AudioCircle

Industry Circles => Sonic Craft => Topic started by: OSIB16 on 16 Jun 2022, 01:55 am

Title: Bang & Olufsen Beosound 4 ((Restoration/Modifications))
Post by: OSIB16 on 16 Jun 2022, 01:55 am
(https://www.audiocircle.com/image.php?id=241744)
I recently purchased a nice Beosound 4 hifi unit with a faulty glass door mechanism (2007 model year). Everything else works fine. I got it for a great low price. However, the factory paintwork on it is deteriorating (common for the age). The sound quality is pretty extraordinary when partnered with my modded Beolab 1 speakers. Plenty of transparency, with a proper 3D soundstage. So my plan is to redo the paint, but with a better colour scheme.

As for the electrical modifications; there isn’t a lot of things that can be done, due to the extremely cramped cabinet as well as some other issues. Below is a list of the tasks that will be undertaken:-


1) PAINT THE MAIN BODY OF THE CABINET IN MATT SILVER (WITH A MATT PURPLE FASCIA).

2) INSTALL INTERNAL FIG 8 POWER CORD WITH CARDAS 11.5AWG COPPER LITZ STRAND (66.6666% PURITY).

3) INSTALL JUMPER CABLE BETWEEN POWER SUPPLY BOARD AND MOTHERBOARD WITH 22AWG OCC SILVER PLATE COPPER (66.6666% PURITY).

4) SWAP ALL ELECTROLYTIC CAPACITORS FOR THE VERY BEST AVAILABLE; MUNDORF HV+ , AUDIO NOTE KAISEI, NICHICON FINE GOLD, ELNA SILMIC II.

5) ATTACH A STATE OF THE ART ‘IFI ZEN BLUE MK2’ BLUETOOTH MUSIC RECEIVER ONTO THE REAR OF CABINET.

Title: Re: Bang & Olufsen Beosound 4 ((Restoration/Modifications))
Post by: OSIB16 on 16 Jun 2022, 01:58 am

(https://www.audiocircle.com/image.php?id=248165)


(https://www.audiocircle.com/image.php?id=248166)


(https://www.audiocircle.com/image.php?id=248167)
Title: Re: Bang & Olufsen Beosound 4 ((Restoration/Modifications))
Post by: OSIB16 on 16 Jun 2022, 02:22 am

(https://www.audiocircle.com/image.php?id=241750)
Title: Re: Bang & Olufsen Beosound 4 ((Restoration/Modifications))
Post by: JCarney on 16 Jun 2022, 03:35 am
Oh good, he's at it again.  :popcorn:

JCarney
Title: Re: Bang & Olufsen Beosound 4 ((Restoration/Modifications))
Post by: Nick B on 16 Jun 2022, 03:37 am
Glad you’re back doing another B & O project   :thumb:
Title: Re: Bang & Olufsen Beosound 4 ((Restoration/Modifications))
Post by: S Clark on 16 Jun 2022, 12:10 pm
Can I send you my two dead B&O turntables?  Fix one for me, keep one. 
Title: Re: Bang & Olufsen Beosound 4 ((Restoration/Modifications))
Post by: OSIB16 on 16 Jun 2022, 03:49 pm
Can I send you my two dead B&O turntables?  Fix one for me, keep one.

Unfortunately I am merely a novice when it comes to repairs. My skill is in re-engineering the cabinet of a hifi unit so that bulky/unwieldy components (i.e. giant Capacitors) can be safely fitted inside. I can do some basic solder work, but afterwards; I tend to leave the more complex stuff to my local Computer/Hifi repair shop.
Title: Re: Bang & Olufsen Beosound 4 ((Restoration/Modifications))
Post by: Nick B on 16 Jun 2022, 04:45 pm
Can I send you my two dead B&O turntables?  Fix one for me, keep one.

