"Camplifier" - Poweramps for the KPA

    Really? I couldn't find anything else in your posts, apart from where you say that you can crank a tube amp up and get a nice distortion. AFAICU, the rest was all about loudness.
    Please point me to the right post in case I've been missing something! Really interested in your opinions :)


    Back to the topic, for me the ability to saturate a tube amp in a musical way doesn't make (strictly) sense when using a good amp simulator, unless you want to also use the amp alone. As long as you stay within the amp's linear window, 1 dB is still 1 dB, ceteris paribus. I'd prefer to know when my power amp starts failing. YMMV :)

    As mentioned yearlier, a 100w is 100w both from tube or ss amp when measured, RMS. compared with exact same setup.
    Yes a tube amp can be pushed above the rating, but that can only add a very small extra dB gain.
    If you double the watt in an amp you only get about 3dB louder.
    So a 200w amp is only 3 dB louder than a 100w amp. A 100w tube amp don't add that much dB over the rating.
    If you want double the percieved volume then we need about 10xW, meaning going from a 100w to a 1000w.
    It's much easier to get louder by using a very loud sensitive speaker.
    sensitivity, also known as SPL (Sound Pressure Level)
    A 40 w amp with a very loud 100dB sensitive speaker will sound louder than a 100w amp with say a 92dB sensitive speaker.
    A 512 w amp coupled with an 86 dB speaker will be just as loud an an 8 watt amplifier with a 104 dB speaker.
    Here is a chart good for interpreting SPL ratings.
    http://www.colomar.com/Shavano/spl.html


    Here is a link with some good food for thought info, Amp Power Myths, tube vs solid state:
    http://www.guitarnuts.com/amps/myths.php


    Here is an informative video on the subject, by Scott Grove.
    Something that he brings up in the video which is often where a myth comes from is that cheap ss amps often have crappy speakers with low dB sensitivity making them sound much lower in volume than a nice tube amp with good speakers with higher dB sensitivity.


    Mythbusting, Are Tube Amps Louder Than Solid State?

    External Content www.youtube.com
    Content embedded from external sources will not be displayed without your consent.
    Through the activation of external content, you agree that personal data may be transferred to third party platforms. We have provided more information on this in our privacy policy.

    [YOUTUBE]
    External Content www.youtube.com
    Content embedded from external sources will not be displayed without your consent.
    Through the activation of external content, you agree that personal data may be transferred to third party platforms. We have provided more information on this in our privacy policy.
    [/YOUTUBE]

    Basically that's what I ment (from Happy Kemper's link):


    "Tubes, even preamp tubes, go into clipping more gently than most solid-state circuits resulting in a slightly smoother transition to distortion."

    ------------------------------------------------------------------------------------
    first name: Guenter / family name: Haas / www.guenterhaas.de

    Edited 9 times, last by guenterhaas ().

    Digging out an old thread just to leave some info :)


    I got a Camplifier 360 and a brand new Mesa Rectifier 4x12 cabinet. The cab has an 8 Ohms input so I connected 1 camplifier channel to this cab input .... only to hear nothing but a silent tshk tshk tshk tshk. WOOOOOW, what's going on? I immediately panicked and called Marco and Tilman of KPA-Solutions. First of all: Both are very nice and helpful guys! After checking a couple of things to troubleshoot, Tilman even offered me to send a replacement unit in case this one has an issue.


    To cut a long story short: The Mesa Rectifier 4x12 is wired with "common ground", even on the 8 Ohms input.
    I'm not into electronics very much but after I re-wired the cabinet to have proper (standard) 8 Ohms input, it immediately worked like a breeze.


    So if you happen to try the Camplifier 360 with a factory Mesa Rectifier 4x12 cab, here's why it won't work. You have to fix the internal wiring to get the standard 8 Ohms input.


    Hope this helps someone, didn't expect this to happen.

    Quote from Ingolf

    Weird that Mesa would use such unconventional wiring.


    Yes, they are a bit unconventional as they use 8 Ohm speakers instead of 16 Ohm (like Marshall and others). That's why they have 8 Ohm mono an 4 Ohm stereo. The jackplate states "Attention, common ground on all inputs". Not an electronics expert but this wiring triggered the Camplifiers safety circuit resulting in the tshk tshk sound.
    Once I rewired the simple and standard way everything worked as expected.

    To get a 4x12 cab with 8 Ohm speakers to work with mono 8 Ohm input, you need to connect 2 speakers in parallel (2 times).... and then connect these 2 pairs in line. If you connect something in line, there can't be anything "common ground". The jackplate says "All inputs have common ground". I didn't investigate the weird original wiring on the jackplate. I just cut the 2 pairs, soldered them in line and connected them to one of the input jacks. Done.

    Just thought that I would chip in as I saw this thread had resurfaced :)


    Recently bought a camplifier 290 and am running it in bridged mono to a zilla studio pro 2x12 with creamback celestions.


    Sounds really really good ! - I am using Guidorist profiles which are very good, but surprisingly I am finding that I get the best results by leaving monitor cab on.


    Respect Tillman.


    Matt


    So you don't bypass the kemper cab?

    No - i tried it both ways and its sounds a little fizzy with cab off - much more authentic with it just left on... which goes against the whole idea of cab on/off buying a nice cab etc but i suppose if it sounds good just go with it :)


    Matt