Marantz 1150 preamp bridge mystery?????

[Poultrygeist]

My garage sale Marantz 1150 integrated amp has no jumpers on its preamp section yet works great. It doesn't appear to be bridged internally so does anyone have a clue how this can be?

[JohnMichael]

Here is a photo of the integrated amp with it's jumpers. If you are using it only as a preamp it would be normal for the jumpers to be removed and the pre out feeding another amp. In which case it should work fine for a preamp. In order to use the internal amp my understanding is the jumpers would need to be in place for the amp to receive the signal. If your speakers are connected to the 1150 and are being powered by the internal amp someone muct have done some kind of modification.

[Poultrygeist]

The jumpers are absent between the main in and preout and it currently drives two sets of speakers. It is not being used as a preamp but as a full integrated amp. The only thing I can figure is that it somehow can automatically sense a connection and switches internally?????

[Poultrygeist]

The power cord on my 1150 was changed so I suspect it may be a foreign model.

[Luvin Da Blues]

I'll betcha that if you take the cover off you'll find that someone has soldered internal jumpers in. They probably lost the jumpers or didn't want to deal with them. Just a thought.