Noise While Raising Volume And Presence Knob On Marshall 1959 Hw

Discussion in 'The Workbench' started by jalexquijano, Jan 5, 2018.

  1. jalexquijano

    jalexquijano Member

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    I own a marshall 1959 HW which i rarely use. Last time i used it was 6 months ago. The thing is that after leaving it on idle and then taking the standby off there is noise when in raise the presence knob to 10 or if i raise the volume 1 knob to 3 or more. It sound like a blowing wind that tends to produce a high pitch sound.

    What could be causing this and how do i fix it?
     
  2. neikeel

    neikeel Well-Known Member

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    Failing preamp valve - next question
     
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  3. ampmadscientist

    ampmadscientist Well-Known Member

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    The noise you are hearing seems like oscillation.

    When you look at the back of the amp, it's usually the first tube 12AX7 on the far right.
    Swap out the preamp tubes w/ a new one, one at a time and retest each time you swap one.
    (you don't need a whole set of tubes - it's usually just 1 preamp tube)
    But also, it can be the input jacks (have switches) and the switch may not be closing when the cable is unplugged from the jack.
    So if you change the tube and that doesn't stop the noise, it could be a bad input jack...
     
    Last edited: Jan 5, 2018
  4. jalexquijano

    jalexquijano Member

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    this amp is not that old! Could be at least 5 to 6 years old. However i rarely use it once every six months!
     
  5. neikeel

    neikeel Well-Known Member

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    Try buying (or borrowing) a known good preamp tube (ECC83, 12AX7 or 7025) replace each preamp tube in turn until you find the one that is failing.
    Whistling wind noises are almost diagnostic for a preamp tube on the blink.
     
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  6. RLW59

    RLW59 Well-Known Member

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    That level of use wouldn't wear out tubes. But they aren't saying any of the tubes have worn out.

    Sometimes tubes just go bad. Sometimes a brand new tube will be bad before you plug it in.

    Normally, tube life is based on wear/use, and an unused tube should be good forever. But again, sometimes they go bad early for no apparent reason.

    With the light use your amp gets, the rest of your tubes should last decades. When you replace the bad tube, the replacement tube should last decades.

    "Should", "probably", "most likely" will last decades. But no guarantee -- that's why transistors have replaced tubes in most things.
     
  7. jalexquijano

    jalexquijano Member

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    well i managed to pull the 3 ecc83 preamp tubes and slide them back and forth. nevertheless, i noticed that whnever i unplugged the guitar from any of the 4 holes the amp starts producing some crackle. Should i drop some deoxit d5 on the input jacks and else?
     
  8. myersbw

    myersbw Well-Known Member

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    DeOxit? Yup. Ever hear the phrase,"If you don't use it, ya lose it?" That just might be what 6 months in a closet gets you. As no plugs are sliding across the jacks...the contacts are just there...taking in the effects of temperature change and humidity level changes and oxygen...and, oxidation occurs. Using the amp is your friend. Semi-regular contact with plugs will deter some of the oxidation...at least lengthen the time it takes to be detrimental. But, letting it sit there for months with no use isn't healthy for it.

    Take a car, for example, used moderately daily to weekly...can run well for years. But, let it sit for several months and the oil internal eventually leaves the parts it needs to lubricate. Then the moisture and oxygen gets to the internal components and it can rust and incur high friction losses from the inside out. Regular, not heavy, use is much preferred.

    Brad
     
  9. jalexquijano

    jalexquijano Member

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    How much deoxit d5 should be sprayed? This is supposed to be a high quality tube amp. Im saving for an attenuator as it is a Non Master Volume amp which need to be tamed or else i would loose my hearing.
     
  10. Gunner64

    Gunner64 Well-Known Member

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    It doesn't take much, and you don't want to coat the intire insides of your amp with it. I wrap a piece of paper towel around whatever I may be spraying, and yes, I take the amp out of the headshell for that. And it's been my experience that this is the best way to get cleaner on the jack contacts, and prevent over spray, which is a giant mess you don't want. I put a little on a plug and work it in and out a few times for the plug to jack contacts as well..others may do things differently, but that is how I do it.
     
  11. myersbw

    myersbw Well-Known Member

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    If you want to test the "quick fix", I also do what gunner does...i.e. I'll twice-spray a 1/4" plug and quickly insert it 3-4 times...rotate it well on the last time. On a fairly new amp, that should do it if it's just a little oxide issue with jacks.

    Regarding your note on 'high quality', everything deteriorates in time...doesn't matter what parts are used. Now, given that, yes, gold plating may buy you a wee bit more time...avoiding dirt cheap inferior steel jacks made in places you don't want to buy from can get you issues quicker. But, your issue doesn't surprise me.

    I made a post about amp manufacturers today and, personally, I'm so disappointed in what should be coming from a used-to-be quality manufacturer...now is no longer. Like some of the "blues & hot rod series" of a certain builder that, when you look to the inside, you see fragile circuit boards where the traces melt from just a quick solder touch...really sad.

    Of all the amps that have crossed my bench over the past years, my fave builds in order of preference and quality and stability are as follows...

    1 - Bad Cat Hot Cat 30...USA-made. Built like a tank and made for the road.
    2 - Dr. Z Maz38. Space for repairs, thick turret board construction, easy to repair without a schematic due to simplicity of the beast.
    3 - PRS 2 Channel H (2011 build) - this might surprise many of you. The chassis, circuit board, pots are first class. It' one of the best PCB-style builds I've ever seen. A nice small strip of PCB that's thick (and made so for durability, not multi-layers). Spacious for working around and troubleshooting. It (at present) is my personal amp. Many don't like this amp (doesn't resell at a high value) and i think mostly it's because it takes time to dial your tones in. The clean channel and reverb is lush. Works for me. The gain channel takes as much work as a Hot Cat 30 to get "your tone". Once you do...I love it.

    Anyhow, apologies for a diversion, but if you're after quality builds that will last? Post here before you purchase or run the model of interest by your local tech.
     

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