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A new development result named EARTUBE is a powerfull headphone amp with no solid state inside the signal path. The result is a clean, detailed sound with a touch of glowth tube amplifiers are known for.

Of course crossfeed is implemented.

The amp uses 3 x 6N3P and 2 x GU17 ( QQE 03/12 ) tubes.

This is an amp for relaxed and comfortable listening.

Details

2 headphone outputs

Maximum output:
30V at 100 Ohm
15V at 20 Ohm

Gain factor 16 dB (at 200 Ohm load).

Variable crossfeed filter switch:
1. Stereo
2. Low level crossfeed

2 pairs of inputs.

Input impedance 47 kOhm

Gold-plated input jacks.

Silver plated headphone jacks (Neutrik).

Silver plated heavy duty switches.

Alps-potentiometer for volume control.

110V and 220V versions available.

Built-in groundloop breaker.

Regulated voltage lines.

Weight: 6 kg.

Size: 28 x 30 x 11 cm.

customers note:

"Most of the Eartube owners in hea-fi said the sound is clear, neutral, and transparent, in general speaking, it’s good as phone amplification with Europe headphones, except AKG K501, K1000, and Grado RS-1 (from USA). Corda Eartube will neutralize the median frequency, the characteristic of RS-1, and K501/Eartube combo would be too neutral like water. K1000/Eartube also wouldn’t a good combo either. Remember! These reviews are on the state of original tubes. The most exciting thing of tube amps is “the sound could be very different by tube-rolling.”

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I use the NBS SIGNATURE II as the power cable on Eartube. I can't figure out precisely how the sound is. In my oppinion, Eartube is quite like Prehead (or HA): fast, pretty wide sound stage, and airy.(at least 70% of Prefead MKII SE) One thing diffst maybe, the sound will be very powerful, even closerent is slightly warmer than HA, Prehead series, but not regularly warm or slow like the normal tube-amp that we know. Remenber! I don't do the tube-rolling yet, maybe, jue to the level of Prehead MKII SE if 6N3Ps are all changed to WE396a. By the way, the Eartube needs to warm up at least 30min (15min in the manual).