Members GRIMESPACE Posted February 29, 2012 Members Share Posted February 29, 2012 Originally Posted by clay189 Thanks, I know you and the other guys probably get tired of these rookie questions but I do appreciate the help. it Good luck, dude - Edge will take care of ya!Which mods are you looking to do? Post pics & clips! Link to comment Share on other sites More sharing options...
Members kocher Posted February 29, 2012 Members Share Posted February 29, 2012 Thanks for sharing all this information guys! Looking forward to do my first mods: depth mod and clean channel. Think I might go with an On-Off-On switch for the clean channel to be able to switch between 39k and 68k - any thoughts on that? I am still not sure were to put the pot for the depth mod: either on the front next to the presence or somewhere on the back. How did the people with the depth mod applied do it? Do you mind posting pictures of your modded amps? Let the modding begin! Still waiting for some remaining parts to be delivered :-) Link to comment Share on other sites More sharing options...
Members GRIMESPACE Posted February 29, 2012 Members Share Posted February 29, 2012 Originally Posted by kocher Thanks for sharing all this information guys!Looking forward to do my first mods: depth mod and clean channel. Think I might go with an On-Off-On switch for the clean channel to be able to switch between 39k and 68k - any thoughts on that?I am still not sure were to put the pot for the depth mod: either on the front next to the presence or somewhere on the back. How did the people with the depth mod applied do it?Do you mind posting pictures of your modded amps?Let the modding begin! Still waiting for some remaining parts to be delivered :-) I located the pot for my depth knob between the Presence knob and Standby switch - centered the hole using the equal spacing from the other pots. Was a little tricky, since the filter caps are right in that area, a little less than 5/8" away from the front panel. I clamped a piece of wood that I had trimmed to just over 1/2" thick to the metal behind where I would be drilling (between the chassis & cap) to prevent me from running through it with my drill. Worked pretty well. I used a smaller pilot bit first, and made sure to cool the bits occasionally with oil, going very slowly and carefully. I used a smaller pot - I think it's the same size as the ones from the factory, and it fitted into the space pretty well. Another thing I did (at least for now) was to remove the NFB wire from the 4 ohm jack rather than cut into it or try desoldering from the board. Since this was my first mod, I wanted to keep it as simple as possible so that I could put it all back with minimal hassle. After pulling the wire back through the zip-tied harness that runs over the board, I folded it back towards the new pot, and soldered it in place. A new piece of wire was then soldered from the pot back to the 4 ohm jack and called it done. Only problem now is that I want to do further mods that will require me to remove the board to desolder components, and my new wire will be in the way. I'm very interested in seeing how Edge and any others have put theirs together. Link to comment Share on other sites More sharing options...
Members kocher Posted March 1, 2012 Members Share Posted March 1, 2012 Originally Posted by GRIMESPACE Another thing I did (at least for now) was to remove the NFB wire from the 4 ohm jack rather than cut into it or try desoldering from the board. That's good to know. I was planning on doing the same thing and avoid soldering on the board when possible. So the cable is long enough to reach the front-mounted pot without extension? Link to comment Share on other sites More sharing options...
Members GRIMESPACE Posted March 1, 2012 Members Share Posted March 1, 2012 Originally Posted by kocher That's good to know. I was planning on doing the same thing and avoid soldering on the board when possible. So the cable is long enough to reach the front-mounted pot without extension? Yeah - the spot on the PCB is close to the front of the chassis - the wire goes from there clear to the back panel. I basically folded it back on itself. If I want to return it to stock layout, it's no problem. If I get a chance, I'll mark up a pic a little later today and post it. Link to comment Share on other sites More sharing options...
Members Edge11 Posted March 1, 2012 Author Members Share Posted March 1, 2012 Originally Posted by kocher Thanks for sharing all this information guys!Looking forward to do my first mods: depth mod and clean channel. Think I might go with an On-Off-On switch for the clean channel to be able to switch between 39k and 68k - any thoughts on that?I am still not sure were to put the pot for the depth mod: either on the front next to the presence or somewhere on the back. How did the people with the depth mod applied do it?Do you mind posting pictures of your modded amps?Let the modding begin! Still waiting for some remaining parts to be delivered :-) Mines on the back, that way I don't have to have a long cable run across the amp. Link to comment Share on other sites More sharing options...
Members kocher Posted March 1, 2012 Members Share Posted March 1, 2012 Originally Posted by Edge11 Mines on the back, that way I don't have to have a long cable run across the amp. Did you keep the cable short in order to reduce negative impact on the sound or to keep the amp as tidy as possible?You think there could be noticable negative effects on the sound of the cable is too long or lies next to certain wires or components?Sorry about all those odd question, but being my first mods I don't want to mess things up too much ;-) Link to comment Share on other sites More sharing options...
