First build - Boothill 5E3 - Need some help

[Alan Cohen]

Hey guys. First build, first post and darn glad I've found this place!

Background - 52 years young, playing more off than on for 40 years, mostly acoustic. Have built a few acoustic guitars. Know very little about electronics but can follow a plan. Considered buying a pre-built for the $800ish, but thought I might get something out of trying one myself. I got something alright, but not sure just what yet.

Got my kit (and cab) from Dave @ Boothill. Transformer bundle from Triode, 12A125A on the way from Weber. So far I've spent a few evenings and most of today getting it together.

First pics: Shellac'd the cab while waiting for the transformers. I used Zinnser Bulls-Eye "Amber" from Home Depot. Went on nice and I like the color.

[Alan Cohen]

Now for the guts. I started by soldering the input jacks and pots on a balsa wood template as recommended in Dave's video. Actually, he recommended cardboard, but I have tons more balsa around than cardboard. The first joints were a bit messy, but got way better as I remembered my soldering skills from Basic Circuits 101 over 30 years ago!

[burninwordz]

Welcome aboard Alan, nice cab allsome!!!!!!

[Alan Cohen]

So I soldered my last wire a few hours ago and bravely flipped the switch. The pilot came on, nothing sizzled or smoked and 4 of 5 tubes started glowing...all but the V1 12AY7. I tried a 12AX7 from my Super Amp that I know works and it didn't glow either. I decided it was time for a nap. After turning it off and unplugging it.

Post nap I disconnected the jacks and pots and wriggled out the board to double check things and found a couple of loose wires. I resolder them solid and reassembled. Still no V1 heat.

I started checking voltages and am getting <220 volts at pins 2 and 8 of the rectifier and the same down the + side of the board so something is wrong.

FWIW I'm using the 40-18021 PT and 40-18022 OT from Triode. The wiring colors did not coincide with the Weber diagram, but I think I figured that part out. I assume the colors on the PT are the same, but I could be mistaken.

If anyone wants to take on a diagnostic project, I'd really appreciate it. I have my high-tech photo studio at the ready and can take close ups of anything.

[Alan Cohen]

Originally Posted by burninwordz

Welcome aboard Alan, nice cab allsome!!!!!!

Thanks!! Glad to be hear.

[Telenut62]

Hmmm ok...here is a better layout...

http://site.triodestore.com/5E3Delux...-18021120V.pdf

Sounds like your going to have to check all your connections and grounds, the V1 is not lighting up when you turn on standby?...check the heater wiring.

When you are ready to try again go through this procedure....

http://www.paulrubyamps.com/info.html#FirstPowerUp

[charisjapan]

Originally Posted by Alan Cohen

So I soldered my last wire a few hours ago and bravely flipped the switch. The pilot came on, nothing sizzled or smoked and 4 of 5 tubes started glowing...all but the V1 12AY7. I tried a 12AX7 from my Super Amp that I know works and it didn't glow either. I decided it was time for a nap. After turning it off and unplugging it.

Post nap I disconnected the jacks and pots and wriggled out the board to double check things and found a couple of loose wires. I resolder them solid and reassembled. Still no V1 heat.

I started checking voltages and am getting <220 volts at pins 2 and 8 of the rectifier and the same down the + side of the board so something is wrong.

FWIW I'm using the 40-18021 PT and 40-18022 OT from Triode. The wiring colors did not coincide with the Weber diagram, but I think I figured that part out. I assume the colors on the PT are the same, but I could be mistaken.

If anyone wants to take on a diagnostic project, I'd really appreciate it. I have my high-tech photo studio at the ready and can take close ups of anything.

Welcome, Alan,

I think that your problem is the filament (heater) wires are parallel all the way to V2, but not to V1. You must connect Pin 8 of V2 to Pin 8 of V1 (as you did) and also Pins4&5 of V2 to 4&5 of V1, and don't connect these two parallel connections (as you did, by connceting V1 Pin 8 to 4&5)

That should get you your heaters all the way down the row!

