First build - Boothill 5E3 - Need some help

[hackworth1]

If you feel like it, redoing your heater wires would be worthwhile.

[Alan Cohen]

Originally Posted by hackworth1

If you feel like it, redoing your heater wires would be worthwhile.

Nag, nag, nag. Ok I'll do it. Can I go one wire gauge smaller than the green wire in the kit? It was hard to get two through the narrow eyelets on the preamp sockets.

[hackworth1]

I use a small round hobby file to open the holes.

The heater wire in the kit is 18 ga. You could use 20 ga., but I do not recommend 22 ga. which is the stuff used for the board/tube socket connections.

[Alan Cohen]

Best I could do with an 18ga rewire. Next time I'll open up the eyelets in the tube sockets prior to installation. They're pretty flimsy and I didn't want to risk breaking one off by manhandling it too much.

Wait...did I say next time?

[Alan Cohen]

Update...new 5Y3 tubes arrived. One is a NOS Magnavox, the other is a Sovtek from Triode.

Results: The NOS 5Y3 yields 295V just as the first one. The Sovtek yields 310V, which I guess is normal since the Triode site says they have a bit more gain than standard anyway.

So...it's not the rectifier. B+ voltage still around 300V instead of 380ish.

Where to next?

[Alan Cohen]

No ideas what might be causing the voltage drop?

[Telenut62]

Got me stumped

[Alan Cohen]

Me too. I'll have some time to dive into it again tomorrow.

[Telenut62]

My only little hunch was your first resistor at the filter cap, I assumed being smaller it was the 4.7K and the bigger one was 22K. However I looked at this build here and the size of the resistors are reversed.

http://www.tdpri.com/forum/shock-bro...cab-first.html

Check the values of the voltage dropping resistors

[Alan Cohen]

I think the size of the 2nd resistor is bigger because it's a higher wattage. Plan calls for a 2W and this looks like a 3W. The color code is funky though. It's red-red-black-red and then another dark red on the end. I'm not sure how to read that.

I was also confused about this yellow component at the Normal volume control. It's supposed to be a .1uF/600V cap and it says 223K/630V. I'm not sure what that means but that was the only part left on the part list when I checked everything in.

[Alan Cohen]

I just stopped by my local radio shack. The 22K resistors there are red-red-orange which is what I would expect. I bought a pack to try but they are only 1/2 watt'ers instead of 2W. What would be the worse case scenario if I tried one temporarily to see if it solves my issue?

[andyfromdenver]

Alan :)
I know this is your first build, I hope you're doing lots of searching and reading. Not to mention being suuuuuuuuper careful when f'ing around in there, you could get killed, seriously.
1. The large resistor is 22k, leave it. it's a 5 band: red2,red2,black0,red00, looks like brown/gold on the end= 1-5% (?) tolerance. It's large for a reason 2 or 3 watts (if it is 3 that's fine). Just keep it in. Don't sub out the crappy radio shack part. When in doubt about a value measure it with your meter. I've seen a number of pots with waaay off values, so you have to get in the habit of this.
2. The cap is .022 microfarads which is different from the schem. I can't recall what change this will affect maybe someone else will chime in I think it's a common mod to address the "farty" bass, or it was misplaced with the .022 off pin 1 of your v2. (i'd have to look back at board pics.)

just as an aside, given the amount of solder on the lugs and the shortness of the leads, I've been told you can potentially cook these parts and change their value/ ruin them. Heat sinks are always a good idea when you need alot of heat for the board lugs. Soldering should be a quick affair. Especially so when you get into the chip/pcb world etc.

good luck with the build, you're really close :)

[andyfromdenver]

actually out of curiosity can you post some up close pics of the board? It's hard to tell but I think a few of the coupling capacitors are different from the 5e3 scheme, hard to see. These may be some popular mods, maybe HWorth will say?
Couple general tips (especially if you want internet help). make all values readable from above. always get a pic of your under board finished prior to install. bonus: line all your resistors up same way, value to tolerance (Leo Fender would have called you out on this :))
And disclaimer, I know jack and am still very much a newb and learning even after building 5 amps now and working a day a week for a tech, so I am only saying this in a fun, non-critical way.
learning tube amps is a dual process of reading and doing. You can't just do a lego kit build without investing the time to learn, you're going to get shocked or hit a wall when it doesn't work.

