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  • Which components affect gain on OD channel only?
    Like the amount of gain?

    Comment


    • Soulcrusher_X
      Soulcrusher_X commented
      Editing a comment

      Motocooney wrote:
      Which components affect gain on OD channel only?
      Like the amount of gain?

      V2 and the associated anode and cathode resistors/capacitors for those two stages. What do you want to change about the OD channel?


  • To Kasebrot
    The resistors I'm using are 1/2watt carbon film.
    I just ordered a bunch of metal film 1/2 and 1watts.

    I actually hate how the two channels are so connected. Because if u set up the normal channel with any kind of gain, it totally makes the OD channel flubby.

    Maybe I'm nitpicking. My marshall was noisier. As I said before, I'm being a little overly critical of this thing right now. You guys know a ton more than me about the internals of these amps. But I've always thought I had a decent ear for good tones. Lol
    Obviously that's completely subjective.
    The 22 OD channel is different than the 100. Up until tonight I've been thinking of them as the same amp, just small and large.

    Comment


    • To Soulcrusher..... How the hell do you quote someone's post on this forum lol

      I want the OD channel to have the smooth almost vintage top end that the crunch channel has but with more saturation and oomph. If that makes sense?

      Comment


      • k
        käsebrot commented
        Editing a comment

        For more saturation, you could increase R19 (on 50H/100H) up to 150k, 180k or even 220k (like on SLO).

        But this will affect both channels.

        For nicer/warmer highs use a higher fizz cap value and/or reduce the coupling cap between 1st and 2nd gain stage (I like 4,7nF best). This makes the bass clearer, give you better articulation.


      • Soulcrusher_X
        Soulcrusher_X commented
        Editing a comment

        Motocooney wrote:
        To Soulcrusher..... How the hell do you quote someone's post on this forum lol

        I want the OD channel to have the smooth almost vintage top end that the crunch channel has but with more saturation and oomph. If that makes sense?


        You had said that at one point during the mods we all discussed, you tried some that both kaesbrot and I had posted and got something close to the OD channel but ballsier. Righteous, is what you said, I believe. Do what he said in the above post (fizz cap adjustment and coupling cap adjustment). Change R32 to 10k-15k. Change C22 to 220p-470p and try something like a 120p in parallel with R39. If the gain increase is too much, change R36 for a 470k. If you want a bit more low-mid, change R38 for a 2k2.

        Or if you really just want to know what the normal channel sounds like with some more balls, put a 1uf poly cap in parallel with R45.

         


    • I'm thinking ill go with the JJs. They're cheap and the consensus is that they are decent tubes.

      I have gone a little crazy with the mods lol. It's hard to just do one thing at a time. I want it all at once.

      C12 is still stock but I think that'll be my next change after raising r19 a bit.
      As far as the slope, I tried 56k all the way down to 15k and 33 sounds the best to me.
      39k seemed to have more highs and less lows. The tone stack calculator shows the same thing

      Your advice (and Soulcrusher) has been invaluable to me.
      My amp sounds killer right now. Thanks to you guys


      I lowered c28(had it on a switch) I didn't care for that too much because it sounded like had the tone knob on my guitar at 5. Just lost its juice.

      Comment


      • k
        käsebrot commented
        Editing a comment

        33k in the slope is overall brighter than 39k.

        The lower the value, the less scooped the sound and more high mids and highs. And yes, the bass is also increasing then, but in a range, that your speakers can't reproduce.


        33k is modern Marshall Style. If you like this, then why not? It's all a matter of taste. The only thing is, if you complain about the amp sounding too bright, you should use 39k like Orange or Diezel.


    • Just out of curiosity....what kind of stuff are you guys into? It occurred to me that this stuff is so super subjective ya know? Not the actual mods themselves but the ultimate goal of shaping the tone of the amp to be closer to what you hear in your head lol.

      Like if a metal guy is recommending mods to a guy that's into playing blues....that might not be that productive.

      Comment


      • Soulcrusher_X
        Soulcrusher_X commented
        Editing a comment
        Melodic Black Death metal only. Nah not really.

        Rock/Metal/heavy blues-driven rock (sabbath/down/coc) punk. I dunno, I could play most stuff with my setup. I Could do some great Megadeth tones. The JB and Greenbacks helped a lot. lol

        What are you aiming for with your JCA? Maybe that's the ultimate question.

    • Are you making fun of my toggle switches? Wtf dude? Lol.
      That's not a bad idea with the nfb resistor.
      A rotary switch using a rear jack spot to select between 3 values would be cool
      i have noticed that the depth control seems more effective on the 22 than the 100. Same pot, same cap. Wonder why.

