# A 5E3



## Always12AM (Sep 2, 2018)

First assembly:


















Took me a couple of hours, followed the Stewmac manual to the T.. all voltages came in dead on. Triple checked every single connection. Buzzed like a banshee in heat as soon as a turned either volume up. Seemed to be isolated to the Tone - Vol - Vol pots.

Rewired it about 7 times. Replaced pots and tubes and input jacks. Replaced some resistors and coupling caps.. still exact same problem. Tried 4 or 5 different grounding methods.. No difference.

Gave up for a couple months. Got some space. Spent a couple hours with @Alan Small and went over what I had at the time. He suggested isolation washers for the pots and to stick to one grounding method among many other very useful suggestions. I went for the Rob Robinette method.

Not to tarnish Jupiter caps. But both amps that I used their “Cosmo” filter caps gave me a lot of problems. Decided to start again from scratch with F&T’s and a thicker 20AWG solid core wire for leads. I also decided to mount the leads from under the top eyelet for organization. Lastly, used some shielded cable to connect the grid stoppers and the grid of V2.

PLUGGED IN.. Viola!! Most issues resolved.. a little hum though.. I attempted to wiggle the heater wires.. off comes one of the pins for the V1 tube socket..

Replaced the V1 tube socket, added some extra wire to the grounding of the shielded wires. Went over connections once more.. added a very fun NOS Mullard tropical fish .0047 and an NOS Jensen 270PF as well as an RCA 12AY7 and JAN GE 12AX7.. she sings!! She is dead silent mechanically and sounds wonderful.

I wanted to share this 5 month long journey, for those who have offered advice and those who may be able to relate to the pain in the ass of trial and errors.

Current assembly:









Filter and Cathode caps leads going directly to ground bus..










I’m not married to the cupcake knobs and blue jewel, nor the tape, but I wanted to make it mine.



















A group shot with my prized fake Princeton, Gibson L-00, Tweed Deluxe and hard tail strat and my real Fender double Esquire.

Next up:
3.06lbs 2 piece pine Esquire.
Going to do my first nitro body and neck.


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## Alan Small (Dec 30, 2019)

Awesome work Ben!!!


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## Mark Brown (Jan 4, 2022)

Looks stellar man!
Nicely done.


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## amp boy (Apr 23, 2009)

Always12AM said:


> Current assembly:
> 
> Filter and Cathode caps leads going directly to ground bus..
> 
> View attachment 430625


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## terminalvertigo (Jun 12, 2010)

CFB Borden!

You military?


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## Paul Running (Apr 12, 2020)

Very neat and meticulous work...congrats on your accomplishments. May I ask about the issues you were encountering with the “Cosmo” filter caps?


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## jdto (Sep 30, 2015)

Amp building blows me away because I doubt I’d ever have the patience to attempt it. The end result here looks very cool.


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## Mark Brown (Jan 4, 2022)

jdto said:


> Amp building blows me away because I doubt I’d ever have the patience to attempt it. The end result here looks very cool.


While I have not attempted to build an amp (yet) I find fiddling with itsy bitsy bits calming. There is something to be said about ordering the chaos.


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## RBlakeney (Mar 12, 2017)

Yours had prettier guts than mine


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## Always12AM (Sep 2, 2018)

amp boy said:


>


IT PUTS THE LOTION ON ITS SKIN… ISNT THAT RIGHT PRECIOUS!!?


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## Always12AM (Sep 2, 2018)

terminalvertigo said:


> CFB Borden!
> 
> You military?





Paul Running said:


> Very neat and meticulous work...congrats on your accomplishments. May I ask about the issues you were encountering with the “Cosmo” filter caps?


Thanks Paul! Each time I had to go back in, the eyelets and the general order of it became less and less clean looking, but that was a part of the learning curve for me.

I’m not sure exactly what the issue is. But I both the National repair and this build, I used their filter caps as I am a big fan of their other products and both amps had filtering issues until I replaced them with Sprague or F&T. All of their tolerances appeared to be within range. Could have been a coincidence, but I grew tired of failing to get both amps quiet. The irony is that I made multiple changes each time I attempted to fix either amp, so it could have been a number of other little things I had missed.


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## Always12AM (Sep 2, 2018)

Mark Brown said:


> While I have not attempted to build an amp (yet) I find fiddling with itsy bitsy bits calming. There is something to be said about ordering the chaos.


I really enjoy it as well. This chassis is less fun than a blackface in terms of being able to organize as well as trying to solder leads to things that are 90 degrees from one another.


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## Always12AM (Sep 2, 2018)

RBlakeney said:


> Yours had prettier guts than mine
> View attachment 430652


I’d have to disagree, I find the turret board to be much prettier than the eyelet. In fact, PTP or turret will be what I prefer moving forward.


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## Always12AM (Sep 2, 2018)

jdto said:


> Amp building blows me away because I doubt I’d ever have the patience to attempt it. The end result here looks very cool.


If you like song writing or painting, I think you’d enjoy this kind of project.


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## Always12AM (Sep 2, 2018)

terminalvertigo said:


> CFB Borden!
> 
> You military?


