5E3 clone build

[Amped]

I wanted to build a 5e3 but also wanted to change it up a little just for fun and to add some flexibility.  I modified a 5e3 turret board to suit, splitting the V1 cathode resistors/bypass caps, and added an extra turret for the bypass cap on V2a.  I started with the 5e3 schematic, and with the help of Robrobinette's website chose 4 mods to incorporate; 1) Negative Feedback/cathode bypass switch, 2) Marshal voiced Channel, 3) elevated heater voltage, 4) Master Volume.  Most of the mods work really well, the MV I chose (PPIMV) may not have been the right choice as there's nothing until 1, then ~2 or 3 you're at full volume.  The pre-phase inverter MV might work better, but I'm not too concerned as I used a switched pot which removes it from the circuit and it does give a weird compressed sound when used (which sounds kinda funky...).  Maybe one day I'll re-visit this(?).

I had a Hammond 1444-20 aluminum chassis so used that as a starting point, and as a bonus it allowed me flexibility to lay out the components how I wanted including allowing for impedance switch, 2 output jacks, mini toggle switch for NFB selector, and extra potentiometer for master volume.  Instead of screen printing or a faceplate, I thought I’d try something a little different so used Water-slide decal and a laser printer with lacquer over the top which worked out well, I’ll get better at it but I definitely think it's worth me trying this again next time.
I used mostly Evatco components for this build, the two stand out components were the Evatco EV660 power transformer and Evatco filter capacitors which both saved a few $$ and worked perfectly, I’d use them again.  I used Belton sockets – I really like those sockets and retainers…

For the cabinet I wanted it to pay my respects to the Tweed Deluxe so started with the online Modulus 5e3 plans altering them a little to make the speaker baffle mounting a bit stronger. I used pine and marine ply as the main materials, and dowels/Gorilla Glue to hold it all together.  The cabinet covering took a while to settle on, I originally thought I would like Tweed cloth but a) Tweed’s really hard and b) I wanted to pay homage – not try and duplicate the 5e3.  I’m not particularly “arty”, so after long discussions with a friend he suggested a few colour schemes and one stood out; Black Bronco for the sides, Vox Faun for the middle, and Black/Silver/Grey speaker cloth with bare corners.  Black Fender style handles round it out and keep the classic look I was going for.  My buddy also offered his help covering the amp too; cheers mate, couldn’t have done it without you!

After getting started I found I had spare timber and Tolex/Grill Cloth, and a 2nd hand Fender speaker, so thought “why not build an extension cabinet to go with it?”  Turns out it was a great idea because the sound of the Tweed through the two different speakers is amazing and makes the amp even more versatile.  And *bonus* I get another cabinet to use with other amps too!
   
The end result is a really good looking, good sounding, versatile amp and I’m super happy with how this project turned out.

[Amped]

Layout and schematic with voltages:

[Amped]

Some more pics:

[Amped]

Some gut shots.  Really like the heater elevation method on Robrob's site, my PT 6.3V didn't have a CT so 2x 100R resistors from the heater pins to the cathode on one power valve socket, and job done.  Simple and worked well for this build, might have to try this again.

[sluckey]

Nice workmanship produced a great looking amp, inside and out.   

[Amped]

Nice workmanship produced a great looking amp, inside and out.   

Thanks Sluckey 

[JB]

Very neat work, congratulations. 

How is it for hiss/hum?  I'm about to rebuild mine to try and quieten it down a bit so am looking at various grounding schemes.  Looks like you've got PA/power side on a transformer bolt and PI/pre bussed along to that ground near the jacks.  Did you use shoulder washers with the jacks or are they grounded to chassis as well?

[shooter]

Nice build!

Turns out it was a great idea because the sound of the Tweed through the two different speakers is amazing and makes the amp even more versatile.

I like when someone dips into the magic sauce 

[bmccowan]

Adding my own tip of the hat to your workmanship. You even got the tolex corners perfect. Since I can never get them quite perfect I am curious as to what method you used? Love the black and faun.

[Amped]

Very neat work, congratulations. 

