Great job Evan, really enjoyed reading your project with all those fantastic pictures!

Looks really nice!

About two years ago, I also restored a Beomaster 4500 to sell. The mirror panel was hacked up and there was no way it could be saved.

I did find out that the panel was just a thin veneer of polished aluminum with a thin layer of mylar affixed to the surface for protection. In removing the panel, I did find sources for the gauge of #8 polished stainless steel that closely matched the top.

That was the easy part. Getting a piece cut to size was no problem.

The hard part was getting a perfect bend with a straight line crease. It looks simple, but in reality, so hard to do. 

Most machine shops in the area have a hydraulic break press to put these sorts of bends in the metal. The problem is that the thin metal buckles as it is being folded. This results in a wavy crease. Not good.

Does anyone know how to get the perfect crease? For that matter, how does one get the perfect cut, where the metal doesn't roll in the direction of the cut on the edge?

If someone on this forum knows how this is done, it may be easy or possible to replicate spare mirror panels for the 4500's.

- John

Dunno about the bend, but I suppose the cutting should be done by a laser or water jet instead of a mechanical cutter.

But #8? Really? That's over 4 mm for stainless steel!

matapan:

 

Does anyone know how to get the perfect crease? For that matter, how does one get the perfect cut, where the metal doesn't roll in the direction of the cut on the edge?

If someone on this forum knows how this is done, it may be easy or possible to replicate spare mirror panels for the 4500's.

- John

 

Something like this might work, sticky back mirror. Providing it is thin enough & shiny enough, especially if you are taking the original layer off first. It says it is 80 micron Vynyl Mirror and you can order samples.

Stoobie

#8 Polish refers to the finish level of the stainless, which is a mirror finish.

So, with this new white obsession of mine, I've started to get a little more detailed...

Custom white audio cables

Once I get back inside of these pieces for the recap, I'll be adding white power cords as well.

Evan, please stop with your white obsession, you already have infected me

Leslie:

Evan, please stop with your white obsession, you already have infected me

The Beovirus has mutated into Beowhitevirus[]

 

Evan:

So, with this new white obsession of mine, I've started to get a little more detailed...
Custom white audio cables.
Once I get back inside of these pieces for the recap, I'll be adding white power cords as well.

Evan, I LOVE what you've done to your Hot-Rod Beosound 4500 "Custom".
The minute attention to details makes your system stand out! It is this attention to deatil that separates a "Show Winner" from the other Hot-rod wannabees!

BTW, after reading this thread I decided to order a few veneers from Alsa corp to try on some older B&O units, just in case.

I'm in the middle of restoring a recently purchased BM4500 and BG4500CD for our guest room, both have loose panels.
Your detailed panel work-flow is my visual service manual... Fortunately the mirror finish is in "As New Condition" on both.

Did you by any chance open up the bottom of the unit to see the bottom of the PCBs?
Mine show two "hot spots" on the Power-supply & Output Amplifier PCB: "Diagram C"

If you don't see/didn't see this, has anybody else seen this? Should I worry?
BM starts and works fine as is, but I don't know if this is normal or foreboding an imminent failure?

Any suggestions?

 

IkeA:

Mine show two "hot spots" on the Power-supply & Output Amplifier PCB: "Diagram C"

If you don't see/didn't see this, has anybody else seen this? Should I worry?
BM starts and works fine as is, but I don't know if this is normal or foreboding an imminent failure?

These are both areas that handle large currents (the other one is under the rectifier diodes, the other one seems like a regulating stage) and therefore generate quite a bit of heat in normal operation. The circuit board material will darken with age around such hot spots. I wouldn't worry.

tournedos:

These are both areas that handle large currents (the other one is under the rectifier diodes, the other one seems like a regulating stage) and therefore generate quite a bit of heat in normal operation. The circuit board material will darken with age around such hot spots. I wouldn't worry.

(Kiitos vastauksesta)

Thanks for the feedback re darkening of PCB.
I was thinking of replacement of components with higher current ratings (diodes) and higher watt rating (resistor), to lower the heat production and heat related aging.

What would be the most efficient way to minimize or eliminate this heating problem, or is this a "go back to sleep"/in my head only, problem? Is the current load much higher when running Beovox speakers on this amp?
Would this still be a problem if the BM4500 was used only with Beolab speakers?

Thanks for all inputs.

IkeA:

What would be the most efficient way to minimize or eliminate this heating problem, or is this a "go back to sleep"/in my head only, problem?

As I said, don't worry The amount of darkening I see in the pics is not a problem, it's quite normal.

You can replace some components with higher rated ones and/or install them farther away from the PCB surface, but it won't affect the generated heat a bit. The same amount of power is still being dissipated.

Some folks like to replace the rectifier diodes with schottky types (lower forward voltage drop -> lower dissipation), but I see no point in that here as this is not a known problem spot, and the original setup will probably last a lifetime anyway.

You're right that running passive speakers will use more power in the amp itself and thus the main power supply. However, at normal listening volumes the difference will be only a few watts, and again, I just wouldn't care. It's just being used as designed!