Grandparent was. So I grew up on base in the beginning. I was on that path, but I think 9/11 shifted a lot of people in my generations focus away from service.


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## jdto (Sep 30, 2015)

Always12AM said:


> If you like song writing or painting, I think you’d enjoy this kind of project.


I enjoy songwriting, although I don’t do it as much as I’d like. Maybe one day I’ll try an amp kit.


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## Always12AM (Sep 2, 2018)

jdto said:


> I enjoy songwriting, although I don’t do it as much as I’d like. Maybe one day I’ll try an amp kit.


Even a pedal kit or a wiring harness is a fun thing to learn at a lower cost.


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## jdto (Sep 30, 2015)

Always12AM said:


> Even a pedal kit or a wiring harness is a fun thing to learn at a lower cost.


Wiring harnesses I have done, but a pedal kit might be interesting. In fact, I’m about to do a new harness for my PRS S2 Standard 22. With amps, the danger factor also gives me pause, because my ADHD could actually kill me.


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## nonreverb (Sep 19, 2006)

Beautiful work and I don't think my workbench has ever been that clean and tidy.


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## Wardo (Feb 5, 2010)

Always12AM said:


> If you like song writing or painting, I think you’d enjoy this kind of project.


I dunno, I write songs about cracked windshields, broken motors and busted lives although I've recently expanded my horizons to include alcoholic dogs that'll bight off yer ass, rusty cars, educated in bars, a gutted deer hangin from an oak, crystal meth and hell yeah we ain't woke. I've built fences and painted them too so maybe that's art .. lol


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## RBlakeney (Mar 12, 2017)

Building simple amps is easier than building pedals in their stupid little boxes.


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## WCGill (Mar 27, 2009)

Very nice job A12AM, nice to see you splurged on the red Jupiters. I used them on a Tremolux rebuild and thought they were superb.


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## Always12AM (Sep 2, 2018)

nonreverb said:


> Beautiful work and your I don't think my workbench has ever been that clean and tidy.


I appreciate both compliments! I put away everything as soon as I’m done and sweep up before I even break out the multimeter. I spent so many years trying to do this kind of stuff in a condo and then in kitchens, so I treat this little kitchenette in a laundry room like it’s a NASA facility lol.


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## Always12AM (Sep 2, 2018)

WCGill said:


> Very nice job A12AM, nice to see you splurged on the red Jupiters. I used them on a Tremolux rebuild and thought they were superb.


I actually bought a bunch of the red Astron Jupiter’s for a Princeton and then reused them in the first assembly. They didn’t make the final cut, but they are now in an AC15 and it’s a very nice combo.

I recently splurged on a pair of .047 Jupiter Comets (the new Vitamin Q style caps) I put one as the V1 coupling cap in the National / Champ conversion. It gave it a lot more low end but also adds a nice crispy response to the tone of the amp.


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## Always12AM (Sep 2, 2018)

RBlakeney said:


> Building simple amps is easier than building pedals in their stupid little boxes.


I found this to be a bit of a weener twister. I’m strongly considering making this a one channel amp with an AB763 tone stack.


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## libtech (May 27, 2008)

Looks great! whats the sparkly bright cap?


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## Always12AM (Sep 2, 2018)

libtech said:


> Looks great! whats the sparkly bright cap?


Its an NOS Aluminium Jensen.
Made in Denmark. It came with a transparent red shell that was shrunken half over one of the leads and I didn’t have any heat shrink with a large enough diameter to cover it.


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## Mark Brown (Jan 4, 2022)

Always12AM said:


> I didn’t have any heat shrink with a large enough diameter to cover it.


Cover it? That is the crown jewel of the whole build man!

I just though it was amp bling, I like it even better with the back story.


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## Always12AM (Sep 2, 2018)

I wasn’t sure if the bare aluminum cap would react as an antenna or if it were to touch a pot if it would bleed treble into the circuit. As it stands, it will never look as pretty as the first assembly. But I don’t think that eyelets feeding lead wire is as efficient as a lead directly from a filter cap or a resistor feeding directly into a pin or a lug on a pot.

The sparkle is just tape covering a bare old aluminum casing. I really like sparkles.

I don’t think I’ll ever use an eyelet board again to be honest. The amount of headache it caused and how difficult it makes it to correct something or add or subtract something can be a lot of headache.


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## Sneaky (Feb 14, 2006)

libtech said:


> Looks great! whats the sparkly bright cap?


Glitter bomb.


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## diyfabtone (Mar 9, 2016)

Always12AM said:


> I appreciate both compliments! I put away everything as soon as I’m done and sweep up before I even break out the multimeter. I spent so many years trying to do this kind of stuff in a condo and then in kitchens, so I treat this little kitchenette in a laundry room like it’s a NASA facility lol.


