Joined in 2023 
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63 About this deal
With the 30V regulated PSU, we get very good suppression of mains components and the SINAD of 84.3 dB. As we can see from noise measurement, this is mainly affected by the residual noise.
The Aiyima published THD+N results for A07 MAX are slightly behind the V3 (0.003% for the V3 and 0.007% for the MAX) this translates into SINAD values of -90 for the V3 and -83 for the MAX. Note: these measurements have not been independently confirmed yet but they are inline with the expectation based on previous results. If you do use any discrete op-amps in these positions... In U2, U3 and U8 you will need Dip8 risers. You will not necessarily need any risers on U9 and U16. With the LM4580 the A07 sounds balanced, with a somewhat lighter bass presentation, but very neutral overall--a cheap and pleasant surprise.
A brief history of TPA3255 amplifiers
The OP amp is powered by a ±12V dual power supply, and the performance of the op amp will be more fully utilized, with better dynamics, and more details at the same time.
In the power-on state, short press the multi-function knob to switch the input mode, the bluetooth indicator light on means entering the bluetooth mode, and the RCA connection indicator light on means entering the RCA connection mode. The amplifier was tested with supplied NE5532 opamps and also with LME4562 opamps. I will always note which one was used. I will also note if the 30V regulated linear power supply or unregulated 50V linear power supply was used. Conventional electronic components are designed to operate over a specified temperature range with upper limits generally set at 70°C for commercial applications, 85°C for industrial applications, and 125°C for military applications. DC24-18V power supply.The DC seat uses all metal materials with fireproof flowers, which is safer to power on. DC seat interface 5.5*2.5MM. The Magnepan LRS's are not the most efficient speakers, at roughly 83dB @ 1W. Their impedance is just about board-flat, and right at 4 Ohms. The Aiyima A07 is very comfortable with 4 Ohm loads, where many other amps simply are not capable of handling impedances that low.
Comparison of the A07MAX and Fosi Audio V3
We don't know if it's load independent or not. Maybe we just see 4 Ohm load, and not 8 Ohm with 20 KHz bandwidth. We get almost similar result with Fosi V3 if we ignore 8 Ohm plot. With LM4562, the noise was -74.9dBV (24kHz), which would make S/N 87.9 dB re 5W/4ohm and 102.7 dB re 150W/4ohm. Realize this.. I'm spearheading this endeavor alongside an electronics engineer who is well suited to the task. Doing this with the intention to save you all a load headaches in the future. You were all advised that I was working closely with the designer of the SparkosLabs op-amps. I am doing the work here so others can make an informed decision and avoid pitfalls. I am not here seeking advice, accolades, affirmation or validation. If any of you wanted to collaborate and work together, the door was always open. I am advising and guiding you through these processes and informing you. Let's try to remember this going forward.
Bluetooth 5.0 Audio Wireless HD transmission: Adopt Qualcomm QCC5125 Chip,wireless music streaming technology with external antenna make a transmission distance of 10m,Support SBC\AAC\APTX\APTX-LL\APTX-HD\LDAC First... The amp has no balanced output or input. It is single ended. So using the term differential in describing U2 and U3 makes no sense. It is single ended, period. The only reason one would compare the A07 pro to the A07 is because "pro" indicates it surpasses the original. The A07 Pro excels at portraying the texture of stringed instruments, from acoustic guitars to violins to electric guitars. However, it doesn’t sacrifice body for detail – the sound is authoritative and full, with unexpected articulation. Great post! & great pics! Pop a temp gauge on your voltage regulators and see what they read. The community, I'm sure will benefit from and appreciate it. The temps of the regulators is the most important thing to observe. Because of what op-amps do... Those can heat up to much and fail. That's why I'm not going to be able to recommend the SparkosLabs for the A07 pro.The Fosi Audio BT20A Pro (review here) features the same TPA3255 amplifier chip as the A07 but sounds distinctly different. In addition, the BT20A Pro has a 3.5mm variable level Pre Out whereas the A07 Pro has a fixed-level Line Out. NE5532: The resolution is average, the high frequency is relatively dry, and the low frequency is relatively muddy and fat. Featuring both SE RCA & Balanced XLR inputs, stereo or mono operation, RCA for SUB out. Single volume control.. No BT, No tone controls and like the A07 Pro, 5 swappable opamps. My thread was primarily about the A07 pro and Sparkos only... But I find that even though I know Andrew and know what these SS3602's do that no other op-amp can... It doesn't automatically make it the best performer overall. None of them are. Only by mixing them up, safely... Can you find what really sounds good to you. Only by trying them out at the various stages can you find what works best where. This is normal. Therefore, I do not need a fan. I only need to vent the enclosure. And even this is just a preferential choice. Not a necessity nor a requirement.
The amplifier switched off itself after about 1 minute of this test, due to overheating. However it has survived.Using a 50V capacitor on a 48V power supply poses a risk of explosion due to the slightest accident in the circuit. I will be conducting a few more tests... But I'm pretty much done trying to serve this community. It's way more trouble than it's worth. I thought I would share some details on the latest Amplifier from Aiyima the A07 MAX. But first a little history of the reasons why this amplifier is special Bluetooth: Version 5.2 Bluetooth support: 16-24bit 44.1-48khz Supported format: sbc/aac/aptx/aptx-hd I totally agree that the Bluetooth side of things with the A07 Pro is phenomenal sounding. No need for op-amp swapping at all actually. I was really impressed.
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