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2275 rebuild project

Hi Paul. Thanks for the nice words. As you can tell, it was a team effort. :)
 
Thanks Dave - I've downloaded and will use this. I'll be creating some of my own spreadsheets for other units - I'll sure share when I do!
 
I have been watching this thread unfold and am thoroughly enjoying it.

I have more time off than I know what to do with over the holidays, so I'll be attacking a full recap (and those noisy transistors, lol) on my 2215 in the coming weeks. This will be my first attempt at an electronics repair of this magnitude, but I'll just do it one board at a time, and verify the receiver's function after every board like you have been.

Depending how it goes, maybe I'll dig into my 2275 next. It sounds nice (like, really nice), but is largely untouched since it left the factory, and the power supply caps look exactly like yours did before you began! Lol

Thanks for taking the time to write a detailed thread about this.

Adam
 
Thanks again for the spreadsheet. It will be of help one of these days :) It was a very interesting thread to follow along with.
 
thxdave said:
I don't see 2275 threads here very often so I hope this will help some of the other newbies like me. All credit has to go to Leestereo for his help with this restoration. I never, ever would have attempted such an extensive project if it wasn't for his offer of help. I know enough about electronics repair to be dangerous despite a lifetime of enjoyment of all things audio. I'll try to keep the updates coming on a regular basis to let you know what I've learned along the way. BTW, I'm firmly in the camp of "If it ain't broke, don't fix it" so this puts me WAY outside my comfort zone. However, this AK forum is SO helpful to folks like me that I know you all won't let me get too far off script.

History
I picked up this 2275 from a guy here in Florida a few months ago. It was mostly functional (noisy controls, burnt out dial light, tuner out of alignment, etc.) and came with a fairly nice wood case. The only odd thing was the power cord which was not original. The seller told me that the original cord had been damaged and had been replaced. I didn't notice at the time (didn't even know to look!) that this was an international model. One of my first posts here was about the odd wiring configuration I found coming off of the transformer which was missing the usual jumper wires. I replaced those jumpers, built my own DBT and held my breath....no problems.

Restoration
As I said, Leestereo was kind enough to help build a spreadsheet for this project. Without his help, I might have done the P800 board, relamped to LED, got the tuner aligned and called it a day. But, with a false sense of security, I've plunged into it all the way.

Before I started the resto, I decided to open up the chassis and poke around. I saw that the original dial lamps had partially melted the plastic housing. So, I got a set of blue LEDs as well as a set of warm whites. The blues were TOO blue, so I opted to install the warm whites. As you can see in the first photo, those WW's had way too much green in their output.
(Also note the face feet....thanks to the AK'er who came up with that one!)


View attachment 795372

Our own dgwojo started stocking a new LED called "Pure White" and I just installed a set. It looks blue in this photo but is a very good neutral white color:

View attachment 795373
Blue LEDs were WAY too blue for me so these Neutral Whites are perfect.

P800 Power Supply board
This was the first board I worked on as everybody here sees this board as the "heart" of the Marantz. Here's the original configuration and as you can see, this 2275 was amazingly clean and looked like it had very low hours on it except for the caps getting cooked by the resistor:

View attachment 795393

Here's the P800 after fitting it with the new parts spec'd by Leestereo:

View attachment 795395

Here's the parts list for P800 with Mouser part numbers in parentheses:
C801 - Original 220uF 63v / Now 470uF 63v (UPW1J471MHD3)
C802 - Original 100uF 50v / Now 220uF 50v (UPW1H221MPD)
C804 - Original 22uF 35v / Now 47uF 50v (UPS1H470MED)
C805 - Original 330uF 50v / Now 680 50v (UPW1H681MHD6)
C806 - Original 470uF 16v / Now 470uF 35v (UPW1V471MPD)
C807 - Original 4.7uF 50v / Now 10uF 50v (UPM1H100MDD)
C808 - Original 47uF 16v / Now 47uF 25v (EKY-250ELL470ME11D)
C809 - Original 220uF 10v / Now 220uF 35v (UPJ1V2211MPD6)
H808 - Original DS131B / Dual Diode (BYQ28E-200,127)
H811 - Original DS131B / Dual Diode (BYQ28E-200,127)
R807 - 150 ohm 5 watt / 150 ohm 7 watt (W221500JRLF)
L801 - MY2Z-02-DC22 relay / Now MY2-020DC24 (MY2-02DC24)

