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  • I'm sorry Kasebrot!! I called u kaoslord lol. He's A douche on another forum haha. My apologies. So do u think I could play with r46 and r19 having the predator mod values in place?

    Comment


    • k
      käsebrot commented
      Editing a comment

      Hi,

      there is no equivalent resistor to R19 (50H/100H) on the 22H.

      And I don't would go lower than 180k at R6. On 22H I like the stock 220k on R6 best. The overdrive channel is voiced less gainy than the 50H/100H overdrive and is a little different.


      I also think, that the JCAs are a bit too dark, fat and wooly in stock condition. Good for singing leads, bad for chunky rhythm.

      Predator Mod recommends to raise that cathode cap from 1uF up to 3,3uF. That is WAY too much. Leave the 1uF or even try 0,68uF.

      And lower the cap between the 1st and 2nd gainstage (C2 on 22H) to something between 2,2nF and 6,8nF. Stock is 22nF. Way too much on an high gain amp! (Predator Mod recommends 47nF...)


      These changes will do a lot to get a nicer, tighter sound and reduce flubbyness.

       

      To archieve even more clarity and openness on the 22H, just swap out R9 (this 1M parallel to C5). This is one of the best things, you can do to this amp. Sounds way better with more definition and a clearer bass.

       

      : )

       


    • kaoslord
      kaoslord commented
      Editing a comment

      douche ? maybe in amp modding yes, but I would pay respect to people you don't know.

      Motocooney wrote:
      I'm sorry Kasebrot!! I called u kaoslord lol. He's A douche on another forum haha. My apologies. So do u think I could play with r46 and r19 having the predator mod values in place?




  • Okay guys I have a problem! Hopefully someone can point me in the right direction

    I was messing with slope resister/treble cap values on the 100. All was good I found something I liked. 33k/560pf

    I decided to try messing with r19/r46 as Kasebrot was talking about I went with 180k(r19) 120k(r46)
    Here's the issue.... When I fired it back up

    It sounded funny to me. Both preamp gain controls are acting weird. If I turn the gain past 5 or 6 on either channel, I actually get less gain and the tone blats out and is super clipped sounding with zero sustain. Both pots are making noise now.
    I put everything back the way it was swapped all the preamp tubes out for known good tubes, checked all solder connections?!?!?

    Both gain controls have a sweet spot at about 5 where they sound normal but anything higher or lower sound terrible like something is fried.
    I have no idea what it could be?

    Please help lol.

    Thanks!!!!!

    Comment


    • k
      käsebrot commented
      Editing a comment

      You should do 180k on R46 and 120k on R19. ; )

       

      Edit: Found the edit-function


  • Do u have any idea what could be wrong with both gain controls? Ive put everything back to stock and still no change its not preamp tubes what other components would effect both channels gain control?
    There no way both gain pots a dying at the same time
    could it be a tube socket?

    Comment


    • k
      käsebrot commented
      Editing a comment

      I don't know, what could be wrong.

      But only with having installed 120k/180k for R46/R19 instead of 180k/120k there shouldn't be anything damaged.

      Maybe a resistor is damaged? I would try new ones and solder them in properly.


      And if you only have these 5 preamp tubes - then go to crunch channel and do all combinations of tube positions you can find. If one combination works fine, then, a damaged tube is in V2 (because V2 is only for overdrive channel - 2nd and 3rd gainstage).


  • Good call. Ill give a shot. I dont think its a resistor because it was the same with the stock and the replacements son of a bitch!!!! Im gonna try to find some new pots tomorrow so i can rule them out

    Comment


    • What do r46 and r19 do? Could i have messed something up in those areas that would case this problem?

      Comment


      • GoKart Mozart
        GoKart Mozart commented
        Editing a comment

        Hi guys,

        This is such an awesome thread. I've owned my JCA22H for about a year and really dig it. Having owned several Peavey amps in the past (5150, JSX), I really missed not having a resonance/depth control on this amp. I just did the depth mod earlier in the week, and WOW...I'm in shock at how much an improvement it made.

        Prior to installing it, I usually set the treble at 3ish and the presence at about 2-3 to tame some of the high-end. With my new depth knob at about 12 o'clock, I'm actually starting to dial in some additional treble & presence to balance things out.

        Also, I used a 1M pot and it seems to me like there is plenty of usable sweep there. I was going to try a different value to start with based on a few other posts I can across, but to me the 1M works fine.

        Again, just wanted to pass along my thanks to everyone who's posted the great info! (especially to Edge & Borderline)

         

         


    • Both channels are screwed up so its not just one tube. There's still normal volume. So it's not transformer or power section.

