Marantz 19 low bass response

[Robert Moser]

Hi,

I have a Marantz Model 19 that I had to undo several modifications on to get the FM to play in stereo, and the left audio channel to work properly. However, the bass response is non-existent. When the bass knob is in the "FLAT" position, the receiver sounds like an old transistor radio. When I turn the bass up all of the way, I get some bass, bu nowhere near where it should be. The tone amp board has been checked out and is fine. If anyone has any ideas, please let me know. Thanks in advance.

 

[txturbo]

Can you post some pictures of the boards?

 

[Robert Moser]

Thanks for the response. Attached are the photos of the tone board. Please note that there are no adjusting pots on it; and the slightly burned yellow caps (0.47 @ 250volts) are still working properly.

 

[foldthe]

I may be wrong. May be remembering a model 18, but those transistors in the pictures do not look stock. Maybe check to see if they are labeled and then check orientation

 

[tonebells]

I have a 19 open. I will look later today and see what the transistors look like.

Tony

 

[Robert Moser]

Thanks for the responses. I have several model 19's, and the transistors on the tone board are the same (TO92 case). If I recall the Model 18, it had the "mushroom" type transistors.