ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
Hi everyone
About 12 months ago I helped a friend acquire a pair of M100's. They are the original mk1 version with overload protection but without the overload LED on the front. I have another friend who got a pair of m100-2 about 18 months ago and since then my other friend has always wanted a pair.
So the mk1 pair never sounded as good as the mk2 pair. The mk1 pair had issues mainly in the high frequencies, they sounded dull, you had to sit directly in front of a speaker to really hear them. Over time the mk1 pair sound seemed to degrade even further with a major loss of treble and the bass seeming to loose its punch. My friend who purchased the mk1 pair is a repair technician and despite me insisting that he have a look at the crossovers, he had resolved that the mk1 must have some difference which made it not sound as good as the mk2. His claim was that the caps couldn't be the issue as they haven't been under that much stress over the years.
After a few glasses of Scotch a few weeks ago and my blatant statement that his KEF 104's sounded way better than his M100's which quite frankly sounded 'crap' in their current state, we pulled the back off one speaker, popped some caps off the board and did some testing.
50uf caps reading anything between 80uf and 120uf
4uf caps reading 8uf
The list goes on, most caps 1.5 and double their resistance, not a single cap was remotely within the spec. So we ordered some nice poly caps for the HF circuit and some reasonable electros for the lf and got to recapping.
First reports from my friend are that the HF is back and very nice, midrange is great and lf is a little more reserved. I am yet to hear them but will be doing so this evening and will report back.
I have always been a fan of recapping speakers. My S45-2s which had silver (not gold) ROE caps I recapped with audiophile poly's and I really dont believe it made a huge difference.
I recapped my S75's with Martins kit and a generic poly 2.2uf to replace poly's which had been burnt by incorrect placement of the resistors on the assembly line. The difference in the S75's was immense with much more top end and major improvement in midrange and tightening of the bass.
I was, however, as was my friend (who is senior tech at 2 major radio stations) quite amazed at how totally off spec the caps in his M100's were. My friends observation was that the caps in his M100s.
Thought some of you might find this interesting :) Here is a pic of some rough on-board testing before we pulled the caps off, not the cap being tested is a bit of a different colour to the others, this was the same in the other cabinet. Drew
Hi everyone,
The recapped boards below;
Hi Drew,
I read about your recapping work with both interest and anxiety because I have had such poor luck in this department.
I recapped my Beogram 8000 but it needed so much more than that took Martin’s Midas touch to make that Beogram right again.
I then tried my hand on the CD player in my BeoCenter 9000, recapped it, another utter failure. Ended up replacing the entire CD unit.
Finally I attempted to improve the sound on my atrocious MC 120.2 speakers by recapping them, to little effect. Trust me on this, if Moses had heard these speakers, there would be another commandment!
Perhaps with time I could learn how to properly test these capacitors, but right now all I have been doing is replacing them en mass.
Which brings me to my “anxiety,” I have four S 75 speakers, all of which have been very badly treated, one pair was found in a trash dumpster (along with the BeoCenter 9000) anther has a cigar burn on the top…. BUT they sound fantastic and add a lot to my day.
When my S 75’s degrade like your M 100’s I see little chance of my having any real enthusiasm in trying to recap them. At least the need has yet to arise.
Keep up the great work my friend; you set a fine example for us all!
Jeff
Beogram 4000, Beogram 4002, Beogram 4004, Beogram 8000, Beogram 8002, Beogram 1602. Beogram 4500 CD player, B&O CDX player, Beocord 4500, Beocord 5000 T4716, Beocord 5000 T4716, Beocord 5000 T4716, Beocord 8004, Beocord 9000, Beomaster 1000, Beomaster 1600, Beomaster 2400.2, Beomaster 2400.2, Beomaster 4400, Beomaster 4500, Beolab 5000, Beomaster 5000, BeoCenter 9000. BeoSound Century, S-45.2, S-45.2, S-75, S-75, M-75, M-100, MC 120.2 speakers; B&O Illuminated Sign (with crown & red logo). B&O grey & black Illuminated Sign, B&O black Plexiglas dealer sign, B&O ash tray, B&O (Orrefors) dealer award vase, B&O Beotime Clock. Navy blue B&O baseball cap, B&O T-shirt X2, B&O black ball point pen, B&O Retail Management Binder
I have always been amazed about the difference a cap change do, the only time I couldn´t hear a difference was in my S45s (2 way).
Where I didnt hear any difference was using the designer, expensive caps instead off the shelve caps, but that may be my faulty hearing.
Collecting Vintage B&O is not a hobby, its a lifestyle.
Hi Soren
Agree, I used Jantzen Cross Caps in my S45-2 and couldn't really hear any difference between them and another pair done with off the shelf electro's.
These M100's have come up a treat since recapping though, the response of the tweeter and super tweeter was very very much down on what it should have been. So a good learning to anyone else looking at a pair of M100's, if they haven't been recapped it is very much worth considering, you may find you have been missing out!
Drew
Since you have essentially SOLD me on either a pair of M 100’s or M 150’s I read with keen interest their need for recapping.
Numerous posts on recapping S 45.2’s and most folks (like you) can’t tell the difference between the before and after.
I keep thinking that age alone dictates that my MUCH admired S 75 speakers should be recapped, but I also am a strong believer in “if it ain’t broke, don’t fix it.”
I have two pairs of S 75’s and they sound exactly alike. I don’t mean similar, I mean identical. So how would I know if they are in need of recapping? Good question, don’t ya think?
Oh yea, before I forget if you haven’t seen my sardine can Media room there are pictures posted on Beomaster 2400 ‘vs Beomaster 4500 under BeoWorld North America.
I have a pair of m 100's I bought new in 1977. mine were the very first set to be sold in Memphis, TN . I need to find out if someone know where to get speaker grill pins. saw early on that these were going get broken easily so bought a box of them. I only have four left and they are on the grills. thanks.
rt
You could try Martin or Leslie.... if they don't have them, they certainly might know where you can find them.