Marantz 2220b restored with help from 3D printing (lots of pics!)

Now, I understand that some people like to have threads that show progress they've made before and after a project. I'm sorry to say that I don't have that many posts of the "before". I only thought about documentation half-way through. Without further delay, my (mostly restored?) Marantz 2220b as told by a lurker.

Before I begin, I started this project to restore my own Marantz 2220b. I've had the little guy...er...rather not so little, for roughly two years. In that time I have loved having it as my main (and only) amp (and it happily replaced my Sony amp from the 90s).

My story begins with my amp (what else!?).
Sorry for this poor photo. This was from a few months ago. I forgot to take 'before pictures'. As you can see in the photo, there are two-ish burnt lamps. Since I took this photo, nearly all of my lamps burned themselves out. That lead me to decide on a project to restore my amp.



Those pretty blue (or in this case-- greenish) lamps...er..normal lamps were in need of replacing. When I had first purchased this (from a smoker), it ended up being pretty filthy on this inside. But at the time, all of the lamps worked. So I spent my time cleaning it out and running DeOxit through the pots and switches.

I had also learned that someone MAY have worked on it in the past (which leads me to the question of "Have some of these caps been replaced (such as the black one?)"



While researching for information about my Marantz amp, I decided I should replace all of the incandescent bulbs and fuses with LEDs. So I made my purchases from ebay (both for the lamps and for the stereo/dial bulbs). I will post links at the bottom to the sellers which I purchased from if you're interested.

I had one problem. Like other people who own an older Marantz with plastic lamp housings, many of them have melted, become broken/brittle or lost shape. I was no exception. My lamp housing was partially melted and my tabs were broken off. They are hard to find in acceptable condition, and when one is found, it costs an arm and a leg to obtain.

I did however discover that a user here on AK (Kudos to bikemandan!) posted a 3D model of a lamp housing he had created. I was able to use that as a starting point for my restoration.

After a bit of research, I concluded that his lamp housing had a very good chance of fitting perfectly with my model (it was about 90% perfect for me). I used his model to help re-create a version more suitable for both my 2220B, and a 3D printer. My result was this.

(Link to file on Thingiverse)


Now I was tasked with trying to find a place to print it. I discovered that 3D printing was expensive! Luckily, I had two friends who both had 3D printers. Unluckily, neither of them had theirs working with no ETA.
That is when I found out that my local university had just very recently purchased a Makerbot Replicator 2.

So I scheduled up a time to work with the 3D printer. That's when I discovered that I was the first person to use it with one of my own designs. This is where I ran into a few issues with the 3D printer.

It started out very nicely.









But then, as the printer approached the top of the design, it could not figure out how to print the top layer without supports (I have a personal opinion on what the algorithm should have done, but that's another story). So near the end of the print, it turned into a stringy disaster.





I had also discovered that during the print job, the temperature of the room had changed by well over 10 degrees. This caused my model to warp in on itself on the built platform. Either way... this model was not going to work.

After that print job, the girl running the printer suggested I could try it again overnight. I agreed quickly added supports to the model and awaited the final product.

The next day, I check on the print job only to find out that it appeared to have stopped 10% of the way through. This seemed like a very odd bug, and I decided to print it again. After about another hour of re-calibrating and re-fixing the build platform, the printing started. It was only taking this long because none of us had ever printed an object of this side and 'sorta complex' before. We kept missing certain parts of the print setup.

Around an hour into the print job, I noticed that the printer was plugged into a power strip with a motion sensor. :sigh: It was at that point that I realized the printer must have been shut off the previous night (Causing the print job to stop & cancel) because no one was around to trip the motion sensor. Because I couldn't stick around for the print job to finish (I had class), I improvised.

This fan blew the rubber bands in front of the sensor causing it to reset its timer every few seconds.



Here is the final photo I took of it printing before leaving. You can see the breakaway supports that are being added at the bottom (or in this case the front of the model).



This quick setup kept the printer from going off for the duration of the 5.5 hour print job.

At the end of the day, I picked up my model, broke off its temporary supports, and prepared it for the rebuild of my Marantz 2220B.

(Part 2 of 2) It was too long for a single post!

Here are a few photos of the final results. You can see the original lamp housing on the left, the failed (string and warped) print job in the middle, and then the final model on the far right. It's worth mentioning that the mode on the right had to be slightly modified; hence the rough edges in the back. I had to increase the size of the hole in the back (which has been updated in my thingiverse model) in order to get the fuse lamps to fit through it.

