Braun L1030 internal update

[kingscoins83]

Hello to all,

It's been a while since my last post and I find myself in need of the forum wisdom again. I'm trying to internal update my daily drivers, a pair of Braun L1030, but I don't know if it's worth it and if yes, if I'm using the correct parts. I should point out from the beginning that the sound that comes out of these speakers is satisfying for me already as it is, but at the same time I've always felt that there's room for improvement. The maximum budget I'm willing to spend on this project is around 200 EUR (I'm located in Europe) and this is one of the reasons why I'm pointing out Jantzen brand parts as suitable replacements, as you will see. The speakers are powered most of time by a Yamaha CR-1000 receiver and sometimes by a Braun A501 amplifier.

I was thinking to tackle this update in three phases:

Phase one - the crossover

The speakers in question are a 3 way type, with the following caps on the crossover (correct me if I'm wrong):
- two caps of 33uF & 47uF, for the bass;
- three caps, two of 10uF and one of 4,7uF, for the mids;
- one cap of 5,1uF, for the highs.


I don't have a schematic but hopefully I've managed to locate the parts well on the back side of the crossover (R stand for resistor & C for coil):


The initial plan was to use Jantzen Cross Caps overall, just as I've seen in other threads located over the internet, or here on audiokarma, but someone told me that if I want to do this wright, I should install Jantzen Standard caps for the mids and Jantzen Superior caps for the highs & low value ones in the mid section. The resistors will be replaced with Jantzen Superes and the coils will be left alone

My questions are:
1. Will there be a noticeable improvement in sound over what I'm herring now if I'm going to change the old MKT's only with Jantzen Cross Caps MKP's?
2. Will there be a noticeable difference between using only Jantzen Cross Caps and the case in which different Jantzen type caps will be used?
3. Does the 4,7uF cap actually belong to the mids section?
4. Should I consider changing the 4,7uF one also with a Jantzen Superior one?

Phase two - the L-Pad attenuators

The speakers have attenuators for the highs and mids, which are full of Vitrohm ceramic resistors and I would like to replace them with the Jantzen Superes ones.

Will that contribute to improving the sound?

Phase three - internal cables

I was also thinking at changing the internal wiring with a 2x2,5mm 100% OFC cooper cable.

Will that contribute to improving the sound?


Sorry for the long post and my indecisiveness. I would like to thank you in advance for your input and I acknowledge that my questions imply a lot of subjectiveness.

Kind regards

 

[Stuart Pedaso]

Traced out a schematic from your excellent images. It appears to agree with your assessment of capacitor locations within the circuit. The base circuit configuration is quite similar to some other Braun / ADS family 3-ways, such as L810 and L630.



High and Mid level control circuits shown are temporary stand-ins -- not confirmed to be correct.
[ EDIT -- schematic updated with MF and HF level control configuration data ... and yet again with some corrections ... ]

I gave schematic components arbitrary numbers to reference against your PCB image similarly labeled.



Having no personal experience with these speakers, I can offer no qualified advice. Quality vintage speaker systems are usually deemed deserving of component upgrades. Whether performance change turns out for the better -- or just different -- is the question. Lacking testimony from those who have already explored various options, one is left with conjecture and experimentation. Which can be fun, if luck favours your efforts, though not necessarily budget friendly.

 

[kingscoins83]

Hello and thank you very much for your detailed and informative answer.

High and Mid level control circuits shown are temporary stand-ins -- not confirmed to be correct. They are loosely derived from an online image showing four resistors per switch:

I confirm that my speakers have the mid & high control levels. As far as I remember the ones without the L-pads were GSL1030. However, I forgot to mention that mine are the 4 ohm version. The L-pads have 16 resistors in total, 8/channel. I don't have pictures, but detailed ones can be consulted in this thread: Braun L 1030/4 Thread | Page 2 | Audiokarma Home Audio Stereo Discussion Forums

Which can be fun, if luck favours your efforts, though not necessarily budget friendly.

