Originally Posted by ALRAINBOW
May I ask you some questions. Or first explain the whole chain to me . Specs included if possible .
I have my Lenovo laptop going to a Yulong D100 Dac/Amp. I run line-out from the D100 to the Tubemagic A1's line in. From there I have the HE4 to the speaker taps via balanced 4-pin XLR to an adapter that goes to bare wires to the speaker taps. Pretty straight forward.
Lenovo Laptop > USB to Yulong D100 > Line-out to Tubemagic A1 > (speaker taps) Balanced 4Pin XLR to HE4
Edit: I'm using the line-in on the front of the A1 vs 'analog in' on the back of the unit. Wonder if that makes a difference? Listed on the very bottom it says the RCA as 1000k ohms, maybe line-in on the front is different.
@john57 mentions: The amp uses a LM1876T chip for the output. If the chip is using bridged mode it is not a common ground amp at the speakers outputs. How are you connecting the headphones?
Here's some info on the D100:
- Inputs: Optical, Coaxial, USB, AES/EBU
- Input digital signal format: 32-192 KHz, 16/24 Bit auto detection. USB supports up to 24Bit 96KHz
- SNR: >120dB.
- DynamicRange: 115dB.
- THD+N: <0.0005% at 1KHZ
- Frequency response: 20-20KHz-0.16dB.
- Headphone output power: 130mW at 300Ohm, and 900mW at 32Ohm
- Headphone output impedance: 16 Ohm to 600 Ohm
- Dimensions: 10" W x 7" D x 2" H
- Net Weight: 1.5Kg / 3.3 lbs
- Packing Size: 12" W x 12" D x 4"H
Included in the packaging: DAC, user manual, USB cable. Power cable
Note: The factory warranty is void if the DAC is opened not by authorized dealer or service center.
WARNING: Both of the RCA and XLR line level outputs are NOT controlled by the Volume knob on front panel, and as always in full output level. Any equipment connected to these outputs must have a proper volume control, otherwise your headphones or speakers might be damaged. It might harm the hearing of audience too. Manufacturer is not responsible for any damages caused by improper usage.
Quoted from an earlier post, here's the A1:
- All RCA connectors are gold-plated
- Volume control is provided for all outputs
- Power outputs: 20 watts per channel (into 8 ohms), 40 watts per channel (into 4 ohms)
- Frequency Response: 20Hz – 25KHz
- Input Impedance: 100K ohms
- Analog RCA outputs signal-to-noise ratio: >90dB
- Tube pre-out outputs signal-to-noise ration: >90dB
- Total harmonic distortion: less than 0.1% (Tube pre-out outputs and analog outputs)
- Headphone maximum output power: 1000mW x 2 (32 ohms), 500mW x 2 (300 ohms), 300mW x 2 (600 ohms)
Additional info on A1:
Edited by Soundsgoodtome - 3/17/14 at 6:07pm
- Analog audio input x 1 (Analog)
- Line-in audio input x 1 (Analog)
- Analog connector: RCA, 1000k ohms