Members Edge11 Posted March 1, 2012 Author Members Share Posted March 1, 2012 Originally Posted by kocher Did you keep the cable short in order to reduce negative impact on the sound or to keep the amp as tidy as possible?You think there could be noticable negative effects on the sound of the cable is too long or lies next to certain wires or components?Sorry about all those odd question, but being my first mods I don't want to mess things up too much ;-) To be honest Both. Drilling the hole in the back is also easier. Link to comment Share on other sites More sharing options...
Members kocher Posted March 3, 2012 Members Share Posted March 3, 2012 So I finished my mods today and I want to share pics on how I did it. Here is the clean mod, where I used a on-off-on switch to be able to have 39k and 68k: [ATTACH=CONFIG]343351[/ATTACH] This is my depth mod. I used an additional 0,1 Link to comment Share on other sites More sharing options...
Members GRIMESPACE Posted March 3, 2012 Members Share Posted March 3, 2012 Originally Posted by kocher So I finished my mods today and I want to share pics on how I did it.Here is the clean mod, where I used a on-off-on switch to be able to have 39k and 68k:[ATTACH=CONFIG]343351[/ATTACH]This is my depth mod. I used an additional 0,1 Link to comment Share on other sites More sharing options...
Members kocher Posted March 3, 2012 Members Share Posted March 3, 2012 Originally Posted by GRIMESPACE Great job! How are you liking the mods? Sound clips?Did you pull the board or were you able to do everything topside? The mods are great and definitely recommendable. But I would just for with one resistor und the clean mod as the difference is pretty small. I did not remove the board when I applied the mods. Wasn't much of a problem. Sorry, don't have a proper setup for recording yet. But if I can make it I might post samples next week or so. Link to comment Share on other sites More sharing options...
Members GRIMESPACE Posted March 5, 2012 Members Share Posted March 5, 2012 Well... after much over-thinking and overanalyzing, I went full-bore into a new set of mods. Installed 4 new switches to do the following: Clean/Crunch, switch in/out the bright cap, scoop, and cathode bypass cap. Was a lot of work, and definitely wouldn't have tried tackling that much at once if I had it to do all over again. Everything seems to be working after buttoning it back up - at least I got familiar sound and nothing caught on fire. Just not sure if it turned out right. Is the clean/crunch mod supposed to result in a pretty substantial volume drop? And, is it supposed to affect both the Crunch & OD channels? Also ,what kind of hook-up wire are you guys using? I'm pretty sure what I'm using was way too big (16 awg stranded) for doing stuff on the preamp. I'll try to get some pics up tomorrow. Still LOVING the depth control. Added the .1uf inline cap recommended by Dues, and I think it really did make a difference in scratchiness when changing settings. Link to comment Share on other sites More sharing options...
Members Edge11 Posted March 5, 2012 Author Members Share Posted March 5, 2012 Originally Posted by GRIMESPACE Well... after much over-thinking and overanalyzing, I went full-bore into a new set of mods. Installed 4 new switches to do the following: Clean/Crunch, switch in/out the bright cap, scoop, and cathode bypass cap.Was a lot of work, and definitely wouldn't have tried tackling that much at once if I had it to do all over again. Everything seems to be working after buttoning it back up - at least I got familiar sound and nothing caught on fire. Just not sure if it turned out right.Is the clean/crunch mod supposed to result in a pretty substantial volume drop? And, is it supposed to affect both the Crunch & OD channels? Also ,what kind of hook-up wire are you guys using? I'm pretty sure what I'm using was way too big (16 awg stranded) for doing stuff on the preamp.I'll try to get some pics up tomorrow.Still LOVING the depth control. Added the .1uf inline cap recommended by Dues, and I think it really did make a difference in scratchiness when changing settings. I have the "slo" clean/ crunch, Scoop mod and "slo" bright switch. Link to comment Share on other sites More sharing options...
Members Edge11 Posted March 5, 2012 Author Members Share Posted March 5, 2012 Originally Posted by GRIMESPACE Was a lot of work, and definitely wouldn't have tried tackling that much at once if I had it to do all over again. Everything seems to be working after buttoning it back up - at least I got familiar sound and nothing caught on fire. Just not sure if it turned out right. I did Everything in one day. I've been at the amp game for a while and I can see how it could be challenging for a beginner. Originally Posted by GRIMESPACE Is the clean/crunch mod supposed to result in a pretty substantial volume drop? And, is it supposed to affect both the Crunch & OD channels? Yes and no. Link to comment Share on other sites More sharing options...
Members kocher Posted March 5, 2012 Members Share Posted March 5, 2012 Originally Posted by Edge11 I have the "slo" clean/ crunch, Scoop mod and "slo" bright switch. Edge, could you please add a description the bright switch? IIRC it was just replacing one cap with two switchable ones, right? Is it also possible to apply without the SLO mods? I am definitely interested in applying the SLO mod and the SLO clean but removing the board is what keeps me away from that for now. Link to comment Share on other sites More sharing options...
