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

[mrfret]

That Amelia looks sweet!

[calgaryben]

This thread has been so helpful for my Jet City setup, especially the effects pedals list. So thanks!

I have recently picked up another JCA100. The one at the practice space has always been stock. But I'm looking to mod this one.
Here's a few things about the amp I'd like to change:

* Make the Crunch channel cleaner
* Tighten up the Overdrive channel, and get rid of some of the flubbyness
* Smooth out the Overdrive channel, making it more defined
* Add a Depth knob

I'm generally playing thrash / death metal. The amp has a great bullish tone, that hits like a train. I don't want to change that so much. I like that it doesn't sound like a 5150 or Recto. I'm currently using it with a Maxon OD808, and have been considering adding an MXR 10 band EQ in the loop, but if the mods can help instead, that'd be better.

What mods are going to help with this?

Any help greatly appreciated.

[Mochi]

Hi all,

Just came to give some feedback on speakers with the JCA50, I really wasn't digging the V30s with this amp, just too much of everything frequency wise (V30s have always been hit or miss for me) anyways, so I got myself a celestion BN12-300s, which is a bass speaker, but is said to be somewhere in between a C90 and an EVM12L, for those interested in what it sounds like (for high gain) here's a video, the only modification i've done on the amp except tube swapping and biasing is I clipped C21 and C28 :

[video]https://www.youtube.com/watch?v=6yzymktWOvs[/video]

[Tortuga]

Doesn't sound too shabby

Kinda backs up my original view of the 50H, though - OD gain above 11:00 just gets tubby and whooly - not my kinda thing.

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@Sahl - when are we gonna get to hear that Amelia & 45?

[esizer]

I'm planning on swapping the depth switch for a depth knob on my JCA20HV...it seems like this would be a straight swap, no?

[Hipster Salad]

Doesn't sound too shabby

Kinda backs up my original view of the 50H, though - OD gain above 11:00 just gets tubby and whooly - not my kinda thing.

----------------------------------


@Sahl - when are we gonna get to hear that Amelia & 45?

Yeah stock the gain gets muddy past halfway on the 2 channel JCA amps (22H, C22, 50H, 100H, HDM). Change the pots to 500k (like the SLO has) and it's more usable.



Here's a few quick clips I recorded over the last couple weeks. Just haven't had much time to sit down and get proper recordings lately.

Amelia -
[video]https://youtu.be/F_0MVZ5DExo[/video]

[video]https://youtu.be/9945h50SKJ4[/video]

[video]https://youtu.be/emeKT9P_LWQ[/video]

direct recording with Celestion IR:

https://app.box.com/s/0qnusnkrchj5zlfx6k0gh24pprm457ct

modded JCA45 -

[video]https://youtu.be/8F-9zakesEk[/video]


The JCA45 is at HvyMtl's house so I haven't had it for a few weeks lol

[Hipster Salad]

I'm planning on swapping the depth switch for a depth knob on my JCA20HV...it seems like this would be a straight swap, no?

Yup. The switch probably goes from two different values. Take the resistor completely out and do a standard depth control as outlined in the first page if memory serves. I did it on my Friedman modded 20H instead of keeping the value Friedman put in. Much prefer the depth control basically on any amp. PM me on FB if you need help brosef.

[esizer]

I'm planning on swapping the depth switch for a depth knob on my JCA20HV...it seems like this would be a straight swap, no?

Yup. The switch probably goes from two different values. Take the resistor completely out and do a standard depth control as outlined in the first page if memory serves. I did it on my Friedman modded 20H instead of keeping the value Friedman put in. Much prefer the depth control basically on any amp. PM me on FB if you need help brosef.

Thanks dude! I'm assuming I'll have to ream the existing cutout for the pot to fit...but it I just wanted to make sure my logic was sound before I got too serious about it.

[Hipster Salad]

This thread has been so helpful for my Jet City setup, especially the effects pedals list. So thanks!

I have recently picked up another JCA100. The one at the practice space has always been stock. But I'm looking to mod this one.
Here's a few things about the amp I'd like to change:

* Make the Crunch channel cleaner
* Tighten up the Overdrive channel, and get rid of some of the flubbyness
* Smooth out the Overdrive channel, making it more defined
* Add a Depth knob

I'm generally playing thrash / death metal. The amp has a great bullish tone, that hits like a train. I don't want to change that so much. I like that it doesn't sound like a 5150 or Recto. I'm currently using it with a Maxon OD808, and have been considering adding an MXR 10 band EQ in the loop, but if the mods can help instead, that'd be better.

What mods are going to help with this?


