Some Mods for Marshall Class 5

Discussion in 'The Squawk Box' started by Lyle Caldwell, Jan 18, 2011.

  1. falkman

    falkman Junior Member

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    As far as tubes go I'd recommend trying some out yourself. There are loads of them available. One tip though. The Sovtek EL84M sounds amazing! BUT, I have read reports of Class 5s not coping well with that particular tube. Myself included, sounded awesome and then...smoke. So I'd stay away from that one.

    VVRs are available from many suppliers. Don't know about the specific one posted in this thread though.
     
  2. BlueCajun

    BlueCajun Senior Member

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    I agree about the Sovtek EL84M. Of all the tubes I tried in my Class 5, that one sounded best. Then one day I really pushed the amp hard: dimed it and boosted the signal coming from my Les Paul with a Tubescreamer. Sounded glorious for about 10 seconds, then silence. Killed the tube and blew one of the fuses on the circuit board.
     
  3. falkman

    falkman Junior Member

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    Right?! It's a shame the Class 5 can't handle that tube, sounds terrific. Maybe someone here knows why that particular tube can't get along with the Class 5?
    It seams to me that other amps can take it.

    On my amp a resistor burned up instead of the fuse. Can't remember which resistor it was. All I know it was close to the tube and rated at 1 watt.
    I have played with the thought of replacing it with a higher rated resistor. But I'm afraid something more expensive will break instead.
     
  4. BlueCajun

    BlueCajun Senior Member

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    Yikes. If I had known that was a possibility, I probably wouldn't have tried the Sovtek. I did know ahead of time that it might blow the fuse. So I bought a bag of fuses just in case.

    I would agree on not changing the resistor value unless you figure out what's going on with that tube. I tried looking around various forums at one point but gave up. I want to say one post speculated that it had to do with the plate voltage of the tube. But I never figured out where precisely that caused an issue with the Class 5 circuit.
     
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  5. gouna

    gouna Member

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  6. Laurent!

    Laurent! Junior Member

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    Hi all

    I have bought a class 5 combo, and make some modifications, put amp on a head, install 1x12 Green berret in cab, and Lyle modifications

    But i have a problem

    I havé install hammond choke 158m with c11 22uf and when i switch between gain positions, one position produce a bad tremolo...

    After remove hammond and replace c11 10uf , no problem ...

    Have you a solution ??

    Tx
     
  7. tweedman2001

    tweedman2001 Senior Member

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    There have been reported problems with installing a choke in the C5. Sometimes they worked fine sometimes not. Quite a few have removed them or never installed them because of this. Lyle himself admitted that the improvement in sound was minimal anyway.

    I have no solution for you if you put the choke back in but perhaps someone more knowledgeable can give you some advice. Personally I never installed a choke.
     
  8. Laurent!

    Laurent! Junior Member

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    Thanks a lot !

    Ok ok 15 dollars fort nothing :-(

    Have you installed a transformer output? Which one ?

    Just with these little modifs with a Green Back this sound really good !

    An output transfomer is really better?
     
  9. tweedman2001

    tweedman2001 Senior Member

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    I kept the stock output transformer and use the 2016CX cab with Celestion G12H-30s
     

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  10. RalphieBoy

    RalphieBoy Junior Member

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    Hello, hope this thread is still alive.......have a volume problem. Did basic mods and just the bright switch. Volume (power? ) now is very low like it is a 1/2 watt amp or being attenuated down. Didn't do the headphone jack mod either. Have version #4 board Head. Anybody have a quick heads up on what could be wrong. Checked all mods 2 - 3 times for mistakes and didn't spot anything. FYI, was working fine when I just did the R20, C10, 1 x 120P bright cap for starters. Also, 2 of those lousy connector pins came loose during breakdown rebuild process and I re-soldered them back in. Could the PT - W1 - W4 connectors if not correctly plugged back onto the same pins cause this.....just a thought. Thanks in advance.
     
  11. RalphieBoy

    RalphieBoy Junior Member

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    guess its dead
     
  12. goodguy

    goodguy Junior Member

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    Trying to keep this thread alive myself.
    Just bought a Class 5 (v3 I think w/headphone jack, etc)

    At first I was dissapointed...thought it sounded boxy and very mid focused.
    Was looking for that warm Bluesbreaker ish tone, Claptonese woman tone....
    how to describe it...A flat papery breakup ..maybe a spongy tone...

    Here is a link to the tone I would love to get someday (I would describe it as spongy, saggy, chewy) but have given up on getting it in a post 1970's modern amp. Nobody would buy it as it is too imperfect sounding - no company would make such an imperfect sounding amp:
    Especially at 1:40 - wonder how to get that tone....

    https://www.youtube.com/watch?v=4dw1efq39qA


    Got the C5 home, plugged it in and thought I had a miss....

    But with all things, you have to give things some time and for your perceptions, history and reference point to adjust.

