This product uses 6j1 tube to do pre-level lm1875 amplifier, with amp function. After 6j1 tube buffer, can significantly reduce the "digital taste" and "transistor sound", so that the whole sound system to bring a sweet natural "bile", the sound is more sweet, soft. Than the average lm3886, tda7294 better listen.

The pre-level is the use of 6J1 fever tube gall bladder before the class: imitation machine music fax X-10D circuit principle design, to be reasonable to optimize, more stable than the original machine performance, the tube to play increased by 10 percent. This machine uses dual AC 18v input, do not have to worry about looking for high voltage power supply The board comes with boost to enjoy you in the low power supply to enjoy the charm of high-voltage tube

Power works: a power supply, tube filament began to heat, then boost from the zero voltage began to boost, and other tube filament hot, the boost is just boost finished, so this is the same with the bile rectification, 4 470UF The capacitor filter is very clean, excellent power supply system will not have the exchange of sound, the filament is DC 12V power supply, the need for two tube filament is in series, the use of DC filament is also to reduce noise.
Before the output level automatically switch to promote the headset or push the rear lm1875 amplifier, that is, after inserting the headset, the amplifier without output, do not insert the headset, is to promote the amplifier output
 
The output of the sound slightly smaller than the digital sound source, thrust in general, if the friends can accept this way, but also the output of the product, Then you can try, after this product sound source processing, headset sound there will be a kind of sweet and delicate "bile." Headphone output function can also be used to do the output level, then the other after the amplifier.
 
After the class lm1875t amplifier: Europe and the United States LM1875T classic design! Wiring is reasonable! Outstanding performance! Have sought by DIY lovers! Store to retain all the original alignment, to retain the original performance of the premise, but also to strengthen the original components of the Oh, the introduction of 6j1 tube to promote the sound more sweet and beautiful!
 
5% precision metal film resistors, Beijing J-class military regulations tube 6J1, nichicon, elna fever tonic capacitor, better performance, the sound of the use of heat Better!
 

Performance parameters:

Power supply voltage: the default dual AC 18v / current 3A, power 60w or more (the maximum voltage can not exceed the dual AC 19V, nor less than 18v, otherwise the tube point is not bright, the sound distortion. If you need to use AC 12v, need to modify the wire buck resistor For 2.2 Europe, then the amplifier output power will be slightly lower)

Amp / front output: magnification about 0.8 times (amp function can try to use, you can promote the high sensitivity of the headset, thrust in general, the amp output can also be used to the current level of function, the output then drive the other amplifier, with tube taste. )

Lm1875t amplifier output power: typical 20W (maximum 30W)

Speaker impedance: 4Ω-8Ω

Total Harmonic Distortion: <0.04%

Signal to noise ratio: 105dB

Frequency response: 14Hz-100kHz (by the RC high and low circuit count the maximum range of 3.29Hz-482.29kHz)

package ：1x finished HIFI 6J1 tube amplifier Headphones amplifiers LM1875T power amplifier 30W