3 prong conversion the RIGHT WAY!

A clip from our DVD series Tube Amps 101. This one from Vol. IV.
Available at www.recycledsound.net

[@gregperrine4614]

When doing this mod, be sure that the white wire connects to the WIDE slot on the receptacle, that is proper neutral. (Reversed in this vid). Other comments regarding SOLDERING the ground wire directly to the chassis are also correct to meet modern standards. The lockwasher assisted bolting to the transformer mount is convenient and was spec. correct at the time of manufacture and will certainly suffice. BUT it is important you know.....

[@mikecamps7226]

The "BLACK" is the "HOT" lead which must pass to the POWER SWITCH and then to the FUSE ...BEFORE going to the Hot Lead of the Power Transformer. The White "NEUTRAL" wire can go directly to the White lead on the Power Transformer. Without converting to a 3 prong aux outlet which is present as a 2 prong here.....I would bypass and NOT use the aux power receptacle ......plus plugging in to such a receptacle could create ground loops with sound equipment should it be a grounded receptacle anyway.

[@drifterdave76]

Thank you so much for posting this video! This was my first time working on an amp and it was as if you were right there to guide me.

[@sionmichel]

Thank you for these clear consise instructions. I switch out my 64 DR two prong cord, got rid of the death cap and amp sounds quieter. Thank you for your generous sharing of this valuable information.

[@brianm9282]

I just did this conversion on my 1967 Blackface Bandmaster head and it worked perfectly, thank you!

[@MrTobiascollins]

Did this procedure on my 1965 Fender Super Reverb. Worked like a charm. Thanks!

[@AfromtheJ]

I believe the hot (black) and neutral (white) wires connecting to the courtesy outlet may be reversed. (see 3:50). When doing this mod, be sure that the white wire connects to the WIDE slot on the receptacle, that is proper neutral.

[@recycledsound]

AfromtheJ My point in this vid was more specifically regarding removal of the “death cap” in order to finish the job. I believe AfromtheJ is correct and technically all those saying that the ground wire must be soldered to the chassis are too! Anyone wanting a drawing that depicts the correct wiring scheme can go here to get one: www.recycledsound.net/indexTA101.html Converting_2_prong_to_3_prong_grounded_plug.pdf

[@twistedwired]

That courtesy receptacle would be old style and have no wide slot though right?

[@ryanybos]

Awesome tutorial thank you recycled sound

[@Finom1]

Great video, please post more!!!

[@1313azriel1313]

great instructional. thanks a lot.

[@MrGTO-ze7vb]

Well done video..!!!

[@fenderbender909]

I was just doing this exact procedure but the ground switch still makes me nervous so I came hunting for a video just like this. With the way the hot and neutral are wired to lugs on opposite ends of the ground switch, is it not even remotely possible that the ground switch could short out internally causing hot and neutral to be combined with no fuse protection?

[@DustInTheWindAZ]

In reviewing the rewiring diagram, it looks like you're just wiring the fuse holder to the other leg of the transformer, which shouldn't be any different. Is there a functional reason for this? Why couldn't you simply add the new 3-prong grounded power cord and cut the "death cap" out? It seems it would have the same effect.

[@60retired]

I have never seen a vintage Fender amp like the one your using for the demo come with a16 gauge cord. I have seen 18 gauge on everyone of them and they were very easy to remove. Try removing a strain relief that has16 gauge like most people are replacing with now days, that can take a little effort. I’ve seen to many amps that have plier jaw marks embedded into the plastic strain relief, wrapping the jaws with several turns of electrical tape before removing it and will save from ruining the strain relief.

[@robertisrael338]

I have a 1951 magnatone combo with no power transformer that uses 3 tubes that add up to mains voltage in series for the filiments. I don't want to change the circuit, so I'm looking for what the best iso transformer for the job would be. I talked to an amp tech and he wanted to change all the tubes to modern ones and add a power tranny. I don't wanna do that as the tone of this amp is great as is. I don't wanna lose that. Any ideas?

[@kenfoland]

Please advise me if this is wrong. I have a '69 Silverface AB165 Bassman Amp. On it, if you wire the auxiliary socket the way shown in the video, then the socket is wired backwards. Afterwards, anything plugged into will be powered incorrectly.