Totally agree with you, maybe this is why I'm hoping someone will stop me )

Kind regards

 

[Stuart Pedaso]

I don't have pictures, but detailed ones can be consulted in this thread: Braun L 1030/4 Thread | Page 2 | Audiokarma Home Audio Stereo Discussion Forums

That thread by @Bratwurst7s has ample images of the level controls to trace out a schematic. Not all resistor values are visible, but the configuration is clear.

I've updated the schematic in post #2. Each L-pad is configured with 4 resistors in series on one side for shunt (parallel) resistance and 4 on the other side for series resistance. The switch engages taps between resistors, adding or subtracting resistance depending on direction of rotation. As a variable L-pad, for higher output settings series resistance is low while shunt resistance is high. The reverse is true for low output settings. Here's an illustrated example for –2dB setting of tweeter Level:
[ Edit -- illustration updated with error corrections and format change ]



If thinking of replacing these resistors, note that they appear to have a built-in support tab to keep from getting knocked about, since they are mounted radial fashion. It might be challenging to source similarly constructed devices in exact values needed while, at the same time, of a higher quality than original.

 

[kingscoins83]

I've updated the schematic in post #2.

Superb work, thank you for your involvement. I will try to provide the values of the resistors in order to fully update the crossover (L-Pad included). It might be harder for the coils as I don't think they have something written on them. The resistors that I have so far identified are those highlighted in the picture bellow.

they appear to have a built-in support tab

You are wright, they do have a lateral sliding system. I was thinking to fix the new resistors to the existing support poles with a glue gun.

 

[kingscoins83]

Not all resistor values are visible

Finally managed to take a peek at the resistors. Here are the values for the 4 ohm version of the Braun L1030 speakers:


Kind regards

 

[Stuart Pedaso]

Here are the values for the 4 ohm version of the Braun L1030 speakers:

Updated the schematics. This crossover is becoming quite well documented. All this data you are sharing will be a welcomed resource for other owners of this version L1030.

 

[kingscoins83]

Updated the schematics. This crossover is becoming quite well documented. All this data you are sharing will be a welcomed resource for other owners of this version L1030.

I'm really glad that I could contribute with something to the wisdom growth of the forum and thank you very much for your help. I've decided to go ahead only with phase one & two from my initial post but it will take some time to put it in practice. I will update the thread as I make any progress.

Kind regards

 

[Nima]

I'm really glad that I could contribute with something to the wisdom growth of the forum and thank you very much for your help. I've decided to go ahead only with phase one & two from my initial post but it will take some time to put it in practice. I will update the thread as I make any progress.

Kind regards

Hi,
Have you done the work and how is the upgrade result?
I've got the same speakers and i'd like to upgrade mijn as well, best wishes

 

[kingscoins83]

Hi,
Have you done the work and how is the upgrade result?
I've got the same speakers and i'd like to upgrade mijn as well, best wishes

Hello and sorry for replying only now, but my notifications are disabled . Unfortunately I haven't upgraded them yet, they've retrograded towards the bottom of a long to do list. Did you manage to do yours?

Kind regards

 

[knotscott]

I've never upgraded a pair of Brauns, but have done similar cap upgrades to several other speakers. What's audible is always a variable depending on the rest of the system, but I always consider it a step in the right direction. The weak link theory applies. The Brauns have good quality drivers, so improving the caps to some good polypropylene offers potential for improved clarity IME.

It's worth mentioning that new polypropylene caps often sound a little bright and sometimes a bit sibilant at first. They should smooth out with some playing time, so don't be too discouraged at first.

 

[kingscoins83]

I've never upgraded a pair of Brauns, but have done similar cap upgrades to several other speakers. What's audible is always a variable depending on the rest of the system, but I always consider it a step in the right direction. The weak link theory applies. The Brauns have good quality drivers, so improving the caps to some good polypropylene offers potential for improved clarity IME.

It's worth mentioning that new polypropylene caps often sound a little bright and sometimes a bit sibilant at first. They should smooth out with some playing time, so don't be too discouraged at first.

I concur with your finds, as I did several upgrades on various speakers until now. I would've been curios about the improvements on this particular model, since the whole upgrade is a pretty costly one, hence the follow-up on our colleague's pos.

Kind regards