Marshall 1987XL Question

Discussion in 'Amps and Cabs' started by leviathan, Jul 28, 2006.


  1. leviathan

    leviathan Member

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    Ok so i just purchased a Marshall 1987XL head. But the problem is i can't not dail the thing in to even sounding decent. On the treble channel everything is icepicks high no matter what the knobs are on. The normal channel is better and i can get a nice crunch on it, but it has a rather large bass to that i can't get out of it. Is it just a matter of breaking it in? I have never had a amp do this to me. Did i just get a dud or something. I am playing a tele straight into it as of right now. If you have any settings that could get me on the right track that woul be great also.:(
     
  2. ripoffriffs

    ripoffriffs Supporting Member

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    Clip off and Disconnect the bright cap on the Lead/Treble channel volume knob. Just clip off one of the 2 legs. All your "brightness" problems will disappear. See http://www.obsoleteelectronics.com/Marshall_Tech/marshall_tech.htm

    This is typical for this amp. But when you turn it up loud (use an attenuator to control volume) this brightness disappears. The amp's tone only reveals itself when played loud!
     
  3. Kiwi

    Kiwi Silver Supporting Member

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    Sounds normal. This is what the 1987xl is, and does, and a Tele will be WAY bright.

    Try snipping the bright cap. Then jumper the channels and try to balance the bright and dark channels. No known cure for the insane jump in volume between 1 and 1.125 on the volume knob, though.

    Used to own one,

    Kiwi
     
  4. leviathan

    leviathan Member

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    Where is the bright cap. Its not located where it is in the photo above
     
  5. ripoffriffs

    ripoffriffs Supporting Member

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    Bright Channel volume pot has a capacitor soldered right on the pot. If it didn't you wouldn't be having this problem.
     
  6. Tuberattler

    Tuberattler Member

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    HEY! welcome to the club! I just went thru the 1987x thing myself. Here's what I had to do.

    First (no disrespect to this board) but go to the Plexi Palace board and you'll find all kinds of suggestions for this amp.

    I did the following. First I removed the bright cap, it's a little puff cap. The first time I was messing with it I took out the wrong cap and took out a tube. Second all the square caps suck so I put in Mallory's and some Orange Drops for most of the tone section. Then I removed the square cap on the presence control and replaced it with an electrolytic of the same value..now it's a totally different animal very nice and thick sounding without the icepick!!

    A little work goes a long way with this amp..also the right speaker comination. I got a 1-12 cab and experimented with speakers until I got one that sounded great with this head. I ended up with the Celestion G12 80 that no one seems to like except me..

    Nice amp when all is said and done..rock on!!
     
  7. leviathan

    leviathan Member

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    Well there is no filter on the pot, it looks just like the other pots
     
  8. ripoffriffs

    ripoffriffs Supporting Member

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    You're saying that you don't see a capacitor on the bright channel volume knob like pictured below (where arrow points to the cap)?

    [​IMG]
     
  9. leviathan

    leviathan Member

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    no, nothing even close. Some other people on another board say that i have to remove it from the C-5 slot on the board, that on the new ones its located on the boards
     
  10. EADGBE

    EADGBE Member

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    What speakers are you using it with?
     
  11. Tuberattler

    Tuberattler Member

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    My bright cap was on the board. I had to undo & pull all the pots and input jacks, loosen up the board (taking the hold down nuts off) and flip it up so I could get undernieth to unsolder the cap, so while I was there I replaced some of the harsh sounding square/rectangle caps.. I'll try to get a picture up later today.
     
  12. sgmarshall

    sgmarshall Member

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    I bought a hotplate for mine (also the XL). The brightness goes away after the volume gets past 2 (which is even too loud to play in a club), The hotplate sounds like it was made for a marshall. I even use one with an older master volume model I have, sounds much better.
     
  13. rockbutt

    rockbutt Member

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    I have a 1987x head i bought new in 04. The bright cap is on the board, it is grey and it looks like a Lego block. It has a 4700uf value. Substitute it for a 100uf cap, and your brightness problems are over.

    You migh have also noticed that on the treble channel you will get a sort of "instant volume" jump at a low volume setting, increasing dramatically with just a slight touch on the volume knob. This problem also goes away by substituting the bright cap, making the volume increase more gradual.
     
  14. A440

    A440 Supporting Member

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    many players like to jumper the channels with cable.

    blending the 2 channels gives the best of both worlds
     
  15. WaltC

    WaltC Member

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    On this model (the XL with the effects loop, BTW the newer ones do have the "bright cap" on the board, not the pot), the signal from both channels runs through the effects loop board (small on the back of the chassis next to the speaker out jacks) all the time.

    Something that works for some is to put a single wire pre-PI master volume pot (50K, 100K, audio or linear taper) in the second speaker out jack and connect it to the post when the signal enters the effects loop board, and use it to tame the signal going to the output. Makes the amp behave better, tames the volume problem and makes the brightness problem much less obnoxious. Easy to install, easily reverseable, and pretty effective.
     
  16. sinner

    sinner Supporting Member

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    +1 this really works out well. Jumper the channels, set your volume with your channel of choice ("bass" or "high-treble"), then blend in the other channel to even out things.

    Also the attenuator also helps (in addition to jumping the channels)--I use both.
     
  17. leviathan

    leviathan Member

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    I am going to try removing the bright cap today and see how i like it. Then i might try putting another cap on later. thanks for the help
     
  18. sgmarshall

    sgmarshall Member

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    Post back and let us know how it works when you remove the cap, I'd like to know if it's worth doing. For me, the solution was the hot plate.
     

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