      Oh I was looking at the schems of some of my favorite amps. Their tone stacks in particular. What's the effect of having a 47nf bass cap instead of 22nf?
      More bass? Also, why are the treble and mid pots linear and the bass pot is audio?
      I just received a bunch of caps and pots I ordered. 500k audio pots.
      A 50k (per your suggestion) for the mid control but they sent me a log pot.
      And a 10k linear for the presence control.
      Will this make the presence have more range? It seems like it doesn't do much in the first 90% of the sweep. Then the last 10% is over the top it's stupid
      I'm bidding on a couple in ecc803 tubes. I'm excited to try them

      I was just downstairs playing "unchained" trying to dial in the tone but its just not there.
      Maybe I wasnt playing it right lol.

      Comment


      • k
        käsebrot commented
        Editing a comment

        The difference of linear and logarithmic/audio is in the response by turning the pot. Full up or full down is the same.


        With a 50k for mids knob, you will get a little bit more mids. That would be Peavey style.


        You've got that Duncan Tone Stack Calculator, the graphics will show the difference, but at least, just listen and decide, what you prefer.


        I'm not making fun of toggle switches, I've got this mod on a JCA 100HDM and the difference between +-10k nfb is really audible and makes sense.

        I would not mess a lot with the tone stack, if you're pleased with 33k/330pF, let the pots do the rest.

        The most important thing is the basic sound of the amp. Should it be more classic or more modern, smooth or tight? Or right in between?

        I think, the stock JCAs are voiced to dark and to fat/flubby/wooly. If just want to play smooth solo licks on the neck pickup of your guitar, this might be ok, but it's not the sound, I like for chunky rhythm playing.

        I'm not an amp tech, but have talked to someone, who mods JCAs, Soldanos and many other amps. And he gave me a lot pieces of really good information, how several components have an influence on the sound. So I've been able to do some mods for myself and judged by listening carefully.
        It's really impressive, what you can do on these amps just by changing some caps and resistors. More than tubes can do.

        Today I only play the 22H models, because they are smaller, have a better crunch sound and a better loop than the bigger ones. I like these amps very much and think, that you can't beat them for that price.

         


    • I think the 22h sounds better too. In every way. But it's just not loud enough. I tried it at practice and it just sounded bad at that volume. I think 4 or so on the volume of that thing is perfect. I'll be using it when we start tracking the new stuff.

      Comment


      • Soulcrusher_X
        Soulcrusher_X commented
        Editing a comment

        The JJ 803 is definitely a nice tube. Now, my take on it's smoothness is in it's playability. It has a little more high end, but more crunch in it's tone, but it feels smoother to play. It's not as percussive as the regular JJ 83s. In the PI spot, it adds a noticable amount of clarity. It worked awesome in my MKIII and Quickrod and I prefer it much more than the Mullard RI and Sovtek LPS for long-plate tubes. The JJ ECC82 is also a nice tube for the PI position. I think the 82 holds together a bit better at higher volumes and it a little warmer. They are both worth a try.

        I have not tried the Invaders, but a lot of dudes out there like them. For Greenback types, I have tried the Celestions, the Eminence GB12, the Private Jack and the Sheffield 1200. The Sheffield is by far, the darkest and least articulate. The GB12 was almost like a cross between the G12T-75 and Greenback. A little more powerful, but not really "sweet" like the real deal. The Private Jack is pretty close, but with smoother highs and fuller mids. I still prefer the real ones. They are just more aggressive and nasty. The Blackback covered quad I have is more aggressive than the Greenback quad I have. Both are G25Ms.

        As far as the presence control, I use 10k controls. It makes the control more useful. With the 25k pot you fight to find that "sweet" spot between "just there, and too much"

        I haven't had my JSX for a while. Forgot to change my sig. I actually sold it to fund an amp build. I got it after I sold my MKIII and Quickrod because like you, realised daycare is too expensive. lol I had one before and liked it, but after the slew of good amps I've had, it was just such a disappointment. lol I sold it and have been putting together a JCA20H style amp. THEN I saw the JCA50 and 100 and the fact that they were just a few bucks more than I sold the JSX for. lol Makes me wish I waited before buying all this stuff.



        For toggles, why not get some push-pulls? That way, it's stealth. Like a sleeper hotrod.


    • That's a beautiful rig man. That guit looks super similar to my old '70 custom. Except....what pickups are those? You said u were rockin a JB?but they're black?

      It's official...band practice tonight and I left my 100h there until next week... It sounded ****************ing awesome
      My only complaint was that id like the crunch channel to be a little brighter but I can live with it.
      Boosting both channels with a modded ts9.
      I'm happy with it for sure

      Comment


      • Soulcrusher_X
        Soulcrusher_X commented
        Editing a comment
        I've gone through a few different pickups in that guitar. This picture was taken when I was using the Gibson/Tony Iommi signature pups. I wanted the chrome ones, but I got such a good deal on the black ones because the chromes were on backorder, so I just put them in. I used those for quite a while, and a pretty good list of Duncans, a few Dimarzios and currently, the Zhangbucker Crushbucker. The JB always ends up back in there. It just has a tone that fits my style, and with all the amps I've owned, it works the best, especially with the Greenbacks. I also have a Screamin' Demon to try out at some point.

