Attention! Marantz PM 17 series users

[east electronics]

Marantz PM 17 series feature a couple of capacitors of 33nf or 333J located directly on the binding post .

I cant exactly imagine the use of them but i can see it as an additional zobel ?? Good ..they tend to fail also fail partially

Unit might play in very low or low power but increasing the power will short the cap and protection will kick in ...

FUNNY PART OF THE STORY

amplifier was in the service center where the tech replaced almost every diode , every zener ,VBE multiplier , all transistors ,drivers and outputs to locate the fault ( probably thinking that protection kicks in for DC reasons ) keep the amp there for more than a month and asked the costumer to allow one more month for proper fault finding ...

Guys i am laughing my brains out !!!

 

[jaycee]

ive seen capacitors directly across the output terminals on several amps. I presume it is about emissions control.

 

[Vostro]

I can imagine how crappy that problem would be to find.
But I've also wondered the purpose of similar capacitors.

Here is a picture from a Yamaha A-S700.
And I'm not sure why all the caps on the speaker terminals,
I thought loading the amp output with capacitors would provide instability.

Regards

 

[jimchan]

I have this amp.... really authorative and laid back sound.

It is now 8 years old and considering swapping the out the power caps. Do you recommend swapping these across the terminals as well?

 

[Welcome]

. Do you recommend swapping these across the terminals as well?

Come on, that's what this entire topic is about.

Atention !! Marantz PM 17 series users

Marantz PM 17 series feature a couple of capacitors of 33nf or 333J located directly on the binding post . they tend to fail also fail partially

 

[jimchan]

Anything useful to add or just spamming ? ;-)

 

[Ian Finch]

.....It is now 8 years old and considering swapping the out the power caps. Do you recommend swapping these across the terminals as well?

Assuming you refer first to the main reservoir electrolytic caps in the power supply, 8 years is way too soon for them to need replacing unless they were total rubbish - but only such electrolytic caps dry out and fail. They can be measured to evaluate their condition. Other solid dielectric types such as film and ceramic should last indefinitely.

Unless you just want to change something in the amplifier for something to do, it shouldn't need any replacement caps inside 20 years.

 

[jimchan]

Aha, thanks Ian.

If this is the cap lifetime, then I will leave the amp alone! They are Gold Tunes, so certainly premium. I have a Honey Badger Build I can work on instead.

The Marantz sounds very powerful and authoritative, can listen for hours. Although have to say it is not an exciting amp - it is very laid back.

 

[who1981]

Safe to Remove Caps?

I inherited a PM-17 and Tannoy m4s from my awesome aunt Nanci (RIP)... I'm having the symptoms described. Is it safe to just remove these capacitors, at least to test, possibly permanently?

Thanks!

 

[Ian Finch]

Read the OP again and note Sakis is not talking about simply removing the caps but replacing them. They are there for a reason so fit similar film types with a sufficient voltage rating.

The type described by Sakis is also 33nF and located on the output terminals, not on the PCB as your image of the MkII version shows. You are probably talking about a different amplifier assembly there.

According to the MkII service manual which also covers the KI version, C909 & 910 are 10nF film caps - no special details so ordinary 100V rated MKT or greencap types should be fine if you want to change them without testing whether they need it or not. I'm sure you could pull the caps and use the amplifier at low level without problems but don't leave it that way for longer than necessary to see if that has any influence on the operation of the protection circuit.