[@scottbridgeman5238]

What is the function of the polarity switch after the change is made? Also, how does this effect the standby switch? Thanks!

[@Turboy65]

It's good safety practice to leave the green ground wire long enough that if you were to yank the cord out of the chassis, the ground wire would be the LAST to break. This way whatever happens if the cord is still plugged into the outlet, the chassis remains grounded and safe. And the ground wire must be attached to a lug which is MECHANICALLY secured, via nut and bolt, to the chassis. Solder alone is not sufficient. Solder alone is not an acceptable means of making a chassis ground by various regulatory codes such as UL in the USA, CSA in Canada, and CE, Europe.

[@gordyschwarz8483]

this is all good but I don't have imput receptical its a 63 tremolux I,m con fussed 8 different ways please advise thank you

[@scrivenervl]

How about installing a properly grounded female IEC connector in place of the auxiliary power socket, thus eliminating the hard-wired power cord install as well as the possibility that a connected power cord could be accidentally yanked out? Wouldn't that be a neater way to go? Thanks in advance for your reply.

[@recycledsound]

We’ll certainly you “could”…. It’s your amp and you can do what you like! Here we are showing the long accepted practice which does NOT devalue a vintage amp and keeps its outward appearance correct!

[@silasfatchett5693]

Losing the death cap even more important with 220/240V mains.

[@buzzcrumhunger7114]

I doubt that! 220V throws you back instead of making you clench, no?

[@flagstamp]

is including the ground switch in the upgrade necessary? or can you just bypass it? what function does it now serve with the transformer leg attached? thank you!

[@recycledsound]

It serves as a junction point for the connections!

[@attilabeats]

Thank you so much for taing the efford to post this video! One question: where do you attacht the ground cable to? The transformator? On what part of it? Hope you can help me out. Greets, attila

[@silasfatchett7380]

To comply with modern standards, the ground wire should be securely soldered to the chassis or connected with an approved ground lug to its own dedicated bolt close to where the power cord enters the chassis. If you use a bolt, first use a star washer (shake proof washer) and a nut well tightened to make solid connection the chassis, then a star washer, your ground lug, another star washer, a nut and a lock nut.

[@derekec]

Confused and maybe dumb...my 1927 house is wired with old 2 prong outlets - breaker boxes grounded to a basement metal pipe. If I convert to 3 prong cord and then forced to use a 2 prong adapter (without connecting the adapter's ground tab) isn't that much more dangerous than simply properly orienting the old 2 prong cord? Better yet just install a modern polarized 2 prong plug assuring proper orientation and therefore grounding. OTOH, I suppose this arrangement would be dangerous in a 3 prong outlet since the wider prong would connect to neutral and totally bypass the lower grounded hole. Do I have this all correct before I start changing cords that might not suit my old house? Thanks in advance.

[@voxpathfinder15r]

Safe to gig with assuming where you gig has solid wiring to ground.

[@SpartanGerar]

I have a peavey audition 110, transistor amp with just 2 prongs Do i have to do the same ? I dont really think it has a polarity switch

[@phoneservice10]

Gerar you should really change to 3 prong to greatly reduce the chance of electricity surging through you

[@WesFanMan]

Better to have fuse holder AFTER the AC switch in the circuit, not before. Might surprise someone changing fuses without turning off amp.

[@recycledsound]

WesFanMan maybe so! However THIS is the industry accepted standard accepted wiring technique for this application!

[@seancurran6727]

Even if you didn't get a shock, messing with the fuse with the amp on is a real dumb move, that alone can cause the fuse to blow.

[@cohara41]

I'm trying to add 3 prong to an Embassy Alamo amp & it looks alot different than this (but I could be wrong) or is it basically the same? Plus I don't see a fuse which kind of scares me. Do I need to add one first thing??

[@recycledsound]

cohara41 just connect your black/white wires from your new 3 prong at the same points your current two power wires are connected.one of the two likely goes to a power switch, if not a fuse. Make that connection the black wire. Then connect green to the chassis.

[@kfowler8]

Is the polarity switch the same as a ground switch on a 60's Traynor? Thanks,

[@recycledsound]

kfowler8 yes

[@zbaby82]

I wish you would have told us which wires were hot, ground and neutral while you were at it.

[@recycledsound]

Green to ground…. Black to the fuse White to the standby switch….