        Have you tried any mods to the crunch channel yet? Maybe bypass VR9 with something around 120p-250p? Or reduce the value of the coupling cap (C29) to something in 4n7 or 10n. Last, try and bypass R45 with a .68u or 1u cap.

    • I did the "sucker punch mod" r34 and c23.... Played with those values a bit.
      C28 I tried 100p up to 1n
      R42 is 470k now, tried 100k and 220k

      That's about it for just the crunch channel.
      Bypassing the crunch gain should brighten it up a bit right.
      R45 comes of the cathode of v1? Is that right?
      So changing that value does what.
      When looking at the schem, how do I know for sure that something will only affect normal/OD channel.
      Thx man

      Comment


      • Soulcrusher_X
        Soulcrusher_X commented
        Editing a comment
        R45, R43, C29, C23 and R34 are for the Crunch channel. The way it's set up, it may still have a little bleed into the OD channel. R45 is the cathode resistor for V1b, the crunch channel second gain stage. Changing the value makes the stage cleaner or dirtier. Bypassing it maximises gain. Small values maximise gain in higher frequencies. Bigger the cap, the more bass. .68 or 1uf should work nicely.

    • Hey guys....thinkin about putting my 22h on Craigslist. I wanna get a 6505 to mess with.
      Thought I'd see if anyone was looking.
      Also what are your opinions on the 6505?

      Comment


      • Soulcrusher_X
        Soulcrusher_X commented
        Editing a comment
        I had a 5150, (same thing as 6505) and it was pretty good. It's tighter and grittier, maaaybe a touch darker than the JCA. I owned one quite a while ago, so I'm hoping my memory serves me well enough.

    • Oh okay. I had a 5150 II for a while and I really liked it. We'll see if anyone wants to buy the jca22h.

      Comment


      • Soulcrusher_X
        Soulcrusher_X commented
        Editing a comment
        The 6505 will be similar. The cleans aren't as nice/clean (still decent) and the tone is slightly darker. Otherwise, a very similar animal to the 5150II.

    • I don't care about cleans at all. Lol. I've never used any sort of super clean tones.

      Comment


      • Promit
        Promit commented
        Editing a comment

        Okay, so I've got a JCA22H and cab on order. Exciting! But my question is, how big a deal is it to replace the stock tubes and do I really have to do all of them? Replacing all seven looks a touch expensive.


    • The power tubes should be okay. Of the preamp tubes, v1/v2/v5 made the most difference to me.
      Go on ebay and just find a few cheap 12ax7s. I tried tung sol, JJ, Mullard and Ruby. To me, JJs in the v1&2 and a Mullard in v5 sounds best. But everyone's different with what sound they're looking for.
      I put Ruby power tubes in it but didn't notice a huge difference.

      As far the mods, start by putting a depth(resonance) control on it. Pretty easy a makes a big improvement in the low end.
      Then try the "sucker punch" mod.
      If you read through the last 7 pages or so, a lot of mods and their effect on the tone have been discussed.

      Good luck dude!!

      Comment


      • Just realized u didn't ask about modding it lol. Sorry.

        Comment


        • Promit
          Promit commented
          Editing a comment

          I do want to mod it, but the schematics on this thread seem to be for the 50. A nice roundup of what mods are available for the 22 and how to do them would be nice.


      • Yea forgot to mention like ^^^^^this guy said, rebiasing even the stock power tubes made a huge difference
        As far as mods, look at the first page of this thread. I would print the schematics for the 50 and the 22. If u look, you'll see that the layout between the 2 is basically the same. The component #s are different. Just figure it out. Or just read the last 10 of so pages of this thread lol.

        Comment


        • k
          käsebrot commented
          Editing a comment

          The tube layout on 22H should be:


          V1: 1st gain stage c and o channel

          V2: 2nd and 3rd gain stage o channel

          V3: 2nd gain stage c and 4th gain stage o channel

          V4: EQ and loop

          V5: Phase inverter

           

          So as you see, V2 is only for the overdrive channel.

          An exchange of the power tubes to JJs makes a big difference, I highly recommend that. And bias it at 16 to 20mA (just do that by listening and take a control with the dmm).

          The circuit of the 22H is a little bit different from the 50H/100H, especially the overdrive section.

           

          If you like the sound overall, there is no need to do a lot of mods.


          What I would do, to tame the flubbyness and this wooly sound a little bit:

          - lower C2 to 4,7nF

          - swap out R9

          - swap out C10, if that's too fizzy, than try the stock 1nF in series with 220k up to 680k (lower R = less treble)

          - change the slope resistor R 26 to 39k

          And do the depth mod, if you need more bottom end.

           

          What also could help to get a better sound is to change all the non-electronic capacitators. I recommend Sozo for all values between 1nf and 1uF, for the 1uF I like the SCR Solen Fast very much and for the lower values up to 1nF I recommend high voltage ceramic caps. Therefore you could also use Silver Micas, but I wouldn't do that because they sound very shrill and have a "ringing treble", also it's possible that you will get problems with dc leakage.

           

          Hope that helps.

           













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