Beolover on utube has done a number of excellent videos on those turntables

https://youtu.be/IxIxHb8sZdg
Title: Re: Bang & Olufsen Beosound 4 ((Restoration/Modifications))
Post by: OSIB16 on 17 Jun 2022, 07:43 pm
SClark
             If you want your turntables to be fixed for the cheapest price, I recommend sending it to a guy called Brent Rowe at www.fidelityaudio.co.uk  He is a genius and should be fully able to get it up and running.
Title: Re: Bang & Olufsen Beosound 4 ((Restoration/Modifications))
Post by: Jeff on 21 Jun 2022, 07:44 pm
I'm not completely clear on your goal here, but I would have only considered changing the large cap on the Mother Board.  Most, if not all, the others appear to be surface mount.  While that might be a chore for a novice without proper equipment on a multilayer board that is using high temp solder...  They appear to be long life, low ESR parts.  The power supply, I'm ok with that, but would select parts carefully.  I'd also look at the differential mode filter caps (I assume that is what the 0.1uF X2 caps are doing), and any common mode caps...  A schematic would be great.
Title: Re: Bang & Olufsen Beosound 4 ((Restoration/Modifications))
Post by: newzooreview on 21 Jun 2022, 09:39 pm
I really enjoy these adventures in passion (obsession?). Please have one vote of endorsement.

I don't know one bit about soldering and circuitry. My Ph.D. did not cultivate any expertise in that direction. So, the enthusiasm and facility you have in disassembling things and making them better or operational is a lot of fun.

I remember hanging out with a friend in high school. His parents had a B&O system in the front room and he put on Elton John's Greatest Hits, Bennie and the Jets. He was an aspiring bass player. I had never really heard the bass lines in that live recording. But on the B&O system I could hear it. It was a lot of fun and gave me a new perspective on the recording.

B&O is an ecosystem with unique pleasures (whatever the objective deficiencies might be).

Party on, Wayne! Party on, Garth!
Title: Re: Bang & Olufsen Beosound 4 ((Restoration/Modifications))
Post by: OSIB16 on 22 Jun 2022, 03:30 pm
I'm not completely clear on your goal here, but I would have only considered changing the large cap on the Mother Board.  Most, if not all, the others appear to be surface mount.  While that might be a chore for a novice without proper equipment on a multilayer board that is using high temp solder...  They appear to be long life, low ESR parts.  The power supply, I'm ok with that, but would select parts carefully.  I'd also look at the differential mode filter caps (I assume that is what the 0.1uF X2 caps are doing), and any common mode caps...  A schematic would be great.

Jeff,
       The sixteen year old Beosound 4 unit is getting on a bit now, so I wanted to replace the existing electrolytic capacitors before they dry out. The faulty glass door also needs attention. So no matter what, it needs to be sent to a Hi-Fi/Computer repair shop. While it’s there I can get them to do the modifications as well (they specialise in replacing surface mount components).

The best quality large cap I could find for the motherboard was Nichicon Fine Gold 3300uf/25v. Unfortunately Audio Note Kaisei, or Elna Silmic II doesn’t make caps in that value.
Title: Re: Bang & Olufsen Beosound 4 ((Restoration/Modifications))
Post by: artur9 on 23 Jun 2022, 01:56 am
Are better components ever detrimental?  Something like how some cars cannot tolerate synthetic oil...?
Title: Re: Bang & Olufsen Beosound 4 ((Restoration/Modifications))
Post by: OSIB16 on 23 Jun 2022, 02:44 pm
Are better components ever detrimental?  Something like how some cars cannot tolerate synthetic oil...?


Yes, sometimes certain high end brands of capacitors are a bad match together  which can result in a collapse of the soundstage or a strident treble.
Title: Re: Bang & Olufsen Beosound 4 ((Restoration/Modifications))
Post by: OSIB16 on 23 Jun 2022, 08:00 pm
Below are images of the diy shelf I created which allows the giant Mundorf caps to be mounted onto the chassis. Unfortunately there is no room on the power supply PCB to accommodate these monsters.
(https://www.audiocircle.com/image.php?id=241979)

(https://www.audiocircle.com/image.php?id=241980)

(https://www.audiocircle.com/image.php?id=241981)


(https://www.audiocircle.com/image.php?id=249351)
Title: Re: Bang & Olufsen Beosound 4 ((Restoration/Modifications))
Post by: OSIB16 on 28 Dec 2022, 12:04 am
These images show the rear panel that I painted matte silver, complete with easy access panel above and below the big caps…
(https://www.audiocircle.com/image.php?id=248154)


(https://www.audiocircle.com/image.php?id=248155)



(https://www.audiocircle.com/image.php?id=248156)



(https://www.audiocircle.com/image.php?id=248157)



(https://www.audiocircle.com/image.php?id=248158)
Title: Re: Bang & Olufsen Beosound 4 ((Restoration/Modifications))
Post by: OSIB16 on 28 Dec 2022, 12:07 am
These images show the large gauge jumper wires used…
(https://www.audiocircle.com/image.php?id=248159)


