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ARCHIVED FORUM -- April 2007 to March 2012
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This is the first Archived Forum which was active between 17th April 2007 and 1st March February 2012

 

Latest post 01-10-2012 3:25 PM by Søren Hammer. 85 replies.
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  • 01-08-2012 5:40 AM In reply to

    • chartz
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    • Joined on 07-20-2009
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    Re: BM 4000 Mexico

    Nice work Søren!

    There is no "ambio" record. There were quadraphonic ones, but you needed four amps to take advantage of them, along with a special cartridge and a 4 channel decoder (Beomaster 6000, and a Beogram 6000 with the special on-board decoder and an MMC6000 cartridge).

    The ambio thing is a pseudo-acoustic trick which involves extra speakers to re-create a depth impression with normal recordings.

     

    Jacques

  • 01-08-2012 6:19 AM In reply to

    Re: BM 4000 Mexico

    Good work, Søren. More thorough than my "simple" 4400 capacitor replacement thread and you're better at explaining the technical stuff. Smile

    As an 18-year-old, I still have a lot to learn in electronics though I was raised by an electrician Stick out tongue

    Beocenter 9300, Beogam CD50, Beocord 5500, Beomaster 3400, Beomaster 4400, 2 Beogram 4000, Beomaster 8000, 2 beogram 8002, Beovox S-75, Beovox MS150.2, Beovox RL6000, Beovox S-35, Beomaster 6000, 2 Beocord 9000, Beocord 8004, Beocord 5000, Form 1, 2x Beolink 1000, Beo4, MX3500, LS4500. Born 1993.

  • 01-08-2012 11:34 AM In reply to

    Re: BM 4000 Mexico

    Søren Hammer:

    Good work, Søren. More thorough than my "simple" 4400 capacitor replacement thread and you're better at explaining the technical stuff. Smile

    As an 18-year-old, I still have a lot to learn in electronics though I was raised by an electrician Stick out tongue

    As a printing m/c tech. I started 40 years ago and the m/c had open relay circuits to command them, most of it 220 V, some of the m/c's had fotocells where the allso the amps was simple things, easy to repair, I am a mecanic but when standing alone with a 40 ton m/c deep in Africa or in some Chinese province, where the electricians are limited to changing light bulbs once in while, you need to start thinking, so I learned to read E drawings, follow them like street maps, and failure search was simple, as in these open circiuts you could see what happened, later, at the end of the 70s, beginning of the 80s they started putting more sofisticated electronics into the m/c's, today it is all computerized and few open circuits, and the E repair is made simple, like: Water feed in unit 4 is not working, the manual says, check for current at pin 19 on PCB No. 8, no current, change the PCB No. 8 and send the old one back to the factory for repair and update.

    Nobody, today goes down to component level on the PCBs, so if you can read a manual you can do it.

    Because of this I never followed up on my El. knowledge, kept to the mecanics. And today I am, as you Søren, fumbling around and starting getting into a new world, but with a Danish electrician at hand you are better of than me.

    What I have learned with more than 40 years as a trouble shooter is, there are no big m/c's, only a lot of small parts, and thats the same in electronics. You start at the feed lines, using the drawings (street maps), and then goes step by step until you are down to the area or component-s that causes the trouble, with these vintage items the main problem is finding spares that fits. We will never get to Martin level, nothing beats experience.

    And as you I feel like 18 year old when I work with these items, but when I get it working, I feel like a 6 year old on Xmas Eve.

    And remember, there are no stupid questions, only stupid people that don't ask them. And making stupid failures is part of a learning process, nothing to be ashamed of, but publish also your failures, somebody will learn from it.

    If you make the same stupid failure 3 times, you are firedBig Smile

     

    Beosound 3000, BL 4000, BL 8000, BG 2404,BG 5000, BG CD50, Beocord 5000, BM 901, BM 2400, BM 4000, BV S45, BV 3702. There is nothing we cannot do, but a lot of things we don't want to do!!

  • 01-08-2012 1:17 PM In reply to

    • Rich
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    • Orlando, Florida, USA
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    Re: BM 4000 Mexico

    chartz:

    Nice work Søren!

    There is no "ambio" record. There were quadraphonic ones, but you needed four amps to take advantage of them, along with a special cartridge and a 4 channel decoder (Beomaster 6000, and a Beogram 6000 with the special on-board decoder and an MMC6000 cartridge).

    The ambio thing is a pseudo-acoustic trick which involves extra speakers to re-create a depth impression with normal recordings.

    Ambio is the left signal minus the right signal, and probably attenuated somewhere between 6 and 12 dB.  I would characterize it as attempting to give a spatial impression, rather than a depth impression.  (EDIT:  on further reflection, I guess "depth" and "spatial" can be essentially the same thing.  But when I talk about "depth," its locating sounds behind the plane of the front left and right loudspeakers.  When I talk about "spatial," its locating sounds in front of the plane of the front left and right loudspeakers.)

    The original Dolby Pro Logic's surround channels were both essentially this, but with 20 millisecond delay as well.  Recall Hi-Fi VHS had a two channel audio track, essentially stereo left and right.  Dolby Pro Logic basically fed the left and right channels of the audio track to the left and right channels unchanged, and fed left plus right to the center channel, and fed left minus right (delayed) to both surround speakers.

