my 5e3 tweed deluxe build

[Stinker]

Hello, recently I've finished my 5E3 Tweed Deluxe build. I'm pretty satisfied with it although there's some noise/hum coming out of the speaker. The noise gets quite loud when I put the volume controls up to 12, but on lower volume settings it's only hearable if you put your head close to the speaker.

I built it accordingly to Modulus Amplification 5E3 layout but with added standby switch. The voltages are all within 5% range of typical 5E3. I also installed two rectifier backup diodes, that's a mod I found on Rob Robinette's website. Other than that I guess you can call it a stock 5e3. The power transformer is Hammond 291BEX and the output transformer is Hammond 1750E.

Anyway, that's my first ever amp build and I would be really glad if you guys maybe could take a look and tell me if you see anything that's not right or should be worked on

 

[monkeybanana]

I had a conductive fiberboard so I moved the 68Ks off the board and flew them to the tube like the later blackface amps. It fixed the DC leak but I would motorboat on 12. Just moving the wires a little with a chopstick solved it. In conclusion the input is very sensitive! Maybe try moving some of the wires up top?

 

[TobyZ28]

Thats a super clean build, love it!
Since you're out hum hunting, i noticed the following two things:

The green loops would have AC in them and since they are not twisted, they could be acting as small transmitters. I would just bridge between pints 5 and 4 using the shortest path possible.
The Green line on the right looks to be parallel to the preamp (yellow) input. I think the green could introduce some hum into the yellow (one of the more sensitive lines). I would suggest adjusting them away from each other or at least perpendicular if they cross.

In my 5E3 I ended up moving my raised 6.3V lines so that they were tucked under the metal chassis lip instead, this reduced some hum for me.

Good luck!

 

[Stinker]

Hey, thank you for the tips guys. I soldered off those 2 green loops and made it so that there's just a short bridge connection between pins 4 and 5 on preamp tube sockets, just as Toby said. I don't know if it's placebo or something, but I think it actually reduced the hum a little

 

[King Fan]

Welcome. That's a tidy build, very well done.

I can't follow all the wiring from your PT. But another common easy fix for hum is to 'elevate' the AC reference of the heater center tap -- if your PT has one (it's sometimes a green/yellow wire) -- by "floating" the AC on top of the 6V6 cathode (DC) voltage. You do this by connecting the heater CT like this, where Rob has drawn it in purple for emphasis (and labeled it "6V Center Tap").

Let us know if your PT doesn't have a heater center tap.

 

[Lone_Poor_Boy]

After building a few guitar kits and taking on some other projects I decided to get a Mojotone 5E3 kit. I have now realized I got in over my head. I can solder but that's a LOT of soldering. And I do not know how to use a multi-meter. D'oh!

I can't speak to the innards but I am envious and still hope to be playing one, one of these days.

 

[King Fan]

After building a few guitar kits and taking on some other projects I decided to get a Mojotone 5E3 kit. I have now realized I got in over my head. I can solder but that's a LOT of soldering. And I do not know how to use a multi-meter. D'oh!

I can't speak to the innards but I am envious and still hope to be playing one, one of these days.

Take your time and enjoy the whole build process. Study, read, practice. Buy a smaller simpler eyelet board (Mojo uses eyelets, right?) and various caps and resistors of sizes like you got in the kit. Practice soldering them to the eyelets in 2s and 3s. Find soldering videos on YouTube -- most are micro-soldering now, but you can find some for turrets and even eyelets.

Mojotone has pretty darn good instructions and a mostly decent layout. In a few areas, like power wiring and grounding, a better, standard, modern layout is by the amazing Rob Robinette.

And start your own planning thread now; if you have questions, ask TDPRI. You'll get plenty of opinions; many of them are even correct! Then a build thread when you feel ready to start, going slowly every step of the way. Planning and practice are fun and safe. Building carefully is really fun. It'll all go by too quickly once it's over.

Build errors and troubleshooting are the opposite of fun. If you want to rush through learning and practicing and building just to play an amp, go buy one.

