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
Good list will use it for my next one
Collecting Vintage B&O is not a hobby, its a lifestyle.
Hi Søren,
I look forward to your “next one” with great anticipation. No surprise there.
I also look forward to your excellent progress photos which alone are worth the “price of admission.”
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
About the transistors,
The SE6002 you replaced with BC550
The BC154 you replaced with BC560
How about the BC109 and the SE8002?
And again, thank your for the most valuable thread!
You are stretching my memory capability (old brain)
I changed all the NPN and PNP transistors looking like a black drop
NPN: BC 115, SE 6002, UW 0029 = BC 550B, B is low noise TR
PNP: BC 154 = BC 560B
I didnt change any BC 109 or SE 8002
Well, the last B does not indicate noise level but HFe range;BC550A (low HFe range)BC550B (medium HFe range)BC550C (high HFe range)All other parameters are basically the same.
Regarding noise-levels:BC107, BC108, BC109 are in reverse order of noise-level. (They will also have the last A,B or C attached for HFe range identification).Same goes for BC546, BC547, BC548, BC549, BC550 - largely speaking.
SE8002 can be replaced by BC141BC109 can be replaced by BC550
When replacing the "vintage" transistor types, I like to use HFe range B transistors.Using C's instead will not necessarily improve anything.
Martin
Right Martin, I am mixing things up from memory, BC 550 has the lowest noise level of the before mentioned and is medium range HFe
Thank You!
BC109 is the same as UW0029.
So:
NPN: BC109, BC 115, SE 6002, UW 0029 = BC 550B ; SE 8002 = BC141
I used BC550CTA and BC560CTA because that was the closest match I could find.
Well, I don't like the = sign.Perhaps we could just say, that they will work as replacements for eachother in this amplifier.
A couple more thoughts;
The BCxxxCTA transistors...The last TA I seem to remember just stating, that the component is put on tape/ammo-belt (for machine mounting).It's not important for the circuit.The C however, is the HFe range identifier (as mentioned above).When you work with output stage amplifiers with silicon devices - like this one and also complementary types - it's almostalways a good idea to keep things a bit on the "low and slow" side.Using low-ESR electrolytic capacitors (caps with a very low series resistance), metal-oxide resistors, Schottky-barrier diodesand transistors with a high current amplification, could up the risk of self-oscillation - oneof the most dangerous situations for an amplifier of this build type.I've seen so many times, that owners wanting to do the very best to their amplifier put all themodern, linear and in any way perfect stuff, they can lay their hands on in there.If all components get "too eager" then the amplifier disappoints with a sterile sound (or runs astray).No, - keep the "elastics" and their "laziness" in there. It will also help preserve the vintage ("warm") sound.That's how I like to do it, anyways.Martin
Dillen: A couple more thoughts; The BCxxxCTA transistors...The last TA I seem to remember just stating, that the component is put on tape/ammo-belt (for machine mounting).It's not important for the circuit.The C however, is the HFe range identifier (as mentioned above).When you work with output stage amplifiers with silicon devices - like this one and also complementary types - it's almostalways a good idea to keep things a bit on the "low and slow" side.Using low-ESR electrolytic capacitors (caps with a very low series resistance), metal-oxide resistors, Schottky-barrier diodesand transistors with a high current amplification, could up the risk of self-oscillation - oneof the most dangerous situations for an amplifier of this build type.I've seen so many times, that owners wanting to do the very best to their amplifier put all themodern, linear and in any way perfect stuff, they can lay their hands on in there.If all components get "too eager" then the amplifier disappoints with a sterile sound (or runs astray).No, - keep the "elastics" and their "laziness" in there. It will also help preserve the vintage ("warm") sound.That's how I like to do it, anyways.Martin
I have been reading Martins opinion here and ...................................
I could not agree more, all Martin's points is correct and really like we should handle the restoration of these fantastic classic products.
A small note to "underline" my statement,
I have been working for Bang a& Olufsen for more than 25 years and 6 or 7 years I was working in the development department responsible for the components approved for use in the products.
Martins statement was really the target for the components choise and what we approved to be accepted for the development engineers to use in new designs.
/Frede
Jacques
Hi Guys, The “laziness" and the vintage ("warm") sound is preciously what attracts me to the BL 5000. Martin and Frede are absolutely right about this. It is, in a way like buying all new lighting for your home, going to intense blue-white LED’s with everything illuminated to the max and every shadow glaring at you….. or using old fashioned incandescent lighting offering a sublet, less “accurate” but infinitely more comfortable view. As for Jacques keeping his all original amplifier, who can argue with that? I love the idea of an amplifier being exactly as it left the factory. However, regardless that I am the non-expert in this group, when it comes time to replacing components, if the originals are available, it makes real sense to go for them. Otherwise, and I am speaking from REAL experience here, find an appropriate equivalent, not NOS. I have read that some capacitors age gracefully and those might well be an exception. But with the remainder, using NOS is basically asking for trouble, Jeff
Hi Guys,
The “laziness" and the vintage ("warm") sound is preciously what attracts me to the BL 5000.
Martin and Frede are absolutely right about this.
It is, in a way like buying all new lighting for your home, going to intense blue-white LED’s with everything illuminated to the max and every shadow glaring at you….. or using old fashioned incandescent lighting offering a sublet, less “accurate” but infinitely more comfortable view.
