay fairly in tune and stable. Below that (notes 3 to 0), it will play lower sounds but out of tune (lower than the expected notes).
However, the main difference between the Minitaur and Sirin (having owned a Minitaur for only 2 years and a Sirin for a year) is not the note ranges but the oscillators sound. Sirin sounds stunningly bright and pure. Minitaur sounds like a bass.
Sirin is objectively more beautiful but I prefer my Minitaur.
Just picked up a cheap used Minitaur to compare with the Sirin I’ve had from new. Was kinda hoping that they would be similar enough that I’d be tempted to sell the Sirin and keep the cheaper Minitaur. However, it currently looks like I’m gonna keep both. 
As noted by previous posters the biggest difference is in the square wave oscillators. Where the Sirin has a purer tone whilst the Minitaur is a bit raspier with a slightly thicker bass presence.
There’s not a lot in it with each offering about 75% of what the other one can do. However, the Sirin is the one I would struggle to part with the most because that square wave does sound very special. They also sound great when layered together with slightly different patches/sequences. Consequently keeping both doesn’t feel quite as gratuitous.
J
Great info, thanks everyone
IIRC, the circuit boards for the Minitar and Sirin are identical.
There may be a few component differences, and certainly a different firmware installed to allow calibrating correctly over a wider range.
I traced out the oscillator circuit for the Minitaur several years ago, and it is virtually identical to the original Taurus from the 70’s. I was told by one of the Moog engineers that this same oscillator design was used in several other Moog products.
There is a trimmer (labeled “square” I think)on the Minitaur board that adjusts the pulse width of the square wave output for each oscillator. Any differences people are hearing is likely due to the initial adjustment (or drift over time) of this trimmer.
On my unit, I’ve adjusted oscillator 1 so it’s a perfect square, and oscillator 2 so it’s a bit narrower (at about 40-45%) to give it a bit more grit, which I like. I’ve considered making each of these trimmers a tiny front panel control, but haven’t gotten around to it.
Interesting, thanks synthguy
That is a useful bit of information, thanks synthguy!