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  • jmp 50watt lead mk2 1976 ?

    I have this Marshall jmp 50w master lead head made in 1976. It is so bright that I have to turn the treble all the way off to get a good sound and it is still pretty bright. Any ideas on how to tame the beast. using kt88 tubes jj tubes

  • #2
    Use old Rola Celestion speakers, or re-issue Greenbacks.

    If your useing V30's or similar that's your problem as JMP's are brite amps.
    <div class="signaturecontainer"><font color="magenta">I endorse Laura &amp; Valve Queen tubes, you should too.<img alt="" border="0" title="Thumbs up Phil" src="http://img3.harmony-central.com/acapella/ubb/Phil-Thumbs-Up-Small.gif"></font><img alt="" border="0" title="love" src="http://img3.harmony-central.com/acapella/ubb/love.gif"><img alt="" border="0" title="love" src="http://img3.harmony-central.com/acapella/ubb/love.gif"><img alt="" border="0" title="love" src="http://img3.harmony-central.com/acapella/ubb/love.gif"><img alt="" border="0" title="love" src="http://img3.harmony-central.com/acapella/ubb/love.gif"><img alt="" border="0" title="love" src="http://img3.harmony-central.com/acapella/ubb/love.gif"><br><font size="5"><font color="Red">Marshall, Gibson, Fender, Charvel/Jackson.</font><img alt="" border="0" title="Snacks" src="http://img3.harmony-central.com/acapella/ubb/snacks.gif"></font><br><font size="4"><font color="Blue">&quot;I'm happy to pay my tech $40 bucks to take the Zap for me.&quot;<img alt="" border="0" title="lol" src="http://img3.harmony-central.com/acapella/ubb/icon_lol.gif"></font></font><br>One kick-butt deal with johnpace2 <img alt="" border="0" title="thumbs up" src="http://img3.harmony-central.com/acapella/ubb/thumb.gif"><br><font size="5"><font color="orange">Dave Friedman of RACKSYSTEMS is a genius.<img alt="" border="0" title="idea" src="http://img3.harmony-central.com/acapella/ubb/idea.gif"></font></font><br><font color="DarkOrange"><font color="Magenta">After the Firebird X, i'm quite convinced Henry Juszkiewicz is crazy.</font></font><br><font size="5"><font color="darkorchid">Member of the JMP Hall of Fame.</font></font></div><br>

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    • #3
      First mod that should be done to any old MV Marshall is clipping the bright cap. Boosts the gain a tad and tames that high end.
      <div class="signaturecontainer"><div align="right"><a href="http://www.billowsdoom.bandcamp.com" target="_blank">There is no order in the world, save what death has put there.</a><br />
      <br />
      <a href="http://www.facebook.com/billowsdoom" target="_blank">Billows</a><br />
      <font face="Courier New">Fender::Matamp::Acoustic</font></div></div>

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      • #4
        yeah it sure is a bright amp. I'm using a jcm900 lead-1960 cab. so what ever came stock in that is what I got. Probably 70watt celestions. thought I would buy an mxr 10 band eq pedal and try that. I tried an alesis meq-230 and it worked fine to roll off more highs. so hopefully the eq pedal will work. thanks

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        • #5
          hey homewrecker. where do I find out how to do that.

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          • #6
            hey homewrecker. where do I find out how to do that.


            I had a tech do it to mine when I had him go through and replace the caps, if you're not familiar with amps I'd highly recommend taking it a tech for a once over, something that old might need the caps replaced. But if you trust yourself I'm sure there's a bunch of DIY sites that can show you how to do it.
            <div class="signaturecontainer"><div align="right"><a href="http://www.billowsdoom.bandcamp.com" target="_blank">There is no order in the world, save what death has put there.</a><br />
            <br />
            <a href="http://www.facebook.com/billowsdoom" target="_blank">Billows</a><br />
            <font face="Courier New">Fender::Matamp::Acoustic</font></div></div>

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            • #7
              yup just found a good forum. vintage amps bulletin board. thanks. will do it tomorrow.no problem.

