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NAD 304

Stereo Integrated Amplifier

NAD 304

Specifications

Power output: 35 watts per channel into 8Ω (stereo)

Frequency response: 3Hz to 70kHz

Total harmonic distortion: 0.03%

Damping factor: 100

Input sensitivity: 2.5mV (MM), 165mV (line)

Signal to noise ratio: 77dB (MM), 106dB (line)

Year: 1995

Price: GBP £249 (1995)

Downloads

service manual (en)

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NAD amplifiers

Comments

No Sound From Speaker Output (A & B)

Dear Sir,
My problem is no sound signal from speaker output, both A and B output, but the headphone jack output seems to be functioning as normal. Can anyone help please? Thank you

THT

304 output

Alltron is probably correct in assuming the relay being "off".

- Protection light on? So the relay will not operate.

- Try to check offset on the amp outputs, not on the rear panel, but inside in the circuit before the relay.

- If you encounter a dc voltage proceed according to my advice below.

- If the error remains, write again.

No Sound

It makes me think of the Speaker Relay not operating, do you hear it click after the 3-5 second delay? Failure of this relay to operate usually indicates defects in the ampl section such as a DC offset.

NAD 304 power amp section , protection ?

Gentlemen,

if you suspect an error in the power output section
(protection light, no signal, unusual drift etc.)
exchange R333, R334 47k 0.5 - 1W first before
starting to proceed. Generally everything will be
fine again then.

About 100 volts are dropped on these, driving them
in a state of unusability.

If you encounter tendency to oscillation remove C313, 314, 315, 316
and put these between collectors and bases of Q323, 324, 325 and 326.

Additionally two ceramic caps of 27 pF may be soldered between
collectors of Q313 and 315 on one channel and Q314 and 316 on the other.

Changing R421, 422 to 1 ohms 3 - 5 watts may be of additional help.

304 not working

The R333, R334 procedure was confirmed again with a new amp service entry,
I had been able to save time if I stuck to my advice above ...

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