High-quality power amplifier. (100W)

High-quality power amplifier. (100W)

Suggested your precious attention amplifier is simple to assemble, terribly simple to set up (it does not actually require it), does not contain a particularly scarce components and with all of this is very bad performance and simply pulls on the so-called hi-fi, so dearly loved by the majority of citizens . 
amplifier can operate the load and the 8W 4 may be used bridged to 8 ohms, and the load it will return to 200W.

Key characteristics are as follows:

Supply voltage,	+ / -35
Current consumption in silent mode, mA	100
Input resistance, ohms	24
Sensitivity (100 watts into 8 ohms), V	1.2
Output power (CG = 0.04%), W	80
Frequency, Hz	10 ... 30000
S / N ratio (unweighted), dB	-73

The amplifier circuit:

Amplifier is on discrete elements without any OS and other tricks. In operation, the load 4Oma and 35V power amplifier has an output of up to 100W. If there is a need to connect the load 8 Ohm power can be increased up to + /-42V, in this case, we get the same 100W. 
very strongly not recommended to increase the supply voltage over 42V, otherwise you can go without the output transistors. When operating in bridged mode should be used, 8-ohm load, or, again, are deprived of any hope of survival output transistors. By the way, it is necessary to take into account that the short-circuit protection of the load is not provided, so be careful. 
To use the amplifier in bridged mode, you must sign in MT bolted to the output of another amplifier to the input of which is signaled. The remaining input is closed on the common. 
Resistor R11 is used to set the quiescent current output transistors. The capacitor C4 detect the correct boundary and reduce the gain is not worth it - get the self-excitation at high frequencies.

The details.
All resistors - 0.25 W except R18, R12, R13, R16, R17. The first three - 0.5 W, the last two - 5 watts. LED HL1 is not for beauty, so no need prisobachivat Super Clear diode in the circuit and display it on the front panel. The diode must be the most common, green - this is important because LEDs of other colors have a different voltage drop. 
If suddenly someone was unlucky and he could not get the output transistors and MJL4281 MJL4302, they can be replaced by MJL21193 and MJL21194 respectively. 
Variable resistor R11 is best to take a multi-turn, although the fit and normal. Nothing critical is not here - just more convenient to set the quiescent current. 
So sign that all was in one place:

Designation in the diagram	Rating	Note
R1, R4	2.2K
R2, R3, R5, R9	22kOm
R6, R7	560
R8, R10	1K
R11	2K	Trimmer
R12, R13	3k3	0.5 W
R14, R15	220
R16, R17	0.33	5W
R18	10	0.5 W
C1	4.7 mkFh25V
C2	220
C3, C6	100
C4	100mkFh25V
C5	100mkFh50V
C7, C8, C9	100 nF
VT1, VT2, VT3, VT5	BC546
VT4	MJE15035	Can be replaced by BD140
VT6	MJE15034
VT7	MJE15035
VT8	MJL4302
VT9	MJL4281
HL1	AL307	GREEN

Actually setting comes to setting the quiescent current output transistors resistor R11 approximately 75-90 mA. 
Output transistors, of course put on the radiators. The area - 300-400 square meters. see for everyone. VT6 VT7 and also can make life easier by screwing them on the radiators of 50-70 square meters. see

PCB can steal here.