That is a really good job Erik!
Thankyou for sharing this, and taking the time to do the excellent photo's!🤒

Andy T.

Hi,
 

Very nice project.  I think if you combine this with the modification of the condensators, suggested by Die Bogener on the old forum, this should be even more impressing!

PS 1: what kind of Icepower amplifier do you use?

PS 2: any tips on removing the cover of the penta, without risking to damage the display? 

kind regards

Joost
 

Excellent job done. But why not an upgrade to the filter.

Just change the caps to polypropylene Audyn cap plus or better, and bridge them with a small 0.01µf cap to make the sound even smoother.

 Thanks  to all,  I`m glad to show my projekt for all in BeoWorld. Its not only the ear that can hear the changes. Here are the visible result  of the projekt 🙂

link

First I have powerede my 4  Penta with 4 X 1000ASP ,- and then the B&W,-PV1 subwoofer have 500 watt ICEpower . My next projekt are to power the Avant (center)speakers with 1 X 250 watt ICEpower

 Here are the amplifier I use for the front Penta, the rear amplifier are the same inside  but in a onother cabinet.

link

Penta, BC2 , B&W- pv1 and BeoVision Avant

link

 I have change the condensator in some others Penta before, but its ekspensive, ( 100- 200 euro each ) therefore i wait with this projekt . I have four Penta !

I have make some notes from the old projekt, and I hope BeoWorld members  will use them

 WHY USE TIME FOR THIS PROJEKT ?

Condensator need to bee change after  while. Here are a picture of a old (open) condensator. It should have been covered by silver , but now there only are a litle in the end.

Typical condensator

link

BeoLab /BeoVox NORMAL FILTER diagram

 link

Here is a diagram if you instead want to make biwiring.

 link

This graf shows the difference betveen a old and new condensator!

Condensatorer in filtrene , to one Penta  speaker (all types ),  are named here

Notice: uF is called "Micro Farrad" and nF is  called "NanoFarrad"

Midrange filter

C1: 22 uF 10% 35 V 

C2: 8,2 uF 10% 35 V

C3: 82 uF 15% 35 V

C4: 3,3 uF 10% 100 V

C5: 10 uF 10% 35 V

C6: 680 nF 10% 63 V -  olso called 0,68 uF

C7: 680 nF 10% 63 V -  olso called 0,68 uF

C8: 22 uF 10% 35 V

Bas and tweeter filter

C1: 68 uF 10% 35 V

C2: 220 uF 20% 35 V

C3: 47 uF 10 % 35 V

C4: 2,2 uF 10% 100 V   (tweeter)

C5: 3,9 uF 10% 100 V   (tweeter)

C6: 680 nF 10% 63 V - is a 0,68 uF   (tweeter)

Always use the best condensators  for tweeter and midrange. Its okay to use different brand in same filter, but keep them together.

 which mean one brand for tweeter and another brand for midrange.

If you not have time or money to change them all, then  first change condensator that are placed in serie, becouse they are most importent for the sound.

Most used brands in Hi-End condensators are these:

(choose MKP or MKT types) and yes- they are expensive,  but popular for DIY

Audyn CAP from Intertechnik,         Mundorf      J E N S E N

                             http://www.lautsprechershop.de/english/index_hifi.htm 

Notice .

If you have one of the first Penta,MK1 and MK2 you also need to change one speciel  resistance called  R1 in the midrange filter.  (See diagram)

It will give you a tiny difference in clear an natural midrange.

 If is a  3.3 ohm (colourcode: Orange, Orange, Black) you shall change it to a  to a smaller one; 2,2  ohm (Colour code: Red, Red, Black) 

 BeoLab with green display (MK3) should proberly already have this modicifation (Mk1 and MK2 with Yellow and Orange display have not).

All BeoVox Penta olso need a check, You can`t see which  version it is outside!

link

Very nice project, and thank you for sharing it with us!

I have one comment:

Penta2 seems to exixt with both versions of filters. I have Penta2 with the 2,2ohm resistor and other components identical to your diagram.  

I discovered that the versions with filters with 3,3ohm resistors has different capacitors and coils also, worth looking in to before ordering parts. This circuit diagram is in the work shop manual for Beolab Penta type 6621, 6622, 6623, 6624, 6625.

My Pentas are type 6621, which is confusing, should that not mean that they are an early version, why would they have the "newer" filters? 

 Here are  how a 20 years old  Penta amplifier look like inside!  Its nearly exploding!! The first sign are humming...😁

link

hi Bulgarien,

could you please tell me if the midrange drivers were ordered directly from B&O? If yes,I would like to know the caracteristics if possible( Brand name and if is 4OHM or 8OHM?).

 I would appreciate if you can provide me that information! (I bought Penta 1 speakers few weeks ago and all the drivers were replaced but not with the originals one so your help will help pe for sure!)

regards,

constantine