[Telenut62]

Also your red and yellow PT secondary wires are on the wrong pins of the rectifier? Unless you have the socket 180 degrees to the normal way

[hackworth1]

I might not be seeing it right, but it Looks like V1 has pin 9 connected to pin 4 and 5.

Check the heater wiring.

If you have lights on in all tubes except that one, this is an indication that there is a miswire or a bad connection at this point.

It would be good to tighten up your twisted heater wire pairs into tighter spirals.

Also shorten some of those leads.

I think I see what telenut is sseing on your rectifier.

4&6 get the red wires

2 and 8 get the yellow

Also important. B+ to the board at first filter cap comes from pin 8

[hackworth1]

Spread apart the 270 ohm resistor and the 25uF cap at the end of the board near the PT.

Can you give us a pic of the power tube sockets up close? Turn the whole amp upside down when you take the pics OK? Flip it 180 degrees.

[Alan Cohen]

Originally Posted by charisjapan

Welcome, Alan,

I think that your problem is the filament (heater) wires are parallel all the way to V2, but not to V1. You must connect Pin 8 of V2 to Pin 8 of V1 (as you did) and also Pins4&5 of V2 to 4&5 of V1, and don't connect these two parallel connections (as you did, by connceting V1 Pin 8 to 4&5)

That should get you your heaters all the way down the row!

Ding ding ding, that was it. I was treating the FIL like grounds and thought it OK to connect them all together. Not. Thanks!

Now my 12AX7 looks anemic compared to the 12AY7

[Alan Cohen]

Originally Posted by hackworth1

Spread apart the 270 ohm resistor and the 25uF cap at the end of the board near the PT.

Can you give us a pic of the power tube sockets up close? Turn the whole amp upside down when you take the pics OK? Flip it 180 degrees.

Here you go..I might not be able to build amps, but I can take a mean close-up picture. Now you can really see how crappy my soldering skills are.

The power tube and rectifier tube sockets are upside down. I believe the rectifier is wired correctly. On the power sockets, pin one has the little black mark.

Oh, and I spread the 270 ohm resistor. While we're on this shot, I grounded that resistor and 25uf cap to the PT lug. You can see it in the picture. OK?

[hackworth1]

Those are upside down too, but it appears that the wires are connected to their corresponding pins.

Look around for some twisted heater wires so you can copy the technique.

You might get some hum from those single runs on the heater wires once you get this amp running.

[Alan Cohen]

Originally Posted by hackworth1

Also important. B+ to the board at first filter cap comes from pin 8

B+ is 290V as best I can read on my analogue meter.

[hackworth1]

Originally Posted by Alan Cohen

Here you go..I might not be able to build amps, but I can take a mean close-up picture. Now you can really see how crappy my soldering skills are.

The power tube and rectifier tube sockets are upside down. I believe the rectifier is wired correctly. On the power sockets, pin one has the little black mark.

Oh, and I spread the 270 ohm resistor. While we're on this shot, I grounded that resistor and 25uf cap to the PT lug. You can see it in the picture. OK?

OK. Does the big 22uF Filter cap go to ground there also?

[hackworth1]

Is that 290V with tubes in and speaker connected?

[Alan Cohen]

Originally Posted by hackworth1

OK. Does the big 22uF Filter cap go to ground there also?

Yes, it is wired under the board to the first pin.

[Alan Cohen]

Originally Posted by hackworth1

Is that 290V with tubes in and speaker connected?

Speaker...what speaker? It needs a speaker? Oh crap, I knew I forgot something.

Seriously, yes with tubes, no speaker.

[hackworth1]

Important that you do not power up again with tubes in and no speaker connected.

Could damage the Output Transformer.

If you have any old working 8 ohm speaker you could use that for testing purposes.

[Alan Cohen]

Originally Posted by Telenut62

Hmmm ok...here is a better layout...

http://site.triodestore.com/5E3Delux...-18021120V.pdf

Sounds like your going to have to check all your connections and grounds, the V1 is not lighting up when you turn on standby?...check the heater wiring.

When you are ready to try again go through this procedure....

http://www.paulrubyamps.com/info.html#FirstPowerUp

Thanks for the links! I guess it would have been better to read the Paul Ruby start up procedure before flipping the switch.