Hello. Someone post a good, close-up photo of a clean A60+ board. On Ali, it’s not even for sale bare. I’d like to see the denominations on silk-screen printing.
Смотри, что есть на AliExpress! Плата усилителя мощности, основанная на стандартной печатной плате, для домашнего аудио, Hi-Fi, моно, для самостоятельной сборки, A60 за 853 ₽
https://sl.aliexpress.ru/p?key=Q289U0y
https://sl.aliexpress.ru/p?key=Q289U0y
Bummer
whenever I click on those links I only get the Russian version. Once I change to German there is no shipping available. Must be Russian stored items.
whenever I click on those links I only get the Russian version. Once I change to German there is no shipping available. Must be Russian stored items.
The photo is small, when enlarged, everything is cloudy. Therefore, I asked if there was a large photo so I could see the denominations of the parts.
Radian.Clear your browser history. After typing your aliexpress, your country should open.On it, look for this seller with the product.
Here you are. I don't think it's too different than the A60+, just more output pairs.
Just a question. In the photo below on the right, closer to the terminal, the base resistor on my board is marked as 2.2 ohms. All the rest are marked as 10 ohms. On some diagrams the base ones are indicated as 10 ohms, on some as 11 ohms. I have 11 ohms installed on my A60+. Where is the truth?
Excellent. A60 will be enough for you. It handles my 3-way acoustics with a 300mm bass driver with ease. Sensitivity 91dB.I'm ready to make monoblocks on A60++ boards🙂
Guys, what is the point in the A60 and A60+ circuits with the installation of 2.2 ohm or 10 ohm or 11 ohm resistors in the bases of the output transistors? What changes and why are the values different on the same circuits? The 22 ohm or 33 ohm is also installed between two 47 ohms on the circuit operational amplifier. Some do not. As I understand it, it plays the role of amplification?
I have not studied the topology of this amplifier yet but in general a small resistor in series with the base is usually to help prevent oscillation. Usually called a base stopper resistor. 10 ohms is what is labelled on the boards I have so that is what i will use. For the 33 ohm resistor - if you mean the one labelled as RF2 on the common schematics it looks like that would mean Feedback Resistor 2 which along with the 1k RF1 would determine closed loop gain.
Thank you, I wanted to know about this. The question is why on the diagrams that I have there it is indicated 2.2 ohm, or 10 ohm, or 11 ohm. On my board they are 11 ohm. The feedback resistor is 22 ohm or 33 ohm, in one circuit there is none at all. Again, on my board it’s marked 33rd and it’s worth 22nd. So I wanted to know, should I change something or leave it as is? Also, who has such boards, what’s in it or is in it, I want to compare it with my board. Thanks to everyone who responded.
The boards I have appear to be identical to the one shown above in post 690 except the PCB is green instead of blue. Looks like the same component values and layout etc.