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
Rich: Introducing the new WWMD bracelet, yours for only US$9.95! So whether you agree with Martin or Menahem, you can show your support for either by purchasing this once in a lifetime, good luck bracelet! Replacing the caps in your loudspeakers with cheap electrolytics? Refoaming your woofers without shimming the voice coils? Guarantee success by wearing this WWMD bracelet while working on your priceless BEO!
Introducing the new WWMD bracelet, yours for only US$9.95!
So whether you agree with Martin or Menahem, you can show your support for either by purchasing this once in a lifetime, good luck bracelet!
Replacing the caps in your loudspeakers with cheap electrolytics? Refoaming your woofers without shimming the voice coils? Guarantee success by wearing this WWMD bracelet while working on your priceless BEO!
As ridiculous as this sounds Rich, there are many audiophiles who would truly believe you, and would testify to hearing a difference in sound if you were an exotic snake-oil producer of products!
Olly
Hey, I'll take a dozen !
My work can only improve, right Rich?
You did guarantee that, didn't you??
Menahem Yachad: Hey, I'll take a dozen ! My work can only improve, right Rich? You did guarantee that, didn't you??
Your order of a dozen qualifies you for a free upgrade! Your WWMD bracelets will not only come with Martin and Menahem compatibility, but Mika as well!
Step1:One more note I am certain B&O only ever chose tants for their small footprint / diameter / height more than anything to do with performance, I would love to know for sure though, and I am sure some clues are locked away in the Struer vaults somewhere!
This is obvious when you look inside many of the '70s and '80s products, and compare the sizes of tantalums and equal spec aluminum electrolytics of the same era. Many of the devices simply wouldn't have fit on the circuit boards if they hadn't used tantalums as much as they did. This was an expensive choice they probably wouldn't have made unless forced to; tantalums are still expensive today!
As hinted earlier, it may not be that easy to make "correct" choices regarding reliability even today. Sure you can read the datasheets and the marketing blurbs, but who's going to know how a certain cap brand / model line will behave in 40 years from now? All the promised reliability figures have been established by statistical analysis of failures during accelerated aging. Still, in normal usage conditions, there may well be surprises along the road as decades pass...
Nice bracelet Rich
--mika
Hi,
Ah yes the old snake oil debate!
Often, I find that component "improvements" tend to make some difference, only for them to fade away after some time...
I remember some guy did cap comparisons a few years ago, and he found that no one could hear any differences whatsoever with a 1000µF electrolytic cap (supposed to be c--p) placed between the outputs of CD players and the inputs of the amp, all belonging to the audiophile camp.
Tantalums. I, too, replace tantalums with tantalums. Also, good luck finding 5 mm 10µF Wimas, let alone 25µF!
I can still find BC blue caps these days. Not as cheap as Jap caps, but I have the satisfaction to be able to replace blue Philips with similar looking caps!
I favour high grade caps in PSUs, especially with valves. For instance, in a phono preamp I use, there is 470V HT, not something to kid with!
Cathode caps will also be high grade electrolytics, for reliability issues.
In B&O, in my modest 3-year experience, I now use original types, like Martin. I understand Menahem's point of view: he likes using higher reliability MKTs and I too use them, but then again only in valve equipment (I've done so for 30 years).
Jacques
Yes it is a bit of a debate that I have seen play out countless times before on the old forums. But anyways I powered it back up at low volume last night just to see if my repairs to the stereo lamp circuit had worked. It did.
Now - about a year ago I rebuilt one of these replacing the tants with Nichicon FW and KW caps and while I enjoy how it sounds I had always wanted to do one that more or less conformed to the original spec and now I have. I think i remember saying something to that affect to Ollie on this very thread about a year ago on the old forum.
It seems, my previous posts in this thread got misunderstood.I have deleted them and will not comment any further on this matter.I apologize for this.
Martin
If anyone wants my complete stock of the red B&O tantalums, they're free - just pay for postage about $5.
I've kept only the in-spec ones, so they're all good, no worries. Capacitance and ESR is checked on every one.
I simply don't use the tantalums, so I have no requirement for them.
There are probably close to 100 pieces, values from 0.22uF to 47uF.
Menahem
I don't want to put more gasolin to fire, but what about those old "mass"resistors (sorry, dont know exact type in english)? If I understod right, they tend to be little unstable and have not so good noisefigure. Is it usefull to change them on signalpath? I can imagine they are not best possible choise in places like RIAA amplifier.
blah-blah and photographs as needed
Orava: I don't want to put more gasolin to fire, but what about those old "mass"resistors (sorry, dont know exact type in english)? If I understod right, they tend to be little unstable and have not so good noisefigure. Is it usefull to change them on signalpath? I can imagine they are not best possible choise in places like RIAA amplifier.