Members GRIMESPACE Posted March 5, 2012 Members Share Posted March 5, 2012 Originally Posted by kocher The mods are great and definitely recommendable. But I would just for with one resistor und the clean mod as the difference is pretty small. I did not remove the board when I applied the mods. Wasn't much of a problem. Sorry, don't have a proper setup for recording yet. But if I can make it I might post samples next week or so. Kocher - did you find that the volume drops a lot when you engage the clean switch? Which resistor value do you like better - 39k or 68k? Is it affecting the OD channel at all? Link to comment Share on other sites More sharing options...
Members GRIMESPACE Posted March 5, 2012 Members Share Posted March 5, 2012 Originally Posted by Edge11 I did Everything in one day. I've been at the amp game for a while and I can see how it could be challenging for a beginner.Yes and no. Definitely a challenge - figuring out how to route wires, remove the board from the chassis, and locating / drilling holes not for the faint of heart. Best thing was when I found the ground for my output transformer had mysteriously popped loose from the output jacks - not fun to reconnect because the wire was really short.After trying it this morning (bedroom levels), I'm finding the scoop and cathode bypass to be pretty bass-heavy, almost muddy. Did you find the same?What type of hook-up wire are you using? Link to comment Share on other sites More sharing options...
Members kocher Posted March 5, 2012 Members Share Posted March 5, 2012 Originally Posted by GRIMESPACE Kocher - did you find that the volume drops a lot when you engage the clean switch? Which resistor value do you like better - 39k or 68k? Is it affecting the OD channel at all? I didn't have too much time yet to play around yet. But yes, the volume drop a lot, when the clean switch is engaged and even with cranked master you would need to raise the clean pre-amp to get in mid-volume ranges of the overdrive channel. I haven't really decided yet which resistor sounds better but I think I used the 39k most of the time.It's not affecting the OD channel in any way. I verified that by toggling the switch while playing and there was no effect whatsoever.I used a 0.8mm (0.0315 inches) copper wire that is specified up to 900V for the clean mod and for the depth mod I used the cable that was already there and the wire from the capacitor. Link to comment Share on other sites More sharing options...
Members kocher Posted March 5, 2012 Members Share Posted March 5, 2012 Originally Posted by GRIMESPACE After trying it this morning (bedroom levels), I'm finding the scoop and cathode bypass to be pretty bass-heavy, almost muddy. Did you find the same? Have you tried lowering the bass and raising the depth? That helps a lot with my ENGL Powerball which is pretty scooped. Link to comment Share on other sites More sharing options...
Members Edge11 Posted March 6, 2012 Author Members Share Posted March 6, 2012 I'm using 18 ga hook up wire. Nope I find that the scoop mod scoops the mids and the cap boost everything but the mids. Sounds very fenderish. good to hear you guys are digging the mods. Link to comment Share on other sites More sharing options...
Members kocher Posted March 8, 2012 Members Share Posted March 8, 2012 I just found an mod for the SLO100 to bring the FX loop down to 0dBm. The loop looks the same on the JCA100H Can anyone verify this? -Add 1kOhm resistor parallel to R25 -Add 22uF cap parallel to R21 This could be done switchable easily and is going to be one of my next mods Link to comment Share on other sites More sharing options...
Members GRIMESPACE Posted March 8, 2012 Members Share Posted March 8, 2012 Originally Posted by kocher I just found an mod for the SLO100 to bring the FX loop down to 0dBm. The loop looks the same on the JCA100H Can anyone verify this?-Add 1kOhm resistor parallel to R25-Add 22uF cap parallel to R21This could be done switchable easily and is going to be one of my next mods Wow - I like the sound of this. Edge - do you know if that'll work? Link to comment Share on other sites More sharing options...
Members Edge11 Posted March 8, 2012 Author Members Share Posted March 8, 2012 Originally Posted by GRIMESPACE Wow - I like the sound of this. Edge - do you know if that'll work? I'm in class right now, I'll check it out when I'm done. Where did you find the mod kosher? However the loop is part of the slo sound. Link to comment Share on other sites More sharing options...
Members clay189 Posted March 11, 2012 Members Share Posted March 11, 2012 surgery done, depth mod and tube change (JJ 6L6's 12AX7's) new bias setting and this amp is badass. Link to comment Share on other sites More sharing options...
Members clay189 Posted March 11, 2012 Members Share Posted March 11, 2012 ? to anybody who as rebiased their Jca50h, what kinda of plate voltage were you getting and on the bias reading from the factory did it seem really on the low side. Thanks to all. Link to comment Share on other sites More sharing options...
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