New 5E3 Build (Weber Kit)

[Basslice]

Hey ya'lls. After rebuilding that '74 Fender Twin Reverb, I got the amp-build itch. I decided on building a '57 Style Tweed Deluxe. I like the ’74 Twin, but it is pretty sterile and after a jam session with a friend I realized that I wanted something much lower wattage that had some unique tonal character. Ready for the story?

Okay, first thing – which kit? At the time of this writing, a person can buy a hand-wired Fender ’57 Tweed Deluxe for $2,349 (free shipping!!). But that would take all the fun out of it, no? So I research the kit market. A Google search of kits leads to a lot of dead leads and outfits that sell partial kits (like no trannies, etc.). Seems like the number of operations selling kits has dwindled. Also, I am dealing with the US market and overseas options were not a reality.

The TubeDepot sells a kit for $750 (https://www.tubedepot.com/products/twee ... be-amp-kit) and it comes with everything you need; chassis, guts, tubes (JJ), cabinet and speaker. The only thing I do not like about their kit is the PCB that comes with it. Not exactly what I think of as hand-wired. One could always buy a eyelet board from the likes of Hoffman or others for less than $20 (https://hoffmanamps.com). Probably good for a beginner though and their tubes are ok. I can’t say what components they use.

The company I thought I wanted to do business with was Mojotone (www.mojotone.com). Good solid reputation. Unfortunately, they are out of their minds on pricing with a full kit costing $973 ($584.00 for chassis and guts + $340.00 cabinet + $85.00 speaker). I am still scratching my head why they are so expensive. You could buy a kit with cheaper components and buy better components from AmplifiedParts.com (https://www.amplifiedparts.com/) or Mouser and still save a couple hundred dollars (I did the math). So anyway, they were out.

I went with the Weber 5E3 @ $702.00 (https://www.mojotone.com/Tweed-Deluxe-Amp-Kit). I read up on them and was fully aware that the tube set they include are cheap, no-name Chinese and that the caps and hardware were gonna be questionable. My plan was to upgrade most of the components and tubes.

So in June I ordered the kit. The communication with Weber was pretty darn good. They told me up-front about the cab build time and it was no prob for me – I had some other projects to get off my bench anyway. I also ordered 1W carbon film resistors, good film capacitors and Mersen/F&T electrolytic caps from amplifiedparts.com. Oh, and CTS pots. I forgot to order Switchcraft jacks - an omission which would come to haunt me with their additional shipping cost.

So in late August I get a note from Weber, the amp was on the truck! Here it is. Finnegan, my shipping and receiving inspector approved.

1 Shipment Arrived.jpg

2 New CAB_01.jpg

3 New CAB_02.jpg

4 New CAB_03.jpg

The cabinet and its workmanship were excellent. The Tweed was tight and no noticeable defects. Finnegan loved it as you can see. It came loaded with a Weber 12A125A, 8 ohm, 30w, standard dustcap, light dope. They retail for $125 but was included in the kit.

5 Whats in the Box.jpg

The chassis is stainless steel and looked nice (I would later remember that you cannot solder to SS.....). It came with a mixture of cloth wire - some real push-back solid core, some "fake push-back" cloth stranded.

The guts were all neatly wrapped. It came with a copper cap rectifier instead of a 5Y3 tube. The resistors and caps were all no-name stuff of questionable origin and quality. The tubes were indeed cheap Chinese-made things but no doubt good enough for the initial build and debug. I will describe some of the other stuff when I get to the build description later. There was no power chord. However, based on my research, I was 90% satisfied so far. Finnegan has some questions, but I told him that I could work around just about anything (which was true).

More to follow.....

[romberg]

Nice! I've built a few amps using weber kits. They are all working fine after nearly 20 years of regular use. Only thing I bothered to upgrade on them were the jacks and switches. But the jacks and switches that came with the ab763 based build I'm working on now look fine (siwtches are carling). So, I'm not even gonna upgrade those this time around.

Mike

P.S. Not all the Chinese tubes are that bad. I actually like Shuguang 12ax7s.