      Comment


      • Alright back in board somehow both preamp gain pots were bad. Stole them from my 22 and everything is good.

        So i settled on r24 33k and c14 560p. Sounds best to me.

        Yea the tungsols in v1 are to bright to me. Also for whatever reason i get some extra noise when i run anything but the jj in v1&2
        good power tubes are next

        Im gonna go swap out r46&19.

        I cant wait until i know what im doing for real. Until then i appreciate the help

        Comment


        • Borderline11
          Borderline11 commented
          Editing a comment

          Motocooney wrote:

          I cant wait until i know what im doing for real. Until then i appreciate the help

          I second that!!!


      • To Kasebrot....

        Dude, did u think I was calling u a douche?

        I wasn't.

        Believe me, that other guy IS a douche!!!

        You've helped me a ton man. I appreciate it. Sorry if I offended you.

        Comment


        • k
          käsebrot commented
          Editing a comment

          No, I haven't thought this - as I know I'm not a douche.

          And I don't know that other gentleman you called so.

          But this isn't the topic. Let's talk about the JCA mods again!


      • To kaoslord:

        Would u believe me if I told you that wasn't talking about you?

        Are u the same guy from Nasioc.com?
        Are into Subarus?
        I'm really really sorry if I offended you man.

        What the hell are the chances of there being 2 "kaoslords"?

        Lol. So ridiculous.

        Comment


        • kaoslord
          kaoslord commented
          Editing a comment

          Motocooney wrote:
          To kaoslord:

          Would u believe me if I told you that wasn't talking about you?

          Are u the same guy from Nasioc.com?
          Are into Subarus?
          I'm really really sorry if I offended you man.

          What the hell are the chances of there being 2 "kaoslords"?

          Lol. So ridiculous.


          mmm.... no, never been into Nasioc.com (what the hell is this?) or into Subarus...

          don't need to apologize. no problem at all )

          the thread is very interesting, hope I can try some of the mods you guys are describing in the next few days ! 


      • Yes back to jca mods.

        I swapped r46/r19 for 180k/120k
        Slope resistor 33k/ treble cap 560 pf
        C30 .0047uf
        C8 1uf

        Everything else predator mod...it's sounds huge and tight!!!!

        Comment


        • To borderline...
          Yes I put the 100 gain pots in the 22...they work fine.

          Ya got me?!? I don't know what the deal was. I'm thinking metal shavings from drilling holes for toggles somehow got into the pots. That's all I got I don't know.

          Comment


          • Before I pulled the gain pots from my 22, I turned them to check that they werent making noise....they were completely silent.
            But now in my 100, those same pots are making noise when I turn them?!
            Also, there's a constant "hum" from my 100 on both channels. It's louder with more gain but its there even with guitar volume turned down

            Pretty much all the capacitors I've swapped out have been replaced with ceramic discs. Can the style of capacitor cause more or less noise.

            The resistors I'm using are just 1/2w from radio shack.
            Does that matter?

            It sounds fantastic right now so I don't wanna mess with it. It's just a little noisy.

            Comment


            • k
              käsebrot commented
              Editing a comment

              If you use Silver Micas (glimmer caps), they can cause many problems because of the possibility of dc leakage. Therefore, better put ceramics in, as you have done.

              Do you use any carbon composition or carbon press resistors? Beside the problem, that the real values are often nothing like they should be and drifting when soldering in (caused by the heat), they produce a lot of hum in most positions. So I only would use metalfilm or metaloxide resistors.

              This is also very important for the input resistor. Stock is 68k like on many other amps. I think, you don't need such a big value, because it's lacking off highs, when rolling off the volume pot of the guitar. I recommend 33k, that's really enough to avoid HF problems. And the signal is overall a little brighter and a little more responsive to picking dynamics.

              If you have too much fizz, firstly raise the fizz cap up to 100pF (on 50H/100H) or even 220pF. Stock is 47pF or 56pF afaik.

              If you only had changed the slope and the cap in the tone stack and the R46/R19, you wouldn't have got more hum.


            • Soulcrusher_X
              Soulcrusher_X commented
              Editing a comment

              Motocooney wrote:
              Before I pulled the gain pots from my 22, I turned them to check that they werent making noise....they were completely silent.
              But now in my 100, those same pots are making noise when I turn them?!
              Also, there's a constant "hum" from my 100 on both channels. It's louder with more gain but its there even with guitar volume turned down

              Pretty much all the capacitors I've swapped out have been replaced with ceramic discs. Can the style of capacitor cause more or less noise.

              The resistors I'm using are just 1/2w from radio shack.
              Does that matter?

              It sounds fantastic right now so I don't wanna mess with it. It's just a little noisy.

