Marantz 2325

[ledd4u]

My marantz 2325, once in a while will seem to cut out and in. Sounds like some muting circuit but with kind of like a thump before it cuts out. Any ideas to what may be causing this intermittent operation?

Thanks

 

[megawatt]

Sounds like the protection circuit is turning on. This should be evaluated ASAP by a tech. The protection circuit is there to protect the output stages. I don’t know how often this is happening, but if it happens with any regularity, I would stop playing the unit. You risk blowing the outputs by allowing the unit to reach this condition over an over. In my opinion, anything that is serious enough to trip the protection circuit is good reason to pull the unit from service until it can be fixed.

This could be something as simple as a bias or DC offset adjustment, or could be an indicators that a component is going south.

Just my opinion…

 

[ledd4u]

It has done it twice since I have had it and only when the unit has not been used for a while. I have replaced the power supply caps thinking that was the problem since the unit ran out of steam at louder levels. Replacement of the caps corrected the that power problem but the other symptom still exists. It is intermitent so finding it might take me some time. I did go over the allignment and did not find anything abnormal with the unit before or after the main cap replacement.

 

[EchoWars]

Marantz units of this vintage seem to have trouble with the amp input differential pairs. Match a new pair and install them.

Good idea to recap the regulator board too.

 

[ledd4u]

Echowars, I am going to look into the protection ckt and investigate the H712, H710 diff amp junction for faults.

 

[Leestereo]

...Good idea to recap the regulator board too.

+1 The regulator board on the 2325 runs hot and the caps around the 5W ceramic resistor often dry out.

 

[catrafter]

Marantz units of this vintage seem to have trouble with the amp input differential pairs. Match a new pair and install them.

Good idea to recap the regulator board too.

+1 The regulator board on the 2325 runs hot and the caps around the 5W ceramic resistor often dry out.

I like to mount the big resistor up as far from the board as possible to allow for better air circulation. The marginally rated 2SD331 transistors can also be replaced with 2SD313 types.

Tom