Both the LA90 and LA90D can operate in mono and stereo modes, giving users flexibility in configuring their audio setups. Trigger Interface: A Unique Feature for the LA90D Any item returned must be complete with all accessories, hardware, manuals, or instructions, and in the same "new" condition as when it was when shipped to you. Please send us photos or videos of it. Accidents, abuse, misuse, improper installation, problems with electrical power, acts of third parties. In terms of inputs, both models are equipped with three sets of balanced inputs: XLR and TRS, offering versatility in connecting various audio sources. Gain Settings: A Closer Look

I am thinking about doing the same as you getting a pair LA90-Ds with an A90-D to upgrade my 2 channel bookshelf system. I might even start with 1 x LA90-D as I have a small desktop setup in a small room. Customers are to bear the consequences and fees incurred, if the parcel was undelivered due to any of the following situation: If you also require a headphone amplifier, it is recommended to use LA90 Discrete with A90 Discrete. They not only provide the headphone amplifier, but also can be used as a pre-amplifier for the LA90 Discrete. It is worth mentioning that, the A90 Discrete also supports remote control and input expansion.use not following the ‘User Guide’ or any additional safety, use, or warnings included in the product materials. When it comes to signal-to-noise ratio (SNR), the LA90D holds the advantage with an impressive 143dB, compared to the LA90's 140dB. A higher SNR means a cleaner, more detailed sound. Built for Heat Dissipation: Both Models Shine Both amplifiers share the same dimensions, making it easy to compare them in terms of physical appearance and integration into your existing setup. Voltage and Dynamic Range: A Small Edge for the LA90D

Topping LA90 houses boat loads of power. In stereo mode, it outputs up to 110W@4Ω of load and in Mono mode, it provides up to 220W@ 8Ω of load. These numbers are extremely good, these reflect the LA90 can power most speaker setups in the industry. It has two level gain settings with +6.7dB gain in Low-Gain mode and +19dB in the high gain mode. It is clear that Topping engineers are bringing their expertise in designing ultra low noise and distortion in headphone amplification to power amplifiers. As such, they have outdone every amplifier I have measured in that regard, getting ahead to capture the #1 position with a large gap to #2 choice.The comparison between the TOPPING LA90 and LA90D provides a fascinating look at the evolution of these power amplifiers. While the LA90 is discontinued, it's interesting to see how TOPPING built upon its design to create the improved LA90D, which boasts an NFCA discrete amplifier circuit, a higher SNR, and more powerful output.