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              • #8
                yup just found a good forum. vintage amps bulletin board. thanks. will do it tomorrow.no problem.


                Good deal man, I've also heard that when the pre is maxed it takes the bright cap out of the circuit, but I'm not certain of that. If that's still not helping I'd go with a tube swap, personally I'm not a fan of JJs but just but 5 or 6 pre amp tubes and swap them in and out of V1 until you find one that does what you want.
                <div class="signaturecontainer"><div align="right"><a href="http://www.billowsdoom.bandcamp.com" target="_blank">There is no order in the world, save what death has put there.</a><br />
                <br />
                <a href="http://www.facebook.com/billowsdoom" target="_blank">Billows</a><br />
                <font face="Courier New">Fender::Matamp::Acoustic</font></div></div>

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                • #9
                  I've run every 2204 I've ever owned the same way...

                  Bass, Middle, Trebble: 10
                  Presence: 0
                  Pre and master to taste... I like them both on about 6.

                  With humbuckers, it should sound pretty balanced with those settings. If not, it might be biased too cold...
                  <div class="signaturecontainer"><b>Amps:</b> Stu-Daddy Deluxe Reverb, Marshall 1987 jmp, Alamo Challenger<br />
                  <b>Guitars:</b> Custom Shop Les Paul Classic, Standard American Tele, Brian Moore i2.13</div>

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                  • #10
                    IMHO you should consider another amp before you ruin a Classic 34 yr old JMP.:cry:
                    <div class="signaturecontainer"><font color="magenta">I endorse Laura &amp; Valve Queen tubes, you should too.<img alt="" border="0" title="Thumbs up Phil" src="http://img3.harmony-central.com/acapella/ubb/Phil-Thumbs-Up-Small.gif"></font><img alt="" border="0" title="love" src="http://img3.harmony-central.com/acapella/ubb/love.gif"><img alt="" border="0" title="love" src="http://img3.harmony-central.com/acapella/ubb/love.gif"><img alt="" border="0" title="love" src="http://img3.harmony-central.com/acapella/ubb/love.gif"><img alt="" border="0" title="love" src="http://img3.harmony-central.com/acapella/ubb/love.gif"><img alt="" border="0" title="love" src="http://img3.harmony-central.com/acapella/ubb/love.gif"><br><font size="5"><font color="Red">Marshall, Gibson, Fender, Charvel/Jackson.</font><img alt="" border="0" title="Snacks" src="http://img3.harmony-central.com/acapella/ubb/snacks.gif"></font><br><font size="4"><font color="Blue">&quot;I'm happy to pay my tech $40 bucks to take the Zap for me.&quot;<img alt="" border="0" title="lol" src="http://img3.harmony-central.com/acapella/ubb/icon_lol.gif"></font></font><br>One kick-butt deal with johnpace2 <img alt="" border="0" title="thumbs up" src="http://img3.harmony-central.com/acapella/ubb/thumb.gif"><br><font size="5"><font color="orange">Dave Friedman of RACKSYSTEMS is a genius.<img alt="" border="0" title="idea" src="http://img3.harmony-central.com/acapella/ubb/idea.gif"></font></font><br><font color="DarkOrange"><font color="Magenta">After the Firebird X, i'm quite convinced Henry Juszkiewicz is crazy.</font></font><br><font size="5"><font color="darkorchid">Member of the JMP Hall of Fame.</font></font></div><br>

                    Comment


                    • #11
                      IMHO you should consider another amp before you ruin a Classic 34 yr old JMP.:cry:


                      ^+100,000
                      Leave that vintage amp alone and don't butcher it.

