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

[Mr_You]

Ah ok. I've heard high gain Hot Rod 25 Crunch demos sound pretty close, but not exactly, so I thought it was doable (just a voicing/gain change).

I've been told a couple times (from biased sources) the Decatone Crunch circuit is identical to the SLO-100 Crunch circuit. But when I played one years ago, there was a noticeable difference and I can hear that tone in Decatone Crunch demos online. I was told maybe the amp biasing(???) was the difference between the two. This just confuses me further.

My previously owned purple Decatone also had the very rare DeYoung transformer option, but it probably made no difference compared to a normal Decatone with the Mercury transformer. I bought mine years ago from a former Maryland Soldano dealer. The Crunch channel with the stock 4x12 with X-12000s was incredible, but I prefer the SLO so I sold it.

Looks like in the end I might mod my 100 LTD for a Decatone Crunch and pair it up with my SLO (first), use a Line6 Helix SLO model in the loop, or consider getting another 100 LTD with an SLO mod. Will see how it goes. I don't think I want to take my SLO out of the house, it's my #1 for life.

I like experimenting with high gain. I got an awesome fuzz tone, by running a Supercharger into a Decatone Crunch, and I'd like to hear SLO Overdrive and Decatone Crunch mixed "side-by-side" and one into the other for that fuzz tone. I also have a Hammond XK-3 keyboard organ with tube preamp overdrive that I'd like to run into them.

I'm definitely a Soldano fan and had a period of time where I could compare the SLO, Decatone, Reverb-O-Sonic, and Supercharger. Have never really had bad amp GAS since.

[GuitarBilly]

Yeah they're not identical, the differences are nothing major but they're there.

I have an 100 LTD stock that I like quite a bit. The thing about that amp is it's biased ice cold from the factory. Mine was biased at 7mA (!!!) per tube. That's below the point of crossover distortion. So changing it to around 30mA definitely helps it quite a bit. Made it punchier, clearer and fuller. But I do want to mod it with a depth pot and move the loop after the tone stack. The LTD has a lot of potential with just some minor tweaks.

[Mr_You]

Epic Amplification has made a "Deca-Crunch" mod for the 50/100 Crunch channel. Will report back when I eventually get it and the SLO Overdrive installed.

[GuitarBilly]

Epic Amplification has made a "Deca-Crunch" mod for the 50/100 Crunch channel. Will report back when I eventually get it and the SLO Overdrive installed.

That's cool. Bryce does good work. If anyone can do this, that's him. I am actually shipping my LTD out to be modded by him tomorrow.

[cliffenstein]

I’m officially part of the club...JCA50H owner - LOVE it!!!!!

Are there any mods by where the footswitch doesn’t need to be plugged in to play through the crunch channel?

[Tortuga]

I’m officially part of the club...JCA50H owner - LOVE it!!!!!

Are there any mods by where the footswitch doesn’t need to be plugged in to play through the crunch channel?

Welcome!

I set up a reference on the first 3 postings of this thread (page 1), but see that my links have stopped working... Must be the forum domain change. I'll have to fix those...

Anywho, here's the link to that mod - viewtopic.php?f=53&t=3424&p=59941#p59941

[GuitarBilly]

I’m officially part of the club...JCA50H owner - LOVE it!!!!!

Are there any mods by where the footswitch doesn’t need to be plugged in to play through the crunch channel?

The easiest way is to get a 1/4" plug, remove the cover and solder the 2 tabs together. Then just leave it permanently plugged into the back of the amp. It's what I do when I'm only using the crunch channel.

[cliffenstein]

I’m officially part of the club...JCA50H owner - LOVE it!!!!!

Are there any mods by where the footswitch doesn’t need to be plugged in to play through the crunch channel?

The easiest way is to get a 1/4" plug, remove the cover and solder the 2 tabs together. Then just leave it permanently plugged into the back of the amp. It's what I do when I'm only using the crunch channel.

That’s the ticket...thank you!!!!

[Mamberg Jr]

I wasn’t really digging the Amelia for a second, but all I had to do was turn the volume on my guitar to about 8. Magical

[BleedingWhiskey]

I’m officially part of the club...JCA50H owner - LOVE it!!!!!

Are there any mods by where the footswitch doesn’t need to be plugged in to play through the crunch channel?

The easiest way is to get a 1/4" plug, remove the cover and solder the 2 tabs together. Then just leave it permanently plugged into the back of the amp. It's what I do when I'm only using the crunch channel.