I modded a friend's 22H (same preamp) to have a cleaner Crunch channel. Simple mod - add a resistor (I forget the exact value but you can play with different ones) to the wiper of the Crunch gain pot and send it to ground.
Any help greatly appreciated.

I would suggest doing the SLO mod, and that will likely address your goals on the Overdrive channel. I was very fond of what it did to my 100H. Depth control is a must-do. My first attempt at amp modding was the SLO mod, and I was very 'green' and uneducated to amp circuitry back then, so don't let it intimidate you. Just as long as you take the necessary steps to discharge the capacitors and understand the LETHAL VOLTAGES you could possibly be working with.

As far as making the Crunch channel a little cleaner, I modded my buddy's 22H (same preamp) to have a little cleaner Crunch channel by putting a resistor (I forget what value) on the Crunch gain pot's wiper and sent it to ground. You can play around with how much signal you take away to suit what you're after. There may be a much better way of doing it, but that's the route I went.

[Hipster Salad]

Sorry bumping this post but where did you get that Custom 22 Schematic ? Something looks weird to me .001 coupling cap with the same cap to ground just behind after 3rd gain stage of OD channel ?

Thx

Bruno

I don't think that anyone has the Custom 22 Schematics ))

who can help me to tame down the gain on the Lead channel?? I've Already changed the R6 from 220k to 110k (switchable) and changed the Slope resister (R26) from 47K to 33k (Marshall feel, also switchable). I want to make it a bit more Marshall flavor.

Also cut the C6 but it made it too much of a dark amp. What value for the C6 (Bright cap) do you guys recommend??

Thank You!!!



Here it is after the mods

Here is what Martin Kidd suggested for reducing gain to a more acceptable level (relayed to me via Doug):

"R17, change to 680K from 470K; R18, change to 220K from 470K and remove C57 which is a 470pF across R58"

I did that to mine yesterday (I actually have a prototype Custom 22), and it did the trick VERY well.

[Mochi]

Doesn't sound too shabby

Kinda backs up my original view of the 50H, though - OD gain above 11:00 just gets tubby and whooly - not my kinda thing.

In a live/rehersal setting I like the gain at somewhere between 5 and 6 coupled with the right overdrive to tighten it up a bit, it gives a nice chugga chugga , though for recording yeah it becomes too mushy, but then I guess it depends what your going for

I'll most certainly give the 500k pots a go though.

I'm really happy with this amp overall, nothing that I really want to change on it, and i've really been searching for what I want to mod. It has made me want to pick up a hot rod +

[Also Lime]

Greetings! The names Lime...Also Lime and cheesy introductions aside. I'm here because I've been on the look out for a new amp for quite some time, and eventually I found this thread and it really has helped sell Jet City to me. I'm also here to try and tap into the experience that you folks have with these amps so I can be as sure as I can possibly be that the amp I go for is the right one for me.

My original idea was to pick up either a 22H or a Custom22, pair it with a 1x12 cab and be done with, but I became concerned about the relative lack of headroom 20 watts provides, especially with an amp that doesn't technically have a clean channel. I do typically play on my own, but I do also have the opportunity to jam with another axe wielder and a particularly loud drummer, and it's that that has made me consider going up in wattage to be sure of getting past the amp with the sticks . Which made me think "okay let's go for the 100HDM, it sounds awesome and has headroom for days", I was all set to go down this route right up until I remembered the Amelia, which seems like a really interesting amp and I'm hoping you guys can shed some more light on it.

I do know it has a clean channel and a lead channel, both with their own EQs, that part I understand, what is confusing me somewhat though is the overdrive knob, would I be correct in saying that this is like an overdrive pedal built straight into the amp or is it different? I'm a total novice when it comes to electrical engineering which is something I want to get experience in as the idea of modding my own amp really appeals to me, but I digress.

The Amelia also has two master volume controls, do they work with both channels? I'm making the assumption that you can set one just that little bit higher than the other and then footswitch them as a solo boost type deal? I know to a lot of the guys here that do know about mods and can read those schematics I probably sound like a real dumbass, but any help you guys can give me would be much appreciated. I guess the other thing I really would like to know is, for a guy like me that likes playing a lot of different stuff from blues, to rock, 80's thrash up to some more modern metal and whos tastes tend to run a bit more to the "British" side of things, what amp is right for me? I know they're all good and that's kinda the problem, this would be so much easier if one of them was awesome and the rest sucked but I haven't heard a bad tone come out of anything with the Jet City logo on it

Thanks again to anyone who made it to the end of that, you rock!

[GuitarBilly]

Welcome!!!! As for your questions:


No the overdrive know is just the amp's own preamp gain. But yes, it's kind of like an OD pedal in the sense that the higher you set it the more distortion you get. But it's all part of the preamp circuit.

