LM4702 + SAP15 amplifier - new design
I just thought that if anyone was interested, maybe they would benefit. The test project was created in EASYEDA and it even looks quite good, after Christmas I will start it.
https://easyeda.com/wawrzo1970_7526/lm4702_darlington_mt200
The project itself is available in four versions:
with transistors: sap15, std03, darlingtons in MT 200 and TO3 housings, the last two versions are in the process of being finished, because they require slightly larger PCBs. I encourage you to modify it yourself.
Comments
Not bad. If I remember correctly, the LM4702 can be found in the Arcam AVR500 and AVR600 series receivers. These receivers were great both for home theater and stereo. I think I have 2 chips and SAP15... [Read more]
Since we have 2 rectifier bridges, was it not possible to build two independent power supply systems on a common transformer? Or at least if there is common filtration, then separate fuses for the right... [Read more]
The LM4702 does not have a separate power supply for both channels and the division of the transistors themselves seems pointless in this case, it will only cause an unnecessary expansion of the system.... [Read more]
The US power supply is not a problem here, but what if one of the channels is defective? E.g. power level? We immediately lose the second channel (there is not even a division into fuses). A diode is... [Read more]
Interesting. It is a pity that both the LM4702 and SAP15P / N transistors are no longer produced and the chance of getting the originals at a reasonable price is probably negligible. [Read more]
As for the parallel connection of the bridges, in this case the assumption was to reduce the dynamic resistance of such a tandem, which causes when the bridges connected in such a way are loaded with a... [Read more]
I still do not understand how this dynamic should look like for two parallel loading bridges for a total filtration of 40 mF in relation to two independent loading bridges for independent filtrations of... [Read more]
To me personally and subjectively, the bass on the two bridges seems warmer, but this is my subjective opinion resulting from listening to the STX Quant 300 speakers and the DIORA WS600 amplifier (with... [Read more]
My colleague knows, sometimes it is an auto-suggestion effect (this topic was once discussed on the forum as a constructor's impression or something). Only specific measurements can indicate something,... [Read more]
How is the "temperature" of the bass measured? [Read more]
You're getting into really difficult terminology. [Read more]
A subjective feeling, if a colleague had doubts, and besides, he does not measure, but feels. We can only measure physical values according to the laws of physics. An example would be temperature. Ehh... [Read more]
Are you clinging? You may have asked what the author thinks that term means. Unfortunately, when describing sound impressions, similar expressions cannot be avoided, either someone understands them intuitively... [Read more]
Warm/warmth – a general downward tilt in the frequency range between 300Hz and 3kHz. The opposite is cold. Stąd: https://diyaudioheaven.wordpress.com/tutorials/how-to-interpret-graphs/frequency-response/ A... [Read more]