As for Jacques keeping his all original amplifier, who can argue with that? I love the idea of an amplifier being exactly as it left the factory.
However, regardless that I am the non-expert in this group, when it comes time to replacing components, if the originals are available, it makes real sense to go for them. Otherwise, and I am speaking from REAL experience here, find an appropriate equivalent, not NOS.
I have read that some capacitors age gracefully and those might well be an exception. But with the remainder, using NOS is basically asking for trouble,
Of course Jeff, I was only talking about transistors. NOS caps don't make any sense at all, unless they are PIO or plastic.
Thank you very much for sharing your audio restoration knowledge with us Martin and Frede. I really appreciate it and will definitely put your suggestions to practice in my restorations. John
chartz:Of course Jeff, I was only talking about transistors. NOS caps don't make any sense at all, unless they are PIO or plastic.
Jacques,
I should have KNOWN that you knew the perils of using NOS capacitors.
Ok, So the suggestion is to try some more to find the b-types? I have not found them at mouser, where I have ordered most of my components.
I guess I will have a deeper look around.
Simon Bring: Ok, So the suggestion is to try some more to find the b-types? I have not found them at mouser, where I have ordered most of my components. I guess I will have a deeper look around.
Or...if the original ones aren't broke, don't replace them. Like Jacques, I don't usually replace the original active components like transistors and diodes if they aren't failing.
Reason I decided to replace them was because more than one person said earlier in this thread that it was good to replace them because they tend to fail / periodic noise. (fairchild transistors/black drop)
Simon Bring: Reason I decided to replace them was because more than one person said earlier in this thread that it was good to replace them because they tend to fail / periodic noise. (fairchild transistors/black drop)
I didnt find the B type either, and put in the C type, it has worked good since I finished the BL and the BM, running for hours on radio, playing records very loud for up to 3-4 hours (party) and no problems ever
sonavor: Or...if the original ones aren't broke, don't replace them. Like Jacques, I don't usually replace the original active components like transistors and diodes if they aren't failing.
There is actually a reason to replace at least small signal transistors.
This is noise performance of the product. Transistors more than 50years old are perhaps not the most noiseless parts you can get even with a noise specification.
The new produced parts will give a a higher performance of your product. I have messured the specifications of a Beolab 5000 with original small signal transistors (not broken) and with new B type small signal replacements...................
Since then I replace the small signal parts.
classic: sonavor: Or...if the original ones aren't broke, don't replace them. Like Jacques, I don't usually replace the original active components like transistors and diodes if they aren't failing. There is actually a reason to replace at least small signal transistors. This is noise performance of the product. Transistors more than 50years old are perhaps not the most noiseless parts you can get even with a noise specification. The new produced parts will give a a higher performance of your product. I have messured the specifications of a Beolab 5000 with original small signal transistors (not broken) and with new B type small signal replacements................... Since then I replace the small signal parts. /Frede
That settles it for me then. B type it is. -sonavor
sonavor:That settles it for me then. B type it is.
No question it is the B-type to be used, so the BIG questions is does anyone know a source for the B-type? If Søren, Simon, and John can’t find them these B-types, they must really be difficult to locate.
Yes,
Farnell / element 14 --- Part no.: 1467880 --- BC550B (and the other B types as well)
And here - a Danish very good supplier: http://www.pc-elektronik.dk/shop/
BC 550/560B Here in Europe, I have searched high and low but dont find anything in the US, Ebay and Amazon has from China but who knows what comes from there
classic: Yes, Farnell / element 14 --- Part no.: 1467880 --- BC550B (and the other B types as well) And here - a Danish very good supplier: http://www.pc-elektronik.dk/shop/ /Frede
Over here it comes like this
BC237B
Transistor Bipolar (BJT) Individual, NPN, 45 V, 200 MHz, 350 mW, 100 mA, 290
Newark has the BC237B in stock. Mouser indicates they will get some BC550B transistors sometime in May.
This is a * brilliant * thread. Thank you very much.
Soren,
I want to thank you very much for this wonderful thread. You make my life much easier and reading it often ton find answers I need.
Keep the good work!
Ah yes, Søren's repair guides... aren't they wonderful?
chartz: Ah yes, Søren's repair guides... aren't they wonderful?
Yes Jacques, it is true. For those who comprehend Søren’s guides, they are indeed, wonderful. For those of us who don’t, they are inspirational. I, as you know, fall into the latter grouping.
Waiting for my Beolab 5000 to arrive from Denmark, this was so inspiring reading.
Restoring to perfection is kind of an artform that I got into two years ago. Some times I feel that the worse the startpoint is, the better the reward. You must feel very good about this incredible project :)
I am very very jelous of your craftmanship! Thank you so much for a fantastic documentation of the project.
I also have one tip I use when i feel it is important to keep the aesthetics of a piece, keep the shell of the big caps, and put the new, smaller cap inside of it. Make it look original with some heatshrink on the top. Or try to maintain the original top-plate of the old cap and fold the top as nice as possible in place again. If the innards of the cap wont come out, pour some boiling water on it. Then pull the innards of the big cap out.
I really look forward to being in the same boat as you wonderful people, owning my own Beolab 5000 :)
BR
Frank, norway
Welcome Frank, looking forward to another BL5000 thread
Søren