hi,
i have bought this one, old orion 250sx.
this amplifier work, but have a strange noise from toroidal trasformer.
this amplifier is repaired (not from me), i have found on power supply BD911 device. is correct? Is power supply TL494 based.
i have bought this one, old orion 250sx.
this amplifier work, but have a strange noise from toroidal trasformer.
this amplifier is repaired (not from me), i have found on power supply BD911 device. is correct? Is power supply TL494 based.
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Is the noise audible in the audio?
Will it be audible when installed in the vehicle?
Typically, if there are no gate/base resistors, the transistors are BJTs. Having gate/base resistors doesn't guarantee that they will be FETs but they generally are. The BD911 in your amp is likely correct.
Will it be audible when installed in the vehicle?
Typically, if there are no gate/base resistors, the transistors are BJTs. Having gate/base resistors doesn't guarantee that they will be FETs but they generally are. The BD911 in your amp is likely correct.
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Hi Perry,
This noise don't is udible on the speakers and don't is audible on the vehicle, is a little noise without cover
This noise don't is udible on the speakers and don't is audible on the vehicle, is a little noise without cover
I wouldn't worry about it. Sometimes simply moving the windings slightly can stop it.
Confirm that the output from the IC is at 20kHz or higher.
Confirm that the output from the IC is at 20kHz or higher.
One another thing, the resistor on the picture attached, on the green circle, 100ohm is correct?
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Wasn't it a 10 ohm in the original photo you posted?
I just looked through some photos and in a different version of the 250SX, it used D44VH7s in the supply. I'd say that's rare in these old amps. The 2N6488 was very common. The 6488 isn't as 'fast' as the D44 but worked well. This isn't to cause confusion. Just a note.
I just looked through some photos and in a different version of the 250SX, it used D44VH7s in the supply. I'd say that's rare in these old amps. The 2N6488 was very common. The 6488 isn't as 'fast' as the D44 but worked well. This isn't to cause confusion. Just a note.
This resistor is present only in the last picture, i have measured 100ohm, but was changed (not from me)
Yes is true, i have 240gx and 280gx first series with 6488 device on the power supply and works fine
There is an identical driver circuit on the other side. Has someone replaced the corresponding resistor in that circuit as well?
OK. I don't know. This circuit was so rare (in my shop) that I never had any reason to draw it out. If you can do that, maybe we can determine what the resistor should be.
I don't have anything that shows that resistor. Bench-test it with the 100 ohm to see if the amp functions normally.
It's VERY rare to see any resistors over 1M in car amps.
If the resistor burned, there's no voltage in the amp that could have done that to a 33M resistor. The resistor was likely 100 ohms or less.
If the resistor burned, there's no voltage in the amp that could have done that to a 33M resistor. The resistor was likely 100 ohms or less.
I've found photos of a 2125SX that uses the same type of drive circuit. The resistors appear to have burned at one time but the replacements are 33.2 ohms.
On one end they go to the bases but the other end doesn't look like it goes to ground. In the first photo, ground is very near one terminal but it doesn't connect to it.
On one end they go to the bases but the other end doesn't look like it goes to ground. In the first photo, ground is very near one terminal but it doesn't connect to it.