I think it's "carbon mass"... I replace those when they are broken or so out of spec that they cause problems - which frankly isn't too often unless there's circuit damage around them. They have the nice property that they don't have any series inductance. Some carbon / metal film resistors have been manufactured by a spiral engraving in the resistive film, which as a side effect makes the component a small inductor. This can be an issue in RF circuits.
Mass resistors are noisier, that's true, but in practice I have never really been bothered with noise, even in RIAA amps that are among the most noise sensitive circuits. I don't expect a 40+ years old receiver to be quiet - it's part of the fun of using them.
From another point of view, I like the look of the original circuits. You can replace stuff with modern components and perhaps make the product perform better, but to me, it's not the same product any more even if the changes were all internal. I'm not going to replace the DC generator in my 1962 Cadillac with an alternator (introduced in '63) even though it would be an easy swap and work much better. But I don't mind if somebody else wants to do that and add a turbocharger as well.
Yes, they are called "carbon composition".
Generally, I like to change them to Metal Film in the signal path, subject to certain considerations which Mika mentioned.
Firstly in RF circuits, above about 14-18KHz, the impedance of a Metal Film resistor changes - see the attached diagram. So you have to be sure about the resistor value and frequency in RF circuits. In Audio Frequency circuits, generally no problem, because the audio signal ceases at about 15KHz.
When I was learning about this phenomenon, I managed to cancel the RF signal completely in a MW radio. I solved the problem quickly with my oscilloscope, and returned the single carbon resistor to its place, but it took me a lot of research to understand why it had happened!
To do it properly, you need a frequency counter at each resistor in the signal path, and measure the frequency being passed throygh that resistor. Then compare the resistor value to the graph, and determine whether it is in the linear "safe" range. If so, you can exchange it.
It's a lot of work, and you need to decide whether it's worth it.
In power circuits it is generally NOT a good idea to remove carbon resistors, as carbon handles the pulses much better than any other type of resistor.
Please read this article
How to Choose Replacement Capacitors and Resistors when Repairing and Restoring Vintage Stereo Equipment
absolutely stunning! How could you manage to get the Acryl coverages for the BL4500? And did you change the orange display of the BL3000 against green ones?
Regards
.
Brengen & Ophalen
Working on my BG 1202, here, then onto changing belts on Beocord 5000 and CD50, belts from Martin, and then I'll have to test recording with my new B&O tapes.
Collecting Vintage B&O is not a hobby, its a lifestyle.
Last night I made a lot of progress on my house-branded headphone amp.
More details HERE.
Beo4 'til I die!
Yesterday the sh1t hit the fan, first my BG 1202 gave in (see thread), and then, as I just got some blank tapes in the door, I tried to do some recording on my Beocord 5000 (80s model), no such luck, read the manual several times, but always got, RECORDING IMPOSSIBLE. Play back is excellent.
Later today I will work on the BG, and after that onto the Beocord.
Hi Søren,
I saw your post on the BG 1202 50 to 60 Hz thread. It sounds like your mechanical work is fine so it very well could be the cartridge or electrical path through the BG 1202. However, it seems like you have several variables in the mix. On your BM 4000, have you checked the phono input on that unit with a different turntable to verify there isn't any problem with the receiver?
-sonavor
sonavor: Hi Søren, I saw your post on the BG 1202 50 to 60 Hz thread. It sounds like your mechanical work is fine so it very well could be the cartridge or electrical path through the BG 1202. However, it seems like you have several variables in the mix. On your BM 4000, have you checked the phono input on that unit with a different turntable to verify there isn't any problem with the receiver? -sonavor
I have to clean the muting switch as all other contacts were very dirty. The BM 4000 is OK plays fine with BG 5000 and BG 2404, will however test the 1202 with BM 2400 or BM 5000 and then again with the 4000, who knows
The virus got to me again, I thought it would keep a little on hold, after the BG 1202 and Beovox 1600, but no, it forced me to bid on this marvel, and I won it, missing plexi on treble control, a job for the long Mexican winter nights. The Fabric Selector is going to kill me, or worth.
