18Watt.com

I noticed that the GDS 18 Watt Chassis (and the GDS JTM 45 Chassis) uses an input jack with a .450 mounting hole.

Where can I get a high quality jack that fits this hole?

What happened to the parts lists that used to be in the download files on the old board?

Also, would it be a sin to use Fender style speaker jacks (switchcraft with a .375 mounting hole) in a Marshall clone?

I am building my own chassis, so I can use whatever size speaker jack hole that I want, but I am using the GDS JTM 45 Plexi front panel, which has the .450 input jack holes, so I have to use the .450 hole for the input jacks.
By the way, I would post this on the JTM 45 board, but it does not get as much traffic, so I thought I would post it on this board.
Thanks

Partsexpress and Mouser both have 'em....

HwyChile wrote:I noticed that the GDS 18 Watt Chassis (and the GDS JTM 45 Chassis) uses an input jack with a .450 mounting hole.

Where can I get a high quality jack that fits this hole?

Depends what you mean by "high quality." The traditional Marshall jacks used in all the old Marshalls are made of plastic with metal ferrules and manufactured by Cliff of England. Mouser and several other firms sell these. Although these are the "real deal," I've never been that fond of the fact they're made of plastic, and you cannot tighten them into their hole very much without the platic threads slipping.

I do like the fact that they're automatically insulated from the chassis, and the fact that both tip and sleeve contacts have a shorting "break" contact.

Genuine Switchcraft jacks are better quality IMO, but you need to get the insulating shoulder washers to keep the sleeve contact from contact with the chassis if you're being careful with your grounding scheme. I also don't know that the threads on the Switchcraft would be deep enough to accomodate both the chassis and the plexi panel.

--mark

OTHO, if you want the genuine Marshall look then the "Cliff" style jacks are the way to go. I have used quite a lot of these and have found their quality is more than adeqaute, even on one very old Marshall amp I have they're still holding on as strong as ever and connecting perfectly. I have actually had more trouble with regular style jacks' mounting nuts working loose....

I need the Marshall style cliff jacks that mount in a .450 hole. Does anyone have a part number for these and do I need to use the same ones for the inputs and the speaker jacks (are the inputs the same type needed for the speaker jacks)? I have a Mouser catalog, but I am not sure which ones are the correct ones. Thanks so much.

Hiway and Mark,

I used Switchcraft jacks + fiber shoulder washers without any trouble in my 18 Watt. I used Switchcraft bushings with the 1/2" long bushings without any problem. You can get everything you need at Mouser.

The Cliff/Rean jacks are quite cheesy IMO. They look nice and are insulated from chassis contact, but I know the Switchcrafts are beefier and work pretty much forever.

Jason

Long time viewer, first post.

Quote: "I also don't know that the threads on the Switchcraft would be deep enough to accomodate both the chassis and the plexi panel."

I don't know about the Switchcraft jacks mentioned here, but I do know that, for standard non-switching mono jacks, they have some with longer threads. I had to get one to repair my son's SG since it mounts in the mahogany body, not in a plastic plate ala the Les Pauls.

Jason,

Do you have any pictures of your amp with those jacks? I am interested in seeing them on the Plexi faceplate. I noticed that the Marshall type jacks have a different looking chrome nut than the switchcraft. Thanks

All,

Here is a pic of the jacks on my 18.

http://www.18watt.com/modules/forums/files/dsc_014.jpg

The bushing is the threaded part of the jack--they come in 3/8" lengths and 1/2" lengths. The 3/8" is standard fare, and I like to use teh 1/2" for my amps where I use isolated fiber shoulder washers and 1/8" thick aluminum chassis. The 18 Watt chassis is a bit thinner [.090"??], so the 1/2" would still work very well. I don't know whether the 3/8" woudl work perfectly [I haven't measured], but it might not be a problem to use these as well.

BTW, I want to post more pics, but I reached my maximum upload limit of 256K--whatever that means. I only posted 3 pics last week and have not been able to post anymore due to this upload limit. Anybody know how long this limit is for?

