Marantz 2600 Refurb Thread

[rBuckner]

This is a fuzzy resemblance of a small red LED soldered to leads. It's real! Dang camera focused on something else although the focus box was on it. It is for the dial pointer lighting to replace the old incandescent bulb (which was working!).

The dial pointer was reassembled and put back in place and the brightness resistor selected and wired in. The red wire is for the Dolby LED and is tacked down with epoxy. I only really needed about half of these but mixed up too much epoxy.

Time to turn attention to converting the scope graticule bulb into a warm white LED. This is one of the fuse lamp boards with just the rectifier and filter cap to convert AC to DC. I soldered on wires which will connect to the LED.

The red and white wires coming in from the right used to go right to the bulb and was 8Vac via a 10 ohm resistor.

You can see where the camera focused - on the board below! I was pointing out that some heatshrink was then applied over the board assembly.

Fired up the beast and turned on the scope and after some knob twiddling in came the spot! That's cool since it had been a bent curved line before so the power supply did have an open cap in it.

Got an FM station tuned in...

COOL! I then placed the graticule on loose and got the scope tube rotated correctly. It was close but needed some tweaking.

I prepped an LED by removing the base flange and sanding the end to disperse light better. It shines forward too much and only needs to go sideways so I am applying several coats of paint to reflect back into the lens and not forward. The problem is it casts light onto the front of the graticule. After another coat of the white primer I will add coats of black to block light.

That's it for the weekend and I be coating the LED in the morning and at lunch and evening but will then turn my attention to doing all of the adjusting and tuner alignments.

 

[Denten]

Wow that looks awesome Randy, the lamp housing turned out very nicely indeed, I'll bet it is stronger now than it ever was, nice save!

 

[Bkphoto]

i look forward to every post...

 

[rBuckner]

Wow that looks awesome Randy, the lamp housing turned out very nicely indeed, I'll bet it is stronger now than it ever was, nice save!

Thanks! The parts I messed with are stronger but just look funny at the unbolstered part and it will split or crumble!

i look forward to every post...

Uh oh, sounds like addiction! Thanks for the compliment. Heck I look forward to every post too as it means I'm getting more done!!

 

[rBuckner]

My wife didn't get in until about 8PM so I had everything adjusted except the scope stuff which I'll do tomorrow.

This is the warm white LED with the end painting finished and run back through the lathe to get the excess off the sides which will light the graticule.

Here's the LED installed, it's epoxied from the back side.

The brightness setting resistor has been selected and installed with heatshrink keeping everything protected.

Here are some shots of what emits light so far. Keep in mind it's as the camera sees it and adjusts the exposure. It's not overly bright. The scope brightness control is actually down from the brightest it can be so there's some life in this tube. Nice!

The top photo's color on the scope is the most like it really looks.


I think I'll get the front panel LEDs' brightness set up next and then tear into the main filter caps, saving them for last. Also to do is to see if I can get at the main amp input RCA jacks' switching contacts as neither makes connection even after DeOxit treatment and plugging in and out many times. If nothing else shorty jumper cables will work just fine. I have some 100% shielded ones 8" long and they even have gold plating!!! Woo-Hoo!!!

 

[rBuckner]

I pivoted the rear panel back this evening and saw that the main in jacks are fully enclosed in the back so there's no bending the switching contacts back in place. So external jumpers will be required.

I got the front panel LEDs all set up as planned and the scope adjustments performed. As mentioned, the only work left to do is the main filter cap remove / restuff / reinstall. Final front panel cleaning and dusting and then reassembly, put the covers on and it will be ready to do audio analyzer testing. A few days burn in and she can go home if all is well. Phew!!

 

[KutzlerTrans]

Nice work so far!, Just be careful with the filter cap orientation..... I bet chucking the light was fun.
Your adherence to sticking with the task is a trait that very few can follow or match. You have our deepest respect

 

[rBuckner]

^^^ Thanks John! I made a careful sketch already before work this morning.

 

[rBuckner]

After starting to undo wiring I thought I better take a picture of the cap wiring to supplement my sketch.

They are out!

With the caps out I cleaned up more dirt down in the void.

The pipe cutter tool is at the distance in the middle of where the cap clamp sits.

Three turns or so and it's apart. You can see the straps between the innards and the terminals on the end cap.

The straps are snipped and it's free. The white center cylinder is one capacitor and the other is wound around it. Each is thin sheets of aluminum and an insulating paper wound around with electrolyte being soaked into the paper. That stuff STINKS!

This one was an SOB to get the guts out. I had to basically drill, hack, pull and chip it all out.

Part of the outer capacitor unwound in a full strip at least.

