[Motorman]

Tignum wrote:

looks very good!

Thank you very much!

[Motorman]

I’m just restoring an Beogram CD 7000 which is optical in a very good condition.
Only the CD Tray had some ugly oxidation marks in the shiny middle area.
Since I also restore cars, I have access to a sandblasting cabin. Since the traces of oxidation cannot be polished away (it was turned shiny at the time), I sandblasted the area. I am quite satisfied with the result. It’s not original, but it almost looks like it 😉
Before:

After:

 

 

[Motorman]

Hi Evan,

thank you very much for this thread! It will come in handy when I start to work on my Penta Amps tomorrow! By the way, did you measure the old filter caps after removal?

[Motorman]

I finished the Beogram CD 5500 today.

Since I was not sure if I could save the drive suspension and the drawer mechanics at all I did not directly order new suspensions from Martin. Instead I cut replacement hangers from a thick old and soft leather belt.

This worked much better than I expected. I then had to build a new mount for the small PCB under the drive for the flex lines and (for whatever reason) at least deburr additionally drilled holes. Now everything works fine again. Visually, the device after cleaning with Isoprob is a real feast for the eyes.

There is only one small downer, the CDM drive that works has no magnetic spindle. the CDs are therefore not properly clamped and slip a little bit when starting. But it still works.
Does anyone know if and if how to change the spindle in the drives?

[Motorman]

Glitch wrote:

You might want to measure your existing capacitors and go from there.

I think that is a very good tip, that is how I will proceed.
Thank you very much!

[Motorman]

Evan wrote:

You can find the full write up here: Evan’s MK2 BeoLab Pentas

Thanks! This will help me with my Penta MKIII.
I will start with the amplifiers over Easter. There is my wife with the children at the in-laws and I can block the dining table with the speakers in peace.

I got the service kit from Martin for this.

The sourrounds of the midrange drivers are currently still OK, so I will take care of it at a later date.

I’m still undecided what to do with the crossovers. Just take the service kit from Martin or maybe do the improvements suggested by Die.Bogener? What do you think?

[Motorman]

Yesterday I got a Beogram CD5500 for 10€ + shipping. Someone took it appart and damaged it terribly. (I think “slaughtered” is a better word) It came with 2 CDM4 drives.

The white case and the front still look very good, so it’s probably worth working on.

In the meantime, it is already playing with one of the two drives again.

After replacing the usual C2103 on the drive PCB, the left channel was back. After a bit of measuring I found out that the resistor R126 which is connected between the right OP amp and its -15V supply was defect. Now after the exchange it plays nicely on both channels again. Now I “only” have to clean up the damage that was done before. To do this, I first need Martin’s rubber mountings for the drive. (They were cut through). Fortunately, all the other parts seem to be there and I have a CD7000 where I can see how everything belongs together.
There were two drives. One CDM4/11 that works and one CDM/4/13 that doesn’t work and has a broken mounting hole.
Does anyone happen to know which of the drives originally belongs in this player?

 

[Motorman]

Danke!

[Motorman]

I I have heard that this glue is very good

https://www.repairyourspeakers.com/en/glue-brush-syringe/glue-for-speaker-repair-1-x-15ml-best-tested/a-1675-11

[Motorman]

Hallo Stereomensch im archivierten Forum hast Du ja mal über die Restaurierung Deiner Pentas MK3 berichtet. Habe ich das richtig verstanden, daß Du die Gummisicken von Audiofriends genommen hast? also diese da:
https://www.repairyourspeakers.com/de/schaumstoff-gummi-sicken/bang-olufsen/bang-olufsen-beovox-beolab-penta-8x-gummi-sicken/a-2478-10000016
Was hast Du an den Frequenzweichen gemacht?

[Motorman]

Hi Guy,

thanks for the picture and I rechecked with mine. 3 Loops is correct. I was “on the wood way” as we say in German ;-). For the sliding doors it is also important that the sliding grooves are really clean and only slightly lubricated. Regrading the loss of power I also agree with you that it is probably a loose cable connection.

[Motorman]

Meine sind MK2 mit ABL von 2004 (schon mit weißem Schaum) und wie gesagt, es ist ja persönlicher Geschmack, mir gefällt der Klang nicht wirklich. Ich finde das sehr Schade, da sie optisch über jeden Zweifel erhaben sind.

Die Pentas integrieren sich zum Glück auch sehr gut in mein Wohnzimmer.

[Motorman]

Hi, das mit dem Klang ist ja immer so eine Geschmacks Sache.

Fehlender Bass ist eine Sache. Ich finde sie aber auch so unausgewogen. Es fehlt irgendwie an den Mitten. Das soll wohl bei den frühen Beol 8000ern besser gewesen sein. Was mich aber am meisten stört ist folgendes. Ich lasse den Ton unseres Fernsehers über die Anlage (BC9500) laufen. Ganz oft bauen die Lautsprecher bei Sprache z.B. Tagesschau sehr unschöne Zischlaute ein. Das war mit den passiven MB Quart Boxen die ich vorher hatte nicht so und die Pentas machen das auch nicht.

[Motorman]

Hallo,
vielen Dank für den Hinweis.
Ich kenne den Thread und habe gerade deswegen schon versucht mit Die_Bogener Kontakt auf zu nehmen.

[Motorman]

Regarding your question with the phono input.

This is possible but not easy.

I have converted the phono input on a Beomaster 1900.

To do this, I rebuilt the preamplifier circuit from the tape input on a small PCB and instead of the RIAA preamplifier circuit between the socket and source switch installed.

Better said I have installed a 3.5mm stereo jack socket to the front and thus realized for my son a phone instead of a phono input.

This should be possible with a Beomaster 3300 too.

[Motorman]

Hi I restored two BC9500. 2 loops around the driving shaft is correct.

The most important thing is that both the shaft and the thread are clean and free of grease. Personally, I have simply mounted the threads the other way around to have clean thread around the shaft again.

The reason for this is that the motor simply has a time control for opening and closing. This means that the friction between the shaft and the thread must be so great that the door moves. As soon as the door is in one of your system, the thread must slip through without overloading the drive.

This is also the reason for the whirring noise when you switch off the system. The BC never knows if the cassette door is open. It therefore always runs the motor for the cassette door when it is switched off in order to close a possibly open door. If it is already closed, the thread on the shaft simply slips through.

[Motorman]

Its a axial 33µF 16V Capacitor. I just exchaned it on a Beogram CD7000:

Old:

New:

I used a radial 33µF 25V one. It worked like a dream.

[Motorman]

Hallo,

zu der Frage was Beolab 8000er so jetzt kosten.

Ich habe vor ca. 1 Jahr für sehr gute MK2 die optisch ohne Fehler sind 650€ bezahlt.

Würde ich allerdings nicht wieder kaufen. Der Klang hat mich enttäuscht.
Ich habe gehört die MK1 sollen besser klingen.

Ist für mich aber egal. Ich habe jetzt ein Paar Penta 3 und die klingen schon nciht überholt für mich viel besser. Noch gehen die Sicken der Mitteltöner. Ich habe aber schon die Teile für die Überholung der Verstärker da und und vielleicht verrät mor Die_Bogener noch wie ich am besten die Frequenzweichen optimiere.

Wenn alles fertig ist werde ich die Beolab 8000er wieder abgeben. Sehen zwar traumhaft aus aber zum Glück passen bei mir die Pentas auch optisch ins Wohnzimmer.

Zu der Anzeige am Anfang des Freds. Wieder einmal der Beweis, daß man Geschmack für krin Geld der Welt kaufen kann. Erinnert mich an die Bilder aus Trumps Villa.

[Author]

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