Jason

I still think this whole thing of the Cliff type jacks being poor quality or cheesy or whatever is being overplayed. In my experience they seem to go on forever, and they're the only kind that look right on a Marshall faceplate. And if they're good enough for real Marshalls, they're good enough for me!

ZP,

Well, the great thing about being a builder is that you can choose exactly which parts you want and discard parts that you don't. Having said that, I will stick by my statement regarding the chessiness of Cliff jacks--low density plastic is not my personal favorite choice for jacks or really any other part on an amp. I'll put it to you this way: I am very opinionated and experienced with different parts/brands. My biases stem from either good/bad experiences or just plain old logic and common sense. Please don't take my opinions the wrong way . I know this much: I recieved a shipment of these exact same jacks recently that had bent jack contacts out of the box. I also don't see how plastic threads [bushing] working against metal threads [nut] make for a good strong connection. Also, I don't like soldering directly adjacent to and in contact with plastic [solder tabs]. Also, the fiber washers are too thin IMO to be used to spread the stresses of the nut and bushing pressure over a larger surface area [the whole point behind using a washer]. So, from a nitpicker's viewpoint, I would wholeheartedly recommend not using these for daily abuse. I personally prefer and recommend overkill engineering/design rather than under doing it .

Your point is well taken [and respected] and defintely holds true with respect of authenticity of Marshall's original intention. Still, I don't feel bad for stating my observations that they are a cheesy product. Yes! I am a parts snob! If you saw the damn switches I like to use you would probably laugh because they are severly overrated--NKK 10 Amp DPST ! Which, BTW, are highly recommended! And they are NICE.

Jason

Hey Jason, I have no problem with that point of view either! I just wanted to provide a view of the the other side of the coin as well. And I have very steady soldering hand - well, apart from the incident in my teens, when I picked the iron up at the wrong end!

I think I am going to try the Marshall style cliff jacks for the look. If I have problems with them, I can always change them out later.

All,

Bushing lengths I posted were wrong! The standard Switchcraft is 1/4" long and the longer one I use is 3/8" long bushing.

Sorry.

Jason

Two more cents on the Cliffs - they do seem to last a long time with one exception - does anyone have an old JCM800 where the "Low Sensitivity" jack still works? The 220x series are some of my favo(u)rite all time Marshalls, but they made a mistake IMO making that shorting contact in the input jack be part of the main signal path.

--mark

Hey Mark,

I was wondering--are the newer Cliff/Rean Jacks the same product that Marshall started out with? In otherwords, were the older Cliff jacks of better quality than the newer ones? What I would love to see is a higher density plastic used on these jacks and better contacts--then I would consider using them. Hell, machine them from Teflon or something ! Even if these were made of some type of metal and specifically designed to be self insulating...just a thought.

The 220X series Marshalls kick ass. Always loved the feel and tone of these a whole lot. Have you experienced problems with the shorting jack becoming bent and not making proper contact and therefore causing problems with these amps?



Jason

No, it's more like the Low jack is weak, buzzy and distorted. I've seen in this in at least two or three of these. I've never actually fixed it because who ever uses the low sensitivity input jack on a 220x...

--mark

FWIW, I've got two JMP MVs, and the input jacks appear to have gold plated contacts (not so in the JCM800s I've seen). Also, I have a later JCM800 2204, and one of the spk. jack contacts was stretched and had lost some tension over time. With regard to the older production being possibly better, Jason may be right. You look at those pictures of really old Marshalls, and the jacks appear to have lug and screw contacts, and the bodies look a bit more robust (military surplus?). I wouldn't be surprised if they decided to lower quality to meet a price point over time. I think both Cliff and Re'an still make gold-plated contact ones. There's one place here that sells one model of Cliff plastic jack that has the gold plating, and I seem to recall Angela offering gold-plated contact Re'an at one time.

Dai