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Restoring joel27's 2245

Jailtime

Jailtime

Standin' on a corner
Here's a nice Marantz 2245 that AKer joel27 brought to me for a little work. It's a bit dirty inside, and the pots are scratchy. Joel wanted me to recap the amp boards, power supply, and the filters. I also installed a new Omron relay. The tuner performs fine, so we decided to leave that alone.

It performed OK with all the original parts, made 49WPC into 8 ohms, and DC offset measured 30mV.

Here's some before pics of the 2245.
 

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I was really impressed with the build quality of the 2245, it's also easy to work on.

I started with the power supply, fresh Panasonic FCs throughout. I also threw in a new Omron relay. The relay is a bit tough to work on, the solder lugs are pretty small.

Next up were the amp boards. The right board is easy to work on, just free the heatsink and the board, they'll open right up for easy access. Be careful with the bias diode that is mounted to the heatsink. There's just three caps on each board, new FC caps were installed on those too.

I had to pull the outputs and remove the heatsink entirely to recap/inspect the left amp board. Kind of a PITA. So since I pulled the outputs, they got new mica insulators and mil-spec heatsink grease.

I trimmed the bar that mounts to the filters a bit so that it would fit the new Panasonic 80V 10000uF filters better. I just made a little hook, crimped it to the pin on the filter, and filled with solder. For the other filter pins, I crimped a ring terminal to the pin, and dropped a bit of solder in the gap. Made a nice clean, shiny joint. Check the pic. I really like the ring terminals for filters. :yes:

The last pic shows the outputs with their fresh insulators and grease.
 

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Now on to the fun part! I hooked up my dummy loads and Tek 2246 scope to see what the restored 2245 would make for power. First pic shows it wide open throttle, made 56WPC! Pretty good numbers for a 45WPC rated unit, I'd say. I also checked the power supply voltage, set DC offset to 2mV, and Deoxit/Faderlubed the switches and pots.

Last few pics show it with all the new parts, cleaned up nice.

I'm listening to it right now with some EPI 100s. Very nice unit.
 

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Last edited:
That looks great! :thmbsp:

I can't wait to hear it. It is gonna be a lesson in patience to wait till I have a chance to pick it up. This will be my first recapped unit. I will give my impressions of it then. Next will be the 2385. (Whenever Catrafter's list gets to me.) :D

Thanks again Kyle, for your time and expertise with this.
 
Excellent work!
Odd that you say the 2245 is easy to work on, it looks almost identical to both of the 2270s that I worked on which were a NIGHTMARE, maybe I was doing something wrong?
Who knows...
very clean job, A+
 
It looks nice.

A question: is it a good idea to replace the mica insulators? Will there be a benefit or is it just for the heck of it? :)
 
Merry Christmas, Joel! :D

attachment.php


2245 all put back together and singing nicely.
 

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joel27 said:
That looks great! :thmbsp:

I can't wait to hear it. It is gonna be a lesson in patience to wait till I have a chance to pick it up. This will be my first recapped unit. I will give my impressions of it then. Next will be the 2385. (Whenever Catrafter's list gets to me.) :D

Thanks again Kyle, for your time and expertise with this.
Click to expand...

You'll see a true expert's work when you get that 2385 back from Tom. :yes: I could only hope to be that good.

Your 2245 is nice. Maybe I'll make you wait a couple weeks, keep it in my system for a while. :D

Sir.Byrd said:
Excellent work!
Odd that you say the 2245 is easy to work on, it looks almost identical to both of the 2270s that I worked on which were a NIGHTMARE, maybe I was doing something wrong?
Who knows...
very clean job, A+
Click to expand...

I didn't recap the tuner section, which looks like a pain. The rest wasn't so bad. Where did you have problems on the 2270, I might have a trick or two that I learned on this 2245.

Coconuts 500 said:
It looks nice.

A question: is it a good idea to replace the mica insulators? Will there be a benefit or is it just for the heck of it? :)
Click to expand...

The original mica insulators will have the nasty, dried out original heatsink grease. They're often cracked too. Mica insulators are cheap, so it's good to start with fresh ones.
 
Jailtime said:
I didn't recap the tuner section, which looks like a pain. The rest wasn't so bad. Where did you have problems on the 2270, I might have a trick or two that I learned on this 2245.
Click to expand...

I tried to recap the tuner section, that was a double stacked board, PITA. The other problem board was the back tuner board, and the amp board on the tuner side because of that shield.
 
Sir.Byrd said:
I tried to recap the tuner section, that was a double stacked board, PITA. The other problem board was the back tuner board, and the amp board on the tuner side because of that shield.
Click to expand...

With careful dis-assembly, all boards on a 2245 or a 2270 except the AM tuner and the FM MUX can be accessed on both sides without disconnecting a single wire.
Except for a few early models where the FM MUX board wires are routed through a hole in the AM tuner support bracket, the AM tuner and FM Mux can be accessed on both sides by disconnecting only 3 wires, J151, J155 and J307.
While the AM tuner and the FM MUX are loose, the 'back tuner',as you call it, (which is actually the FM Muting amp) will have plenty of wire slack so that it can be flipped over.
The shield on the left side is easily removed by loosening a few screws and heating one solder lug.

Tom
 
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