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

[Jay]

Yes, those are some of them. Try some different tubes, and if you still need a change, we can guide you along to what you might like.

[murph100]

Hey Jay,

Lowering the value of some of the coupling caps and slightly increasing the peakers will add clarity, or if you want to get nuts, I'll go over a huge (but easy) mod to really add some scream.

Sounds great, soldering iron ready & waiting for the huge ( but easy ) mod !!

Would this be in addition to the SLO mod ?

[Jay]

No, this is a totally different beast all together. I'll post a thread in the DIY section later about it. I have done it to the 22H, but not the bigger brothers. I'm trying to convince my buddy to let me do it to his 100H to see how it turns out.

I will say, not a whole lot of the JCA/Soldano tone will be left after the change.

[murph100]

Hmmm ... I guess I can always reverse it. I'm looking for more 'grind' on the OD channel, the Crunch channel is miles ahead for that mid bite.

So would this mod give me that ?

[Jay]

First off, I am not taking any credit for this mod. A friend of mine asked me to make his 22H more Marshally, so I used some values from one of my favorite hotrod Marshall amps and they happened to really jive with this amp. It will definitely bring some grind and scream, rather than the bark that the JCAs have going on.

This will only be for the OD channel.

Change R9 to 475k
Change C5 to 1n or 2n2 (I kept it as 1n, but 2n2 also works nice)
Remove C6 or put it on a toggle for a "bright" switch
Change R16 to 2k7
Change R17 to 475k with a 1n cap in parallel
Change R18 to 68k
Change R23 to 2k7
Change R42 to 68k
Change C21 to 680n

These positions are for the 22H only.

[mjtripper]

I bought one of the jca2212 on sale recently and it looks to be a newer board design. The traces are covered on both sides, components are moved around, and traces have different paths.

[neilrocks25]

Does anyone know any tonestack mods to get the JCA20 more marshally sounding?

[Tortuga]

Does anyone know any tonestack mods to get the JCA20 more marshally sounding?

Neil, check page 2 & 3 of this thread - a couple of us added a 33k slope resistor and a switch to change the stock value (47k) for a bit of that sound. I really like it, and pretty much always leave it set that way now.

I think Jay had some good advice a few pages back, too. Hopefully he'll be along soon

[mjtripper]

The big ones are the 33k slope as already mentioned, change the cold clipper to 10k and the treble peaker to 470k/470p. You will probably have to reduce some gain here and there, I usually take the 470k-1m before the cold clipper to 470k-470k and add a 220k in seres right after c11. Those will get you close with the least effort. For a little more modern but still marshally sound I prefer a 39k slope with a 470k/1000p treble peaker. If you get too much fizz I like to run the first three coupling caps in the OD at 1n, 2.2n, and 4.7n.

[jhall]

As much as my newer ( I got rid of a JCA 2112 RC) JCA 2212C sounds miles better than the previous one,
I almost never use it now. Yes it sounds most excellent no doubt. I should be using it more and at least break in the speaker.
It is sitting on my "small amp" shelf next to my modded Marshall Haze 40 combo with a V-30 and a few excellent circuit mods,
and a homebrew Marshall 18 watt clone I built on top of a homebrew 2x12 with a pair of brandy new Emenence GB 128 cones . And a
Vox AC15C-1. I find myself just not turning on the JCA now but it IS definitely a great amp with killer sound.

[mjtripper]

To kill the channel bleed on the jca2212, which has a different board then the jca22, you have have to move the relay connection from the 3rd stage grid to the 2nd stage grid. This lets you turn the normal into a true clean channel since the od won't bleed into it anymore. I have a post a few pages ago on how to do this with the jca22 board. Here is how to move the relay connection for the jca2212:

[randumb.tune]

The following list of effects found to be compatible with the JCA effects loop was compiled by GuitarBilly74. I'll continue to update / modify the list as needed.

Modulation:
Eventide Mod Factor
Eventide Pitch Factor
TC Nova Modulator
TC Vortex Flanger
TC Shaker Vibrato
TC Corona Chorus
TC SCF Stereo Chorus Flanger

Delay:
Hardwire Delay
TC Nova Delay
TC Nova Repeater Delay
TC Flashback
Boss DD-20
Tech 21 D.L.A/boost
Eventide Time Factor

Reverb:
Hardwire Reverb
TC Hall of Fame Reverb
Blue Sky Reverb
TC Nova Reverb
Eventide Space
Tech 21 RVB

Add BYOC-Reverb2 to that list.
And also TC Electronics Ditto works fine. And I also confirm that the TC-Electronics Flashback Delay And Looper works fine too.

EHX-Nano Small Stone, works somewhat OK in Crunch-channel, but not in Overdrive-channel. But sounds better in front of the amp.

