5E3 Testing and troubleshooting

[Mojojtm]

I didn't ask for help yet but I have something to report maybe @Martin could review?

I noticed the buzzy noise is there even when I remove the preamp tubes, therefore the issue comes from power amp, don't you agree?

Now I am checking wiring connections from primary side of OT could be that they are wrong?

I have posted a photo previously .

Now I think the whole issue here is that due to my limited experience but mainly to the fact that I bought this bloody Chinese kit, the PT and OT wiring standard or most color convention doesn't exist at all. i was not provided with any schematics for the PT or OT neither for the kit but that is OK.

The OT has 3 colored wires (primary side) Black blue Red

It says on the label 3.3KOhm - 0 - 3.3KOhm (Black blue Red)

I connected the red to pin 8 on 5Y3 socket
I connected the blue to pin 3 on 6V6 Socket
I connected the black to pin 8 on second 6V6 socket

See photos of OT and connections:

[martin manning]

Blue is the center tap, which goes to pin 8 on the 5Y3, the other two are the plate leads, which go to pin 3's on the 6V6’s.

[Mojojtm]

Blue is the center tap, which goes to pin 8 on the 5Y3, the other two are the plate leads, which go to pin 3's on the 6V6’s.

There you go so I thought the center tap was the red, instead is the blue Dear god

Therefore I can do the following

Swap the red with blue and leave the black where already is, right?

[martin manning]

That's it. Another step on the road to success.

[Mojojtm]

Hey All

Thanks Martin for the full help provided you helped succeeding and thanks everyone else that interacted.

The Amp seems to be working fine now, I get sound and I played a bit of guitar.

I am measuring again the whole voltages and report back but I think we are good now.

There is some hum from one to ten I would say 4 the 5E3 seems quieter but I am fixing a bit of wires dressing I think the hum is not so much and if I increase the volume the hum doesn't increase

[Mojojtm]

Yes I need to work on reducing the hum as it is not too pleasant

I'm glad that works but it has to work better I actually think hum should be less.

Wires are twisted referring to the heater wires and OT and PT wires are also twisted what else can cause hum ?

[martin manning]

Glad it's working now. You can mark this as your graduation from the paint-by-number school of amp building. :^)

You mentioned that the hum does not increase when you turn the volume up. See if the hum is there when the power tubes are removed. If it is, that would be magnetic coupling of the power transformer to the output transformer, and there is not much you can do about that. Another thing to try is removing one of the preamp tubes at a time to identify and isolate the source.

[Mojojtm]

Glad it's working now. You can mark this as your graduation from the paint-by-number school of amp building. :^)

You mentioned that the hum does not increase when you turn the volume up. See if the hum is there when the power tubes are removed. If it is, that would be magnetic coupling of the power transformer to the output transformer, and there is not much you can do about that. Another thing to try is removing one of the preamp tubes at a time to identify and isolate the source.

hehehehehe so did I pass my exam lol

I have twisted better the wires pulled heater wire further away and the hum decreased a bit

In addition normal channel either 1 or 2 has very low hum almost none, I mean is totally acceptable a very low hum, and one more thing I have noticed is, if I put my hand near the inside chassis near the heater wires hum reduces consistently on Bright channel too.

Would aluminum tape to the wooden panel that covers the chassis help to reduce hum?

[martin manning]

Would aluminum tape to the wooden panel that covers the chassis help to reduce hum?

Yes, that would probably help, especially if your environment is electrically noisy. Recall on the current production Fender '57 Deluxe there is metal tape on the back panel and a wire grounding that to the chassis. Is your hum 50 Hz or 100Hz? 50 Hz can be from outside, or from the heater circuit, 100 Hz is more likely from rectified voltage inside the chassis. It's 60 or 120 Hz over here, of course.

[Mojojtm]

So after revising all connections, reinforcing all the soldered connections and redressing wiring the hum is reduced dramatically

I bought a 12AY7 valve and the value DC voltage on eyelet 39 is 1.87 so perfect I'd say now is good.

Happy and ...the sound of it is great I always played 18Watts Marshall including Bluesbreaker reissue, I also own an 1962 original Marshall super Tremolo but this little monster "5E3" despite may lack professional way on how it was built it has a fantastic sound now. I really love it, and thanks to Martin and all of you I have built an Amazing Amp really like it.

[martin manning]

Great, good to hear that it's working correctly. Making a few mistakes here and there is an excellent way to learn. Have a beer to celebrate, something good like a Trappist ale.

[Mojojtm]

Great, good to hear that it's working correctly. Making a few mistakes here and there is an excellent way to learn. Have a beer to celebrate, something good like a Trappist ale.

Hehehehe I am already having Trappist style beer every night , usually just one tonight maybe 2 , usually Kwark is my favorite one , cheers ... and again thank you I couldn't do it without your help.

[pompeiisneaks]

Great, good to hear that it's working correctly. Making a few mistakes here and there is an excellent way to learn. Have a beer to celebrate, something good like a Trappist ale.

Hehehehe I am already having Trappist style beer every night , usually just one tonight maybe 2 , usually Kwark is my favorite one , cheers ... and again thank you I couldn't do it without your help.

oh you like the sours eh (I think that may be what the Belgians call kveik? I was in brussels a few years back and got to drink a bottle of Westvleteren Outstanding trappist beer. Mostly we see only Chimay here in the US, but there are more over time.

Love beer myself

~Phil

[martin manning]

I think that was supposed to be Kwak? Kwark is cheese. Kreik is lambic with sour cherries added, not a Trappist, but very tasty. There are quite a few Trappist beers available here, though. Chimay, Westvleteren, Westmalle, St. Bernardus, Orval, Rochefort, and LaTrappe are the ones I see locally.

[pompeiisneaks]

I think that was supposed to be Kwak? Kwark is cheese. Kreik is lambic with sour cherries added, not a Trappist, but very tasty. There are quite a few Trappist beers available here, though. Chimay, Westvleteren, Westmalle, St. Bernardus, Orval, Rochefort, and LaTrappe are the ones I see locally.

you get westvleteren locally? OOF, that is one the monk's only allow 1 case per person per year or something. didn't know you could get it in the states now. I should have looked, it's been a while since I saw what you can get here in WA state, but its probably similar, I stopped buying belgians after going to belgium and tasting them there, because now it's part of the 'experience' SO I mostly drink belgian inspired american beers etc, here.

~Phil