Beloab 150 / Penta Upgrades

26 replies
M(
Offline
machineage (archived2)
Bronze
Posted March 22, 2014 at 00:27 GMT
#2199745

Hi all 🙂

I've decided to carry out some work on my ageing Beloab 150 amps / Pentas. They were originally Beovox Penta Mk1's to which I later added Beloab 150's when they turned up.

Anyway they have given good service over the years - and they are currently running cool. I feel though they are of an age where I should now carry out preventative work by way of replacing some components - and upgrade as I go. I'm on a budget so I intend doing the amps first - then possibly the Xovers at a later date.

First the electrolytics which I will replace with 105°C rated components. I wonder if anyone could recommend what electrolytic manufacturer / series I should go with - Panasonic / Vishay / Nichicon ?

I understand most of these are not in the signal path - but some of the caps are. Which ones are in the signal path and what should I replace them with? WIMA MKS2?

I will also replace the 10,000uF caps. There seem to be loads of Elna & Nippon caps on eBay, but I've read a lot about them being fakes 🙁

I wonder if these too are fakes:

C(
Offline
cordobaman (archived2)
Bronze
Posted March 22, 2014 at 16:31 GMT
#2199746

I've attempted this upgrade, replaced C1, C2, C5, IC2.  Also R65, R66, R73 because they looked like they got hot.  Plus the caps in the power supply.  Now the amps will turn on, put I get zero output...not even hiss. 

Suggestions on where to look?

M(
Offline
machineage (archived2)
Bronze
Posted March 22, 2014 at 23:42 GMT
#2199747

Can anyone help with my questions 🙂

In the meantime I've ordered replacement foams for the midranges from Good HiFi. Mine are all still intact - but I daren't touch them 😐

 

I read too on the archived forum about a mod to get rid of the 'pop' on power up - but the link to the mod doesn't seem to work:

/forum/beogram/beogram-rx2-thumping-noise

 

Thanks 🙂

BO
Offline
bos00
Bronze
Posted March 23, 2014 at 14:57 GMT
#2199748

machineage wrote:
but the link to the mod doesn't seem to work

/forum/general-discussion-and-questions/beoplay-a2-just-released#post-2026433

Beobuddy
Offline
Beobuddy
BronzeFounder
Posted March 23, 2014 at 19:28 GMT
#2199749

machineage wrote:

In the meantime I've ordered replacement foams for the midranges from Good HiFi.  

 

Don't! Audiofriends has the right ones!

Location: Utrecht

Quite a challenge to achieve "Less is More" while having the Beovirus.
M(
Offline
machineage (archived2)
Bronze
Posted March 23, 2014 at 19:50 GMT
#2199750

Oh 🙁

It's a bit late as i've already paid for them...

 

Are they completely wrong for the drivers? Should I ask for a refund?

BO
Offline
bos00
Bronze
Posted March 23, 2014 at 20:54 GMT
#2199751
Beobuddy wrote:

Don't! Audiofriends has the right ones!

I can confirm this!
M(
Offline
machineage (archived2)
Bronze
Posted March 23, 2014 at 21:14 GMT
#2199752

Oh dear 

 

There's not much I can do now - unless I ask for a refund if they haven't already beens sent.

 

I will ask

Beobuddy
Offline
Beobuddy
BronzeFounder
Posted March 24, 2014 at 07:19 GMT
#2199753

Even then, I wouldn't doubt investing in another set of foamsurrounds.

You will have the opportunity to compare the surrounds. You will notice the difference!

Again, I'm repeating myself, do not use the Good Hifi version. Among the more then hundred drivers I've done so far, there where several with the wrong surrounds fitted. They became loose around the chassis where the coil-wiring goes in. Or were simply bad placed caused by the wrong dimensions.

Location: Utrecht

Quite a challenge to achieve "Less is More" while having the Beovirus.
Beobuddy
Offline
Beobuddy
BronzeFounder
Posted March 24, 2014 at 07:22 GMT
#2199754

And order some speakerglue with it. You will get glue which stays elastic. Don't use PVA as I've seen which gets hard.

Location: Utrecht

Quite a challenge to achieve "Less is More" while having the Beovirus.
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