The end cost to me was free (it probably won't happen again) because they have not figured out a way to charge students at my university on printed objects. But, I was also the first student they've ever had use their printer for a project. Every object printed up to this point were small objects found built into the device or from the popular sections of thingiverse.









Now I had a perfectly built lamp housing to go in as a replacement for my old one.

I added in the model to my Marantz and you can see that it fits without any issues.



(with my new LED Lights/Lamps on)



An overview of my Marantz with the part placed inside.



Close up, and then with the faceplate on.






Now I'm putting it all back together (with new vellum)





Of course, also re-adjusted my amp's voltage and amplifier biases (All 4).

Here are the final results of it all in action. (For those of you wondering about the feet; Yes, I still have them. But I removed them because they hang over my speakers just on the edge causing damage to the wooden speaker cabinets.)
Overall, it is very red and blue. Maybe too blue.. but I think it will grow on me more than the green... maybe.







Nice even lighting, adjusted bias, and a great looking amplifier. I hope you've enjoyed this post as much as I have!


I have 2 quick questions (if you don't mind). (If you missed the one above, here it is again).

1. Have some of these caps been replaced (such as the black one?). I ask this because when I first purchased it, the guy said it had some work done at a local audio shop (such as a re-lamp before he bought it). It also appears that some of these capacitors are not original such as the black one in the photo below. It also does not appear to have any bursting caps on it, and it sounds great. Is it possible that this has already been partially re-capped?
   
   
   
   
   
2. I have a setup where my computer is running out a line from my sound card. That line has a y split in it. One end goes to my computer monitor (for those times where it is too early/late to run sound from short YouTube clips over my loudspeakers), the other goes to my Marantz (through the aux connection).
   
   Now, I only just realized this after my calibration of the amp bias. When I am running music from my computer, IF my Marantz has its selector set to "Aux" whether it is powered on or off, I can hear the music from my computer monitors (and my loudspeakers assuming my amp is on).
   
   If I switch the selector nob to any other source (Again, doesn't matter if unit is on or off), it will ALMOST completely mute my computer monitor speakers almost as if it is imputing all of the signal that it can, and not allowing it back into the circuit. Could someone please explain what is happening here?

If you have any questions about the process or would like you know anything else, feel free to ask!


--Lots of information and links that somebody might want to know--

Printer Used: Makerbot Replicator 2
Plastic: PLA (Blue)
Time to print (With automatic supports): 5.5 hours on default standard settings.
Marantz Model: 2220B
Turntable: Rega Planar 3 (With 24V motor upgrade.. it needed a new motor at the time, decided to upgrade during replacement)
Speakers: Sansui SP-1700 pair (Only one is shown. Grills are removed. I love the look). They sound amazing paired with the 2220B.
Headphones: Sony MDR-V6 circa early 1990s

Blue LED Fuses were purchased from investmentaudio.
LED Stereo "bulb" + Amber indicator LED were purchased from wlyn5455.
Original Lamp Housing Design
My Lamp Housing Re-Design

Excellent piece of work, on both the post and the housing....:thmbsp::thmbsp:

That black cap looks factory.

Man, you are SO 21st Century!!

Thank you!

bktheking said:

That black cap looks factory.

Click to expand...

Additionally, thank you for that information. I just wasn't sure. The black caps seemed too different from the other caps.

Curious; I know many users have different opinions about recaps. Some say that it should be done only if necessary while others claim that is should be done over any equipment over 20 years old.

I am currently happy with the sound it is producing, but should be worried about a cap bursting and ruining other components? I understand that caps have come a long way in nearly 40 years, and that caps as old as mine have a tendency to at least dry out.

Even more, should I be looking into re-capping it myself? I've read into a few threads that discuss this (many of which mention to pay close attention to the polarity). My soldering skills are minimal, but existent (i.e. I soldered the spliced wires to the amber indicator LED and the stereo LED to its posts). I'd either prefer to do it myself (if needed) or visit an AK member/someone trustworthy in west Michigan to teach me (not now, but sometime later).