    I have this theory that your brain gets accustomed to want.expect a certain tone...in my case, I was really into Fender amps...Own a 59' Bassman RI, Princeton 68' Custom, Bassbreaker 007, Ramparte, Vaporizer, 78' Fender Musicmaster, Superchamp XD, BJR, Pro Junior, Peeavy Classic 30 & Classic 50, Crate Palomino V16, and a few others...

    I think my tonal memory (or expectation) was recently challenged when the Fender Bassbreaker line came out...Hated it at first..thought it was flat, boxy, dull and toy like sounding...and wrote it off. As my quest for tone evolved, I kept going back to try the bassbreaker line and eventually bought the 007 which is a great amp. The Bassbreaker nails that flat papery OD tone I was looking for (not as retro spongy saggy as I was seeking but still good).

    As my mind opened up to the possibility that all amps don't have to be a Twin Reverb clean and loud, I started to appreciate amps like the Bassbreaker 007. Which led me to the possibility of the Class 5... was not really thrilled with the reviews I found on it. Ended up trading another amp for it and after a few days, really really like it. Stock, no mods. Yes, the tone control range is limited and yes it is a bot boxy and mid sounding. Probably will do something to get better EQ, bright switch?

    But as I A/B it against my Princeton, Bassbreaker, Bassman 59', I have come to realize it is great sounding amp for what it is ... the Fenders seem to have something more chimey and more bassy ..almost like they have removed the cuppy mids the tonal spectrum without it sounding mid scooped ... which frankly is more forgiving than the in your face mids of the Class 5. You hit a wrong note on the Class 5 and you can hear it ... the Fenders seem to blend them all together which IS a good sound (am I explaining that right ?)

    That being said, the Fenders sound more full spectrum and are wonderful...but the Class 5 is in a "class" of its own and sounds decent. Not as many highs and lows but good pop on the notes you hit. So there are some things i like about the Class 5 and others I wish it had more of. Perhaps the mods will help a bit.

    It seems to me, reading through so many pages of mods and ways to change the amp ... perhaps peoples tonal expectation for the Class 5 was a bit optimistic (like they wanted a Plexi on the cheap and were frustrated they didn't get it). I think the amp is good for what it is and it is growing on me. I sort of look at amps like an expensive pedal (with a speaker).

    Thanks...
     
  13. goodguy

    goodguy Junior Member

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    Had a similar issue on my Peavey Classic 30..blew out a protection diode and cooked a resistor....problem was one of the tube socket pins shorted out to the chassis.... also a bad or wrong tube can cause this .... i could keep the same resistor value and have the tubes checked out.

    I would just keep the amp stock, too much time and energy screwing around and possibly bricking your amp. Just use pedals (or a different amp) for different tone.
     
  14. Iron Broadsword

    Iron Broadsword Senior Member

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    There was a lot of love and hate about this amp when it first got released.. on one hand it does sound a lot like the plexis of olde, in a very portable package at a volume you can use. On the other hand, it's not perfect and it does kinda have its own sound, which is not that far off from the Astoria line that marshall is currently doing. What they should have done was release this same 5w with a 1959slp preamp and called it a day, but instead people were a little miffed that it wasn't perfect. So we have some mods that get it closer to what people are expecting.. and IMHO the mods Lyle posted here are quite awesome and I've certainly been enjoying them. I wasn't a believer at first, but after trying it I won't go back. I still use two class 5's live, both with lyle's mods and also orpheus777's attenuator (from the marshall forum). Very useful for gigging with marshally power tube crunch if you have the ability to mic the amp.. The only other way to get it is to bring a bigger amp and attenuate, but then you are carrying heavier gear.
     
  15. goodguy

    goodguy Junior Member

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    Great points... I think I will try some of the mods to brighten up the amp (switchable)..I just got tired after about reading page 20....
     
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  16. Iron Broadsword

    Iron Broadsword Senior Member

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    Cool. FYI that's what I did first as well... I added the bright switch and also the plexi lows switch. With the stock amp, these give you exactly that.. no tone change except for those two aspects. But when I did the rest of the mods I found that having these on a switch was useless, since leaving them engaged all the time is really the way to go. So try hardwiring it before doing a switch since less switches = cleaner look. That's just an aesthetic though, it might come in handy some day.
     
  17. penguinchit

    penguinchit Senior Member

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  18. gouna

    gouna Member

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    Hello! (sorry for my bad english....)
    Today I've replaced the original speaker with a Tayden True Brit.
    I modified the front panel, and add shims 20mm thick not to bump the frame.

    [​IMG]
    ClassicTone OT & Hammond Choke
    [​IMG]

    [​IMG]

    [​IMG]

    With a Epiphone SG and a Vintage V52 télécaster
    [​IMG]
     
  19. gouna

    gouna Member

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    Hi!
    I want to install AmpMaker VCB kit (Hall VVR) .

    So, how prevents scratchy guitar pot? (my combo is a V3 with separate tubes)

    Thanks!
     
  20. rjwilson37

    rjwilson37 Senior Member

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    Wow, this thread is coming up on 6 years in January. People are still loving and modding the Class 5 amps.

    Are they still available new anywhere?
     

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