My first tube amp ever Dsl1c. But hum and hiss

Discussion in 'Marshall Amps' started by Dom Dom, Oct 12, 2019.

  1. Dom Dom

    Dom Dom New Member

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    Hi guys!! I'm new here and I just bought a used DSL1c and it's my first tube amp ever!!!! I play alone. No band. I played in a band a couple of years ago but I had a solid state amp.

    But, I don't know what is normal or not with the sound of it.

    1 - When there is nothing plugged in and all the volume down, I hear a sound like hum sound. I thought it was a ground loop problem, so I removed the ground pin to isolate that (i know it's not safe but it was just for testing. I changed the cable with new one with ground pin... lol). It still humming without the ground pin.

    2- when I put volume up on the clean channel I start hearing a hissing sound + the humming sound. It's doing the same thing on the gain channel and it's worst.

    3- when I plugged my guitar it's worst. If I turn my guitar volume down I get more humming sound. If I put my tone to 0. The humming sound is a lot attenuated.

    Where is 3 youtube link of my problem :







    I know it's a newbie question. And the problem is that I don't have any reference.

    Thank you
     
    Last edited: Oct 12, 2019
  2. South Park

    South Park Active Member

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    That hum sound means that the amp is working. All tubes amps hum some more some less . It could be a lot of things like preamp tubes bad cables pickups cold solder joints.when it sounds like a chain saw you have a ploblem
     
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  3. Dom Dom

    Dom Dom New Member

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    There was no guitar plugged at that moment.
     
  4. pedecamp

    pedecamp Well-Known Member

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    Get a spare set of tubes, that little amp doesnt take many, its good to have spare tubes if you own a tube amp. Replace all the tubes with the spare set, keep the old ones as spares.
     
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  5. South Park

    South Park Active Member

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    So it hums right . The grid on the on the gain stage is ground sucking up power from the amp
     
  6. South Park

    South Park Active Member

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    The noice is from the gain stage the first tube. To check this pull the first tube. To isolate the noice. The first video is a voltage spike when you hit the switch.claen the first tube socket with electrical cleaner. That is a good start. The amp is working just some trouble shooting
     
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  7. Neil Skene

    Neil Skene Well-Known Member

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    It doesn't sound that loud. All amps will make some noise.
    Most of the time it is electro magnetic interference, try moving the amp around to different parts of the room.
    Even take it outside of the house on an extension lead.
    Just to demonstrate this, plug a lead in with no guitar, turn the amp up a little and hold the end of the lead up near power points, lights, switches and transformers that are being used and watch how bad things get. the wiring around above and under the amp in the room can cause lots of noise.
     
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  8. South Park

    South Park Active Member

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    Yes you right my last build had no grid stopper I was getting Mexican radio You could could picking up something. Change the location
     
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  9. scozz

    scozz Well-Known Member

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    Welcome to a tube amp! I’m not hearing anything unusual, I have the same amp except the head version.

    I wouldn’t worry about it, if you are do what @pedecamp suggested. There’s only 3 tubes with this amp, 1 power tube, (ECC82), and 2 preamp tubes, (12AX7).
     
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  10. Deerhunter1972

    Deerhunter1972 Active Member

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    I have the head version and the DSL20HR, and both make the same noise. That is normal tube hiss in my opinion.
     
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  11. John BNY

    John BNY Well-Known Member

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    Hard to tell how loud the hum is, but the placement of the amp in relation to other electronic devices can cause hum. My 100 watt amps in my home studio are dead quiet, but my 15 watt DSL in my office next to a refrigerator has a hum. Try plugging the amp in other parts of the house and see how it does.
     
  12. pedecamp

    pedecamp Well-Known Member

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    Its worth a shot, 9 out of 10 times when a tube amp has a problem it's gonna be the tubes. The cost of $30 it's worth checking or you'll never know. If that's not the problem you'll have that spare set of tubes every tube amp owner should have. :yesway:
     
  13. Midnight Blues

    Midnight Blues Well-Known Member

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    :wave: and :welcome: to the MF Dom Dom!

    The hum doesn't sound all that loud to me either. Since you mentioned that it got worse once you plugged your guitar in, if you have single coil pups, the amp will hum more as well.

    If you're still concerned about it and addition to the suggestions others have provided, if you have an electronics shop, particularly one that repairs amps, close by, bring it in and have them give it "The Once Over".

    Congrats, HNMAD :applause: :rock: dude: :headbanger: and welcome to the Marshall club!


    :cheers:
     
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  14. ampmadscientist

    ampmadscientist Well-Known Member

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    Start the reactor... Free Mars!
    1 - When there is nothing plugged in and all the volume down, I hear a sound like hum sound. I thought it was a ground loop problem, so I removed the ground pin to isolate that (i know it's not safe but it was just for testing. I changed the cable with new one with ground pin... lol). It still humming without the ground pin.

    The hum comes from the tube filaments and it's normal.

    2- when I put volume up on the clean channel I start hearing a hissing sound + the humming sound. It's doing the same thing on the gain channel and it's worst.

    The hiss comes from the resistors in the amp circuit and it's normal.

    3- when I plugged my guitar it's worst. If I turn my guitar volume down I get more humming sound. If I put my tone to 0. The humming sound is a lot attenuated.

    The guitar does add noise.
    Especially if there is single coil pickups instead of humbucking pickups.
    But what you can do is shield the insides of the guitar and this will help a lot.

    There is nothing wrong, all the noise is normal noise.
     
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  15. SkyMonkey

    SkyMonkey Well-Known Member

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    Do you have a noise gate pedal?

    If not, try a BOSS NS-2. It is designed to work out front (guitar RF hum) and in the FX loop (preamp hiss) simultaneously. They are purpose made for these kinds of unavoidable valve amp noise.
     
  16. Dom Dom

    Dom Dom New Member

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    I Will check it tommorow.. thanx
     
  17. Dom Dom

    Dom Dom New Member

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    I did buy them today. I will change them tomorrow!!!! Thanx for your input
     
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  18. Dom Dom

    Dom Dom New Member

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    If that sounds are normal, I will sell it. It's very annoying!! But I will change the tubes tomorrow in case that it could do better...
     
  19. Dom Dom

    Dom Dom New Member

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    I don't have noise gate. I will read on that.. thanx for the input..
     
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  20. ampmadscientist

    ampmadscientist Well-Known Member

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    Start the reactor... Free Mars!
    I almost forgot welcome to the forum:cheers:.

    The amp can be changed to eliminate most of the hum from filaments.
    There is numerous methods of dealing with hiss in high gain guitar amps...
    http://www.marshallforum.com/threads/jtm45-newb-help-gz34-voltage.109565/#post-1880156
    This thread going on right now is talking about reducing hiss.

    Other than that pickups and shielding the guitar are a large factor.
     

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