I've got to try developing a little more discipline seeing that lovely organised workbench. Mine is always a mess:


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## Always12AM (Sep 2, 2018)

diyfabtone said:


> I've got to try developing a little more discipline seeing that lovely organised workbench. Mine is always a mess:
> View attachment 430774


It looks like an organized mess to me, which is more functional in some cases. If I’m plugging away at something that needs to get done, to hell with being organized about it. But these amps and guitar projects are things that I have to remind myself to enjoy and take slow.

I found a nice old dresser at the side of the road and took one shelf and claimed it’s hardwood top and used that to mount all of the tools and spools Lol.

The cupboards are pretty handy and organized as well. But it’s mainly because I have ADHD and I won’t get anything done if I don’t start and finish with a sterile work bench.


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## Sneaky (Feb 14, 2006)

diyfabtone said:


> I've got to try developing a little more discipline seeing that lovely organised workbench. Mine is always a mess:
> View attachment 430774


It’s not a mess if you know where everything is.


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## WCGill (Mar 27, 2009)

Always12AM said:


> I actually bought a bunch of the red Astron Jupiter’s for a Princeton and then reused them in the first assembly. They didn’t make the final cut, but they are now in an AC15 and it’s a very nice combo.
> 
> I recently splurged on a pair of .047 Jupiter Comets (the new Vitamin Q style caps) I put one as the V1 coupling cap in the National / Champ conversion. It gave it a lot more low end but also adds a nice crispy response to the tone of the amp.


On 2nd look (3rd?) I see "COSMOS" on Jupiters. I'm not familiar with them as I've not been building for a few years. Here's some Illinois Jensen caps, .02, circa 1962 Denmark mfg. I've used them and although they don't measure all that great, they sound very nice.


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## Always12AM (Sep 2, 2018)

WCGill said:


> On 2nd look (3rd?) I see "COSMOS" on Jupiters. I'm not familiar with them as I've not been building for a few years. Here's some Illinois Jensen caps, .02, circa 1962 Denmark mfg. I've used them and although they don't measure all that great, they sound very nice.
> 
> View attachment 430975


I started off using Jupiter cosmo’s for Electrolytics, every amp I’ve used them in has hummed badly or didn’t work at all. This is also likely error on my end.

But F&T’s seem to do their job even better than Sprague’s. As for signal caps, I really really like the Jupiter Yellow’s and Comets. On this amp I have a Denmark MfG Jensen. Like you said, the ones I have are way off spec, but they are outstanding.


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## Mark Brown (Jan 4, 2022)

I put all my eggs in the F&T basket so here's to hope 

How do you come to determine which to use, just try a bunch and sort out what suits you best?

I can't really see their being a better way to know but if there is I would not mind knowing it.


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## WCGill (Mar 27, 2009)

F & T's!


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## Always12AM (Sep 2, 2018)

Mark Brown said:


> I put all my eggs in the F&T basket so here's to hope
> 
> How do you come to determine which to use, just try a bunch and sort out what suits you best?
> 
> I can't really see their being a better way to know but if there is I would not mind knowing it.


I base my criteria on how quiet the amp operates with them employed. F&T wins every time. Worht it for the main B+ filters.


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## Paul Running (Apr 12, 2020)

Get yourself a good analog scope so, you can see what's going on...you'll be amazed at how much more accurate your fault finding will progress.


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## Always12AM (Sep 2, 2018)

Paul Running said:


> Get yourself a good analog scope so, you can see what's going on...you'll be amazed at how much more accurate your fault finding will progress.


I’m contemplating a scope. Do you have any suggestions or are they sort of like Texas Instruments calculators and work or don’t?


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## Paul Running (Apr 12, 2020)

I presently use a Philips PM3233 that I picked out of the garbage 20 years ago, repaired it and has worked ever since. When I worked in the industry, most companies used Tektronix which are popular and reliable. I would recommend a dual-trace scope for viewing inputs and outputs at the same time...good for superimposing waveforms for comparison. Sometimes universities upgrade their lab equipment and send them to an electronic recycler. It used to be you could find early model scopes at the recyclers for small coin however, they are large and heavy...contain a wealth of HQ parts for salvage purposes.

Here's one like the one I use...a fair price:








Oscilloscope Phillips PM3233 10MHz | General Electronics | Mississauga / Peel Region | Kijiji


Oscilloscope Phillips PM3233 10MHz, 35 nS Nice working condition. I have two oscilloscopes for sale. Offer accepted. www.robotronics.ca




www.kijiji.ca


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## Always12AM (Sep 2, 2018)

Paul Running said:


> I presently use a Philips PM3233 that I picked out of the garbage 20 years ago, repaired it and has worked ever since. When I worked in the industry, most companies used Tektronix which are popular and reliable. I would recommend a dual-trace scope for viewing inputs and outputs at the same time...good for superimposing waveforms for comparison. Sometimes universities upgrade their lab equipment and send them to an electronic recycler. It used to be you could find early model scopes at the recyclers for small coin however, they are large and heavy...contain a wealth of HQ parts for salvage purposes.
> 
> Here's one like the one I use...a fair price:
> 
> ...


That’s a nice looking unit. I have a couple other projects on the go, but it seems like I could justify owning a scope at some point soon either way as I’ve been really enjoying going over these amps.


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