[@dtworzguitar5775]

Hey guys,I have an old Silverstone tube amp.i replaced the 2 prong with a 3 prong but did not see a death cap.Do you have any instructions for that amp to convert it to 3 prong? Thanks Dave

[@recycledsound]

David Tworz if it is a “regular” amp, just attaching your ground wire to the chassis will suffice, however if you have an amp with just 3 tubes and the numbers on the tubes are 35, 50, 12...... You have a “Widowmaker” style amp which likely has just one transformer (output). This type of amp requires an isolation transformer be installed to be safe!

[@chrischwaz7788]

I bought the first DVD and I didn’t receive a second disc with printable drawings and or schematic. Your videos are very good I have three of your DVDs

[@SlowMenThinking]

Silly Question this mid sixty's amp twin prong power why was it this way in the first place or at the very least it could have been double insulated. Where we are 240VAC at 50HZ anything wired that way would have been considered a death trap even then.

[@recycledsound]

retroman33366 Seems crazy now, but that was indeed the AC wiring standard at the time .

[@60retired]

You didn’t mention anything in the video about wiring the auxiliary outlet correctly by making sure the white neutral wire goes to the larger opening of the outlet which is for the neutral prong. You hooked it up wrong in the video. Maybe if you do a 3rd video you will get it right.

[@call5sam]

How does the schematic show this conversion?

[@recycledsound]

I don't understand your question, but we DO include access to our drawing of this conversion along with much more written, printable material, with the purchase of our DVDs.

[@shanemichaels8289]

I have a 73 fender twin reverb that’s been trying to kill Me. Does it have a death cap. It’s got a 3 prong cord installed

[@recycledsound]

Yes!

[@shanemichaels8289]

@@recycledsound I was playing a gig in a casino last night. Playing my guitar went to sing , I saw a bright white flash of light in my eyes then everything went black for at least a second. It shocked me so hard it knocked me out. No sight no sound no anything. I think I died for a second

[@BM0v0]

I want to do this with my 1965 Fender Showman amp but I want to do it right or give it to a reputable person. I've been shocking myself way too much when I touch anything metallic and it will get rid of this electrical static noise when the guitar isn't touched by my hand. Otherwise, it sounds clean.

[@volcanowb]

Are there any integrated devices?

[@josephcote6120]

Seems like once the death cap is out the polarity switch does nothing and all the original wiring could be left alone.

[@rickcypher4240]

Maybe I’m wrong but I believe neutral and ground are tied together back at the utility pole, so in one position neutral and ground connect, the other position ties hot to ground. Am I thinking correctly?

[@linardskinard8199]

Why dont you all just look and see how more recent Marshall tube amps are wired and simply copy that ?

[@TheOzthewiz]

Congratulations know you have just introduced a new set of problems.....................GROUND LOOPS!!!

[@gregperrine4614]

Interesting you might think so! The methodology shown in this vid is and has been widely accepted practice by techs for decades. But thanks for watching!

[@CL-ty6wp]

I don't think thats an issue since it has an isolate transformer unlike a hallicrafters aa5.

[@birdsong2552]

Mike Ehrmantraut? Is that you?

[@kardRatzinger]

Yeah, that's not anywhiofere near the right way, in fact, this amp would be illegal to sell in many parts of the world. It is a bad practice and generally a terrible idea to connect the safety lead to a screw that's already used for something else, and the power transformer is probably the worst of all choices. The PT is heavy, if the amp ever gets trashed around on the road or while being shipped, it may get loose - happens all the time - and the safety lead may fail to make good contact, making the amp dangerous to operate. Furthermore, the safety lead needs to be longer than the live lead or the neutral lead, so that if one anyone should trip over the power cord and rip it of, the safety lead would be the last one to fail. So not only this is not "the right way", it's pretty much a tutorial on how not to do it.

[@recycledsound]

Stick and Tissue if you’re completely anal, yes I agree.... however most musicians barely understand changing tubes, let alone have a Big Bertha soldering iron capable of heating up a chassis! This method has been acceptable for 50 years and FAR outweighs not doing it at all! Lighten up a little....

[@J.C...]

Why would you leave that useless switch in the circuit? There's no reason to leave it in there whatsoever.

[@recycledsound]

It’s all about vintage …. If you don’t know…. You don’t know!