[pdf64]

If you’ve not already done do, I suggest to build a light bulb limiter and get hold of a few different bulb wattages.

[johnnyreece]

It's my understanding that they've upgraded to Switchcraft jacks and Carling switches now, so don't toss the ones that came with it!

[Basslice]

If you’ve not already done do, I suggest to build a light bulb limiter and get hold of a few different bulb wattages.

Yup. Good advice for anyone. I have a pretty well equipped shop. Limiters, Variacs, external powre supplies, tone generators, osc scopes, DVMs, etc.

[Basslice]

It's my understanding that they've upgraded to Switchcraft jacks and Carling switches now, so don't toss the ones that came with it!

The jacks in my kit are not Switchcrafts. One already easily bent out of shape (grounding switch) and is in the recycling bin....

I used their switches. I used my own CTS pots.

[johnnyreece]

Sorry for my poor memory. They use Neutrik, not Switchcraft. Been a minute since I bought a kit from them!

[Basslice]

Nice! I've built a few amps using weber kits. They are all working fine after nearly 20 years of regular use. Only thing I bothered to upgrade on them were the jacks and switches. But the jacks and switches that came with the ab763 based build I'm working on now look fine (siwtches are carling). So, I'm not even gonna upgrade those this time around.

Mike

P.S. Not all the Chinese tubes are that bad. I actually like Shuguang 12ax7s.

I went with Carbon Films for most of the resistors, except for the PI Tail (56k), and the power supply dropping resistors (4.7k and 22k 2W) - these I used metal films. I also the Power tube cathode resistor was supposed to be a 250ohm/5W. I read that this is a nominal value and I had a 250ohm/15W lying around so I threw that in. I will explain more of the subs I made in following posts.

[Basslice]

The next step was a long one and started well before I even ordered the kit. I like to do a lot of research. I watch lots of videos, I read books and lots of online resources. I studied the schematics and note the difference in layout from one design to another (it seems each of the online layouts are slightly different). I also made my own BOM for the build and see if there are parts that I want to order to sub for kit parts.

Here is a short list of resources I found useful.

Mojotone Resources

• Tweed Deluxe Manual (https://mojotone.com/Amp_Kits/Tweed/Del ... Manual.pdf)

• Tweed Deluxe Schematic (https://mojotone.com/Amp_Kits/Tweed/Champ_5F1_SCH.pdf)

• Tweed Deluxe Wiring Diagram (https://mojotone.com/Amp_Kits/Tweed/Champ_5F1_WD.pdf)

Rob Robinette Resources

• How the 5E3 Deluxe Works (https://robrobinette.com/How_The_5E3_Deluxe_Works.htm)

• 5E3 Mods (https://robrobinette.com/5e3_Modifications.htm)

• Build an Amp (https://robrobinette.com/How_To_Build_a_Tube_Amp.htm)

• Amp Startup (https://robrobinette.com/Tube_Amp_Startup.htm)

• Troubleshooting (https://robrobinette.com/Tube_Guitar_Am ... ooting.htm)

Aiken Amplifiers

• Glossary of Terms – Great info (http://www.aikenamps.com/index.php/white-papers)

Hoffmann and EL4world

• Chassis Grounding Notes (https://el34world.com/charts/grounds.htm)

[ChopSauce]

Not that short a list...

... but let's add (moderately) anyway: I've been using https://www.stewmac.com/globalassets/vi ... structions too.

[pdf64]

I noticed this layout included many technically beneficial improvements https://robrobinette.com/images/Guitar/ ... Layout.pdf

[Basslice]

I noticed this layout included many technically beneficial improvements https://robrobinette.com/images/Guitar/ ... Layout.pdf

I love Robinette's site and lists of mods. In my build, I wanted to as close to original as possible. I took extra care to implement a decent grounding scheme. I can always modify it later if I want. I may add a negative feedback loop, but right now, standard.

[Basslice]

Not that short a list...

... but let's add (moderately) anyway: I've been using https://www.stewmac.com/globalassets/vi ... structions too.

Trust me, if you were to look at my computer and all the resources I have read and links I have, what I posted was a very short list!!