How is it for hiss/hum?  I'm about to rebuild mine to try and quieten it down a bit so am looking at various grounding schemes.  Looks like you've got PA/power side on a transformer bolt and PI/pre bussed along to that ground near the jacks.  Did you use shoulder washers with the jacks or are they grounded to chassis as well?

Thanks mate I had a lot of fun with this build.  This amp is really quiet, when I first powered it up I thought it was broken until I picked up the guitar... 

The grounding scheme took a little bit of thought to decide on, what I ended up doing seems the most common layout but there are others I found including modified star ground layout, and a single ground buss where everything goes back to the transformer high voltage center tap.  After looking at the options I decided to keep it simple with the tried-and-true split buss and happily, it's paid off.

Yes I did use isolating washers on all jacks - inputs and outputs too, seems to work well in my build.

[Amped]

Nice build!

Turns out it was a great idea because the sound of the Tweed through the two different speakers is amazing and makes the amp even more versatile.

I like when someone dips into the magic sauce 

I'm definitely a convert of the magic sauce

[Amped]

Adding my own tip of the hat to your workmanship. You even got the tolex corners perfect. Since I can never get them quite perfect I am curious as to what method you used? Love the black and faun.

Thanks mate, I had a lot of help from a friend who's built a lot of amps, I'm still learning, but what I've learned so far:

First thing he told me was; "Light colours are hard, black hides a multitude of sins...".  It turns out its so true.  Some patterns can be difficult too because you have to be more aware of how they line up with orientation in context with the cabinet, corners and cuts/joins etc, and tweed is really hard.

Corners are difficult.  We did them in 2 goes, first applied the glue in the middle (flat) strip - not around the routed edge or corners and also to the middle of the tolex (we marked/glued the tolex so there's as little over the edges as possible - doesn't matter too much if a bit short even you can push glue a bit up under the tolex with a brush if needed).  We then laid the tolex from one side and stuck it to the flats (a roller like is used for screen printing is good for pushing out bubbles).  We cut at 45 from the top of the corner and applied glue to the routed edge, corners, and inside for 1-1 1/2 inches or so for inside wrap around, and (when dry) rolled the tolex around the rounded edge working towards the corners and overlapped them but (important) didn't push the corners down (just lay it over the corner).  Then sharp knife we cut along the inside edges so the flaps can wrap around to inside, and rolled the blade around the corner at 45 again from top to bottom cutting 2 wedges out of the overlap (careful not to push down the tolex too hard), the top wedge comes off easy, the one under you have to lift the Tolex and use needle nose pliers to remove.  Sometimes the glue goes with it but you can dab a little more in there if needed.  Roll the tolex back and wrap underneath and trim into the corner.  it will probably take a bit more slicing along the 45 corner cut and working the edges together to get the join work nice, but the next important bit is that for the next few hours you have to keep coming back often and push the joins together (fingers, finger nails, small flat blade screwdriver works too, tolex is pretty tough but but try not tear it).  The more often you do this the more likely it will look good.  A small soft hammer or similar can be used to tap at it to smooth the join out too.

https://www.evatco.com.au/how-to-tolex-a-cabinet/

It's pretty hard to describe how to do that sorry, but hopefully that was helpful.

[Amped]

Forgot to add:  Do this all as quickly as you can (no rush but don't leave it for hours and come back).  When you're pushing glue up to the edge of an already glued section (like the routed edges/corners or up under the tolex a little) pull the tolex back, apply the glue then while still wet roll the tolex over the glue to push out some of the glue and pull back again to let dry (it will look all stringy which is perfect). This just moves the glue line so you don't get a line/lump where the older glue/newer glue meet.

[Champ_49]

Very neat work, congratulations. 

How is it for hiss/hum?  I'm about to rebuild mine to try and quieten it down a bit so am looking at various grounding schemes.  Looks like you've got PA/power side on a transformer bolt and PI/pre bussed along to that ground near the jacks.  Did you use shoulder washers with the jacks or are they grounded to chassis as well?

Thanks mate I had a lot of fun with this build.  This amp is really quiet, when I first powered it up I thought it was broken until I picked up the guitar... 

The grounding scheme took a little bit of thought to decide on, what I ended up doing seems the most common layout but there are others I found including modified star ground layout, and a single ground buss where everything goes back to the transformer high voltage center tap.  After looking at the options I decided to keep it simple with the tried-and-true split buss and happily, it's paid off.

