JCA OWNERS!!! (RE)JOIN THE JET CITY LOUNGE!!!

[Big John]

Nope, but fixing the loop is next on the list. It's tough to figure out when you have a limited knowledge base to draw from. I know just enough to be an idiot.

[justinjag77]

I just ordered a cheap delay, hope it works

http://www.nuxefx.com/product_detail.ph ... =49&id2=46

[blue25ina]

Hi,

Did anybody here even think to move the loop before the tone stack?

[Big John]

If I'm reading the schemo right (with my amateur brain), the fx loop is one gain stage before the tone stack. I've been doing some snooping, and the instructions for both the Metro and MojoTone loop kits say to insert their loops' send/receive between the treble pot and master. Those instructions don't say anything about going from the treble pot and feeding two masters, but I don't think that would matter much after looking at the JC schemo. Still snooping....

[blue25ina]

If I'm reading the schemo right (with my amateur brain), the fx loop is one gain stage before the tone stack. I've been doing some snooping, and the instructions for both the Metro and MojoTone loop kits say to insert their loops' send/receive between the treble pot and master. Those instructions don't say anything about going from the treble pot and feeding two masters, but I don't think that would matter much after looking at the JC schemo. Still snooping....

i see, you must be have jca50 or jca100. i forgot to mention that i have jca22h which has issue on fx loop. because in jca22h, fx loop is after master level.

for reference, you could see on Laney GH100L schematic, the amp have fx loop after treble pot, before master level pot.

[Promit]

Can someone get me the specs on the JCA100H(DM) transformers? I'm trying to figure out some potential replacements.

[Motocooney]

Hey guys I thought I would post a link to my CL ad here.

I would rather not sell my JCA100 but I Really need the money. Pretty bummed.

It sounds perfect!!!! Everything that should be done to it is done. Please text me 616-617-8694 with any questions.

http://grandrapids.craigslist.org/msg/4535557534.html

Thx!

[justinjag77]

Here is that cheap delay that works in the loop of my JCA5012c
[video]https://www.youtube.com/watch?v=G4F2kPzLo3w[/video]

[Tortuga]

@ Big John - FANTASTIC job on the heater wiring pictorial. Thanks so much!

Question - did the curve you put in for V1 help anything?

[blue25ina]

Hi,

how to remove the the rear panel?i already unscrew the 6 screw, but the board still attached so hard. i'm affraid if i pull it too much i will break the wood. any idea?

[Tortuga]

Hi - welcome to the group. I forgot about the back panel - yep, it seems that they tend to stick together, as you've found. Just gotta dig in and pull. As long as the screws are out, it should release cleanly.

[blue25ina]

@GRIMESPACE : thanks for the greeting. finally, after so much effort i can remove the backpanel.
then i remove the board from the chasis. i replace the supply filter caps Jamicon 22uf & 47uf 450v, with F&T 22uf&47uf 500v.
also i replace coupling caps&tone stack with Orange Drops & Silver Mica, hope this will improve the quality of this amp. next will doing SLO100 Mod , Depth Mod, and Choke Mod

[gorkyporky]

Hi guys, I got my JCA50 head about 3 months ago, and i love it. It's my first tube amp, and im just blown away by the tone of the thing, but i have a few issues. First, I use the amp to gig with my band. I use the crunch channel for cleans and the overdrive channel for rhythm and lead. Now, i didnt know about the weird effects loop before i bought the thing, so my plan to boost the overdrive louder trough that kinda failed. But the list says that the effects loop tolerates MXR Micro Amp and the TC Booster Line Driver. Would putting that in the loop boost my overdrive channel a bit louder as well? Because when i put an overdrive in front of the amp, it just gets more gain and changes the tone, but not the volume. I don't really wanna do any mods to it, since its still in waranty, and i don't really know anything about electronics to mess around with it. I hope this question isnt to "low level" for all the tech talk in this thread . Anyway, thanks in advance.

P.S. I saw that the ZoomG3 is in the list for the loop approved effects. I have one, and i found that it depends on the effect you are trying to use, and at what level your global setting are. Delays, reverbs and stuff like that goes trough pretty well, but the overdrives and distortions just makes the amp sound like its dying.

[Big John]

...the list says that the effects loop tolerates MXR Micro Amp and the TC Booster Line Driver. Would putting that in the loop boost my overdrive channel a bit louder as well? Because when i put an overdrive in front of the amp, it just gets more gain and changes the tone, but not the volume...

You can use a clean boost in the loop for raising the amp's overall volume and it won't change the tone of the amp if the pedal is neutral sounding. Awesome way to bring up solos if the soundman is asleep. Myself, I prefer to go the other way and use a rhythm cut pedal, then kick it off (bypassing the pot) for solos.

Homebrew with RatShack parts...

[Big John]

...did the curve you put in for V1 help anything?

Honestly, I can't tell any difference between the two amps. I was able to get a pretty tight twist on the wires, so maybe that helped?

[gorkyporky]

...the list says that the effects loop tolerates MXR Micro Amp and the TC Booster Line Driver. Would putting that in the loop boost my overdrive channel a bit louder as well? Because when i put an overdrive in front of the amp, it just gets more gain and changes the tone, but not the volume...

