Weber 800? Sure okay.

[Tadpui]

Wow, this one looks like a real chore so far with all of the accommodations made on Weber's behalf. Nice work, and great job working through the complications. I bet it's going to sound awesome. And it also makes me never want to buy a Weber kit

[Greg_L]

Wow, this one looks like a real chore so far with all of the accommodations made on Weber's behalf. Nice work, and great job working through the complications. I bet it's going to sound awesome. And it also makes me never want to buy a Weber kit

I think this is the fifth Weber kit I've done for various people and this one is by far the most tedious and furthest stylistically from the original amp it's cloning. Their other offerings seem to be much more authentic to the originals. I don't know why they strayed so far on this one. But as long as it ends up sounding right, then it's all good.

[Armistice]

Wow, this one looks like a real chore so far with all of the accommodations made on Weber's behalf. Nice work, and great job working through the complications. I bet it's going to sound awesome. And it also makes me never want to buy a Weber kit

I think this is the fifth Weber kit I've done for various people and this one is by far the most tedious and furthest stylistically from the original amp it's cloning. Their other offerings seem to be much more authentic to the originals. I don't know why they strayed so far on this one. But as long as it ends up sounding right, then it's all good.

Are you doing this on some sort of mate's rates friendly commercial basis for people - obviously there are significant costs involved in just the parts - but jeez you're putting significant effort into it as well. Or is it just a thing you enjoy doing and learning and you're just doing it on a cost recovery basis?

[Greg_L]

Are you doing this on some sort of mate's rates friendly commercial basis for people - obviously there are significant costs involved in just the parts - but jeez you're putting significant effort into it as well. Or is it just a thing you enjoy doing and learning and you're just doing it on a cost recovery basis?

For people in my immediate orbit, I don't usually charge for minor stuff. They can buy me some lunch or a few beers or whatever next time we go out. For big stuff like this...this guy is in one of my bands and I'm not technically charging him anything but he'll give me something. This guy is on a tight budget and he's been moaning about JCM 800s for years. Every time I bring one of mine out he foams at the mouth. So this is probably as close as he can get right now and I'm really happy to do it because I get to learn something too. For other people....they pay. I don't advertise but musicians in my little scene know about what I can do - fix amps and make bad ass recordings. I'm sort of in demand for both. I do charge people that aren't personally connected to me in some way but they do get a good deal and I get things done pretty quick because I'm not backlogged with having to take in everything. This isn't my job. I can pick and choose what I do and who I'll do it for. And with that I can make a little extra cash but not have to charge shop rates.

[WhiskeyJack]

Sick dude.

So based on all of this that you are seeing and doing irght now do you still thikn this is will sound and act like an 800 2203?

I guess why i am asking is because i thought i read (possibly here somewhere on our forum maybe) that something like just how heater wires are put together and organized or something like that can affect how an amp sounds. So if that were to be the case and the layout is an entirely different kettle of fish from an actual 800 2203 is the potential thee for it to sound wildly different? Or maybe even just a tiny bit different. Or does the electricity just flow thru the pipes as intended the sound is the sound?

[Greg_L]

Sick dude.

So based on all of this that you are seeing and doing irght now do you still thikn this is will sound and act like an 800 2203?

I guess why i am asking is because i thought i read (possibly here somewhere on our forum maybe) that something like just how heater wires are put together and organized or something like that can affect how an amp sounds. So if that were to be the case and the layout is an entirely different kettle of fish from an actual 800 2203 is the potential thee for it to sound wildly different? Or maybe even just a tiny bit different. Or does the electricity just flow thru the pipes as intended the sound is the sound?

Heater wires affect the sound only by how much noise and hum they can inject into the circuit. There is no "sound" in heater wiring but bad "lead dress"...that's what wire routing is called....will definitely impact the sound of the amp. Usually what happens is you get hum kind of riding on top of everything. Sometimes there's like a blanket over the sound because of inaudible oscillations and trash frequencies riding along with the guitar signal. All this bad shit eats up headroom and space that should be going towards god-like tones. Bad lead dress can and will cause all sorts of terrible things to happen from just bad sound to actual tube failure.

