Iron - a small stereo amplifier circuit for the ZX Spectrum.

 Stereo amplifier.             
                                          
   This article is dedicated to all those who have 
lam AY 8910/12 and General Sound.           
 If you have the above 
audio playback devices, but not 
have a power amplifier, then I suggest 
You wave a soldering iron and assemble m-a-a-a 
lazy diagram.  she is two- 
digital power amplifier.  Actually 
the reason for writing this article was 
lived that I assembled this amplifier and 
I was very pleased with it.                 
                                          
 This amplifier has a number of advantages: 
entities worth listing:         
 - good output power (2xZW);  
 - excellent sound quality;           
 - low energy consumption;           
 - supply voltage range: 5-15V; 
 - small dimensions that depend 
solely on the dimensions used 
parts, for example, if you use them 
tailor radio components, then it is possible, when determining 
effort, place it all on 
board, sizesmaller than a matchbox 
ka;                                       
 - low cost (all radio components 
with the exception of ICs they cost a couple of thousand 
a thousand old rubles, but the microcircuit costs 
about 10 thousand. Well, all together no more 
20 thousand rubles along with the board, solder 
etc. , which you will agree - quite a bit). 
                                          
 Now specifically about the amplifier circuit.       
                                          
   This whole thing is assembled on the ICTEA 2025, 
and several hanging elements (see pe- 
list of elements). Because this little thing is so 
gets very hot (especially if the 
tanning 12 B) it is advisable to install a radiator 
(I used it as a heat sink 
a bar from a children's construction set, soldered 
ee to the feet 4.5and 12.1Z top of the body 
microcircuits).  Analogs of this mikruhi are used 
shown on the circuit diagram of the amplifier. 
   the rest of the parts can be used 
any, even with denominations slightly different - 
differing from those shown in the diagram (values 
elements listed in section"Note- 
niya"of the list of elements correspond to the elements 
cops I used during assembly 
this amplifier), if only on both channels - 
lah they were the same.                 
                                          
 Details shown on the principle 
dotted diagram are optional:            
                                          
 - two resistors at the input, designated 
Rc  and Rc'  are needed to configure the input 
signal.  That is  if your speakers start 
make sounds similar to... I don’t even know 
to which, most likely, to gurgling and wheezing 
singing, then you need to put it at the entrance 
set a variable for each channel 
resistor or one paired for both channels - 
la right away. Then changing the resistance of the re- 
resistors to achieve the required quality 
sound. After setting up, you only need to 
measure the resulting alternating resistance 
resistors with a tester or ommetpom and 
replace them with two ordinary ones, with 
received denominations, although it is possible 
leave everything as it is.                      
 Attention!  Reserved in the wiring diagram 
pobaho place for resistors Rc and Rc'.      
 - two resistors at the output, designated 
Rr  and Rl are needed to adjust the output 
voltage or simply sound volume 
emitted by the speakers. Instead of these two 
resistances can be supplied paired 
variable resistor like the ones they have 
in tape recorders "KOMETA", "HoTA" or them 
similar, but then the opportunity is lost 
separate volume control for each 
one channel. It is advisable to select a resistor 
tors with linear dependence of resistance 
depending on the position of the resistor handle.         
 If you don’t need these bells and whistles, you can 
feel free to delete them.                      
                                          
   There is nothing more to say about the details, but... 
We're talking about a printed circuit board. Approximate time 
vodka amplifier board you can see 
on the wiring diagram. This option is 
vodka is the easiest to implement in the do- 
home conditions, although far from ontuma-flax.  If you do not have the ability to manufacture 
a printed circuit board can be used 
wired installation, although such reliability 
designs are significantly lower.             
                                          
 That seems to be all I had to tell you - 
shield.                                     
                                          
   P.S.  I almost forgot the most important thing. 
This diagram was taken from the demo  
written Nikolay Kosnitskyor another 
gomu  SNB from Legion of Steel Warriors 
(SNB/L.o.S.W.).How he writes on the run 
the diagram was previously drawn from 
piece of paper supplied with the amplifier PIoNEER. 
The schematic diagram was drawn by Cosnitsky 
Nikolay , I just changed it a little 
and drew a wiring diagram. I hopeSNB 
will not be offended by me for using 
I used this picture.                
                                          
 P.P.S.  Who wants to listen to how sings 
microcircuit (this is not a typo! it 
really sings, and without speakers :)) 
collect and hear what I, for example, 
never heard of it before.               
                                          
                                          
         List of elements.            
┌-------┬-------------┬------┬----------┐ 
│Position│ Denomination │Quantity│Note│ 
├-------┴------------┴------┴----------┤ 
│  Capacitors  │ 
├-------┬------------┬------┬----------┤ 
│C1,C2 │1 µF 50 V │ 2 │ │ 
│SZ-C8 │100 uF 16 V │ 6 │ │ 
│C9,C10 │470 µF 16 V │ 2 │ 500 µF │ 
│C11,C12│0.1 uF │ 2 │ │ 
├-------┴------------┴------┴----------┤ 
│  Resistors  │ 
├-------┬------------┬------┬----------┤ 
│R1,R2 │30 com │ 2 │ 33 com │ 
│RЗ,R4 │82 ohm │ 2 │ 100 ohm │ 
│R5,R6 │1 ohm │ 2 │ │ 
│Rc,Rc' │100 com │ 2 │select │ 
├-------┴------------┼------┼----------┤ 
│ICTEA 2025 │ 1 │see analogues│ 
└---------------------┴------┴----------┘ 
                                          
   Another one P.S.  Today is 29.03.1999. Usi-
lock works just fine. Collect-
you won't regret it.                        
                                          
      Schematic diagram of the amplifier.     
                                          
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
                                          
              
              
                                          
        Монтажная схема усилителя.        
                                          
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