              What kind of resistors did you use? Carbon Comp. or Carbon Film can be noisy, though it's USUALLY a low hiss. I usually use 1 watt Metal Film for all of my mods/builds. Recheck your solder jionts and wire routing. If any have to be in close proximity, wires for circuits of different potentials should only cross perpendicularly. Long wire pairs on one circuit can be twisted to minimise hum, like bright switches/cathode bypass switches.

               

              Also, check your tubes. Besides being overly bright at times, my only gripe with the Tung Sol reissue is that they would sometimes develop "mechanical noise" like hums, pops, pings or weird static.

              Good luck dude.


            • Borderline11
              Borderline11 commented
              Editing a comment

              Motocooney wrote:
              Before I pulled the gain pots from my 22, I turned them to check that they werent making noise....they were completely silent.
              But now in my 100, those same pots are making noise when I turn them?!
              Also, there's a constant "hum" from my 100 on both channels. It's louder with more gain but its there even with guitar volume turned down

              Pretty much all the capacitors I've swapped out have been replaced with ceramic discs. Can the style of capacitor cause more or less noise.

              The resistors I'm using are just 1/2w from radio shack.
              Does that matter?

              It sounds fantastic right now so I don't wanna mess with it. It's just a little noisy.

              My inexperienced opinion is that there is a cap that is not functioning as intended. I read where forum user "VH4 (Duesentrieb)" added an additional 1uf cap to his depth mod to prevent scratchy pot noise. If there is a cap that is not working correctly or maybe of an incorrect type or voltage, then maybe it's allowing more noise to happen?

              Also, regarding cap types, Edge11 in post 190 said "I would go silver mica on the pf values and polypropylene on the uf values". I don't know if they would also affect the noise you are experiencing?

              I can't wait to try the combination you settled on! My parts should arrive next weekend.


          • The hum noise has been there since I did the predator mod. I think maybe I'm becoming ultra aware overly sensitive about every little noise and nuance of the amps sound.

            I've run into the same problem with tuning cars.....it becomes impossible to enjoy driving the thing when you can't stop worrying about how it's running.

            I'm doing the same thing with this amp. I think I need to just sit back and jam out a little lol. It is sounding ridiculous though

            The last few changes I made sealed the deal.
            I spent almost a year tweaking a dsl 100 and never got anything sweet out of it
            I've had the jca100 for a few weeks and it owns almost every amp I've had before.
            Bogner uberschall and modded 5150ii. Being the exceptions. But I have no doubt that this thing will end up sounding better than both of those
            I'm gonna order some different resistors. I have a bunch of caps on the way. All kinds....$30 worth lol. That's a lot of caps!
            Most of the stock resistors are 1/2w aren't they? They're a bit smaller than the 1 watts I have.

            Comment


            • Soulcrusher_X
              Soulcrusher_X commented
              Editing a comment

              Motocooney wrote:
              The hum noise has been there since I did the predator mod. I think maybe I'm becoming ultra aware overly sensitive about every little noise and nuance of the amps sound.

              I've run into the same problem with tuning cars.....it becomes impossible to enjoy driving the thing when you can't stop worrying about how it's running.

              I'm doing the same thing with this amp. I think I need to just sit back and jam out a little lol. It is sounding ridiculous though

              The last few changes I made sealed the deal.
              I spent almost a year tweaking a dsl 100 and never got anything sweet out of it
              I've had the jca100 for a few weeks and it owns almost every amp I've had before.
              Bogner uberschall and modded 5150ii. Being the exceptions. But I have no doubt that this thing will end up sounding better than both of those
              I'm gonna order some different resistors. I have a bunch of caps on the way. All kinds....$30 worth lol. That's a lot of caps!
              Most of the stock resistors are 1/2w aren't they? They're a bit smaller than the 1 watts I have.

              I know what you mean with cars. From computer-tuning my turbo RX7s to figuring out the proper timing curve and jet stagger on my vintage iron, tweaking has gotten the best of me from time to time. lol

              The different caps are fun to play with. Speaking of Uberschall, the first bright cap and second coupling stage for the Uber use two caps in parallel of different value and different composition (one mica, one ceramic and/or two poly types of different values/brands for added texture, making it more 3D. The Uber was one of the thickest-sounding amps Ive tried, without it being a giant mudfest.

               

              Did you do the FX loop mod? I can't remember if you removed that. If so, did you notice a change? Some JCA-ers on the GAB said they didn't like how it changed the tone/feel of the amp quite a bit. I need to pick up a JCA 50 or 100 to try for myself, but I'm wondering if the SLO loop mod doesn't translate to the JCA as well due to the JCA vs SLO values in and around the FX loop.