[Basslice]

The Build
There were not many serious challenges in building the amp. I wish I was a little better at soldering and tight fitting wires. Some of my lead dress were a little long (1/2” here, 1’4: there). Big, slightly arthritic hands and thumbs did not help. I am now in LOVE with pushback wire.

6 Build_01.jpg

I started by putting in the jacks, pots (CTS upgrade), and switches. I mounted the transformers. Then I started the eyelet board. I installed the jumper wires and components. I soldered as I went. I know some people hook up everything then solder at the end, but that never works for me. I checked the resistance and capacitance of each component as I went. I marked the foil end of the caps using my scope.

7 Build_02 (external hardware and Trannies).jpg

9 Build_04 (populate board).jpg

10 Build_05 (tube sockets in).jpg

There were a few QC issues that I fault Weber for:

• The voltage dropping resistor for B+2 was supposed to be a 4.7K 2W metal foil resistor (Yellow/Violet/Black/Brown). All of the parts & component were thrown together in a ziplock and my poor eyes have trouble distinguishing the color codes. Nevertheless, I went through the whole pile and there was no 4.7K 2W. I did find a 4.3K 2W in the pile (Yellow/Orange/Black/Brown). I double-checked all of the values and confirmed it was 4.3K. Not that it should make a huge difference, but it is 8.5% less than spec. I searched my spare parts and did not have one handy so I went with the 4.3K.
• There was no AC power cord (went to Home Depot)
• There were no screws for securing the board to the chassis.
• The pilot light was metalized plastic - I don’t really ding them for that as I knew that the components would be functional but less than top-notch. I bought a new one.

I did the board. I put in a copper rail for the ground bus. I did not use the copper plate provided. Then I put in the AC chord and wired it up and grounded. Then I wired up the rectifier. Wired up the PT. I trimmed the unused wires, capped with shrink wrap, zipped tied and tucked away. I used power drill to twist the requisite AC wires. Then I put in the board and started wiring everything else up.

11 Build_06 (stuff the chassis).jpg

12 Build_07 (wire it up).jpg

13 Build_08 (wire it up).jpg

While putting in the board I ended up bending the grounding switch of the cheapo speaker jack and replaced with a Switchcraft. I worked from left to right, power tubes then the preamps. Made sure everything was grounded well. The last thing I did was wire up the pots. Wait, that is not true, the last thing I did was wire up the heaters!

14 Build_09 (wire it up).jpg

Next update will be the testing...

[Basslice]

Test

• Made the speaker connection. But for initial testing hooked up to a 8ohm dummy load.
• Brought up with Variac and LB limiter with no tubes. Checked voltages (ok)
• Put in Copper Cap rectifier. The damn ceramic sockets were too tight. I couldn’t get it in and ended up snapping off the locator pin! I reamed out all of the pins with an awl.
• Tested voltages from rectifier (ok)
• Put in preamp tubes and tested (ok)
• Put in 6V6GTs, again the pins were too damn tight. Almost broke on tube trying to insert it. Checked all voltages still with LB limiter.
• Good thing I had the limiter because at one point my grounding stick shorted to the heater taps on the pilot light!! Yikes! Fortunately, the only thing that happened is the lightbulb lit up. No harm, no foul.
• Created voltage chart (all ok).
  Voltage Chart.png
  Put chassis in cabinet and connected to speaker.
• Plugged into regular wall socket. Plugged in guitar and…. It worked!!!!

It sounded really cool but after about an hour of playing very loud I started getting some horrible noise. Like a short or something. If I turned it down it went away, but then came back. It was very vibration sensitive. I turned it off. I checked all the pre-amp solder connections. Still noise. Took out one preamp tube – noise gone. Put back in and removed the other – no noise. Bad tube? Switched tubes – noise back. Hmmmmm (scratches head)? WTF? Then I noticed some shabby work on my part – the nut on one of the input jacks was loose!! Call QC and fire this guy! Tightened and all is well. It was an intermittent ground.

17 Build_12 (assemble it).jpg

20 Build_15 (assemble it).jpg

24 Done 1.jpg