    A common late 80s, early 90s DIY was to make something akin to an ambio circuit.  You can do it without an ambio circuit (and without electrical attenuation) by simply wiring a second set of speakers like this.  Plus terminal of your amplifier right output to the plus terminal of your right speaker.  Plus terminal of your amplifier left output to the plus terminal of your left speaker.  Then wire both speakers minus terminal together.

    Current primary listening:  SMMC20EN -> BG4002 -> BM4000 -> Beovox M70

     

  • 01-08-2012 4:08 PM In reply to

    Re: BM 4000 Mexico

    Now playing 3 hours, volome level 6, cooling elements get a little more than hand warm, next week I will connect my Bvox 3000 panels as ambio speakers just to hear it, today I'm alone at home, so I will be rocking the whole day, Denver Broncos wild card game with no sound, a good working BM 4000, a cuba in my hand, Suzi screaming har lungs out.

    Can life get any betterDrinks 

    Beosound 3000, BL 4000, BL 8000, BG 2404,BG 5000, BG CD50, Beocord 5000, BM 901, BM 2400, BM 4000, BV S45, BV 3702. There is nothing we cannot do, but a lot of things we don't want to do!!

  • 01-08-2012 4:38 PM In reply to

    • chartz
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    • Joined on 07-20-2009
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    Re: BM 4000 Mexico

    Cheers mate! Beer

    Jacques

  • 01-08-2012 7:00 PM In reply to

    • Step1
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    • Joined on 07-06-2008
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    Re: BM 4000 Mexico

    I think you are refering to Dolby Surround Sound Rich Pro Logic was actually quite a bit more complex as there was a little bit of 'encoding / decoding' of extra surround information in the stereo source (+/- 90 signal so that it was canceled out under stereo conditions) but also based on various levels the signal was routed more effectively to its appropriate speaker using the pro-logic part. There is of course ProLogic II but I have never heard this myself.

    Connecting a speaker across channel l / r is very useful for setting up channel balance with those little preset pots under the 4000 etc. :) Basically if you have a mono source adjust trimmers until desirable level say, compared to radio, with speaker connected normally. Then connect speaker across L+R positive outputs and adjust one of the trimmers for minimum sound. There will always be some sound coming through due to tolerance of components but this is about as good as you'll get without taking measurements etc... You can do this with a stereo source as long as there is some sort of sound that is equal in both channels. Normally singers have a reverb so while the main content of their singing voice will dissapear, the reverb effect may remain, leaving a ghostly effect...

     

    Rich:

    chartz:

    Nice work Søren!

    There is no "ambio" record. There were quadraphonic ones, but you needed four amps to take advantage of them, along with a special cartridge and a 4 channel decoder (Beomaster 6000, and a Beogram 6000 with the special on-board decoder and an MMC6000 cartridge).

    The ambio thing is a pseudo-acoustic trick which involves extra speakers to re-create a depth impression with normal recordings.

    Ambio is the left signal minus the right signal, and probably attenuated somewhere between 6 and 12 dB.  I would characterize it as attempting to give a spatial impression, rather than a depth impression.  (EDIT:  on further reflection, I guess "depth" and "spatial" can be essentially the same thing.  But when I talk about "depth," its locating sounds behind the plane of the front left and right loudspeakers.  When I talk about "spatial," its locating sounds in front of the plane of the front left and right loudspeakers.)

    The original Dolby Pro Logic's surround channels were both essentially this, but with 20 millisecond delay as well.  Recall Hi-Fi VHS had a two channel audio track, essentially stereo left and right.  Dolby Pro Logic basically fed the left and right channels of the audio track to the left and right channels unchanged, and fed left plus right to the center channel, and fed left minus right (delayed) to both surround speakers.

    A common late 80s, early 90s DIY was to make something akin to an ambio circuit.  You can do it without an ambio circuit (and without electrical attenuation) by simply wiring a second set of speakers like this.  Plus terminal of your amplifier right output to the plus terminal of your right speaker.  Plus terminal of your amplifier left output to the plus terminal of your left speaker.  Then wire both speakers minus terminal together.

     

    Olly.

  • 01-09-2012 1:55 PM In reply to

    Re: BM 4000 Mexico

    Søren Mexico:

    Søren Hammer:

    Good work, Søren. More thorough than my "simple" 4400 capacitor replacement thread and you're better at explaining the technical stuff. Smile

    As an 18-year-old, I still have a lot to learn in electronics though I was raised by an electrician Stick out tongue

    As a printing m/c tech. I started 40 years ago and the m/c had open relay circuits to command them, most of it 220 V, some of the m/c's had fotocells where the allso the amps was simple things, easy to repair, I am a mecanic but when standing alone with a 40 ton m/c deep in Africa or in some Chinese province, where the electricians are limited to changing light bulbs once in while, you need to start thinking, so I learned to read E drawings, follow them like street maps, and failure search was simple, as in these open circiuts you could see what happened, later, at the end of the 70s, beginning of the 80s they started putting more sofisticated electronics into the m/c's, today it is all computerized and few open circuits, and the E repair is made simple, like: Water feed in unit 4 is not working, the manual says, check for current at pin 19 on PCB No. 8, no current, change the PCB No. 8 and send the old one back to the factory for repair and update.