Coming up.....P700 power amp boards
Click to expand...
Amazing project! I just finished doing the same to my G-9000DB and the 2275 is on the bench. Quick question, where did you get the face feet from? I've been searching AK for 2 days and couldn't find who makes them. If you built them yourself, can you please post the specs for the parts? Thank you :)
 
Yep, it was Tom's idea and I just added felt pads to his original idea. Here's a closeup of one of mine. The official size of the screw is M5-.80 x 35mm:

DSCN5045.jpg
 
Thanks. Decided to try to preserve my nice workbench top.....see new thread!
 
Hi Dave and thread posters... I've been watching this thread for a while. Just some short background.. I purchased a 2275 a couple of years ago; it's been humming along nicely but a few months ago it started acting strange on power up, having to do with either the P800 or P700 boards. I will create a separate thread for a question on that. But as far as the rebuild goes, I've been reading some things that has me a little confused.This is specifically aimed to the P700 power amp boards. Looking at the Marantz 2275 Dave Morrison final.xlsx in the Capacitor section, only C701 - C708 is recommended for replacement AND there are Mouser part numbers. :rockon: Should the other caps on the board be replaced?

I've seen others say that anything below 3.3uF can and may be replaced with film capacitors and anything above replaced with electrolytic.... so what do we all think is the best thing to do? I'm not sure I'm in favor of replacing the ceramic caps (why invite trouble, unless the general opinion is YES) but C710, 711, 712 717, 718, 719, 720 are all film caps. Does anyone have Mouser part numbers for those? :bye::smoke: And can other cap values be substituted, such as what is recommended with C701 - C704? I know it depends on what the function of the cap is in the circuit and I used to be an electronic technician WAY back in the day so I know you can always go up on the voltage but the capacitance value is a little more tricky. Filtering and DC blocks can be more forgiving.. if I remember.

BTW, Dave, I noticed that H701 and H702 were replaced on your board. Did you use the hfe setting on a DVM to match and how close did you get them to match?
Thanks for all the good reading.. I've sunk all kinds of hours here just looking around. And thanks in advance for reading and answering the post. Cheers!!:beerchug:
 
Parts selections happened at a higher pay grade than me. I was helped by Leestereo on this (my first) rebuild. So, I'd be hard pressed to tell you about any part substitutions. Maybe Lee will jump in here to help out. As to hfe comparisons, I didn't have the gear to do it at the time so I'm praying that the parts were at least "in the ballpark".
dave
 
Currently doing this to a 2275. Lots of good info!
Thank you Leestereo for the spreadsheet!
Getting the parts ordered, seems lots of places are low or out of stock on the good caps!??
 
Wanted to add an update to this project. I've updated the link to the parts list so hope everyone can get to it without problems. 2275 is still working great and my thanks still go out to everybody who helped. One issue that came up was a tiny bit of corrosion on the Input Selector switch as well as the Tone Control switch. I discovered a tiny, sporadic signal dropout on the Left channel and it would come back with some gentle rocking of the knob. So, I need to do another clean-up of the wafer switches. Otherwise, I couldn't be happier!

P.S. offer still stands for anybody who wants to try a piece of the woven sleeve materials mentioned at the top of the thread
 
Getting ready to Rebuild a 2275 using this thread. Anyone have any additional tips? We will see how the pandemic(i thought I'd document it here) has affected parts availability. Any chance anyone has a mouser build sheet for this? Thanks all and stay safe!
 
Rubbermolder said:
Getting ready to Rebuild a 2275 using this thread. Anyone have any additional tips? We will see how the pandemic(i thought I'd document it here) has affected parts availability. Any chance anyone has a mouser build sheet for this? Thanks all and stay safe!
Click to expand...
l rebuilt a 2275 about the time this thread was running. He was a bit ahead of me, and I found it very helpful in my rebuild. With this thread and Leestereo's parts list reference in the first post, you should be good to go.
 
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