2265B Reno - The other one

[John Hale]

Hello All - Just finished recap of my 2265B. Comparee to the pioneer SX-3800 I previus;y did this was pretty straight forward. EXCEPT - the "B" is qute different than the normal 2265. layout is different component where different. to top that off I bought the parts list for a 2270 thinking it would be close enough... well yes and no. I managed to get through the recapp with shop stock but took some digging. As a very simple example the prtection relay for the "B" has different pin out than the normal 2265 0r 2270. All in all a fun project so far.

Question: I didn't replace any transistors or diodes on this. Wondering if replacing the driver transistors would improve things.. Not the same on this model as 2270 or 2265 normal. It sounds pretty good but maybe a little bright in the mid and lower high freqs.

BTW - this model doesn't have any of the bad acting transstor "459" , if i remeber the number correctly.

If any interest, I can post some pics of the process-- might be interesting to compare the differences.

 

[Jailtime]

2SC458 is probably that unreliable transistor you're thinking of. I'd like to see some pictures of the rebuild, been in plenty of Marantz receivers but never a silver dial face "B" model.

I always replace the differential pairs in my rebuilds, that might be worth doing. A matched pair makes it easy to zero DC offset, and improves stability a bit.

 

[MBuras]

+1 on the pictures. Not really a rebuild post without them.

FYI...the silver faced B series are completely different from their predecessors in both build design and sound. I tend to think of them as a little more mid & treble focused. And both the 2252b and 2265b I’ve worked on have single amp boards as opposed to discrete boards in previous generations. Oh, and the power supply is on that same board too!

Mike

 

[John Hale]

Thanks felleas for the reply! OK I'll post some pics-- but I live in Germany and its 1230AM here so prob tomorrow. Cause I'm listening to vintage tune on my vintage receiver-----

Jailtime - I'm real interested in replacing differential pairs but am unsure what the right ones are for this unit. I assume they are the ones that are coupled together with heat shrink-- correct?

Maybe when I post the pics it will be more clear.

Thanks for watchin'
John

 

[Jailtime]

Q701/702 and Q751/752 are the diff pairs, should be 2SA722s. More than likely heat shrinked together. Replace with KSA992, gain matched if you can.

 

[John Hale]

Jailtime- Awesome! KSA992 installed ,, matched as best as possible out of 16 candidates. Just listening now, did a FM alignment this afternoon (that took some time, my first one). Boy those transistors make a difference. everything a little crisper, more balanced across the frequency spectrum. I wouldn't say the bass was "flabby" before but boy it tightened up with this change. Thank You, Thank You, Thank You.

Sorry didn't post pics today-- all wrapped up with radio alignment ---- more to come.

 

[John Hale]

Sorry no pics yet but I got to thinkin'-- If the transistor replacement above showed such dramatic sonic gain. Are there others in the Amp , pre -amp, tone board that could improve things even more. I'm really pleased with the sound , however, comparing it to my Pioneer SX-3800 (which had ALL the silicon replace. There is a bit more carity, air definition (alll those audiophile words) in the SX-3800. I want to give the 2265B the best, so I think some transistor swap would be helpful--- what do ya'll think?

 

[quadmatrix82]

I’d change the power switch and safety cap they are known to fail on these Marantz receivers

 

[Pdow]

Second on the build pics for 2265b
As I have 2.
One even works.
Thanks
Paul

 

[John Hale]

OK this one has gone under a few iterations but the final outcome is magic. first to answer the mail on pics. I'm gonna try to tell part of the story but I'll admit the purpose of my pictures is to help me rebuild so -- here goes:

first before and after of naked 2265b

 

[John Hale]

Now After

 

[John Hale]

Can somebody help decipher this date code?

 

[John Hale]

Power supply section is in a different place than regular 2265: Also some general grunge

 

[John Hale]

different angle: grunge also

 

[John Hale]

Pics with amp and filter capps removed (you can see how power supply is mounted. Amp comes out easy (two minutes) -- this gives best acces to pwer supply (of course I didn't do it this way, I wrestled with wires and such.

 

[John Hale]

another look at accessing power supply the hard way.

 

[John Hale]

Amp board:
before

 

[John Hale]

More before (half amp)

 

[John Hale]

Amp recapped:



A pause from the pics for a minute. I don't have pics of all transistors replaced. However that effort is what made this receiver MAGIC! originally I did replce the driver transistors and it was a bit of improvement (as you can read earlier in this thread). Later I "re-transistored" the pre/tone board. Again an incremental improvement. once I "re-transistored" the whole amp it changed everything for the better. Just to point out all the original transistors I tested passed (on my cheapy chinese tester) but the sound difference was AWESOME ! (hope I'm not gushing to much but I can't say enough about it).

 

[John Hale]

back of amp:



heatsink romoved -- just a note those little white tab looking things on top are double diodes, very fragile and made of unobtainium --- all caution handling the amp in this configuration. If you are like me-- I change a part or two and test, change a part or two and test. That is a lot of take apart and put back together, rinse and repeat..... so go slow and careful everytime.