Beiträge von polifemo

  • A15MkII - Choice of speaker?

    Zitat von Smertehyl;227500

    Thank you for answering. -Is it possibe to use other tubes in the A15MkII for more power?


    You can use other brands of 6V6´s, but it won´t do much to the overall volume.
    One would get a little bit more volume if one could get a B+ at about 450V, but that´s not possible with this PT.
    If you would get another PT that could deliver 450V you would need another OT.

    If buying new PT/OT one might as well buy a PT/OT for EL34`s and rebuild the amp totally.

    Would give you about 50W, and a lot of work ;)

  • Wrong jacks in kit...

    Zitat von KlausSp;227359

    Hi!

    It seems with your delivery you got the new chassis but the bags with the "old" parts. That´s why all jacks were not fitting. Have fun with your amp :)

    Best regards

    Klaus

    I will! (when it´s ready, that is...)

  • Pot confusion...

    Hi Martin,


    Believe it or not, it´s me again...

    On your parts list the pots are stated as:
    - 10k lin x 1
    - 22k lin x 1
    - 220k lin x 2
    - 220k log x 1
    - 470k log x 1
    - 1M log x 3


    In my kit I´ve got:

    - 10K A x1
    - B25K x 1
    - B250K x 2
    - A250K x 1
    - A500K x 1
    - A1M x 3

    OK,

    A = log ?
    B = lin ?

    Shouldn´t the 10K pot have been an "B" in order to be a linear?

    As I suppose that you have spent much time finetuning your design and finally taken the decison for certain values, shouldn´t the pots have been according to your list in order to get "your" sound?

    Maybe 25 is "close enough" to 22 and maybe 250 is "close enough" to 220 and 500 might be "close enough" to 470, but for some reason you went for 22 not 25, 220 not 250 and 470 instead of 500.

    I just want my Madamp to sound the way you intended it to do.

    kind regards

    peter

    Edit:

    Seems like the 22/25, 220/250 and 470/500-pots are interchangeable, so my only question is regarding the 10K bias pot.

  • Mk1/Mk2 differencies?

    Re: Mk1/Mk2 differencies?

    Zitat von MAD


    Hi Peter,
    you've received the right parts. I don't care about colors of caps as long as they are the right polypropylene types and I also don't care about the color of resistors as long as they are the right metal film types ;) So the parts might look different, but physically (derived from, what a guitar amp needs) they are the same :)
    Regards,
    Martin

    OK Martin, so I´d better start building then ;)

  • Mk1/Mk2 differencies?

    Hi Martin,

    I´ve got a Mk1 kit (and a Mk2 chassi!) that I haven´t built yet... But now´s the time to do it 8)

    I have ordered the footswitch opotion, and when doing so I also asked for the components for upgrading my kit to Mk2 specs.
    What I did receive was 3 resistors + 3 caps + a jack.

    When comparing the layout of the Mk1 mainboard:
    [Blockierte Grafik: http://i26.photobucket.com/albums/c109/prof2915/Mk1.jpg]

    with the layout of the Mk2 mainboard:
    [Blockierte Grafik: http://i26.photobucket.com/albums/c109/prof2915/Mk2.jpg]

    One can see that you are using different caps (Silver Mica?) as well as different resistors (mostly the green ones ;) )

    Could you please advice those of us that want to upgrade our Mk1 its to the 100% Mk2 specs, EXACTLY which caps/resistors to get!?

    Thanks :)

    /Peter

  • A15Mk2 Documentation and OT.

    Re: A15Mk2 Documentation and OT.

    That looks great!

    I´ve also started building my cabinet without having built the amp yet...

    [Blockierte Grafik: http://i26.photobucket.com/albums/c109/prof2915/P1010090.jpg]

    [Blockierte Grafik: http://i26.photobucket.com/albums/c109/prof2915/P1010100.jpg]

    This one is supposed to be translucent Burgundy Red when finished.

    I´ll do some "ventilation tracks" on top to prevent the amp from running to hot.
    (My initial idea was to have an open front, but I decided for a closed one instead)

  • Wrong chassi...

    Re: Wrong chassi...

    Zitat von MAD


    Hi,
    the size of the M15 and A15 chassis is exactly the same.
    Regards,
    Martin

    Thanks Martin,

    That´s great news :)

    Let´s hope that Klaus will get in touch with me soon as well.

    kind regards

    /Peter

  • Wrong chassi...

    Today I realised that I had received the wrong chassi with my kit...
    I had ordered an A15Mk1 deluxe-kit, but I received an M15Mk1 chassi... (Tubes and components seem to be the right one though)

    I expect Klaus to correct his misstake (hopefully really quick) but as I´ve already started making a wooden cabinet for the amp I would like to know if the size of the both chassis are exactly the same?

    The cabinet is made to a tight fit for the M15 chassi...

  • A15MK2

    Re: A15MK2

    Zitat von MAD


    better output transformer

    Hi,

    What´s the specs of the new OT?
    The Hammond was desribed as 15W/80mA.

    The manufacturer rates the new OT at 10W*, but I found no info about the mA.

    * HiFi rating

  • 2x6V6=25watt?

    Re: 2x6V6=25watt?

    Zitat von Bierschinken


    I would consider building a new amp with the preamp of the A15 and a 2x 6L6 PP Poweramp if you really need more power.

    Yes, or 2 EL34`s.

    Need some beefier trannys first...

    Update: I´ve been able to try a A15 Mk1 at gigging level, and it´s loud enough ;D. I´m going for the stock PT/OT!

  • 2x6V6=25watt?

    Re: 2x6V6=25watt?

    Zitat von MAD


    Hi polifemo,
    as the M15 and the A15 have the same PT, they both run with 300V. To get more output power from the A15 you need more B+ (new PT) and a new OT :(
    Regards,
    Martin

    I might go for that as I consider the A15 to be a mighty fine amp by design!

    If I get some more power out of it and get my idea for a tubedriven parallell loop working, I´m pretty sure that it will be my main amp :)

  • 2x6V6=25watt?

    Re: 2x6V6=25watt?

    I´ve asked around at several forums, and it seems to depend a lot on B+ .
    If one runs the tubes at about 450V, one seem to be able to get around 25w.

    Martin, what´s the B+ of the PT used in the A15Mk1!? :P
    I suppose one will need a higher rated OT as well, if going for higher output?

    I have high expectations for my Mad Amp A15, but I need a bit more power to turn it into my main amp.