IkeA:

Evan, I LOVE what you've done to your Hot-Rod Beosound 4500 "Custom".
The minute attention to details makes your system stand out! It is this attention to deatil that separates a "Show Winner" from the other Hot-rod wannabees!

Hello IkeA, thank you for your wonderful comment!!! I am also delighted that my thread has been able to assist you

Come to think of it, I never did look at the bottom of my BeoMaster. It was in 100% perfect working order so I didn't bother. At first, your pictures did alarm me but Mika's comments calmed me down!

I do have plans to resume this thread and do a technical restoration this summer. I want my amp in top spec because I have this crazy idea of adding more speakers...

I thought I would inform you all that the white strain of the BeoVirus has mutated again! This disease is widening its reach! Warning, Apple gear may worsen your infection!

exquisite ?

or should I say exquisite ?  

elephant:

exquisite

Much better!! 

Hi Evan,

Congratulations on another great thread, I keep stumbling across these great reads, and get inspired. Thank you for creating these threads. I look forward to stumbling across another one. I a thinking of doing something similar to a Beocenter 8000 but I was going to use the stick-on plastic sheets that can be cut and stuck on to the surfaces. When I tackle this project I also hope to create a picture write-up just like this. Your work is inspirational. I do have one question and that is can I get this sticky plastic sheets in Gold, as I really like the idea of Black and Gold as a classy and unique colour scheme which is rarely seen on B&O equipment. Hope to hear fro you soon Buddy.

Nidul

Thanks Nidul!! Glad these old threads are still enjoyable.

I have organized all of my projects with direct links in my profile, for everyone.

As far as the material you are looking for, I'm sure it is available, I just don't know of any. However, if you re-read the thread carefully you will notice a few other members have posted links to companies who produce such products.

If you enjoy working with your hands, I would suggest using paint in your projects as well - there is a great sense of satisfaction that comes with hard work. If your pieces are in mint condition and you want a process that is reversible, proceed with your original plan.

And please, post your progress! All of us here on BeoWorld love these threads. Good luck on your new project!!

Good evening all,

Sitting down with my 4500 pieces tonight to itemize them for a capacitor change. They started acting up a while ago and could use some attention in the electrical areas - something I neglected during the original restoration work.

BeoGram CD 4500 (Type 5173) Parts List

Main Board:
4700uF 25v
2200uF 25v
470uF 40v (2x)
10uF 35v (2x)
2.2uF 50v
22uF 16v
1uF 50v (3x)
22uF 10v (2x)
100uF 35v (4x)
220uF 10v
47uF 10v (6x)
3.3uF 50v
5.8uF 25v
47uF 50v

Servo Board:
220uF 16v (2x)
47uF 25v (2x)
1.5uF 50v
33uF 16v (bipolar)

NOTE: The values above are original equipment.

Evan:

NOTE: The values above are original equipment.

Hi Evan looking forward to see your work advancing;

Did you take the values direct in the BG CD, or from the manual list, if from the list, be careful, its not always the same as in the actual BG.

Forgot to tell you, when I get kits from Martin he nearly always provide one voltage step higher on the caps, surfing the net and learning I have seen this same recommondation on more websites, and dont forget your trimmers.

Søren Mexico:

Hi Evan looking forward to see your work advancing;

Did you take the values direct in the BG CD, or from the manual list, if from the list, be careful, its not always the same as in the actual BG.

The changeout of the caps in this machine will probably take a while, the 4500 is second in line to my 3000-2!

Yes, I know better than to trust the service manuals I recorded these values directly from the capacitors.

Søren Mexico:

Forgot to tell you, when I get kits from Martin he nearly always provide one voltage step higher on the caps, surfing the net and learning I have seen this same recommondation on more websites, and dont forget your trimmers.

 

Yes, this is very good advice. I always do this when recapping. This does seem to be a universal method.

I published the standard values and recommend oversizing. The reason I haven't posted the oversized caps is because I do not want people to double oversize their order and end up with caps that won't fit.

 

By the way, I have also recorded the caps in the BM4500, will post them later tonight. Will also include trimmers.

BeoMaster 4500 (Type 2963) Parts List

Main Board
6800uF 50v (x2) 32mm h  x 35mm dia.
4700uF 50v 42mm h x 21mm dia.
220uF 100v bipolar
10uF 25v (x2)
10uF 16v (x9)
47uF 40v (x2)
10uF 50v
47uF 16v (x2)
47uF 63v (x2)
22uF 10v (x2)
4.7uF 25v
0.47uF 50v
1uF 50v
250v 5a fuse (x2)
250v 2a fuse

FM Board
10uF 50v
0.68uF 50v
22uF 10v (x2)
10uF 16v (x5)
3.3uF 50v (x2)
100uF 16v
4.7uF 25v (x2)
1uF 50v (x4)
47uF 16v
0.47uF 50v

AM Board
100uF 16v
2.2uF 63v bipolar
4.7uF 16v (x2) bipolar
10uF 63v (x2) bipolar

Microcontroller Enclosure
10uF 16v
470uF 6.3v
100uF 10v (x2) bipolar
3v Li battery CR2450

NOTE:
The above values are original equipment.

This list is incomplete, there are some caps that could not be identified and will be added later. The trimmers and their values will also be added soon.