diagram ingram

1. Keep sensitive circuits of the transformer, casing dimensions are not
too small.
One blog even suggested to use two-bok, bok special one for the
transformer. For the toroid transformer or amplifier with a large
transformer, should only contain a series of power amps, with no tone
control. 

2. Change the position of the transformer, side by side into the lower side (the transformer is high) with
facing a series of sensitive posts 

3. Use a spacer on each PCB board as high as half the height of the
transformer, eg as high as 2.5 cm or more so that the PCB board parallel
to the core / center of the transformer, here the effect of the weakest
fields. 

4. We recommend using a stereo module instead of two mono modules
This avoids wiring errors. If forced to, try to size
cable between the right and left modules as long and as short as possible. 

5. Should take the ground path for the speaker of ct ct elco instead of the transformer,
if the board pcb mounted two big elco (like elco power supply), take
ground path of the speakers here, and check to hear! 

6. Power supply for radio (TX or RX) is very sensitive, use a capacitor
4x100nf, 4 pairs of these capacitors in parallel to each mem-diode (bridge). 

7. At the tone control circuit IC op-amp that uses a symmetric power supply,
sufficient ground wiring is taken from the signal ground wires only. should
IC power supply (7812) installed near the main power supply, not
mounted near the tone control. 

8. Always use a stereo cable shrouded perfect (color stereo cable
red-white-covered ground and wrapped in transparent skin. 

9. For power supply, use capacitors of 2200uF per ampere elco 

10. Zoom and ground wires as short as possible, especially a pair of
elco (ct line between elco) power supply (can be tried for the amplifier
blazer) 

11. For the amplifier should be mounted to the computer casing when not in the ground soil is diground PC casing soil 

12. Pairs of each kit to the circuit without passing groundnya nut /
baud / spacer. Do not let the existing ground line at the hole pcb
connected to the casing / box. Do not follow this ground. ground
attached to the casing should have one. if necessary use a plastic
spacer

overcome the noise: 

1. Use the active component (IC) that qualified as TL084, TL074, not
LM324. LM324 any brand of noise. TL084 is more guaranteed authentic
yellow (ST), not white. For now, the IC TL084 is printed white-work
unstable frequency
high (treble breaks and more noise). For IC 4558 (NE5532) use plain
white silk screening JRC4558D or TL072 - TL082 yellow, LF353 noise.
LM741 (NE5534) can be replaced with the Hitachi HA17741, LF351 noise may
also, has never been tried.
we do not have to look for the brand and the price is more expensive
because it is the most low noise. 

2. If necessary, the circuit power amplifier OCL, lowering its gain by lowering the value of
resistor in the path gain from 33k to 22k speaker, mimics the gain-clone lower amplifier noise. 

3. Should simplify the circuit, the circuit is too complex is more susceptible to noise and interference. 

4. Should then potentio / volume mounted on the input-power amplifier, such as professional amplifier without tone control.