Yes I did use isolating washers on all jacks - inputs and outputs too, seems to work well in my build.

Really neat build. Exceptional work in terms of neatness. The cabinet looks really nice. 

I am currently in the process of building a 5e3 (all stock)as we speak which is posted here on another thread. Just documented the component board which is pretty much done now. Next will be to wire in the leads. I am using the ground buss method tied to one point on the chassis and also isolated all jacks including the inputs and speakers.
Only other ground point will be the mains. I found Kevin Oconner's from The Ultimate Tone books to be the one that worked the best for me. I built two high gain (cascading gain stages) modified Jcm800 amps and incorporated this scheme. It worked really well and for an amp like that it is really quiet. The 5E3 is not hard to make quiet anyways. The last one I built just used the old random grounds and it was still dead quiet. But i am incorporating this scheme onto the 5E3 i am building now as it doesnt hurt to incorporate a good grounding scheme and get into the practice of using it.


Was a bit of extra work drilling to accommodate the bushings and hope it was well worth it.  Always learning.

[yorgle]

I absolutely love that color/texture combo.  That’s a truly inspiring build!

[Amped]

I absolutely love that color/texture combo.  That’s a truly inspiring build!

Thanks for the great feedback mate, all the best.

[Amped]

Really neat build. Exceptional work in terms of neatness. The cabinet looks really nice. 

I am currently in the process of building a 5e3 (all stock)as we speak which is posted here on another thread. Just documented the component board which is pretty much done now. Next will be to wire in the leads. I am using the ground buss method tied to one point on the chassis and also isolated all jacks including the inputs and speakers.
Only other ground point will be the mains. I found Kevin Oconner's from The Ultimate Tone books to be the one that worked the best for me. I built two high gain (cascading gain stages) modified Jcm800 amps and incorporated this scheme. It worked really well and for an amp like that it is really quiet. The 5E3 is not hard to make quiet anyways. The last one I built just used the old random grounds and it was still dead quiet. But i am incorporating this scheme onto the 5E3 i am building now as it doesnt hurt to incorporate a good grounding scheme and get into the practice of using it.

Was a bit of extra work drilling to accommodate the bushings and hope it was well worth it.  Always learning.

Cheers Champ_49  .  I had a read through your build log on the forum here, nice going looks really nice.  I look forward to reading how it evolves/turns out. 

Me, I'm starting to think about my next build.  Got some ideas, maybe a Vox/Matchless 30W base with some additional mojo (which I'll probably regret).  Takes a while this process...

Agreed - always learning...

[d95err]

That cross-line PPIMV is completely useless, IMHO. It works as you describe - nothing happens until you go really low. At that point it’s also acting as a highpass filter, cutting out all the bass.

If you use one of the dual pot PPiMV variants, you’ll find it works much better.

[bmccowan]

Hey Amped,
Thanks for posting the Tolex instructions - there are a few tips in your description, and the link, that I know will help the next time I tackle the job. It'd be worth posting in the cabinets section of the Forum, if its not there already.

[Amped]

That cross-line PPIMV is completely useless, IMHO. It works as you describe - nothing happens until you go really low. At that point it’s also acting as a highpass filter, cutting out all the bass.

If you use one of the dual pot PPiMV variants, you’ll find it works much better.

Thanks, it's not great as a master volume on this amp I completely agree.  I'll get around to changing it up one day, was thinking of trying a pre-phase inverter MV like this one: https://robrobinette.com/5e3_Modifications.htm#Add_Master_Volume
but a Lar Mar or Frondelli PPIMV might fit the layout better(?).  In the mean time its an awesome little amp to play on 

[Amped]

Hey Amped,
Thanks for posting the Tolex instructions - there are a few tips in your description, and the link, that I know will help the next time I tackle the job. It'd be worth posting in the cabinets section of the Forum, if its not there already.

Glad my ramblings might be helpful - one mistake I found when I read back through it (well at least one obvious one anyway), when I said "45" [degrees] I meant 90 - straight out from the corner...  In my defense it was late :-(