ShortScale.org

Ceriatone JCM800 2204 HW
http://www.ceriatone.com/productSubPage ... 0_2204.htm PROBLEM
Volume sometimes stays very low and then seems to intermittently work properly after being on for some time. Owner contacted Ceriatone and was told to check solder joints on V3.

DIAGNOSIS
Found Lo input jack faulty. The jacks are Cliff 501 1/4" mono switching jacks (Cliff brand from UK). Hi input runs through Lo input and when plug is inserted into Lo, it breaks the signal from Hi. The Lo jack's contacts where not making a proper connection when the plug was removed, therefore keeping the Hi input disconnected at all times.

I attempted to remedy the mechanical operation of the Lo jack but a plastic tab that keeps the metal contact in place has broken and causes the metal piece to slide up and away from the other contact point. Part will need to be ordered for a proper fix.

PARTS
Cliff 501 jack from Tubedepot.com is $2.45 plus shipping.
> http://www.tubedepot.com/p-cl-501.htm

A similar, perhaps better, Neutrik jack from Partsexpress.com is $1.06 plus shipping. I will order a few Neutrik jacks and replace both jacks on the amp if these seem more reliable.
> http://www.parts-express.com/pe/pshowde ... 2&scqty=10


TO BE CONTINUED...

Exciting.

Mike wrote:Exciting.

I'm not sure of the tone of that, but I think I'm going to post every amp repair i do on here, just so people can find junk on google and LEARN.
Also, I should be able to get some SONDKLIPZ.

No I'm genuinely excited mate, you know me better than that. I love all your repair journals and you seem to be doing a cracking job of debugging this stuff.

I'm amazed it broke in the first place to be honest, I've always thought they make really solid stuff, and the gutshots are beautiful. Plus - I have a 2204. Great, great amps.

FIX'D!

Got the new jacks in, they're way more solid than the original ones, and cheaper here in the States. Will try to get a good comparison shot.

The only other thing wrong was the V1 preamp tube was bad. Hence no signal from the Hi input (Lo input bypass that tube for clean sonds).


It sounds really good, definitely gets that 'vintage marshall' tonemojo. It's very clean inside, I like that. I'm glad my new joints didn't shit it up. haha. I'm getting better and better at soldering everday. luv it!



pics/sonds to come....

Pardon my noob ignorance here. Is this basically like a BYOC amp company?

taylornutt wrote:Pardon my noob ignorance here. Is this basically like a BYOC amp company?

Yeah, you can buy kits or you can buy the whole amp assembled, check it out. Quality seems really good and from what I've read the customer service is great.

I am always interested in learning something new that is guitar related. I envy Mike's knowledge of Electrical engineering and how it helps him build his cool pedals. The BYOC craze is cool because you can make anything just like you want it to be. Pedals and amps seem like magic and it's cool when you can demystify it and get in there and make your own stuff. It's how the personal computer started out.

Outside shot of amp.



Notice the more aggressive bend on the Neutrik (on right) that would keep that metal under more pressure, leading to a much improved connection through repeated use.


The Neutrik also sports a better system for keeping the metal tabs in place. The other jack has a very small plastic bump going through the metal, that breaks and causes the tab to lift out of place when a plug is inserted. When the plug is taken out, the tab doesn't not fall back down and the connection remains interrupted.

Are you going to drop the amp into an enclosure or head box at a some point?

Crate Blue Voodoo cab with Celestion G12 75T's and WGS Veteran 30's.
Audix i5 on G12-75T, Shure SM-57 on Veteran 30, Studio Projects B1 as room mic for more natural sound.

Three different takes for each sample, two rhythm tracks panned hard left and right with an accent track in the middle. Each take is comprised of all three mics.
No eq on individual tracks, but there is master buss compression/eq, i have a saved preset that i slap on tracks to bring them up in my phones and didn't take it off. nothing drastic going on, basically just makes it louder.


DRIVE
http://bestnetworx.com/uploader/files/5 ... lbreak.mp3
High Input > Presence, Low, Mid, High, Master Vol @ 12:00, Preamp @ 3:00
Epiphone Goth Les Paul with GFS '59 Vintage bridge humbucker
Accent track: wah lick at end

CLEAN
http://bestnetworx.com/uploader/files/5 ... nclean.mp3
Low Input > Presence, Low, Mid, High, Master Vol @ 12:00, Preamp @ 3:00
Ibanez Artcore AFS75T with GFS Mean 90 in bridge
Accent track: open chords

taylornutt wrote:Are you going to drop the amp into an enclosure or head box at a some point?

it's not mine, i'm just working on it for someone. i know they sell enclosures there too and they look pretty good, but you end up paying more of course.

I was looking on their site and saw that this JCM800 was priced 360 this for a kit. "All components with assembled board, front plate, rear plate, and chassis. No OT, no PT, no choke and no tubes."

No OT, no PT, no choke

WTF are these and how much are they?

cobascis wrote:I was looking on their site and saw that this JCM800 was priced 360 this for a kit. "All components with assembled board, front plate, rear plate, and chassis. No OT, no PT, no choke and no tubes."

No OT, no PT, no choke

WTF are these and how much are they?

OT= Output Transformer
PT = Power Transformer
Choke = choke


These are the bigass heavy shits that sit on the amp and do the big power handling. They are usually the more expensive parts.