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AIYIMA A07 TPA3255 2.0 Channel Power Amplifier 300Wx2 HiFi Class D Stereo Digital Audio Amplifiers Sound Amp For Passive Speaker Home Audio DIY with 32V Power Adapter

£9.9£99Clearance
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They have different components inside compared to previous lots. I bought 4. The 4th I returned for this very reason. They are all different. Some have lower voltage tolerances some higher. Different caps in each unit. Differently wound inductors. This has has also been reported by others here that different lots present with different components... Many of these Chi-Fi companies also start with good components and then phase them out for cheaper ones. Some put top components into review units and then cheaper ones in the retail offering. But in fairness... The differing components was also most definitely affected by the reported supply issues that nearly everyone faced. But it also happened before this. In my listening space the Aiyima will play at levels that are truly painful, and that's with the volume knob set at about 50%. From the ASR review I know that there is a known issue with the amp (or power supply) shutting down at around 77 watts. Even at the 77W output level the measured distortion (ASR review) is quite low. Because I'm not experiencing the shutdown, I am confident that at the 50% volume knob setting, the amp is not even driving 77W... A more capable power supply is supposed to get this amp to higher power outputs without shutting down.

Currently, the op chip used on AIYIMA A04 & A07 is NE5532. Although NE5532 performs well, many audiophiles still want to improve the sound quality by replacing the OP chip. Their own THD measurements are about 0.0075%, roughly double or more compered with Fosi v3 ( 0.003%). Practical funtions to simplify use:aluminum alloy case is specially designed, cool and unique to decorate your desktop space. The amp has an auxiliary line level out which is not controlled by the volume knob. I use that to feed my Topping A30 headphone amp and that works great.This is a small, tiny, cheap amplifier. Concerning its ultra low cost, it does not behave badly. At lower frequencies it measures well. Better SINAD parameters would be obtained if the intrinsic noise was lower. Care should be taken because both output terminals are always at ½ PSU voltage, with respect to the amplifier signal ground and metal case. The results obtained highly depend on the power supply used. My recommendation would be a linear, regulated power supply. Maybe also a SMPS with very clean output. Remember that output spectrum of higher harmonics depended strongly on power supply cleanliness. Another issue is frequency response peaking with high load impedance. This may easily happen with some speakers when impedance at tweeter band frequencies rises. 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.

So.. It begs the question why would the Aiyima Rep tell us the U2 and U3 do two distinctly different things... This makes absolutely no sense at all. Burson's should fit. The case will need to be cut or their adapters used. I am working to secure a set because based on the research done by others. A combination of Sparkos and Burson V6 vivids will yield the best results. 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. Those 4 little nichicon 25v 10uf muse caps are an end-of-life product as far as my research has determined, so at some point these will be no longer available. Just a heads up on that one I can remove the SparkosLabs op-amps and reinstall the NE5532 op-amps. And under those conditions, a fan IS NOT necessary at all. Neither is case venting.

I am using the V3 and MAX amps with the supplied 5332 op-amps. I had changed out both of the older Aiyima amps to 4562s. You were fully abreast of the emergent situation and therefore your advisory statement was warranted and valid because it was from an informed position. This is why some have found great results with a Sparkos in the volume stage and the Burson in the output gain stage. These do similar things, but the end results are that they sound different from each other and those difference are noticeable. Put them together though and you can get the best of both worlds... But only in that configurationkfor certain devices) . Swapping the Burson to the volume stage and the SparkoS to the gain stage doesn't give the same results.

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.

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. When measuring A07, one has to bear in mind that it is a BTL (bridged) amplifier, thus both speaker output terminals are “Live”. There is always a DC voltage of ½ PSU voltage at each terminal. The speaker sees the voltage difference, so no problem, but SE input soundcard could not be used for measurements, as it would short one of the output terminals to ground. Please also note that in case of grounded 48Vdc power supply, each of the A07 output terminals would be at hard 24Vdc vs. ground. This will also happen with class II power supply but some of the audio chain components in class I, thus grounded. And it's ultimately chasing something you convinced yourself existed and that you believed you could catch.

Also... It is important to note that it literally makes no sense what the Aiyima rep said about these op-amp positions. This is the frequency response into 10ohm. Note the 50kHz LC filter cut-off and also gain peaking at 45kHz because of lower damping of the output LC by 10ohm load. What is my opinion from the subjectivity of just listening to music?, I think it is a great product considering its price. I don't see the point in comparing it to the Aiyima a07 for two simple reasons, the first is that I don't have an a07, and the second is that I simply needed the addition of Bluetooth. I have no doubt that the a07 is a great product, but in this specific case it is not exactly what I needed. However, seeing the quality of this product, I will definitely buy an a07 which is useful to use in another office I have. However, you could reduce that edge by removing it and sanding that edge down a bit. Make sure you have thermal paste for the chip if you remove it. Clean it up and apply new paste. Many of you will know this

Comparison of the A07MAX and Fosi Audio V3​

Using a 50V capacitor on a 48V power supply poses a risk of explosion due to the slightest accident in the circuit. This was covered from the very beginning and anticipated just as the needed heatsinks for the voltage regulators were. Guess everyone skimmed those details and didn't catch on. At least that is what you all decided to prove. But regardless, I have already conveyed my sentiments about this A07 Pro... LT1057: The two ends extend well, and the speed, dynamics and resolution are also quite good, but it is a cool tone. So we have a problem. Below is the frequency response into JBL Control1 Pro, measured at amp terminals. There is a big interaction of the output filter with the speaker impedance and this may be audible. I think it is the peaking between 3kHz and 10kHz that might be audible. Offering advice without it being asked for, is for the most part considered offensive because it can be viewed that the advice giver thinks that the person he is advising is too stupid to know better. This is why you don't give advice unless it is asked for. Advice, when not asked for is discouraged because it is discourteous and rude

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