For this amp it is indeed laid out very differently from a real JCM 800 2203. But it shouldn't affect the sound unless my lead dress is bad somewhere. To a certain extent the signal does just flow through the pipes and if the flow and components are correct it should sound in the ballpark of a real JCM 800. I say ballpark because even two real 800s don't sound the same so you just gotta kind of know what they're supposed to sound like. Also...voltages. We know what voltages to expect and where to expect them. If all the component values are correct (I know they are), and my layout is correct and my lead dress is good (I think it is), and we get the right voltages in the right spots, then it should work great and sound like it's supposed to even though the layout is goofy as hell. The only two things that can keep it from working is human error or a component failure.

[Greg_L]

Well I'm done wiring it up...looks pretty good. I'm not thrilled with this layout, but I'm happy with all my lead dress and connections.


And...it works!!!






There are still some things to do. The quadruple bias controls work really well. But the range is terrible. I've got the bias control set as cold as it can go yet the tubes are running just a hair too hot. I've got to change the bias feed resistor to get the bias into a more usable range. Not a big deal but I have to locate the right resistor - basically a 5W 17k ohm resistor. I don't have one.

Also I may juggle around some different value dropping resistors in the B+ rail. There are two secondary windings I can use off the power transformer. I'm using the milder winding right now. This allows for some really nice voltages in the preamp and phase inverter, but the plate voltage on the output tubes is on the lower end of what you'd expect from a mighty JCM 800 2203. I'm right around 405 volts DC on the plates. I'd like around 440-460 VDC. I can get that with the hotter PT winding, but that will throw the voltages downstream higher too and I don't necessarily want that. Or I could use the hotter winding and more dropping resistors to keep the downstream voltage in check. Don't know yet. I need to just try it as-is and see how it sounds. It might be great! So far it sounds pretty damn good in just a quick test. No noise, no hum, just Marshally sounds.

[rayc]

The best night light on the market.

[JD01]

Bloody'ell, that was quick!
Seems like the first time you did this we had a thread running for weeks... now you're knocking an amp out in a few days.

[Greg_L]

Bloody'ell, that was quick!
Seems like the first time you did this we had a thread running for weeks... now you're knocking an amp out in a few days.

Well it's not totally finished. I've only gotten it to the point where I can turn it on and test it. But yeah it went a little faster than some of the others. I've got a process now that works pretty well for me when it comes to the standard stuff that all amps have - power supply, switches, fuses, heater wiring, etc. That stuff is mostly the same from amp to amp. The rest of this amp was spent sitting there wondering "where the fuck am I gonna put this"?

These Weber kits are pretty cool in that they give you everything you need for a great price. They're not cool in the sense that they give you no guidance and their reference materials are shoddy at best. You have to improvise and figure it out on your own. Also some of the parts are WTF. You need to seriously upgrade some things. IMO this is the worst Weber kit I've come across. Their layout and schematic are wrong. I used an actual late 80s Marshall schematic. That's what this amp is. It's essentially a horizontal input era later 80s JCM 800 2203. And if I didn't know better this amp would not work properly. This kit is definitely not for beginners. You have to know something already to make this one work.

I know this amp is gonna be this guy's main amp and it's gonna be gigged a lot. It needs to be rock solid. My spite build 2204 is rock solid. My Tender Assman is rock solid. I'm trying to make this one to the same bulletproof standard as those.

[JD01]

I know this amp is gonna be this guy's main amp and it's gonna be gigged a lot. It needs to be rock solid. My spite build 2204 is rock solid. My Tender Assman is rock solid. I'm trying to make this one to the same bulletproof standard as those.

That's really good.

Reminds me of this time I was chatting to a guy on site about his old Triumph Spitfire that he'd stripped and re-built. My sister had a Triumph Spitfire in the late 80s and it was even more unreliable than my Chevette. I asked him how he was getting on with it given all the mileage he does with work and he said "fortunately British Leyland didn't build it. I did!".

[Greg_L]

That's really good.

Reminds me of this time I was chatting to a guy on site about his old Triumph Spitfire that he'd stripped and re-built. My sister had a Triumph Spitfire in the late 80s and it was even more unreliable than my Chevette. I asked him how he was getting on with it given all the mileage he does with work and he said "fortunately British Leyland didn't build it. I did!".