                      Comment


                      • #12
                        IMHO you should consider another amp before you ruin a Classic 34 yr old JMP.:cry:


                        Clipping the bright cap is FAR from ruining a vintage amp, you literally just snip one wire.
                        <div class="signaturecontainer"><div align="right"><a href="http://www.billowsdoom.bandcamp.com" target="_blank">There is no order in the world, save what death has put there.</a><br />
                        <br />
                        <a href="http://www.facebook.com/billowsdoom" target="_blank">Billows</a><br />
                        <font face="Courier New">Fender::Matamp::Acoustic</font></div></div>

                        Comment


                        • #13
                          Clipping the bright cap is FAR from ruining a vintage amp, you literally just snip one wire.
                          If it's stock & in good shape it's one of the finest amps made.

                          He sounds young, it starts with a nip & tuck, then it's extra gain stages>>> pretty soon it's not a JMP anymore.

                          Hate to see that happen to a classic, but i can't save amps cept my own...my.02
                          <div class="signaturecontainer"><font color="magenta">I endorse Laura &amp; Valve Queen tubes, you should too.<img alt="" border="0" title="Thumbs up Phil" src="http://img3.harmony-central.com/acapella/ubb/Phil-Thumbs-Up-Small.gif"></font><img alt="" border="0" title="love" src="http://img3.harmony-central.com/acapella/ubb/love.gif"><img alt="" border="0" title="love" src="http://img3.harmony-central.com/acapella/ubb/love.gif"><img alt="" border="0" title="love" src="http://img3.harmony-central.com/acapella/ubb/love.gif"><img alt="" border="0" title="love" src="http://img3.harmony-central.com/acapella/ubb/love.gif"><img alt="" border="0" title="love" src="http://img3.harmony-central.com/acapella/ubb/love.gif"><br><font size="5"><font color="Red">Marshall, Gibson, Fender, Charvel/Jackson.</font><img alt="" border="0" title="Snacks" src="http://img3.harmony-central.com/acapella/ubb/snacks.gif"></font><br><font size="4"><font color="Blue">&quot;I'm happy to pay my tech $40 bucks to take the Zap for me.&quot;<img alt="" border="0" title="lol" src="http://img3.harmony-central.com/acapella/ubb/icon_lol.gif"></font></font><br>One kick-butt deal with johnpace2 <img alt="" border="0" title="thumbs up" src="http://img3.harmony-central.com/acapella/ubb/thumb.gif"><br><font size="5"><font color="orange">Dave Friedman of RACKSYSTEMS is a genius.<img alt="" border="0" title="idea" src="http://img3.harmony-central.com/acapella/ubb/idea.gif"></font></font><br><font color="DarkOrange"><font color="Magenta">After the Firebird X, i'm quite convinced Henry Juszkiewicz is crazy.</font></font><br><font size="5"><font color="darkorchid">Member of the JMP Hall of Fame.</font></font></div><br>

                          Comment


                          • #14
                            so charveldan what would you reccomend I do to tame the treble excess. Oh and for the record if you are older than me God help you I'm just after the tone that is in my head and this amp is just too trebley.I am taking all suggestions. I sure don't want to butcher the thing


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                            • #15
                              I have the same amp, and mine is uncomfortably bright with all of my guitars.
                              LPs, JP Juniors, teles, etc.

                              Thing is, it didn't used to be this bright.. I swear it wasn't AS bright. Always somewhat bright when the master or pre is turned down

                              It sounds great when pre-amp and master are cranked, but then it's also unsuable. High sensitivity input when near 10 just squeals with any guitar.
                              Massive hum + hiss.

                              I replaced the filter caps about a week ago, no change.

                              I tried snipping the bright cap, but then the amp lost all balls. brightness was gone, but it also didn't have the note articulation that it used to have.


                              I've brought it to two 'well known' tech guys here, and one told me "it's just a noisy amp", and the other said to change the pre-amp tubes, which I did and it did nothing.


                              What am I missing *sigh* - if you have great results let me know.

                              maybe I just need a smaller value bright cap

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