I got my JCA100HDM today, running in with a FRAMUS-2x12 Cabinet with Celestion V30, and also got a few effect pedals hooked up too :

https://www.facebook.com/photo.php?fbid ... 613261634a

[neilrocks25]

Does anyone know any tonestack mods to get the JCA20 more marshally sounding?

Neil, check page 2 & 3 of this thread - a couple of us added a 33k slope resistor and a switch to change the stock value (47k) for a bit of that sound. I really like it, and pretty much always leave it set that way now.

I think Jay had some good advice a few pages back, too. Hopefully he'll be along soon

Ok sweet

[neilrocks25]

The big ones are the 33k slope as already mentioned, change the cold clipper to 10k and the treble peaker to 470k/470p. You will probably have to reduce some gain here and there, I usually take the 470k-1m before the cold clipper to 470k-470k and add a 220k in seres right after c11. Those will get you close with the least effort. For a little more modern but still marshally sound I prefer a 39k slope with a 470k/1000p treble peaker. If you get too much fizz I like to run the first three coupling caps in the OD at 1n, 2.2n, and 4.7n.

Thanks for the info I will check what the resisters are on the JCA20 (it's the 1 channel combo Jca2012rc)

[mjtripper]

The big ones are the 33k slope as already mentioned, change the cold clipper to 10k and the treble peaker to 470k/470p. You will probably have to reduce some gain here and there, I usually take the 470k-1m before the cold clipper to 470k-470k and add a 220k in seres right after c11. Those will get you close with the least effort. For a little more modern but still marshally sound I prefer a 39k slope with a 470k/1000p treble peaker. If you get too much fizz I like to run the first three coupling caps in the OD at 1n, 2.2n, and 4.7n.

Thanks for the info I will check what the resisters are on the JCA20 (it's the 1 channel combo Jca2012rc)

Oops, sorry - misread your post and thought you were talking the jca22. For the jca20 which has one less gain stage there are two options I like, one is pretty much match the preamp to a jcm800 but for more gain you can take the three cathodes to 1.8k/1uf with 4.7nf and 10nf couplers, change the resistor right before the gain pot to 470k and right before the 3rd stage use 470k/470p-470k for a brighter sound or just 470k-470k for something a little more neutral which is what I prefer. If I can find my notes I can give you the actual resistor and capacitor numbers on the board.

[neilrocks25]

The big ones are the 33k slope as already mentioned, change the cold clipper to 10k and the treble peaker to 470k/470p. You will probably have to reduce some gain here and there, I usually take the 470k-1m before the cold clipper to 470k-470k and add a 220k in seres right after c11. Those will get you close with the least effort. For a little more modern but still marshally sound I prefer a 39k slope with a 470k/1000p treble peaker. If you get too much fizz I like to run the first three coupling caps in the OD at 1n, 2.2n, and 4.7n.

Thanks for the info I will check what the resisters are on the JCA20 (it's the 1 channel combo Jca2012rc)

Oops, sorry - misread your post and thought you were talking the jca22. For the jca20 which has one less gain stage there are two options I like, one is pretty much match the preamp to a jcm800 but for more gain you can take the three cathodes to 1.8k/1uf with 4.7nf and 10nf couplers, change the resistor right before the gain pot to 470k and right before the 3rd stage use 470k/470p-470k for a brighter sound or just 470k-470k for something a little more neutral which is what I prefer. If I can find my notes I can give you the actual resistor and capacitor numbers on the board.

wow thanks, great info and any notes you might have would be very helpful.
Much appreciated.

[keto]

Just a quick note about the JC 1x12 cab. I don't know what the magic is but, in my band situation, it mics up REALLY well and sounds hella better than another 1x12 that I have used with 4 different speakers - a Greenback, a 12-65, a WSG Invader and (I'm losing my mind and forget offhand).

I've used the JC 1x12 with the JCA22, a JCM900 MK III, a DSL50, and my TriWatt (22W Hiwatt clone). It sounds good in the room but sometimes not better than the other speakers/cab above, but EVERY TIME I stick a mic in front of it, it wins handily.

[Tortuga]

Just a quick note about the JC 1x12 cab. I don't know what the magic is but, in my band situation, it mics up REALLY well and sounds hella better than another 1x12 that I have used with 4 different speakers - a Greenback, a 12-65, a WSG Invader and (I'm losing my mind and forget offhand).

I've used the JC 1x12 with the JCA22, a JCM900 MK III, a DSL50, and my TriWatt (22W Hiwatt clone). It sounds good in the room but sometimes not better than the other speakers/cab above, but EVERY TIME I stick a mic in front of it, it wins handily.

Welcome, and thanks for the info. Just to clarify, this is the JC cab with the stock (Eminence) speaker, right?

[Tortuga]

The following list of effects found to be compatible with the JCA effects loop was compiled by GuitarBilly74. I'll continue to update / modify the list as needed.