That’s the ticket...thank you!!!!

I used to do the exact same thing, but I kept losing or breaker the 1/4" jack. So this past weekend I installed this switch mod that was original posted by Jay (see link below). It's super simple and he even linked the parts you would need (switch and a shunt tip 1/4" jack), which are also pretty cheap. Like less than $5. I did, however, have to buy a metal tap drill bit, but that was only $20, so it wasn't to bad.

http://www.guitargearforum.com/forum/viewtopic.php?f=53&t=3424&p=59941#p59941

[GuitarBilly]

I’m officially part of the club...JCA50H owner - LOVE it!!!!!

Are there any mods by where the footswitch doesn’t need to be plugged in to play through the crunch channel?

The easiest way is to get a 1/4" plug, remove the cover and solder the 2 tabs together. Then just leave it permanently plugged into the back of the amp. It's what I do when I'm only using the crunch channel.

That’s the ticket...thank you!!!!

I used to do the exact same thing, but I kept losing or breaker the 1/4" jack. So this past weekend I installed this switch mod that was original posted by Jay (see link below). It's super simple and he even linked the parts you would need (switch and a shunt tip 1/4" jack), which are also pretty cheap. Like less than $5. I did, however, have to buy a metal tap drill bit, but that was only $20, so it wasn't to bad.

http://www.guitargearforum.com/forum/viewtopic.php?f=53&t=3424&p=59941#p59941

Yeah the switch is probably the better way to go. The plug is just easier.

You won't break the jack if you remove the plug cover and just use the actual plug. The way I have mine, it doesn't stick out of the headshell at all. You can also use a flat "pancake" plug.

[BleedingWhiskey]

I’m officially part of the club...JCA50H owner - LOVE it!!!!!

Are there any mods by where the footswitch doesn’t need to be plugged in to play through the crunch channel?

The easiest way is to get a 1/4" plug, remove the cover and solder the 2 tabs together. Then just leave it permanently plugged into the back of the amp. It's what I do when I'm only using the crunch channel.

That’s the ticket...thank you!!!!

I used to do the exact same thing, but I kept losing or breaker the 1/4" jack. So this past weekend I installed this switch mod that was original posted by Jay (see link below). It's super simple and he even linked the parts you would need (switch and a shunt tip 1/4" jack), which are also pretty cheap. Like less than $5. I did, however, have to buy a metal tap drill bit, but that was only $20, so it wasn't to bad.

http://www.guitargearforum.com/forum/viewtopic.php?f=53&t=3424&p=59941#p59941

Yeah the switch is probably the better way to go. The plug is just easier.

You won't break the jack if you remove the plug cover and just use the actual plug. The way I have mine, it doesn't stick out of the headshell at all. You can also use a flat "pancake" plug.

I was using the pancake style jacks, but I would either lose it or after a while the tab would break away from the barrel and it would stop working. I mean, it took almost 2 years for one to break, so losing it was more of an issue for me. I lost 4 of them over the 8 years I've played Jet City amps

[Bardagh]

I'm going to perform the elevated heater mod using twisted pair wiring soon because my JCA50H has ungodly hum going on. On that mylespaul forum thread, one guy did this replacing all the traces with the wire, and another guy who sent his amp to Jet City ended up with the same fix but only for v1-v3. It would seem that if this was determined to be good enough by the team at Jet City that it's probably good enough for me, but has anyone compared the results? Like has anybody done the v1-v3 and still had hum and found they still needed to do the whole shebang?

I don't want to do any more sitting around clipping traces than I have to, but if it's necessary to do them all I'd rather do it in one go.

[Tortuga]

I'm going to perform the elevated heater mod using twisted pair wiring soon because my JCA50H has ungodly hum going on. On that mylespaul forum thread, one guy did this replacing all the traces with the wire, and another guy who sent his amp to Jet City ended up with the same fix but only for v1-v3. It would seem that if this was determined to be good enough by the team at Jet City that it's probably good enough for me, but has anyone compared the results? Like has anybody done the v1-v3 and still had hum and found they still needed to do the whole shebang?

I don't want to do any more sitting around clipping traces than I have to, but if it's necessary to do them all I'd rather do it in one go.

I did the elevated heater mod to all 5 of my 12ax7s by cutting the traces and wiring in twisted bell (solid core) wire. Honestly, I don't think it made a massive difference in the amount of hum/noise, and I wish I hadn't done it, as I feel that I've somewhat weakened the amp's integrity/reliability and probably wouldn't feel good selling it at this point.

