Pros: Price, Construction, Sound-tailoring Options
Cons: Power, Chassis Design (sort of)
The I+ from Little Dot is an excellent tube hybrid that offers much more than its sub-$150 price tag would suggest.
This is the first piece of head-fi equipment that I've owned twice. Bought one from a fellow Alabamian head-fier a couple months ago and had it for a little more than a month before deciding to sell as my "best" pair of cans weren't benefitting as much from amping. Within a week of the sale, I missed the LD too much and pulled the trigger on a new one! (Oh well, you live and you learn).
I purchased the I+ after reading up on how well it pairs with Grados, my flavor of choice. And let me tell you, it certainly performs brilliantly!
1st: Price: Inexpensive. These can be purchased from Little Dot's webstore for ~$140 shipped to North America and currently from Amazon for ~$120 with Prime shipping. For a hybrid tube amp with tube/opamp roll-ability, excellent sound and sturdy construction, why keep looking? This is it!
2nd: Design: Simple. 1/4" plug, volume pot, RCA inputs, and power supply. That's what you get. All sturdily built and thoughtfully implemented. While we're on the topic, the thick aluminum frame of the I+ feels great and hasn't shown any signs of component failure or weakness. The board is assembled very well and when I open it up to change the opamp, I don't feel afraid to touch the I+'s innards. Ain't nothin' goin' nowhere. The volume pot also turns very smoothly, the tube sockets are of sound quality, and the included power supply doesn't make me feel like LD tried to cut corners.
3rd: Sound: Natural. Since the I+ is a hybrid, the syrupy smoothness a.k.a. "tubeyness" is tempered with the detail and resolution of solid state technology. IMHO the LD is the amp equivalent of the Colorfly C3's sound: organic, musical, and neither so flat that it sounds boring nor so fun as to seem artificial. The best is yet to come however - you can roll tubes. AND opamps.
Options for tailoring your sound are virtually endless. Thanks to its interchangeable jumper capabilities, the I+ accepts tubes from the EF91, EF92, and EF95 families (not to mention others that may have to be adapted). That's plenty of tubes! From the punchy detail of the Voskhod 6ZH1P-EV to the buttery smoothness of the Tung Sol 6AK5, sound signatures are easily changed just by swapping tubes. The circuitry within also makes the I+ very quiet (as in noise floor) and it will warm tubes rather quickly. Opamps are also swappable, any DIP8 will fit (along with any that will fit onto a dual-to-mono adapter), so yet again, sound-tailoring is easy and abundant. So whether you're a vinyl junkie yearning for the super smooth tube sound of yesteryear or a digital wizard who likes the ultra modern edge of solid state, you can modify the SQ of this little amp quickly and easily to your taste.
As far as cons go, there aren't any real issues, just a few shortcomings that I may as well mention. 1. This is not the most powerful amp in the world. It will power all but the most hungry cans so, if you have THE MOST HUNGRY CANS, you may want to keep looking. 2. Opening the chassis to swap jumpers or opamps is a little inconvenient. Just to swap one or two pieces of plastic, I have to remove all 8 screws. Not hard to do, but the screws that hold the base to the upper half are tiny and sometimes hard to re-screw. Not to mention they are a part of the ground circuit, so if you lose one, you may open your amp up to noise. EDIT: Don't know why this didn't dawn on me, but I could just loosen the lower 2 screws on each side to open the amp up... Whoops!
So overall, the LD I+ is an excellent choice for those looking to get tube capability with plenty of variety available for tube/opamp rolling. The sub-$150 price tag makes this amp very affordable and the quality design makes operation very easy. I certainly recommend!
P.S. It plays wonderfully well with Grados. Enjoying Kind of Blue with my 325is as I finish this review!