MARANTZ Model(s) 27 (Twenty Seven) - 6-button vs 7-button

[jd2005]

Hello forum,

I am very much confused !

I have two MARANTZ Model 27 for restoration - One 7-button and the other 6-button.



The 6-button is / was with a dead all burned power amplifier and the 7-button is/was/ still is with dead FM-IF and hissy preamp.

This is the 6-button P500 Power Amplifier (half) board - burned...


I have found the service manual for what I thought will cover both.

https://www.hifiengine.com/manual_library/marantz/model-27.shtml

The service manual found here is relevant for the 7-button.... but looking for images of the MARANTZ Model 27 I have never that the 7-button model is more rare.

One of the main differences is the P500 power amplifier.

They share some similarities like having a 2N3055, MJ2955 complimentary couple output transistors. However the 7-buttom P500 board includes an IC while the 6-button MARANTZ Model 27 do not. And it seems to be much older ...

This is the 7-button P500 Power Amplifier board.



Anyway, I have done what i can do in order to restore the 6-button power amp. It will probably work fine, but i am still puzzled...

This is the 6-button P500 Power Amplifier (half) board.


Can anyone help solving the puzzle ? – What are these two configurations ?

Can anyone help finding the Marantz model 27 6-button service manual ?


Thanks !

 

[Isaac C.]

If I remember correctly, the six button version is the earlier model. They were prone to have power supply issues. Unfortunately, thats all I know, I'm not the one to ask about circuitry. I will say that my grandfather had the 6 button version and it suffered from a power supply issue. Hopefully someone with experience can chime in.

 

[jd2005]

Thanks for the update.
The power supplies on both the 6-button and 7-button looks similar. And they are quite simple in terms of electronics, also for repair.

 

[cemerson]

Which ever one has the best looking face plate, make that one whole again..... my two cents.

 

[wlhd1610]

I have an original 27 service manual here.
It shows it as being a six pushbutton model but the P500 board is like your second pic.









I do have a couple of six button 27 receivers here that I could pop the top cover to see what version P500 they have if that would help.


Bob

 

[wlhd1610]

I was curious so I pulled the cover on one of my six button 27's.

The amp board is the same as the one in your first pic.

Is it possible that your six button P500 is not original?





Bob

 

[jd2005]

wow.
This would be extremely strange and difficult to comprehend.
It's seems that my 6-button P500 is made of two separate boards.
However their dimensions when fit beside each other are exactly as the full P500 board.
Maybe I have a prototype in that MARANTZ 27 ?

 

[ancien]

wow.
This would be extremely strange and difficult to comprehend.
It's seems that my 6-button P500 is made of two separate boards.
However their dimensions when fit beside each other are exactly as the full P500 board.
Maybe I have a prototype in that MARANTZ 27 ?

This is not a prototype, Model 27, 6 buttons is the early one, which came with green dial.
The one on top of the woodcase is a late model with blue dial, like I have one.

A prototype can be seen in the serial (there stands model 1 on it) and it has a red dial pointer instead of a white one! I have seen a prototype and seen some ads by Marantz where they are featured.
regards