There were a couple of postings about changing the heaters over to DC (see the list of links I posted in the first three of this thread on page 1), and I think that's probably got a lot more merit than doing the elevated heaters, especially if this is an amp that you intend to gig and/or sell.

[Bardagh]

Yeesh, that seems like something I wouldn't want to do if I was going to sell it, personally. Rigging up a PSU seems a lot more dubious to me than replacing traces with solid wire, even if it is more effective. Honestly, I paid $250 for this and if it's just gonna hum like this I'll probably hang onto it until I track down another amp or two in the next couple months, then sell it off for about what I paid.

On an unrelated note, the glass on one of the 6L6's totally and suddenly separated from the base of the tube earlier. Never had that happen before, but I had another matched pair to pop in and all SEEMS fine...

[Tortuga]

Are you certain that the hum is all the amp? Do you have another amp you can plug into same outlet and put in same place to see if you're not getting interference from noisy circuits / lights / etc?

[Bardagh]

Are you certain that the hum is all the amp? Do you have another amp you can plug into same outlet and put in same place to see if you're not getting interference from noisy circuits / lights / etc?

I have plugged the amp into a few different circuits in my house it sounds the same all over. It's present on the Crunch channel too, but much lower. If you put the preamp all the way down and crank the volume you don't hear it on the Crunch, but as soon as you engage some preamp it's there, and it gets fairly audible at high volume levels with any decent amount preamp gain, but it is a fractional of the noise present on the OD channel. Strangely the hum/buzz doesn't come across nearly as loudly on a miked signal as it seem in the room. I think because it probably isn't actually all that loud compared to the actual sound of the amp - it's just such an annoying sound! It would make a good sound effect of someone being electrocuted in a cartoon or something.

[Tortuga]

I was talking to an engineer some time ago about this, and he recommended getting a ferrite core to attach around the power cord. That's not something I'd heard before, but this guy knows his shit. They're used as noise suppressors for a lot of other stuff, so why not this???

I recommend giving one of these a try. They're cheap, super easy to install/remove, and might just take care of a lot of the issue.

This is what they look like. Just search "ferrite core" or "ferrite clamp-on core"

[Bardagh]

I was talking to an engineer some time ago about this, and he recommended getting a ferrite core to attach around the power cord. That's not something I'd heard before, but this guy knows his shit. They're used as noise suppressors for a lot of other stuff, so why not this???

I recommend giving one of these a try. They're cheap, super easy to install/remove, and might just take care of a lot of the issue.

This is what they look like. Just search "ferrite core" or "ferrite clamp-on core"

Well yeah those are for suppressing EMI which is why you may see them on things like USB cables. I really don't think that's what is going on here, although I have a bunch of them in a box somewhere so I could try it for shits and giggles, but if it worked I would be very confused about how and why.

[Tortuga]

Dude - try one out and PLEASE let us know if it makes any difference

[Bardagh]

Will do. I'll report back with my findings.

[GuitarBilly]

I'm going to perform the elevated heater mod using twisted pair wiring soon because my JCA50H has ungodly hum going on. On that mylespaul forum thread, one guy did this replacing all the traces with the wire, and another guy who sent his amp to Jet City ended up with the same fix but only for v1-v3. It would seem that if this was determined to be good enough by the team at Jet City that it's probably good enough for me, but has anyone compared the results? Like has anybody done the v1-v3 and still had hum and found they still needed to do the whole shebang?

I don't want to do any more sitting around clipping traces than I have to, but if it's necessary to do them all I'd rather do it in one go.

What tubes are you using? This amp is very sensitive to tubes. I recently helped someone troubleshoot their amp and he found out that the amp was humming every time he put JJ's in any position.

I'd recommend Sovtek 5881 power tubes and a Sovtek LPS in the PI, with Chinese tubes in the other preamp positions.

[Bardagh]

It came with Ruby 6L6GC (now has another pair of the same) and all Chinese 12ax7. The ones in V1 and V2 are the "HG" ones selected for low noise etc.

I've swapped around all kinds of preamp tubes and I don't know that I can say it made any difference one way or another.

[Bardagh]

Well I hate to tell you this but putting a ferrite bead on the power cable does nothing. It really wouldn't have made sense if it did, so in a way I'm glad.

[GuitarBilly]