The GG version, fully known as Gaincard, is a highly optimized LM1875 circuit from abroad that has undergone repeated comparison and verification. It boasts a wide frequency bandwidth, exquisite sound quality, pleasant listening experience, and excellent midpoint stability. If you haven't tried the LM1875, I recommend giving it a try. For users who have already purchased the LM1875, it can also serve as an upgrade.
The principle is that the voltages at the two input terminals of the inverting amplifier circuit are always 0 and do not change with the input signal. The input voltage of the transistor (field-effect transistor) at the amplifier input terminal remains constant, and the bias state always maintains a suitable operating point.
Generally, the single output of LM8175 is 4A current, according to official specifications. With low drive sensitivity and a large speaker, even using BTL (Bridge Tied Load) is ineffective, as the driving force falls short of expectations. By adopting a quad output, the drive current can be doubled to 16A. This results in a better soundstage, fuller mid- and low-frequency response, and increased power.
The sound channel is outputted by four LM1875 chips, with a quiescent current four times higher than that of a single chip. The total board current is approximately 0.5A. At medium and low volumes, it operates in pure Class A mode, producing vocals that are very delicate and natural, full-bodied, and more comfortable than the 1969 Class A. Meanwhile, it can be successfully set up without requiring cumbersome adjustments.
Product Highlights:
►Adopting the high-quality CG circuit architecture, the sound is very delicate and pleasant to listen to, with stable mid-point 4-channel and X2 small Class A output .
►40000UF large-capacity filtering, with excellent low-frequency dive .
►Double-sided gold-plated military-grade PCB, with good conductivity and resistance to oxidation .
►Adding red pentoxy copper inductance to the output, eliminating interference and clutter, resulting in purer and more natural sound quality.
►Japanese Omron protection circuit, for greater peace of mind .
►Fully high-grade component configuration.
Power range: AC12-AC22X2
Output power: 45W-8 ohms, 60W 4 ohms (5W in pure class A)
Impedance range: 1-8 ohms
Frequency response: 10Hz-40kHz
Size: 200*40*62