 

[rBuckner]

The can then got cleaned out better, but not done yet.


The second cap was then cut open and I was able to grab part of the inner "windings" with pliers and the whole center popped out. Well thank you very much!!

After finishing the gut job, I used small needlenose pliers to work my way around the lip, straightening out the indentation from the cutting tool.

A test fit of the new caps provides some mental relief for me. I've been nervous about this for weeks. Note there are a few small bump-outs from my prying the guts out.

Here is where I should mention that I received a much welcome suggestion from member 'skibjr' about the exact part number and configuration / fitment of the following. I am most grateful as there is n other solution that I could find! Thanks Dave!!

I rubber banded each group of 4 together to hold them for taping. Each cap being 1800uF gives a perfect 7200uF as was the original value. Instead of the stock 105V rating, these are 160V and 105C rated to boot.

All taped up and the parallel connections have been started.

One down, 4 to go.

I'm going to place the lower pack with the terminal side down. I will be cutting insulating disks out of sheet lexan at work tomorrow that will go into the bottom of the can. The wires will be routed up the middle. The upper pack will go in terminal side up so there doesn't need to be any insulation between the lower and upper packs.

I have all 4 sets wired and ready to pot on Thursday. I find that I will have to take the electrical tape off for the packs to slide into the cans. The fit is that tight!

 

[rBuckner]

These did get potted today. The material used is thermally conductive so there is little extra heat buildup on these caps. They need to cure overnight and can be assembled and reinstalled tomorrow.




I rotated these and re-saved them and they still came in sideways, sorry!

 

[rBuckner]

Eagle eye and brain (Tracy) Denten asked be about what insulated the lower capacitor set from shorting to the can. I forgot to show that I had cut a disk of lexan and glued it into the bottom of the can first with a spot of potting epoxy. I did mention it a post before but a picture would have been much better! I have disks cut for the can "lids" to keep the upper pack from shorting to the rivets for the terminals and will show that later today.

Thanks again Mr. Denten!

 

[catrafter]

Great work, as always!
Have you ever tried using a corkscrew to get those cap guts out?

Tom

 

[rBuckner]

I have not tried one. The inner section has somewhat of a hollow center, like an air core inductor so I'm not sure it would work. Putting it in off center could do it though. I'd have to get a dedicated one for this purpose as the guts of these have that foul electrolyte that should never be consumed. Besides, Connie would kill me if she knew I used a corkscrew for that!

 

[rBuckner]

Here are the cap ids with their insulators before the holes were drilled for the wires to pass through.

The terminals all desoldered and cleaned up.

Top end wiring is done.

The red and white wires passing through the insulator and out the top of the cap lid.

Due to the height of the new caps inside, the lid won't quite fit where it had before.

Next the lids are taped in place with electrical tape.

The wires are stripped as close as I could get with a stripper.

Using diagonal cutters carefully, the insulation is snipped in several places and then used to pull off another bit of insulation.

The wire is then wrapped around the base of the terminal lug using a hardwood stick as an aid.

The wire is then soldered front and back.

 

[rBuckner]

All wired! I had cleaned the top with alcohol and a Q-Tip, leaving a bit of fuzz.

Next I cut bands of 3" heatshrink to strengthen the gap where the can was cut open.

After the use of a heat gun.

Alas, I found out during trial fit into the chassis that the heatshrink caused the mounting clamp to be expanded so much that the holes couldn't align up to screw it down. So I had to cut the heatshrink off and rely on the tape. It ended up being very solid so no biggie.

Here is the view after wiring the caps in place. I had to add heatshrink to cover the damaged insulation cooked when unwiring them. I also added 2.2uF film bypass caps.

After slowly bring up the mains voltage with a variac, I listened to it for awhile.
I tie wrapped the loose wiring at the top back of the unit to make it neater.

I got the front panel waxed up and windows cleaned and put it on along with the pushbutton caps. Lookin' good.

 

[rBuckner]

A few more glamour shots...

Time to do some testing on the Panasonic analyzer. The preamp and tone /filter controls worked as expected. Here the amps are being tested.

Distortion at 1kHz and 1 watt output is 0.00262%.

At 160 watts (half power) the distortion on both channels was 0.002%. It was putting out 330 watts a side, both channels loaded at the onset of clipping, about .02%. After disconnecting the loads, I tested the peak LEDs and they came on at about 470 watts.

So it is then finished and is in the shop sound setup, burning in for a few days before it can go home. Sounds great!!
Thanks for following along.

 

[rBuckner]

I forgot the old pile of parts picture!

 

[tonebells]

A fine job.

 

[rBuckner]

Thanks Tony!