Recent Changes

Saturday, February 18

  1. msg Peavey Valveking 20 MH footswitch issue message posted Peavey Valveking 20 MH footswitch issue Hello there, I'm new to this forum. I'd like to ask some help to fix the "volume issue" …
    Peavey Valveking 20 MH footswitch issue
    Hello there, I'm new to this forum.
    I'd like to ask some help to fix the "volume issue" when you plug the footswitch in a Valveking 20 MH.
    In my case only the channel switching works (ring), while the boos function doesent work properly.
    When you plug a footswitch you will notice a dramatic loss in overall volume and by pressing the other switch (tip) the overall volume falls so you have the perception to increase the volume by pressing the boost function (the volume comes back to mormal).
    In reality the boost function in the fron panel works in a complitely different way indeed....it adds some mid and treble frequencies and a slight increase in volume.
    I just want to do with the footswitch what I normally do with the button in the front panel (without the footswitch plugged in).
    Could someone please help me?

    P.S.: I have the original schematic

    Thank you so much in advance
    9:28 am

Friday, October 7

Wednesday, June 22

  1. msg EL34 tube mod message posted EL34 tube mod Having acquired a VK100, I wanted to look at a few of the mods you can do to this amp. Mods applies…
    EL34 tube mod
    Having acquired a VK100, I wanted to look at a few of the mods you can do to this amp. Mods applies so far are: 1 the bypass of one gain stage in the lead channel to get a more Marshall tone, 2. a switch to lift the cathode on two of the output tubes, and 3. a bias pot so that I can fit EL34s. It all worked fine - for a while. Now I'm finding the preamp tubes are dropping like flies, particularly the phase splitter.

    Having looked at various posts on the subject, the received wisdom seems to be that all that is required is a re-bias of the output tubes. However, my reading of the schematic is that there is a potential problem with the the way the heaters are wired in the VK100. Specifically, the 6L6s draw 900mA and the output tubes are wired in series before feeding into the (presumably nominal) 6v line across the three 12AX7s in parallel. The 12AX7s are rated at 300mA so they should also draw 900mA in parallel. By my reckoning, that should put the voltage of HTR at around 30v, although it's not marked on the schematic, EL34s, however, draw 1.5A of heater current. Again,a basic calculation suggests that, assuming an HTR of around 30v, you're going to get around 1.3A of heater current (and the 6v line will therefore actually be at around 8.8v).

    Does that sound right and is that why my 12AX7s are suffering? I will be putting the 6L6s back to compare but would be grateful for any thoughts in the meantime.
    3:27 pm

Tuesday, June 7

  1. msg valveking 112 issues message posted valveking 112 issues my valveking's volume control must be bad, turning it up just a little bit past all the way down wi…
    valveking 112 issues
    my valveking's volume control must be bad, turning it up just a little bit past all the way down will skyrocket the volume and trying to fine tune it will make a lot of crackling noises...what gives?

    also, whenever i try to use the loop, a screeching feedback come on.

    my speakers are new. this has been happening since i bought the amp
    3:21 pm

Saturday, May 7

  1. msg Can you run 5581 power tubes safely? message posted Can you run 5581 power tubes safely? You mean 5881 tubes and they would have to stand 460V Plate Current. I don't think they would work.…
    Can you run 5581 power tubes safely?
    You mean 5881 tubes and they would have to stand 460V Plate Current. I don't think they would work. I don't think they would damage the amp. The only thing that might happen is the tubes would burn out if voltage is too high. I would not recommend using them. RCA manual says 400 plate volts max.
    11:57 am

Wednesday, April 6

  1. msg Can you run 5581 power tubes safely? message posted Can you run 5581 power tubes safely? Hi everyone, Brand new to the forum so please forgive any protocol mistakes. I was wonderin…
    Can you run 5581 power tubes safely?
    Hi everyone,


    Brand new to the forum so please forgive any protocol mistakes. I was wondering if anyone can add sime clarity to my situation. I was given a vintage set of tung sol 5581 tubes from a fellow valveking owner who claims they can be swapped with the stock 6l6gc tubes and plug and play in my valveking 112. Is that correct or will i damage my amp?

    Thanks in advance in

    Mike
    2:18 pm

Tuesday, April 5

  1. page home edited ... If you spam this wiki, you will be blocked, and memberships to it will become limited. The di…
    ...
    If you spam this wiki, you will be blocked, and memberships to it will become limited.
    The discussion tab is no longer in use. If you wish to ask questions regarding the Valveking, please refer to the most recent thread on UG. A link can be located in the Links section of this wiki.
    Any UG members are free to register,Membership is Restricted, See above, but be
    Anyone who is not a UG member (recommended to become one), interested in becoming a member PM dudey5691 on Ultimate-Guitar describing your interest, and you will be considered for membership.\
    ANY AND ALL MEMBERS OF THIS WIKI CAN EDIT PAGES, AND ARE ENCOURAGED TO DO SO. You cannot Edit unless you are a member! Membership at this time is restricted to only 100 members meaning we have to trim some to meet the requirement. Members who have not been active as of 10-29-2014 will be trimmed! I am trimming long time inactives first. cap47
    (view changes)
    5:47 pm

Sunday, February 7

  1. msg To all possible members: If you do not give me a Valid reason to become a member I will deny your request. message posted To all possible members: If you do not give me a Valid reason to become a member I will deny your r… To all possible members: If you do not give me a Valid reason to become a member I will deny yo…
    To all possible members: If you do not give me a Valid reason to become a member I will deny your request.


    To all possible members: If you do not give me a Valid reason to become a member I will deny your request. We have a limit by the WIKI people of 100 members. If you give me a Valid reason why you should be a member I will consider it. New material that we don't already have. Such as mods and new model mods. will be a good reason.
    You are still able to browse and use our content without a Membership!
    6:00 am

Friday, December 11

Saturday, October 17

  1. msg Schematic help!!?!? Please! message posted Schematic help!!?!? Please! So I have a valveking 212 combo and I've done the jcm800 mod and some grounding fixes as well. I ha…
    Schematic help!!?!? Please!
    So I have a valveking 212 combo and I've done the jcm800 mod and some grounding fixes as well. I have now decided I want to remove the preamp circuitry altogether and use just the power amp right now, adding a volume pot for the input into the power amp. My end goal is to find a schematic for a different preamp circuit and hand wire it before the power amp. So my question right now is what all do I remove to remove the preamp circuit?
    6:38 pm

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