Im looking to purchase a tube headphone amp. I have not heard one before and I was wondering if there is a different between the tube amps and digital amps?
First off, there isn't such a thing as a "
digital amp." Amplifier circuits amplify an analogue signal, whether it was purely analogue like from a TT or converted from digital by a DAC. The closest thing to a digital amp is called a Power DAC, like the Wadia and Peachtree products, which instead of just cramming a regular DAC and amp circuit into the same box, basically has the DAC chip's output fed directly into the amp output stage to minimize the analogue circuit path and coloration.
Second, there isn't a single kind of tube amp. Most common when it comes to headphone amps are OTL, or
Output
Transformer
less designs. These have a high output impedance and spit out more power at high impedance, and are typically used for high impedance cans (and sometimes on high efficiency, low impedance headphones that won't be adversely affected, if at least not by making them sound like tin cans; ie, Grados tend to sound thicker with some OTL amps). These were primarily designed to skirt around the costs of producing transformer coupled designs, which tend to be larger, heavier, cost more to produce (ie some that can compete with good solid state designs are much larger and have three transformers, plus a heck of a lot of tubes), and in turn, also cost more to pack, ship, and store.
Then there are hybrid amps with a tube gain stage mated to a solid state output stage.
People say the sound is different. Isnt the sound supposed to be replicated to the original the best it can? So do tube amps add a different sound or change it?
Some tube amps behave more like good solid state headphone amps, ie, there are bad amps regardless of whether they are solid state or tube.
That said, OTL amps have a very high output impedance and aren't really designed for low impedance loads, so if you're using something like a K701, you need a transformer coupled amp, or just get a hybrid or solid state. Transformer-coupled amps tend to be expensive, so take that into account.
Some tube amps are bad from a technical standpoint since they're designed to introduce a lot of harmonic distortion instead of just simply amplifying the sound. My Little Dot MkII made Norah Jones sound like she needs to snort spicy chicken soup to clear her sinuses when the HD600 is on anything more worn than brand new earpads. It had the same warming effect on my SR225.
Personally, just get a hybrid with a low noise preamp tube, and then get a low noise, not too low gain, warm tube if it doesn't come with one. That will introduce just enough of the warming harmonic distortion to make Loudness War recordings slightly less glaring.
Also would I need or should I get a DAC with the tube amp? Id like to buy american made or good quality stuff so does anyone have any recommendations?
DACs : JDS Labs EL or OL DAC, Schiit Modi
Given you have the Fiio X1 Id much rather just get the tube/hybrid amp. Try the Vali2 if you have low impedance headphones, or the Darkvoice DV336se if you have any low impedance, lower sensitivity headphones.
