New to Marantz, new old 2270, recommendations

[cortico]

You got it! It's a pioneer PL-530 built in 76 I think... It wasn't working when I got it, it happened to have a loose fuse clamp inside. I pulled my air until I spoted it! Have fixed that, instaled a new cartridge, new headshell wiring and now the interconnects.

It spins like a timepiece!

 

[HVHiFI]

Shure m97xe? Nice cartridge.

 

[cortico]

Finally tonight I have jumped on the amp board. Lucky me I only had to access to ends of both boards.

In the beginning, I felt like defusing a bomb but things run well, extra care was taken when removing the tinny diode attached to the heat sink.

There was a set back in the end when adjusting the bias on the left channel, it wouldn't go below 12mv which freaked me out a bit! I started the troubleshooting with the bias diode+transistor assembly and reinstalled it. It's running well now the trim pots taps all the way down to 0mv, probably the diode was out of place. Very likely, I probed the wrong terminals.

I still have an issue on the bias setting, never got a clear answer and read contradictory information. When reading between j754 and j756 what should I have 5mv or 10mv? I seted it at 8.5mv is running for an hour with no issues.

Threads without pictures are useless, right?
Releasing the left board, this offset screw driver was priceless!


The left side, i raised the board about 2" from bottom and holding it with a chopstick.


On the right side, a 2" gap was all I needed to replace the caps and clean the board.


I spent almost 2 hours per board to change two (C759, C760) 10uf caps and the (C701) 22uf cap. Had to mark the 22uf cap, I almost got one installed wrong.


These are the parts I got out in this partial recap. The picture is missing the big filters, dial diffuser, light bulbs and the power resistor. I am thinking that I should do the tuner boards as well. Then, to be in piece of mind I would like to have the unit professionally checked and setup.


The test, idle current set to 8.5mv and DC balance set to 0.00mv

 

[cortico]

Shure m97xe? Nice cartridge.

Yes! Pretty good and the price is ok.

 

[patfont]

To save time if you do it again:

For the left channel you may want to remove the metal shield, and also remove the srews that hold the heat sinks in place on both channels that way the board/heatsink can be opened up like a book. And then it would take minutes to do the 3 caps on each board.

Very nice work and well documented!

Did you replace the 2 2SC458 transistors on the phono board I do not see them in your pile of parts.:scratch2:

 

[cortico]

To save time if you do it again:

For the left channel you may want to remove the metal shield, and also remove the srews that hold the heat sinks in place on both channels that way the board/heatsink can be opened up like a book. And then it would take minutes to do the 3 caps on each board.

Very nice work and well documented!

Did you replace the 2 2SC458 transistors on the phono board I do not see them in your pile of parts.:scratch2:

Thanks patfont!

The phono transistors are on my list but I haven't changed it yet. I have ordered the 1845 but read here that the 2240 are superior and may try those. I thought changing the caps and diodes give it a listen for a while and then proceed to the transistors. For me, it would be easier to troubleshoot if something goes off...

 

[bktheking]

What is the sn of your unit?

 

[cortico]

What is the sn of your unit?

Serial number is 81050.
Thanks

 

[bktheking]

Later model, should be the 10mv spec.

 

[rBuckner]

I have ordered the 1845 but read here that the 2240 are superior and may try those.

Some folks prefer them, I do not. I had them oscillate in the phono section and putting in the 1845's in that board solved it. So I've switched to the 1845's and I haven't seen that since.

 

[HVHiFI]

No need for anything more robust in the phono section then KSC1845. They a quiet and sound great.

 

[bktheking]

Some folks prefer them, I do not. I had them oscillate in the phono section and putting in the 1845's in that board solved it. So I've switched to the 1845's and I haven't seen that since.

Any chance they were fakes?

 

[cortico]

Later model, should be the 10mv spec.

Thanks! I left it at 8.5mv, should I go back and raise it up? Sounds good to me, it's a pain have to unplug everything and remove the 2270 from the cabinet…

 

[patfont]

You are good!

Thanks! I left it at 8.5mv, should I go back and raise it up? Sounds good to me, it's a pain have to unplug everything and remove the 2270 from the cabinet…

 

[patfont]

hFE for phono that I have measured from the batches I have here now.

458's 150
1845's 367
2240's 397

Some folks prefer them, I do not. I had them oscillate in the phono section and putting in the 1845's in that board solved it. So I've switched to the 1845's and I haven't seen that since.

 

[rBuckner]

Any chance they were fakes?

I suppose but I did get them from Mouser, they're usually reliable.

 

[bktheking]

2sc2240's from mouser? Must have been a long time ago, they haven't carried 2240's since I got into this hobby over 3 years ago.

 

[rBuckner]

That would be about when I got them!

 

[cortico]

Gents, the following question is a bit off topic.

I will be fine using Panasonic FC a turntable power supply and driver board, correct?

:thmbsp:

 

[cortico]

Sound check::tresbon:
There is already a decent amount of hours in the power supply caps, and maybe about 50 on the tone and phono. I have to admit how impressed I am with this 2270.

The warm vocals on the Lisa Ekdhal "when did you leave" sounds no less that perfect to me. Also impressive is the upright bass sound on Peggy lee's "fever", I am listening while I type, makes my pants shake yet defined without overpowering. The sound looks very real and instruments well separated.