Hi-Fi stereo-eelvõimendi

Suurus: 80 × 116 × 28 mm

This is a new multi-function Preamp designed by Douk Audio and Little Bear, you can used it as MM phono preamp or HiFi Tube Pre-Amplifier . Mini size can give you warm tube sound, alluminum chassis with charming tube light and Hi-end terminal, all of this c reate her perfect look. Furthermore , her warm tone definitely will give you the amazing music experience.

NOTIC:

Phono function Only for MM (Moving-Maganetic Cartridge) turntable only. not support MC truntable,
AUX function only for CD or DAC or PC or cellphone or similar player.

Quick guide:

This is HiFi PHONO RIAA and CD multi-function preamplifier.phono RIAA function part is I am re-design it refer DENON-AVR-2310CI AV amplifier, there is Very good music replay, sound restore to original. if you had a turntable already, now, it’s time to revisit the classic. AUX function is tube buffer function to get the better warm sound, so you can setup T7 work for AUX or phono by input selector….

Parameters:

①RIAA phono part:

RIAA freq response 20hz-20kHz +/- 0.5dB, S / N ratio> 85dB
THD <0.05%, input sensitivity 3.0mV, gain 40dB,
Nominal / max output 300mV / 1.8V
Output impedance 200 ohms, input 47k ohm / 220 pF

②AUX part:

Input voltage: AC12 ~ 18V
Frequency response: 20 HZ – 20 KHZ
Input sensitivity 300 mv
SNR: 96 db
Total harmonic distortion <3% (1 KHZ)
Power range output: 0.2 W
Output impedance: 100K
Input impedance: 50K

Default Tube model: 6J1 (Can directly replace tube model: 5654,6AK5, EF95 etc.)

Chassis size: (W)80 × (D)116 × (H)28 mm

Net weight: 0.24Kg (0.55Kg with package)

Package included:

1 x preamplifier
1 x power supply
2 x 6J1 tubes

Wiring Diagram Details:

Now according to customer needs, we add the Gain control switch on the PCB, you can switch it by yourself.

Q&A about the hum problem

Q: I got a loud hum with this T7 phono preamp.

A: For the hum noise, in the beginning, we have to clarified that all phono preamps have a certain of background noise. It won’t be loud, while a little loud is just normal. Turntable is a kind of analog players and cannot be compared with digital players in this respect. Besides, there are many factors which may lead to bad noise. To find the right reason, you need to do some tests and here are some instructions.

Reason A: T7 isn’t connected to ground well.

This is the most common and unnoticed reason. Please test it following the steps as below.

While the device is playing music, picking up the GND copper part of T7 with your fingers. If the background noise is much lower, then T7 isn’t connected to the ground. For this issue, we prepared a 3m wire in the package for you to solve it by yourself. Just use it to connect the GND with any large mental item in your home like windows or mental tables.

Reason B: T7 doesn’t match with your amplifier well.

There is a possibility that T7 may not match with some digital amplifiers well, which may lead to very loud noise.,(we’ve test it with few T and D Class digital amplifier. And found that. The T Class amplifier is best. Very quite back noise.. But. The D Class amplifier with loud noise. )

That’s why we recommend using professional pure HiFi amplifiers like AV amplifier or vacuum tube amplifiers (it will be better if the amplifier isn’t equipped with Bluetooth).

Reason C: The RCA wire has a poor quality.

A good RCA wire will be equipped with an anti-jamming magnetic ring, which can effectively reduce various interference.

Q&A about the sound distortion problem:

Reason A: your turntable output signal isn’t PHONO. Maybe is LINE OUT. Please check the turntable output JACK. if there is a PHONO/LINE OUT switch. Please set it in “PHONO’ mode.

Reason B: T7’s RIAA function part broken. Please contact us to get replacement main board. (or if you’re DIYer. You also can repalcement it. It’s 80% the OP chip burn. (the IC mode is: 2068, you can repalce it to 5532 or similar chip.