Thierry
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Birthday:
Mar 17, 1958 (Age: 60)
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Paris, France

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Thierry

Tape with a passion, Male, 60, from Paris, France

Hello ! Dec 30, 2018

    1. jrczz
      jrczz
      You nailed it..a cracked solder joint eliminating c1, cr21, cr20, and r58 from the circuit, I haven't put it under load yet...notice this amplifier inverts phase from input to output..normal? I'll put a 10 ohm load on it tomorrow and run it up a bit...Thanks..
      1. Thierry likes this.
      2. Thierry
        Thierry
        Hey there, glad you found the culprit. Otherwise this thing is built like a tank.
        Cheers,
        Thierry
        Dec 31, 2018
    2. Thierry
    3. jrczz
      jrczz
      've got an 1800 open right now and the channel 1 heat sink goes up to 110 degrees F. with 2 leds showing from the 1k signal no load..channel 2 stays at 66 degrees F. I have to dig out my O scope, and will, but is this something you have seen? I changed the input IC on one of these channels 2 or three years ago and it worked fine for a couple years....I'll look for distortion when I get me scope out...TNX
      1. Thierry
        Thierry
        Yes I have seen this when something goes wrong in the global feedback loop. Can be tricky to sort out, many issues can be found. I would first investigate for dry solder joints around U1 and its passive layout parts.
        Either this channel is oscillating (ground fault) or the negative feedback loop is open somewhere. Good luck and Happy New Year
        Dec 30, 2018
        jrczz likes this.
    4. Monad
      Monad
      hi Thierry- referred by Bilbo Baggins IRT my Bose 1800 Series VI pro amp.

      Right now I'm PC >> Schiit Modi Multibit (or Phono) into Schiit Freya preamp >> Bose 1800 amp >> KEF 105.4s (new Falcon caps).. The sound often seems 2D and muddled, delivers fatigue, even with HD Track quality files or LP.

      Is this common using this model in home? ..possibly a problem with the Amp, DAC/ Pre or the Listener? :D

      Patrick
      1. Thierry
        Thierry
        Hi Patrick,
        Sorry for very late reply.
        What you describe is strange because the 1800 VI has exactly opposite character on any system I have tried it : have you tried another source ?
        Happy New Year,
        Thierry
        Dec 31, 2018
      2. Thierry
        Thierry
        As a side note, I sold 2 of my 1800 VIs to guys with various speaker systems and they describe it as a noticeable improvement in their setup (lifelike sound, lots of details and depth) hence my doubts about your sources, including DAC and preamp.
        Dec 31, 2018
    5. JS4000
      JS4000
      Hello Thierry, I have read your 1801 builds and you have done some fantastic work! I have just bought one and will be doing the full overhaul, I can work from your thread pics but I thought worth asking if you had a parts list? Can I ask why you populated C10 and C11 on the modules as they were empty from factory? thanks, Jason
      1. Thierry
        Thierry
        Hi Jason, thanks for the good words :-)
        Indeed I did not populate those parts, where did you see this ?
        Bets,
        Thierry
        Aug 8, 2017
      2. JS4000
    6. stevew1953
      stevew1953
      I see you already have experience with repair of this amplifier. I need a replacement transistor 102433 with Red logo for Bose 1800. I seek to avoid replacing all 14 devices with new. Do you have any that you could let me have, please? Good used parts will be fine!

      Thanks, Steve
      1. Thierry
        Thierry
        Hi Steve, Un fortunately I don't have any of these left. Did you try eBay ?
        Thierry
        Nov 27, 2016
    7. Aref
      Aref
      Hi Thierry,
      Tomorrow, my speaker will be ready. I have another one of these speakers(A723),which is not working and it doesn't have the drivers. I can give it for fixing, but what can I use in place of these three drivers? Do you recommend doing it?
      Thanks
    8. gehportier
      gehportier
      Hi Thierry, I did download a hifi engine 40 page pdf, that says it is the service manual, but desnt really list all the capacitors or resistors or transistors, etc...
      Is what you have have those details?
      Else I may purchase it from ebay?
      Best, Henk
    9. gehportier
      gehportier
      Hello Thierry, I was reading your message on the AR Model R; I have one where the output voltage R = 1volt, L = .4volt. So it looks like I have to replace the amplifier components.
      Would appreciate your Service Manual for this and any suggestions you may have, in your own experience.

      Thanks

      Henk Portier 781-449-9990
      Data Recovery, Inc.
    10. rhschneider
      rhschneider
      Hello Thierry,
      Thanks for the praise! Yes indeed, I have a lot of work to do. And this is the reason, I can't tell much about the sound of the 1801 - it is still in work. Man, I can tell you... I decided to change the mica plates into ceramics. And the ceramics are 3mm thick, so the damn screws are to short. It was more trouble to get these american screws (a little longer) than changing it against european norm screws. So I took sixtyfour 3.5mm brass screw nuts, removed the old ones and soldered them on to the pcb. I think it will take two weeks till I have one side ready to test. What do you think about the new place for the bias adjustment trimmer?
      Meanwhile I keep on soldering and making snapshots of the work. If the amp will run as good as it's brother 4401 I will be very happy. As long as I work at the 1801 I use my Technics SU-VX800 for power amp. Sound is not bad but four 901's really need a muscle amp instead this integrated Amplifier.
      Greetings Richard
    11. rhschneider
      rhschneider
      hello Thierry,
      I have startet an album called bose1801 restauration, first pics are there...
      greetings Richard
    12. rhschneider
      rhschneider
      Hello Thierry,
      since i renewed the OP-Amps in my 4401 - great! This time i did not use the glue, instead of this stuff i used the little heatsinks with the pads (same as you used).
      You where right, the glue between the OP contacts and the heatsinks made a capacitive connection and so the heatsinks changed into antennas.
      And now i am working at the good old 1801.
      Again thanks a lot for your support!

      Greetings Richard

      btw - if you are interrestet in photos, i made a lot...
    13. guiller
      guiller
      Thanks for accepting my invitation!
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    Gender:
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    Birthday:
    Mar 17, 1958 (Age: 60)
    Home Page:
    http://audiolalies.blogspot.fr/
    Location:
    Paris, France
    So much to do and so little time

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