I just got the Sense G3 this Xmas. I bought it the 25th and I got a visit from the mailman on the 27th! I don't think they celebrate Xmas the way we do over there in China. 
The downside is the seller used DHL, which means I had to pay extra fees and tax. Normally it slips right through but DHL declares by default so as to get an extra fee.
Sense G3
This is the version with 3 6N11 tubes. And as far as I can see identical to the Phenix. It looks and feels very well made. The separate power supply is a bit bulky but works well and keeps the size of the main box small and cute. The on/off switch is situated on the powersupply. Not very convenient because you can't tuck it away somewhere under the desk. But is is sensible in respect to sound quality otherwise you would have to loop an extra 2 high voltage AC wires through the DC power cord. First thing I did was put a power cord with a euro-plug on the powersupply. The powersupply is full of hotmelt and double-sided foamtape, so nothing will resonate.
So why did I choose this amp and version?
I was looking for a real tube amplifier I could hook up to my modded Muse NOS 4xTDA DAC so I could listen to any difference or improvements in sound. I wanted something not too expensive (there goes the majority of HP-amps), using tubes that are current (so no Little Dot), not too expensive replacing and good for audio. I have come upon a batch of Philips Miniwatt tubes last month that had several ECC8* tubes. The $50 Indeed/Muse is a hybrid transistor that has severe high rolloff so there wasn't much left out there. Then I stumbled upon this (item had no photo) in the Ebay store of a Chinese seller that has some nice pre-modded stuff. This turned out to be exactly what I was looking for. I wouldn't opt for the G3 T7 with the ECC81 in the middle because that's a bit of a wimpy tube.
Even though the inside wasn't exactly what was advertised (Wima MKP 10 turned out to be Ero 1860 polycarbonate which some find to be very good but I didn't). The power switch seems to be a bit oxidized in storage because it wasn't very reliable at first. I needed to flip-flop it a few times to work the first week. Yhe volumepot gives me some static because I modded my NOS DAC so it has no output caps and thus quite some DC on the output.
How does it sound?
Actually quite good. A bit muffled and the sense of space could be better. It is dead quiet. Good dynamics, good bass, nice mids and highs. Overall very good but not sensational and grabbing as in real high end. So, on to the soldering iron for some improvements.
What to mod?
Well, that's easy. I am fortunate to have 2 Sprague 0.47µF 200V PiO left. I measured the unit while switching on and it went just over 200V for a few seconds and then dropped again considerably (<150V) and rather quickly. So, no problem with a cold start and margin on the caps (safetymargin is related to time and temperature). I also didn't like the 3-wire ribbon from input to pot (crosstalk). So I replaces that with some seperate silvered OFC/teflon wire. And the oldstyle green LED had to go. And the input RCA's are guilded, but one whiff and the gold is gone. They are also very loose because you see the grooves from machining. Later I notices why they used these because on the inside of the case they are very short. Mine were a bit longer so the wire is pressed against the big elco. I put some shrinkwrap around the wire. I don't especially appreciate the little white plug on the wires but it's easier to disassemble that way. So I just put it in again. The potmeter is an open type Alps (prone to aging and clogging up). But I can't fit in a blue velvet.
Maybe I'll replace it later or short it.
So here's the result.
And of course I put in my 2 Philips SQ E88CC a bit later so I could hear the difference of the cap-mod first. I left the middle Chinese 6N11, to be replaced later. That one has the least influence on sound. The stock tubes are actually very good. The signal path is volumepot>middle tube 1 side> coupling-cap> outer tube channel 1> channel 2> out.
So, what gives?
Well, this is what it is supposed to sound like. Open, airy, sweet and neutral. The nasties in the treble have gone. It sounds clean and with great ambiance and space.
I have no problems driving my 250Ohm DT880's. It is finally giving it's best performance ever after using it for years on the pc.
With the Etymotic HF5 it sounds a bit more strained (it's not in the same price-league is it?).
I also tried the MDR-F1 as low impedance HP and I don't have any issues that I notice. I haven't used it in 6 years, the DT880 is much better. Or so I thought, but there is more... At first I thought it sounded a bit oversaturated on some voices but that is not the fault of the headphone or the combination (I checked it on the dac/hp-out of the Monitor02, hence different dac and (op)amp+ diff HP).
All headphones were equalized under Foobar>Musiland monitor 02US>4xTDA NOS>Sense G3.
Actually, now I properly equalized the F1 (it needs a LOT of extra treble >10kHz) it sounds pretty good. It is even better than the DT880 at stagewidth and depth. Wearing comfort is as good as before. I am really enjoying it again.
I have only a few minor mods to go but this sounds very good to me. High end at a bargain price. Just the way I like it.
Conclusion.
I think it is a very competent headphone amplifier for a very modest price. If you know how to mod it right (don't put your hopes on stellar priced NOS tubes) its a regular steal. It gives you real tube sound without all the nasty side effects like hiss, hum, distortion or flabby bass. It's just 3 tubehalves and a condenser away from straight wire. Simplicity is a sign of beauty.
![]eep](https://cdn.head-fi.org/avatars/m/139/139747.jpg?1273084439){kind=avatar}