Exactly. I had a 79 Jag XJ6 a long time ago. It was a piece of shit until we put a small block Chevy V8 in it and replaced all the limey nonsense. Then it was bad ass. I wish I still had it.

I'm not reinventing the wheel or anything with these amps but I can make them better in some ways. Two things about my amps - they can take some serious abuse and they idle quietly. Those are good qualities to have for a gigging/recording musician's amp. My grounding scheme madness is paying off. The only horrible noises that comes from my amps are intentional.

[JD01]

That's really good.

Reminds me of this time I was chatting to a guy on site about his old Triumph Spitfire that he'd stripped and re-built. My sister had a Triumph Spitfire in the late 80s and it was even more unreliable than my Chevette. I asked him how he was getting on with it given all the mileage he does with work and he said "fortunately British Leyland didn't build it. I did!".

Exactly. I had a 79 Jag XJ6 a long time ago. It was a piece of shit until we put a small block Chevy V8 in it and replaced all the limey nonsense. Then it was bad ass. I wish I still had it.

I'm not reinventing the wheel or anything with these amps but I can make them better in some ways. Two things about my amps - they can take some serious abuse and they idle quietly. Those are good qualities to have for a gigging/recording musician's amp. My grounding scheme madness is paying off. The only horrible noises that comes from my amps are intentional.

I bet that was cool as fuck. Looked like a tweed wearing gent but went like a musclecar

[Greg_L]

I bet that was cool as fuck. Looked like a tweed wearing gent but went like a musclecar

Yeah it was cool. Putting Chevy smallblocks into Jags isn't a new idea. Lots of people do it for those 70s and 80s Jags. A Chevy V8 is about umpteen trillion times better and more reliable and easier to mess with than a Jag straight 6. They don't race em up though. Most V8 conversions were mild just for driving. Mine made so much power it also needed a GM transmission to go along with it. Then it broke the rear end, so I had to fix that. But once all that was done it would roast the tires like no other Jag on earth.

[JD01]

I had a gold XJ, late 90s model, for a little while. It was awful. Borrowed it off my dad when I was in between cars. I think even then, it was only a 3 speed auto.

[Greg_L]

I had a gold XJ, late 90s model, for a little while. It was awful. Borrowed it off my dad when I was in between cars. I think even then, it was only a 3 speed auto.

I think Ford owned them by then.

Mine was pretty nice really. It was a beautiful car. Jet black, tan leather interior. Still had the big 70s headlights and grill. Leaping cat hood ornament. And like all Jags, none of the electronics worked worth a fuck. But it was fast.

[Greg_L]

Well I think it's pretty much totally done...and I must say it sounds pretty great! It definitely has "the sound" you'd want from an amp kit that claims to be JCM 800-ish. It sounds like an actual 2203. I'm impressed...of course with myself as always but also that it works lol.

Some final shots....


The boot leather cab texture...


Here's it's size compared to real Marshalls. You can see it's a little smaller...about the size as a small-box Plexi or an Orange or something.




So I've put about two hours of "on time" through it. It's really quiet. I left it sitting idle for a while last night and I forgot it was even on until I turned my light off to leave the room. No hums, hiss, cracks, or pops. Really nice. So I guess tones coming soon!

[JD01]

Looks great. Really impressed with that.

[Greg_L]

I did have to slightly modify the rear of the head cab. It has no back panel.



The vertical cleat on the OT side of the head box was too large. Or I guess it was normal size and the OT we put in is too large. Or I could have moved the OT over about an inch if I'd known. I didn't think OT clearance would be a problem, but it was. So I gently peeled back the tolex, removed the large cleat, and made a thinner cleat so the chassis could slide in. Re-glued the tolex and you can't even tell besides the cleat being a little thinner on that side of the cab. We still need to come up with something for a rear panel though.

[JD01]

We still need to come up with something for a rear panel though.

Plexi?

When you post the tones can you post them back to back with one of your real 800s dialed in the same way. Maybe even blind test us see if we can tell what the real one is.