Modulation:
Eventide Mod Factor
Eventide Pitch Factor
TC Nova Modulator
TC Vortex Flanger
TC Shaker Vibrato
TC Corona Chorus
TC SCF Stereo Chorus Flanger

Delay:
Hardwire Delay
TC Nova Delay
TC Nova Repeater Delay
TC Flashback
Boss DD-20
Tech 21 D.L.A/boost
Eventide Time Factor

Reverb:
Hardwire Reverb
TC Hall of Fame Reverb
Blue Sky Reverb
TC Nova Reverb
Eventide Space
Tech 21 RVB

Add BYOC-Reverb2 to that list.
And also TC Electronics Ditto works fine. And I also confirm that the TC-Electronics Flashback Delay And Looper works fine too.

EHX-Nano Small Stone, works somewhat OK in Crunch-channel, but not in Overdrive-channel. But sounds better in front of the amp.

I got my JCA100HDM today, running in with a FRAMUS-2x12 Cabinet with Celestion V30, and also got a few effect pedals hooked up too :

https://www.facebook.com/photo.php?fbid ... 613261634a

Hiya, and thanks for the input. I have one of those Flashback delays, and keep meaning to try it in the loop of my JCA50 (had been running it with my Fender Pro Reverb at church). I also have a Small Clone, and had similar results to what you report with the Small Stone. I think we need to make a list of pedals that do not work...

I'll get the list updated with your input.

[Tortuga]

I'm also adding the Line6 POD HD500X to the list, which appears to work really using the 4-cable method from my initial testing. I've also done a quick test with my MXR Micro Amp and old TC BLD (before it quit on me) for a clean boost, and it seemed to work pretty well for leads. I'll do more testing when I get my studio up and report back then.

[keto]

Just a quick note about the JC 1x12 cab. I don't know what the magic is but, in my band situation, it mics up REALLY well and sounds hella better than another 1x12 that I have used with 4 different speakers - a Greenback, a 12-65, a WSG Invader and (I'm losing my mind and forget offhand).

I've used the JC 1x12 with the JCA22, a JCM900 MK III, a DSL50, and my TriWatt (22W Hiwatt clone). It sounds good in the room but sometimes not better than the other speakers/cab above, but EVERY TIME I stick a mic in front of it, it wins handily.

Welcome, and thanks for the info. Just to clarify, this is the JC cab with the stock (Eminence) speaker, right?

Yeah, the stock Emi. I've read good and bad opinions about it, but have enough amps (see above) run thru it to form my own opinion. I was running my DSL50 through it tonight, it was sorta meh. But I used that amp + cab at band jam a couple weeks ago, which we recorded, and it sounded...splendid

[mjtripper]

I found a very simple way to get rid of that loud pop for the standby switch on the picovalve. It's how the switch is connected on some other soldano and jca amps where it's before the choke instead of after the last filter cap.

1. Remove the two wires from the standby switch and unsolder them from the board.
2. Use a small wire to jump the two solder pads for the switch on the board.
3. Unsolder one side of the choke at the l1 connection which is the one closest to the transformer side.
4. Solder that choke wire to one of the standby switch lugs.
5. Connect the other standby switch lug to that l1 choke connection on the board.
6. Enjoy your new pop-less standby switch

[mjtripper]

I didn't see that anybody had posted an updated schematic for the picovalve so here is one I put together a while ago. Some of the values might still be wrong but at least the signal path and component names printed on the pcb are corrected instead of using the univalve ones. This is from tracing out the one I have that I've done mods to.

[JohnB]

i got a 2212 during the 299 sale & the combo had a problem that affected both channels - drop-out & crackle sounding like it was going on standby. but it was intermittent - when it worked i liked the amp. suspected tubes, but a full swap did not fix it - so it went back on exchange. Just got the replacement & it does the exact same thing - except it isnt intermittent. what the heck?

edit: reseated tubes & it seems happy now. i dont believe in 'wiggle it' fixes so i suspect a crappy solder joint is still sitting in there. monitoring .....

edit2: .... and no good. worked for a while, but then started dropping out. going back.

edit3: .... got 3rd one & it works out of the box. monitoring .....

edit4: .... used #3 a couple weeks & it started making noise. opened up for tube swap & sure enough colorful tube fail:



replaced with the JJ set I had purchased earlier & found out that one of those was arcing out of the box. no tube returns at the place i bought them

what a chore. working with an unmatched set now with new JJs on the way.

[randumb.tune]

Looper:
TC Ditto Looper

Hey Mr Grimespace, sorry for this, but please strike off the Ditto Looper, it works all right only for clean stuff on Overdrive channel there is big volume drop, I've been talking with the support at TC, and they told me that there is a soft-clipper that clips the level if input level is too high. Due to Christmas vacation most of their staff is absent currently, but they might introduce a new firmware update latter, when they have arrived upon a feasible solution to this issue. But for now, you can remove Ditto-looper from the list. I will report back when there any updates regarding this.