 

[Lone_Poor_Boy]

Excellent feedback and thanks for taking the time. My plan was and is to take it slow and get it right each step along the way, approaching it pretty much how you laid out. Their instructions are very good but I found conflicting info on pages 14 and 15 of the manual and could not seem to get a straight reply to my question from them, and maybe that's on my lack of knowledge, so I lost some confidence and decided to step away from it a bit and come back to it. I think I answered the conflict for myself in the end, and thanks for the linked diagram, as my question was around the two wiring approaches they have in the manual, and the 'modern' is what I landed on. And I decided to ignore the manual and go with the diagram, and I'll now use the one you linked.

If you saw some of the other things I took on I think you'd see I don't rush through and I get it right.

I did get the Tweed lacquering part done though!



Leather amp refinish
https://imgur.com/a/LnvDu4D

Guitar kit - I had no idea what I was getting into with a hollow body
https://imgur.com/gallery/D7teotE

Take your time and enjoy the whole build process. Study, read, practice. Buy a smaller simpler eyelet board (Mojo uses eyelets, right?) and various caps and resistors of sizes like you got in the kit. Practice soldering them to the eyelets in 2s and 3s. Find soldering videos on YouTube -- most are micro-soldering now, but you can find some for turrets and even eyelets.

Mojotone has pretty darn good instructions and a mostly decent layout. In a few areas, like power wiring and grounding, a better, standard, modern layout is by the amazing Rob Robinette.

And start your own planning thread now; if you have questions, ask TDPRI. You'll get plenty of opinions; many of them are even correct! Then a build thread when you feel ready to start, going slowly every step of the way. Planning and practice are fun and safe. Building carefully is really fun. It'll all go by too quickly once it's over.

Build errors and troubleshooting are the opposite of fun. If you want to rush through learning and practicing and building just to play an amp, go buy one.

 

[TobyZ28]

Hey, thank you for the tips guys. I soldered off those 2 green loops and made it so that there's just a short bridge connection between pins 4 and 5 on preamp tube sockets, just as Toby said. I don't know if it's placebo or something, but I think it actually reduced the hum a little

That's awesome if it was a real change! It's hard to tell placebo vs real but honestly if you feel better about it in the end - that still counts. On paper it makes sense to address anything AC that can cause interference close to the preamp lines first - so I'm guessing that the change is more likely real not just a placebo!

I second @King Fan 's suggestion on elevating the 6.3v Center tap, this made a huge difference on my amp - recently I replaced the transformer on the amp and it did not have a 6.3v center tap, everything else was near identical in layout etc and i had a noticable hum happening. I added an artificial center tap back in and the difference was huge!

 

[Stinker]

Welcome. That's a tidy build, very well done.

I can't follow all the wiring from your PT. But another common easy fix for hum is to 'elevate' the AC reference of the heater center tap -- if your PT has one (it's sometimes a green/yellow wire) -- by "floating" the AC on top of the 6V6 cathode (DC) voltage. You do this by connecting the heater CT like this, where Rob has drawn it in purple for emphasis (and labeled it "6V Center Tap").

View attachment 903015

Let us know if your PT doesn't have a heater center tap.

Thank you
The 6.3V and 5V secondaries on my PT aren't center tapped, but the artificial center tap 'mod' was already included in the layout from which I built the amp.

I think that I've read somewhere that it's normal for Tweed Deluxe to hiss when you crank the volumes up to 12. Is that true?

 

[TobyZ28]

A subjective yes, as I believe you have also carbon comp resistors, so you should have some slight high pitched hiss from them - Carbon comp resistors are desirable by many as they were used in the original 5E3 circuit adding to the tone/character of the amp. I believe in terms of quietness it goes Carbon Comp < Carbon Film < Metal oxide < Metal film < Wire wound. Others choose to go metal film resistors on some or all resistors to silence things more. You're obviously a details guy, I remember going through much of the same questions on my first amp build to get things "perfect". I think you have achieved said goal if it's "Ear At the Speaker while Cranked" levels. No sane person should have their ear that close in reality while you're playing (or they won't be hearing anything for much longer) haha

 

[King Fan]

Thank you
The 6.3V and 5V secondaries on my PT aren't center tapped, but the artificial center tap 'mod' was already included in the layout from which I built the amp. View attachment 903079

Good for you, just right. I found a version of the modulus layout that didn't show the 100Rs there. And now I see them there in your build pics. So the CT is elevated (an 'elevated artificial CT') and yes, some white noise or hiss is expected at 12 on the volume dial. When you mentioned hum I think we sort of thought heaters, since they're a common hum source. But if it’s not a problem when playing, not to worry.