Søren Mexico: Yesterday the sh1t hit the fan, first my BG 1202 gave in (see thread), and then, as I just got some blank tapes in the door, I tried to do some recording on my Beocord 5000 (80s model), no such luck, read the manual several times, but always got, RECORDING IMPOSSIBLE. Play back is excellent. Later today I will work on the BG, and after that onto the Beocord.
The problem with the Beocord is possibly just the contact that feels if the cassette is 'recording protected'...Maybe a bad soldering/broken wire..?
I am about to start working on my Beomaster 3300 seems the IR Sensor has gone out at least that's my guess. Will be my first time dealing with IR sensor's wish me luck!
Taylor T.
Beosystem 4500 With Beogram rx2
Beomaster & Beocord 3300
Beocenter 9000
Beosound 2000
Beolab 6000
Rl 140 & Rl 35
Beovox S75
Søren Mexico: The virus got to me again, I thought it would keep a little on hold, after the BG 1202 and Beovox 1600, but no, it forced me to bid on this marvel, and I won it, missing plexi on treble control, a job for the long Mexican winter nights. The Fabric Selector is going to kill me, or worth.
You wont be disappointed in the least. I like mine so much I am probably going to sell off my 4000's. Get a set of S-75's to go with it.
eugene1960:You wont be disappointed in the least. I like mine so much I am probably going to sell off my 4000's. Get a set of S-75's to go with it.
At the moment I play mostly on my 5000 pizza boxes, the CD50 is a gift from somewhere above, the BM 4000 does not come near to the BM 5000, I've been trying with different speakers on both of them, and the 5000 is to my ears the best every time, only beaten by my BM 2400 with the S45 and Beovox 1600, lets see what the 4400 can bring, S75s I would like to, but I'm running out of space here, next step is the garage like Rich.
Søren Mexico: eugene1960:You wont be disappointed in the least. I like mine so much I am probably going to sell off my 4000's. Get a set of S-75's to go with it. At the moment I play mostly on my 5000 pizza boxes, the CD50 is a gift from somewhere above, the BM 4000 does not come near to the BM 5000, I've been trying with different speakers on both of them, and the 5000 is to my ears the best every time, only beaten by my BM 2400 with the S45 and Beovox 1600, lets see what the 4400 can bring, S75s I would like to, but I'm running out of space here, next step is the garage like Rich.
Keep givin in to your virus Soren and the next step might be "living" in the garage or worse - living in Rich's garage. I am sure he has an old cot somewhere you can use.
eugene1960:Keep givin in to your virus Soren and the next step might be "living" in the garage or worse - living in Rich's garage. I am sure he has an old cot somewhere you can use.
Søren Mexico: eugene1960:Keep givin in to your virus Soren and the next step might be "living" in the garage or worse - living in Rich's garage. I am sure he has an old cot somewhere you can use.
No old cot, but plenty of air mattresses and sleeping bags out there in the camping gear!
Sleepover!
Steffen:The problem with the Beocord is possibly just the contact that feels if the cassette is 'recording protected'...Maybe a bad soldering/broken wire..?
Cleaned the contacts, didn't help, got angry, disconnected all jacks cleaned all connections, again, checked for bad solder points, again. aligned the tape unit, again, banged a little on the small relay on the main board, put everything back, and it works perfectly.
I think I must have magic hands , Next time I'm at the see or a lake, I will try to walk on the water.
A little preview of what you will be working on soon Soren. I will be working on this for the next week or so.
Did some hard work this evening, started checking my 45s, they have been packed away for more than a year, here some of the 500+.
Of course I had to listen to one
And I just couldn't stop myself, and started grabbing
Close up
As I was at it, I grabbed 2 60 min. tapes, here a sample of one of them, Daniel Boone, on Penny Farthing Records, maybe I can find something with Davy Crockett too.
I get some 20 + - 45s on a 60 min. tape, and I only have 8 tapes, so I will have to get more if I want to grab all of them.
Well done Leslie. Is that the "closet" in the back ground ?
......and when are you going to finish that roof job........... :-))
Leslie:"roof job
Ladder and roof tiles on grass.
Leslie:shed (closet)?
Is this where you keep all your B&O works in progress ?
My kind of work Leslie, did you threat the wood with something ??
Nice, main thing is to protect the wood, your mahogany is surely some kind of oil, I prefer Danish Oil
Leslie: hardwood
hardwood
That could be the right word. Hardwood is a class of woods, like oak, walnut, etc.
Leslie: "woodpaint"
"woodpaint"
"Stain" was probably the word you were looking for.
Here's a favorite of mine: Minwax Wood Finish in Red Mahogany - "Penetrates, stains and seals."