Marantz 2270 Survey

[soundweasel]

Some were covered with black sticky adhesive(probably to hold the metal cover or housing in place?).

When first installed it was a piece of adhesive-backed foam rubber to provide a little cushion between the metal case and the frame/chassis to eliminate any vibration from a sound source, like speakers, and are/were located at the front and rear of the piece.

Like deteriorated foam rubber speaker surrounds, this strip has turned into sticky goo over the years. A true "restoration" of a Marantz receiver should include replacing these strips. :yes:

 

[sssmokin99]

I've noticed over the years that marantz has used different ouput transistors. Can anybody tell me if there is any difference between the three or four that were used? Thanks, jay

Jay,
Do you mean the manufacturer or the part number? Marantz didn't actually make ANY of those transistors; Motorola, Fairchild, Toshiba were the primary OEM's I believe. A good replacement PNP/NPN pair for most of them are the ON Semi MJ21193G/MJ21194G devices.

 

[signal-dude]

A good replacement PNP/NPN pair for most of them are the ON Semi MJ21193G/MJ21194G devices.

Also the OnSemi MJ15024 and 15025 work fine. Gain match them as close as possible, within 10 and they are sweet. No oscillations or nasties seen on my scope.

 

[jstang]

I have been using ON Semi MJ21195G/MJ21196G devices for the 500 and they have been very nice so far. Even under an accidental over load (don't ask), not a single issue. The 500 needs the extra Vce of the 5/6, the 2270 should be fine with the 3/4s, but I have not used them.

The MJ21195/6 have very very linear gain....I would think the 3/4s are designed the same.

jk

 

[jcarswell]

Output Transistors

Hey sssmokin99 how's it going? Thanks for all the goodies for my power board. It sure sounds sweet.

I wasn't sure if marantz manufactured output transistors for the 2270 and so I was trying to figure out if there was any difference between Motorola, Fairchild, Toshiba? I have Motorola in one of my 2270s and Fairchild in the other two 2270s.

Jay,
Do you mean the manufacturer or the part number? Marantz didn't actually make ANY of those transistors; Motorola, Fairchild, Toshiba were the primary OEM's I believe. A good replacement PNP/NPN pair for most of them are the ON Semi MJ21193G/MJ21194G devices.