Rogers LS55, Crossover recaps

[clint e.]

I have recap all the crossover caps from my Rogers LS 55 speakers.I thought it was time to do it, mainly because this set of speakers have more than 15 years of old and also because they have IMO bad electrolytic axial caps from Alcap.

I still have two Epcos polypropylene caps left from my MF X10-D mods, so i'd put them for filtering the high frequencies. They have an excellent "sound",so why not use them...?!

For the mids i used polyester film caps from Philips, the same for the lows, but with a small change; I'd put two polyester film caps from Philips in parallel.

The conclusions after only 15h. of listening (these caps needs at least 50 to 100h. of "burn-in") are very good.

The high & mid frequencies are now much more liquid, detail, accurate and that reflects in the three dimensionally soundstage spectre of music. The improvements was felt also in the lows and even the pace of songs in a better perception of the music rhythm.

In resume, dynamics, harmonic integrity, depth and tight bass sounds are a great gain with this simple mods.

The cds i used for testing were :

- Bjork's Debut, for the rhythm, voice timbre natural dimension and electronic low frequencies.
- REM's Automatic For The People, for the mids, many little high frequencies details and soundstage depth.
- Chet Baker's Chet Sings, for voice colorations and organic & acoustic instruments.
- Massive Attack's Mezzanine, for deep low bass rhythms & harmonics and also bottom end frequencies.

Here's a few pix :

Old caps out:



New caps in:

[dingus]

nice Alvaro, a sweet sound just got sweeter.

[clint e.]

Because every little thing in audio matters... With only 10€ i'd made a sweet upgrade, and you're right Scott, sweet is the exact word.
That's a great analogy. A film cap is like putting a little sugar in the sound.

[hifi_nut]

Rogers, one of the most respected names amongst british manufacturers, was unfortunately going down at the time they introduced the LS-55, which were probably their last model. That, in itself, would explain why they used what are obviously lower quality capacitors, in order to mantain costs in check.

I´m curious, Alvaro, did you stick to the original cap values?

Also, what´s to gain by adding another cap in paralel, as you have done? Doesn´t that change the filter´s slope at the crossover frequency?

As usual your handy work looks pretty impressive. I haven´t forgotten you offered to mod my Musical Fidelity X-Cans headphone amp.

Jorge

[clint e.]

About the original cap values...of course i'd stick to the values 'cause it was not my intention screw up with crossover frequencies, at all. They are beautiful done why botter...?!

About the parallel caps...from what i read & learned through out the years of electronic audio, parallel caps effectively increases capacitance, reduces parasitic noise and inductance, and also reduces ESR witch is the great importance for audio gear.
Sometimes the problem to do this is a matter of room between other electronic components.



Concerning your X-Can, next time we meet you'll bring it over and i'll upgrade for you.

This post has been edited by clint e. on October 05, 2007 12:07 pm