The 2 master volumes do work for both channels. The idea is you set one for your rhythm sound and the second a bit higher for your leads and switch between the 2.

[Also Lime]

Cheers GuitarBilly! So would I be right in saying that the overdrive control is like an optional extra tube gain stage for the lead channel? If so that seems pretty awesome as it should still give the option to stick a tubescreamer or the like in front of it if you really need to melt some faces.

Ah now I understand how the master volumes work, sometimes takes me a bit longer to wrap my luddite head around these things . Seems like the Amelia has versatility in spades though, I'm very impressed.

[Hipster Salad]

It's not an extra 'tube' gain stage, but yes it's like adding an additional gain stage. Of course you can still add a Tubescreamer type pedal in front of the amp and use it on top of the Overdrive function. It's pretty versatile, and I really dig mine.

[Also Lime]

Thanks for the input Sahl, I seen that you posted some clips of it in action, really appreciate it people take the time to do that, it's really cool.

[sefloval]

WOW this thread is still going!
After owning the JCA50 head for a year now, I thought I'd chime in on what I've found. Some of you are overthinking this amp with mods . A Boss EQ in the loop to taste and a Boss SD-1 on out front (gain 0, level all the way up and tone where you want it) sounds killer. I've been playing it live with my band and currently using it in the studio recording our album. The EQ gives it some more low end/chunk that was missing and the SD-1 keeps it tight with a little bit more bite....perfect combination....for me. A great solid workhorse of an amp!

[Also Lime]

That's a really good point actually Sefloval! I know I'm often guilty of over thinking things, especially when it comes to gear. I'm leaning more and more towards picking up a 100HDM cause it just seems like such a ridiculous amount of amp for the money. The only quirk I can think of is the fx loop which I understand is line level which can cause some issues with certain pedals. I see that the OP of this thread has a list of pedals that do work, which is awesome, but would I be correct in assuming that if a pedal has been shown to work well with a Soldano amp, then it should work well in a Jet City fx loop also?

[sefloval]

I haven't had a pedal NOT work in the loop so far. The loop is kinda weird with this amp as it sounds better with something in the loop than without. If I play it without something in the loop it sounds a little ratty on the top end. The EQ in the loop is a night and day difference of the tone. Way more full and clear sounding with a nice round bottom end on the clean channel. All my TC Electronic pedals seem to do well in the loop as well. Would like to try the 100 HDM. If you pick one up definitely share your thoughts on it.

[heavyredmetalneck]

Hey guys! I converted my JCA50H to EL34s. I'm digging' it

[video]https://youtu.be/nIJ5Ws6L0vI[/video]

[Jim999]

Hi guys and gals. My story....

Ok so I got a JCA 20h gave it to a amp guy to do this mod - http://s150.photobucket.com/user/TnP...d%20-%20JCA20H

Got it back and it sounded awful.

Took it back. He checked it all out and he is confident that it's exactly as the mod says. It cost me £180gbp for the mod.

He still has the amp but he's tearing his hair out trying figure out the problem.

Any help advice welcome

Jim

[kaoslord]

Hi All,

I have strange problem in my JCA100.
I was wondering if you had ever noticed the same thing or not.
try to do this: both gains at 0, rise the master volume up.
you will notice that the level of hum in the lead channel is huge compared to the clean that is very quiet.

now, I was trying to troobleshoting this, and i have removed the C24 (coupling cap of the 2nd stage) to check whether it was a leaking cap.

big surprise: if I increase the OD gain, i can hear the sound coming from the guitar, eve nif at vey low volume.
how can it be ???

a leaking board ? interference between the OT and the 2nd tube ?

[Hipster Salad]

Jim999 - we're talking on FB so hopefully we'll get it worked out.

[Hipster Salad]

I've done some mods to my JCA45 (JTM45 clone) to get it close to what I refer to as "EVH specs", plus a little extra. I originally did the 'one wire mod', but it was just too much gain for what I was after, and I did IMO take away from the 'plexi' feel of the amp. So I removed it and tried a more traditional approach to goosing it a little.

I converted the shared V1 cathode to split (I may revert back to shared but I dunno), changed the NFB resistor to 47k (it was 27k stock!!!!), added the Jet City HV solid state effects loop, Channel 1 bypass cap to .0022uf (.022uf stock), added a PPIMV, and tomorrow will change the fizz cap to 100pf (47pf stock), and a solid state rectifier plug-in. Also have a 50 watt OT coming in to properly convert to EL34.

Stock:




Here's what my board looks like as it sits now:

[Tortuga]