Capacitor technology has come a long way from 35 yrs ago, for example, film caps replacing electrolytic capacitors, opportunity to increase capacitance while adhering to space requirements etc etc. People who think a recap isn't beneficial are kidding themselves,they are either too cheap or lazy to do the work. I say if it is worth it to the owner then redo it. I see it all the time, units up on ebay claiming to be serviced running the same old caps from 35 years ago. People also claiming that it sounds good have nothing to compare to. This is not an attack on you at all, don't take this post as that. I say listen to it for a month then redo the entire unit, let it burn in and then tell me it doesn't sound better- there hasn't been one unit pass over my bench that I finished up saying to myself - boy was that a mistake.

Alright, thank you very much. I'll probably spend time researching caps for a while (models/sizes/methods/brands(?)), order them, and then spend time working on it once December comes around (my next chance I'll have for uninterrupted work on the unit).

Fantastic work!

Incredible work.

I am not familiar with this particular receiver but have owned some Sansuis.

Anyway, if I may - I have a very small criticism - maybe out of ignorance. Are'nt those LEDs just a bit too bright compared to the original incandescents?

I agree with replacing incandescent lamps with LEDs and have done so on a B&O 4002 turntable and some amplifiers including my Dynaco SCA35.

When I replaced my Quad 405's red LED with a blue item, the LED was so bright it just about lit up the room and I quickly changed it to similar light output to what it had originally, in blue of course.

My son in law's brother has a 3D printer. they are awesome! nice job!

Tripod said:

Incredible work.

(...)

Anyway, if I may - I have a very small criticism - maybe out of ignorance. Are'nt those LEDs just a bit too bright compared to the original incandescents?

(..)

Click to expand...

I haven't noticed the lights being too bright as much as being too blue. To me, it appears to be the same brightness, maybe a tad brighter. But I think there are a number of factors taking place for me.

My old lamp housing was slightly warped and didn't have a perfect fit allowing light from the old incandescent bulbs to escape out the back (however, not the same effect as a bright face plate). With the new housing, I don't notice a significant amount of light pollution except for what is shining through the plastic which may be counter balancing the ambient light from the unit.

Another factor is that I usually don't have it turned on in a pitch black dark room. I'll usually have light coming from my computer monitors, lamps, or the sun.

I do agree that when I was first installing the LED lamps (without the face plate covers on), it was blindingly bright. But after everything was put back together, it wasn't making a large enough difference to bother me.

It's the camera.

i wonder if Echowars has seen this...about 10 years ago, i sent him a 2325 that needed help- purchased as 'gone through and in good working condition' from Vintage Electronics in Colorado, and upon opening it up, the lamp shroud was found to be disfigured from heat/age/whatever, and propped up with hot glue and cardboard...truly shabby work. several sharp guys went to work trying to configure a new shroud, and i finally donated the unit to AK. ....this here newfangled 3D printing could have had us in bidness in no time. cool stuff

Great work!

Thanks for the detailed pictures and narrative.

JIJ@k2esK said:

I haven't noticed the lights being too bright as much as being too blue. To me, it appears to be the same brightness, maybe a tad brighter. But I think there are a number of factors taking place for me.

My old lamp housing was slightly warped and didn't have a perfect fit allowing light from the old incandescent bulbs to escape out the back (however, not the same effect as a bright face plate). With the new housing, I don't notice a significant amount of light pollution except for what is shining through the plastic which may be counter balancing the ambient light from the unit.

Another factor is that I usually don't have it turned on in a pitch black dark room. I'll usually have light coming from my computer monitors, lamps, or the sun.

I do agree that when I was first installing the LED lamps (without the face plate covers on), it was blindingly bright. But after everything was put back together, it wasn't making a large enough difference to bother me.

Click to expand...

Thanks for your kind reply. That makes sense. I probably also looked at the wrong pic.

I think you inspired me to 3D build a little number for my Grundig tuner which is a little warped. I have already replaced the vellum with a sandwich of 4 sheets of draughtsman tracing paper. The original had 4 brass eyelets and I had some of these and the tool for fitting them.

Congratulations on a job well done.

tripod

Fantastic read!!
That 3d printing stuff is just what we need more of!

Bought myself a 2220b this morning. The original plastic housing had become very brittle and one of the tabs were broken. Luckily I found your post and thought I'd give it a shot. Print won't be finished until tomorrow though. I'm thinking I will probably switch from the original type of lights to cooler LED's (a couple needed to be changed anyways). Also, I'm not entirely confident about the heat resisting properties in the PLA.

You printed yours 8 year's ago. What's your experience with it been like?