You can use a clean boost in the loop for raising the amp's overall volume and it won't change the tone of the amp if the pedal is neutral sounding. Awesome way to bring up solos if the soundman is asleep. Myself, I prefer to go the other way and use a rhythm cut pedal, then kick it off (bypassing the pot) for solos.

So this clean boost would work even with heavily distorted channels and at high volumes? I have my volume for the overdrive channel set at about 6 during practice. Would it still work? I mean this two specific pedals, the micro amp and the line driver?

[sleewell]

Can I join?

[Big John]

So this clean boost would work even with heavily distorted channels and at high volumes? I have my volume for the overdrive channel set at about 6 during practice. Would it still work? I mean this two specific pedals, the micro amp and the line driver?

I think the TC pedal would be the better of the two choices since it supposedly can handle the line level signal that the JCA50's loop operates at. The insert point for the loops on these amps seems to be the biggest headache with folks: pre-eq/pre-master. This is (1) why I use a cut pedal with a 10k pot instead of a boost pedal and (2) why I'm still snooping around to find the best overall fix for the loop.

[gorkyporky]

Just out of curiosity, is there any way to "fix" the effects loop to make it operate like a normal loop? It would just make life so much simpler.

[midnightlaundry]

I've decided that 6L6's are to harsh in the JCA5012C. I think EL34's are the ticket. Has anyone done to mod yet?

[midnightlaundry]

Nevermind, my bias pot has enough swing to bias up the tubes I have, and it's a huge improvement.

The icepick highs are rounded off, the notchy mids are evened out, and the woofy bass is tighter.

[Tortuga]

Glad to hear you were able to work it out. What 6L6s are you running?

I have talked on and off with Jay about doing a couple of mods to enable running EL34s. Everything from SGRs to transformer changes was considered. I posted a vid some time ago where Mike Soldano changed a 50H over to EL34s (I think) with a few component changes - no transformer - so it might be pretty straightfoward. At some point, I'd like to give it a shot. I'll tell you what, though - the slope resistor / voicing mod we did back on the first couple of pages made a huge difference in sweetening the overall tone for me.

[midnightlaundry]

I use JJ's. But I think EL34's sound better. They have a wider breakup and vibe that's better for distortion sounds.

Also, I'm aware that EL34's draw more heater current, but the amp only has 2 power tubes, so I'm not worried about a meltdown. I've changed over 100 watt amps, and never had a problem there either.

[flowmastergfunk]

After getting my Verellen JCA20h, I finally feel at peace with the lack of a silverface bassman in my life.

I still haven't had a chance to do a video comparison between the stock version and the Verellen clean version. Unfortunately, the cabs that I am using have different speakers at the moment. I would very much like to have identical speakers before I make a video, so the comparison is fair and unbiased. (no pun intended as far as tube bias )

I want to get the video done soon though so I can duplicate the mod on the second amp! I can hardly wait to play out of both of them in stereo!

I am also ordering the Hammond chokes for both amps and peripherals for the depth mod as well. I am debating on a recap though.

I was looking into orange drops, and was wondering if anyone had anything good to say about the Viikin version that Mammoth offers. For enough 0.022uF and 0.1uf caps to do both amps, it would cost $6 for the Viikin orange drops from Mammoth and around $35 for the Cornell Dubilier orange drops from Mouser! The Viikin price sounds too good to be true, and the Sprague sounds too good to be afforded! I think if anything, I am just going to replace the ceramic 470p and 120p caps with silver mica caps for now. Those seem like a safe bet and the most likely to offer a noticeable improvement .

[Tortuga]

After getting my Verellen JCA20h, I finally feel at peace with the lack of a silverface bassman in my life.

I still haven't had a chance to do a video comparison between the stock version and the Verellen clean version. Unfortunately, the cabs that I am using have different speakers at the moment. I would very much like to have identical speakers before I make a video, so the comparison is fair and unbiased. (no pun intended as far as tube bias )

I want to get the video done soon though so I can duplicate the mod on the second amp! I can hardly wait to play out of both of them in stereo!

I am also ordering the Hammond chokes for both amps and peripherals for the depth mod as well. I am debating on a recap though.

I was looking into orange drops, and was wondering if anyone had anything good to say about the Viikin version that Mammoth offers. For enough 0.022uF and 0.1uf caps to do both amps, it would cost $6 for the Viikin orange drops from Mammoth and around $35 for the Cornell Dubilier orange drops from Mouser! The Viikin price sounds too good to be true, and the Sprague sounds too good to be afforded! I think if anything, I am just going to replace the ceramic 470p and 120p caps with silver mica caps for now. Those seem like a safe bet and the most likely to offer a noticeable improvement .

Hiya - welcome to the group!

Hopefully Jay, MidnightLaundry, BigJohn, or one of the other regulars will pipe in on this. Caps are definitely something I'm interested in going through at some point. First on my list, however, is to install new heater wiring and probably an external bias & probes.

Please tell us more about the Verellen. This was one of the early modded versions that JCA sold, right? Very interested in any gut shots & details as to what the changes actually comprise.