    Nobody, today goes down to component level on the PCBs, so if you can read a manual you can do it.

    Because of this I never followed up on my El. knowledge, kept to the mecanics. And today I am, as you Søren, fumbling around and starting getting into a new world, but with a Danish electrician at hand you are better of than me.

    What I have learned with more than 40 years as a trouble shooter is, there are no big m/c's, only a lot of small parts, and thats the same in electronics. You start at the feed lines, using the drawings (street maps), and then goes step by step until you are down to the area or component-s that causes the trouble, with these vintage items the main problem is finding spares that fits. We will never get to Martin level, nothing beats experience.

    And as you I feel like 18 year old when I work with these items, but when I get it working, I feel like a 6 year old on Xmas Eve.

    And remember, there are no stupid questions, only stupid people that don't ask them. And making stupid failures is part of a learning process, nothing to be ashamed of, but publish also your failures, somebody will learn from it.

    If you make the same stupid failure 3 times, you are firedBig Smile

    I get your point, but it is really unfair to compare us with Martin at any circumstance Stick out tongue He must be a BeoGod.

    My Father took his apprenticeship back in '79, and he can't really remember much about his time working with electronics, but generally a good guide when working on anything. I am very interested in science and how the components actually were "invented", it's a joy to work on B&O, though they sometimes makes "bloopers" that indicates some capacitor is mounted with wrong polarity etc. It was confusing in the start, but got all the caps installed right the first time. Your electrical exprerience must count something when working on B&O Smile

    I like to spend some nights being thorough and having fun while working on gear. I hate troubleshooting when the work can be done right the first time.

    I normally use the quote "Learn from other people's mistakes, you'll not live long enough to make them all" Wink

    Beocenter 9300, Beogam CD50, Beocord 5500, Beomaster 3400, Beomaster 4400, 2 Beogram 4000, Beomaster 8000, 2 beogram 8002, Beovox S-75, Beovox MS150.2, Beovox RL6000, Beovox S-35, Beomaster 6000, 2 Beocord 9000, Beocord 8004, Beocord 5000, Form 1, 2x Beolink 1000, Beo4, MX3500, LS4500. Born 1993.

  • 01-10-2012 4:25 AM In reply to

    • Step1
    • Top 75 Contributor
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    • Joined on 07-06-2008
    • Manchester
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    • Gold Member

    Re: BM 4000 Mexico

    Søren Hammer:

     

    I normally use the quote "Learn from other people's mistakes, you'll not live long enough to make them all" Wink

    You know I would have once agreed with that, but then I had kids, and no matter how much you tell them they only ever learn by making their own mistakes! It is true, when you make a mistake you tend to anylise why you did things that way and learn more that you could by not making the mistake - this is how we learn ;-)

    Olly.

  • 01-10-2012 9:11 AM In reply to

    Re: BM 4000 Mexico

    Step1:

    Søren Hammer:

     

    I normally use the quote "Learn from other people's mistakes, you'll not live long enough to make them all" Wink

    You know I would have once agreed with that, but then I had kids, and no matter how much you tell them they only ever learn by making their own mistakes! It is true, when you make a mistake you tend to anylise why you did things that way and learn more that you could by not making the mistake - this is how we learn ;-)

    Agree with Step, with 4 kids (boys) all grown up now, all my wisdom was wasted, they did their mistakes, and all I could do, was, "I told you so"Laughing

     

    Beosound 3000, BL 4000, BL 8000, BG 2404,BG 5000, BG CD50, Beocord 5000, BM 901, BM 2400, BM 4000, BV S45, BV 3702. There is nothing we cannot do, but a lot of things we don't want to do!!

  • 01-10-2012 3:25 PM In reply to

    Re: BM 4000 Mexico

    Søren Mexico:

    Step1:

    Søren Hammer:

     

    I normally use the quote "Learn from other people's mistakes, you'll not live long enough to make them all" Wink

    You know I would have once agreed with that, but then I had kids, and no matter how much you tell them they only ever learn by making their own mistakes! It is true, when you make a mistake you tend to anylise why you did things that way and learn more that you could by not making the mistake - this is how we learn ;-)

    Agree with Step, with 4 kids (boys) all grown up now, all my wisdom was wasted, they did their mistakes, and all I could do, was, "I told you so"Laughing

     

    Hmm, I guess that you are right that wee just have to make some mistakes to learn from them, but some can be avoided with proper guidance and help from Beoworld Stick out tongue

    Beocenter 9300, Beogam CD50, Beocord 5500, Beomaster 3400, Beomaster 4400, 2 Beogram 4000, Beomaster 8000, 2 beogram 8002, Beovox S-75, Beovox MS150.2, Beovox RL6000, Beovox S-35, Beomaster 6000, 2 Beocord 9000, Beocord 8004, Beocord 5000, Form 1, 2x Beolink 1000, Beo4, MX3500, LS4500. Born 1993.

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