(https://www.audiocircle.com/image.php?id=248160)
Title: Re: Bang & Olufsen Beosound 4 ((Restoration/Modifications))
Post by: OSIB16 on 28 Dec 2022, 12:09 am
Here is the larger than original gauge umbilical cord that I created with blue heat shrink wrap. It links the power supply board to the motherboard. This is the thickest high purity solid core wire that I could fit into the cramped plugs…


(https://www.audiocircle.com/image.php?id=248168)


(https://www.audiocircle.com/image.php?id=248169)


(https://www.audiocircle.com/image.php?id=248161)
Title: Re: Bang & Olufsen Beosound 4 ((Restoration/Modifications))
Post by: JCarney on 28 Dec 2022, 12:12 am
WooHoo! He's back. Been awhile OSIB16, you been ok?

JCarney

PS
A link to my madness on a pair of speakers I've had for 20+ years.

https://www.audiocircle.com/index.php?topic=183606.0
Title: Re: Bang & Olufsen Beosound 4 ((Restoration/Modifications))
Post by: OSIB16 on 28 Dec 2022, 12:19 am
WooHoo! He's back. Been awhile OSIB16, you been ok?

JCarney

PS
A link to my madness on a pair of speakers I've had for 20+ years.

https://www.audiocircle.com/index.php?topic=183606.0

Yeah ok thanks. Hope you had a great Christmas. That Martin Logan speaker project you did looks like a lot of hard work.
Title: Re: Bang & Olufsen Beosound 4 ((Restoration/Modifications))
Post by: Nick B on 28 Dec 2022, 12:23 am
Here is the larger than original gauge umbilical cord that I created, which links the power supply board to the motherboard. This is the thickest solid core wire that I could fit into the cramped plugs…
(https://www.audiocircle.com/image.php?id=248161)

Very nice work…nice to see what you’re up to
Title: Re: Bang & Olufsen Beosound 4 ((Restoration/Modifications))
Post by: OSIB16 on 28 Dec 2022, 12:31 am
Very nice work…nice to see what you’re up to

Thanks Nick, it was a bloody nightmare putting it together. The original jumper cable used really puny 26 gauge bell wires. However, the thicker copper that I swapped it for is 99.9999% purity. Should really give things a healthy boost in performance.
Title: Re: Bang & Olufsen Beosound 4 ((Restoration/Modifications))
Post by: JCarney on 28 Dec 2022, 12:34 am
Yeah ok thanks. Hope you had a great Christmas. That Martin Logan speaker project you did looks like a lot of hard work.

Glad to hear you've been well. We did have a nice day, thanks.

So far the hurdles have been little things I did not take into account when planning. Making changes on the fly as it were seems to be the theme of this rebuild. I'm still working on it, but I believe I have all but one hurdle cleared, and I will have to solve that on the fly when I do the final assembly.

JCarney
Title: Re: Bang & Olufsen Beosound 4 ((Restoration/Modifications))
Post by: OSIB16 on 28 Dec 2022, 02:03 am
Glad to hear you've been well. We did have a nice day, thanks.

So far the hurdles have been little things I did not take into account when planning. Making changes on the fly as it were seems to be the theme of this rebuild. I'm still working on it, but I believe I have all but one hurdle cleared, and I will have to solve that on the fly when I do the final assembly.

JCarney

That’s the whole beauty of this modifications game. Once the hurdles are out of the way, the next part is the best (i.e. listening)
Title: Re: Bang & Olufsen Beosound 4 ((Restoration/Modifications))
Post by: OSIB16 on 3 Jan 2023, 07:56 pm
Just finished creating (from scratch) an aluminium bracket to fit the Beosound 4 unit onto the optional floor stand…
(https://www.audiocircle.com/image.php?id=248378)


(https://www.audiocircle.com/image.php?id=248379)


(https://www.audiocircle.com/image.php?id=248380)


(https://www.audiocircle.com/image.php?id=248381)


(https://www.audiocircle.com/image.php?id=248382)


Title: Re: Bang & Olufsen Beosound 4 ((Restoration/Modifications))
Post by: duvi on 31 Mar 2024, 08:09 pm
Hi,

I've just joined and was wondering if anybody has experience of the Beosound 5?

Cheers

Duvi