              On my SLOClone, I noticed a little extra brightness and a little bit of stiffness, but since my other amps were a Splawn Quickrod and a Mark III at the time I built my last SLO, I was already accustomed to "unforgiving".

               


          • I see the 715/716 orange drops everywhere but I can't seem to find the 225.
            I'm all about warmer and less harsh. My 2 main guitars (strat and tele) are bright guitars and my cab has v30s which are bright upper mid heavy speakers so anytime I can smooth tame the highs I do.
            Another thing, I havent paid a ton of attention to the voltage ratings for a lot of the smaller caps I've been messing with. Wonder if that's gonna be a problem?

            To Kasebrot :
            So are u saying that lowering the input resistor from 68k could help reduce noise a bit? Without affecting tone too much?

            To Soulcrusher:
            With the fx loop mod.....I'm not sure if I noticed any added brightness or stiffness. I know that it made my eq pedal usable as a boost through the loop. Maybe I'll undo it and see if it sounds different to me.
            This is 1uf//r25 and r21 1k right?

            Turbo rx7 sounds fun......I just got outta the car modding thing for awhile...expensive lol
            I had 2 built STIs and an EVO..... Now I have a 2001 lifted Cherokee haha.
            It's so friggin slow. Oh well

            Comment


            • k
              käsebrot commented
              Editing a comment

              The brand/type of the input resistor could possibly reduce the noise. The stock metalfilm resistor is ok. But if you put in a carbon composition, that will increase the hum. Same here at the slope resistor position.

              The main job of the input resistor is to avoid HF problems like getting the sound of radio moscow out of your amp. ; )

              Most amps are built with the classic 68k - but there are also ones, which don't use any input resistor like f.e. Engl. Depends on the schematic, if there is a need to.

              Just try 33k and listen, how your guitar now sounds when rolling back the volume on it. And also the overall sound will change a little bit, will be a tad brighter/fuller, less dark.

              If you don't use the volume of the guitar, then leave the 68k in the amp.


            • Soulcrusher_X
              Soulcrusher_X commented
              Editing a comment

              Motocooney wrote:
              I see the 715/716 orange drops everywhere but I can't seem to find the 225.
              I'm all about warmer and less harsh. My 2 main guitars (strat and tele) are bright guitars and my cab has v30s which are bright upper mid heavy speakers so anytime I can smooth tame the highs I do.
              Another thing, I havent paid a ton of attention to the voltage ratings for a lot of the smaller caps I've been messing with. Wonder if that's gonna be a problem?

              To Kasebrot :
              So are u saying that lowering the input resistor from 68k could help reduce noise a bit? Without affecting tone too much?

              To Soulcrusher:
              With the fx loop mod.....I'm not sure if I noticed any added brightness or stiffness. I know that it made my eq pedal usable as a boost through the loop. Maybe I'll undo it and see if it sounds different to me.
              This is 1uf//r25 and r21 1k right?

              Turbo rx7 sounds fun......I just got outta the car modding thing for awhile...expensive lol
              I had 2 built STIs and an EVO..... Now I have a 2001 lifted Cherokee haha.
              It's so friggin slow. Oh well

              No need to undo it if it's working well for you. I was just curious if you noticed a serious change.


          • I've been dicking with preamp tubes tonight....I decided to plug into the 22 which has the same mods done as the 100. It's seems a ton gainer and smoother overall.
            V1&2 old Marshall wk42?(no idea) and the rest stock chinese.

            So I swapped all 5 into the 100 which I put all my "good" preamp tubes and it sounds a ton better lol. Stupid.
            It's sounding very marshall ish. Which I'm not sure about.

            The 100 is definitely noiser that the 22 which is dead quiet. Same components. Why?

            Comment


            • k
              käsebrot commented
              Editing a comment

              The circuit of the 22H isn't the same as the 50H/100H circuit, especially on the overdrive channel. The 22H has less gain (stock).

              I haven't noticed, that the amps are noisy at all. There are amps which are much more noisy like several Marshalls, Peavey etc..

              Maybe, it's because of the components, you put put in. Bad resistor material, damaged pots etc.

              Also your modded loop could do this. The 22H loop isn't the same, it's behind the master and works with 0db, not like the "in the preamp"-loop of the 50H/100H, which works with line level (+4db).

              For this reason, you will never have problems with pedals and racks either using them with the 22H.

              I hate the loop of the 50H/100H, couldn't understand, why Mike build this like over 20 years ago, maybe because it's a part of the Soldano trademark sound. Afaik there are many people out there, who modded the loop on 50H/100H or on their SLOs and undoing this, because of the lacking sound quality.

              If you don't use effect pedals, you have no need to do the loop mod on 50H/100H.













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