[blueshawk100]

Looking at the last picture, the solder joints look cold to me. Does anyone else think that? I notice, for example, solder has not smoothed out over the top of the turrets.

You might need a higher wattage soldering iron for working on this (than say solid state components). My soldering used to look like that until I learned to heat the part (turret) until the solder melts, rather than melting solder over the joint onto cold parts.

I would be surprised if that one resister that has solder on the end of it is not damaged.

[Telenut62]

The resistor band colours shows you have them correctly placed, as blueshawk says take them out and check their actual value

[Alan Cohen]

Originally Posted by Telenut62

The resistor band colours shows you have them correctly placed, as blueshawk says take them out and check their actual value

I tried that with the 22K but my crappy little volt meter, that says it measures in K Ohms, can't get a reading other than 0 and infinity.

Speaking of which, I guess it's time to upgrade the $11 VM. I'm not ready to drop 100s of $$$, but any recommendations on a useful measuring device for my new hobby?

I ended up breaking off what little leg remained on that resistor so I need to replace it anyway. It is quite possible in my soldering relearning curve I might have fried a component or two. I think I'll ask Dave to sell me a new resistor and capacitor only kit and start replacing things one at a time.

[Alan Cohen]

Originally Posted by blueshawk100

Looking at the last picture, the solder joints look cold to me. Does anyone else think that? I notice, for example, solder has not smoothed out over the top of the turrets.

You might need a higher wattage soldering iron for working on this (than say solid state components). My soldering used to look like that until I learned to heat the part (turret) until the solder melts, rather than melting solder over the joint onto cold parts.

I would be surprised if that one resister that has solder on the end of it is not damaged.

I bought a 40W soldering iron from Radio Shack before starting this project and it burned up the first night. Dead, dead, dead. Piece of junk. I went to my back up which I believe is a 25Wer and it did nicely.

I don't think there are any cold solder joints. My MO is to heat the turret, not so much the wire and let the solder wick in when it gets hot enough. All wires were pre-tinned.

That said, it is possible I cooked a component or two. I should have watched this first:

http://www.youtube.com/watch?v=RZmTkwTcC6Q

[Alan Cohen]

Originally Posted by andyfromdenver

actually out of curiosity can you post some up close pics of the board? It's hard to tell but I think a few of the coupling capacitors are different from the 5e3 scheme, hard to see. These may be some popular mods, maybe HWorth will say?
Couple general tips (especially if you want internet help). make all values readable from above. always get a pic of your under board finished prior to install. bonus: line all your resistors up same way, value to tolerance (Leo Fender would have called you out on this :))
And disclaimer, I know jack and am still very much a newb and learning even after building 5 amps now and working a day a week for a tech, so I am only saying this in a fun, non-critical way.
learning tube amps is a dual process of reading and doing. You can't just do a lego kit build without investing the time to learn, you're going to get shocked or hit a wall when it doesn't work.

Thanks...very good advice indeed. I will improve my component housekeeping on the next build.

[Alan Cohen]

Originally Posted by Alan Cohen

Speaking of which, I guess it's time to upgrade the $11 VM. I'm not ready to drop 100s of $$$, but any recommendations on a useful measuring device for my new hobby?

I just picked up this one off Amazon. True RMS and auto ranging for $39. A lot of stores including Sears seem to carry it. Can't be all bad. Now I can test my components and circuits.

http://www.amazon.com/gp/product/B00...ls_o01_s00_i00

[Cruisin Home]

I am late to this POST but this POST is pretty busy in nature and you've had lots of different issues caused by miswires, missing gnds, no speaker etc.

Clarify what problems remain. low B+ ? if so let start at the beginning of the circuit and go thru to the end.
1)Thus to start, remove all tubes, desolder the B+ connection (i like to desolder at pin 8 of rectifier) and measure voltage at pin 8 Vdc? Thus disconnecting everything and only measuring the PT/Rectifier combination.

2) if you Pass the first item then resolder and measure at board (without tubes). If that is bad you can then start liftin the end of each resistor as you move down the line and measure.

somewhere along the way you are loading down the B+ line. could be at any of the B+ branches to all tubes and OT.

Try step 1 and report back. Again no tubes