18Watt.com

Here is my exactly the same turretboard.
Watch out with your screen grid resistor wattage and the B+ dropping resistor next to them. I use 5 W for those. Look at the big green resistors on my board between the bias circuit ant the big filter cap.

Here is my exactly the same turretboard.
Watch out with your screen grid resistor wattage and the B+ dropping resistor next to them. I use 5 W for those. Look at the big green resistors on my board between the bias circuit ant the big filter cap.

I was wondering about that. These are 1/2w.
I’ve got a 1k 3.75w or 3w. Both wirewound.
Will these work?
Attached pics so far.

Yes those 3W will work. The ones you are using now will burn away..

Also double check this often made mistake: the orientation of the 2 10uf electrolytic caps in the bias circuit. Positive side to ground! I can't see the orientation in your pics, but make sure you get this right.
Also, I use a 2W 100k resistor between those caps.

In contrast to you I always use 2W carbon oxide resistors at the plates. Those are connected to B+ nodes and can get pretty hot.

As I can see you wired the preamp socket of V2 (Reverb driver tube) for a 6N2P? This should be wired for a 12AT7 IMHO. I wire mine V1, V2 and V5 for 12A*7 and V3 V4 for 6N2P.
V1 and V5 for possibly applying a lower gain valve, and V2 because it should be a 12AT7 definitely.
Also, you need to twist the wires closer together at the sockets.

Yes those 3W will work. The ones you are using now will burn away..

Also double check this often made mistake: the orientation of the 2 10uf electrolytic caps in the bias circuit. Positive side to ground! I can't see the orientation in your pics, but make sure you get this right.
Also, I use a 2W 100k resistor between those caps.

In contrast to you I always use 2W carbon oxide resistors at the plates. Those are connected to B+ nodes and can get pretty hot.

As I can see you wired the preamp socket of V2 (Reverb driver tube) for a 6N2P? This should be wired for a 12AT7 IMHO. I wire mine V1, V2 and V5 for 12A*7 and V3 V4 for 6N2P.
V1 and V5 for possibly applying a lower gain valve, and V2 because it should be a 12AT7 definitely.
Also, you need to twist the wires closer together at the sockets.

Good stuff
Thx
Dave

[Also double check this often made mistake: the orientation of the 2 10uf electrolytic caps in the bias circuit. Positive side to ground! I can't see the orientation in your pics, but make sure you get this right.

These 10uF E caps are bipolar. Do you suggest I remove and replace with standard polarized caps?
Thx
Dave

Another question please.
Is this Master Volume pot wired correctly?
Shielded wire. 2.2m resistors. Black wire to Intensity pot, right? Do I hit that lower lug too before heading to the Intensity pot?
I can’t decipher the layout or gut shots.
Thx
Dave

foreverstrung wrote: ↑

Mon 11/17/25 6:51 am

[Also double check this often made mistake: the orientation of the 2 10uf electrolytic caps in the bias circuit. Positive side to ground! I can't see the orientation in your pics, but make sure you get this right.

These 10uF E caps are bipolar. Do you suggest I remove and replace with standard polarized caps?
Thx
Dave

They should be electrolytic. This is part of the power supply.

foreverstrung wrote: ↑

Mon 11/17/25 8:06 pm

Another question please.
Is this Master Volume pot wired correctly?
Shielded wire. 2.2m resistors. Black wire to Intensity pot, right? Do I hit that lower lug too before heading to the Intensity pot?
I can’t decipher the layout or gut shots.
Thx
Dave

It's wired correctly with the correct type of wire. The black wire (ground reference) should indeed be jumpered between both 3rd lugs. And from there onto the wiper of the intensity pot.

Also double check this often made mistake: the orientation of the 2 10uf electrolytic caps in the bias circuit. Positive side to ground! I can't see the orientation in your pics, but make sure you get this right.

My new 10uF E caps showed up today. I purchased 450v. Is this ok in these positions? I’ve got 25v and 50v too. The caps I’m replacing were 50v. I don’t recall where or if I even did ever verify the voltage.
I’m sure the 450v will be good.
Dave

foreverstrung wrote: ↑

Wed 11/19/25 9:29 pm

Also double check this often made mistake: the orientation of the 2 10uf electrolytic caps in the bias circuit. Positive side to ground! I can't see the orientation in your pics, but make sure you get this right.

My new 10uF E caps showed up today. I purchased 450v. Is this ok in these positions? I’ve got 25v and 50v too. The caps I’m replacing were 50v. I don’t recall where or if I even did ever verify the voltage.
I’m sure the 450v will be good.
Dave

450V is overkill and probably kinda huge. I use 10uf 100V caps. 50V is borderline given the bias voltage

Attached are a couple pics of the guts so far. Still waiting on a couple things to arrive. This tefzel wire is tough to manage. It doesn’t want to lay or mold into place easily.
I’m considering bumping the turret board over 3/4’s of an inch to center better. This would give me more room to dress out these valves. Appreciate thoughts.
Any constructive criticism regarding assembly is welcomed.
Thx
Dave

I know some types of wire can be a PITA to lay out the way you’d want. In contrast to some people I do use cloth wire for that reason. Plus there is no cutting off insulation involved either. Some people advise against the use of cloth wire for various reasons like susceptible to problems in moist or damp environments, fire hazard,… but Leo has done that for decades and his amps are statistically among the most reliable amps ever. An amp would have to deal with a lot of other issues when used regularly in moist environments.
Small remark of your build: you’ve gone through a lot of hassle to ground the shields of the wires coming from the MV pot. I would have bolted a solder lug under the nut of the turret board that is between the coupling caps of the PI to the power tube grids. Just for the looks maybe..

Bieworm wrote: ↑

Fri 11/21/25 9:25 am

I would have bolted a solder lug under the nut of the turret board that is between the coupling caps of the PI to the power tube grids. Just for the looks maybe..

Grounds and shield connections should serve no other purpose.

I know some types of wire can be a PITA to lay out the way you’d want. In contrast to some people I do use cloth wire for that reason. Plus there is no cutting off insulation involved either. Some people advise against the use of cloth wire for various reasons like susceptible to problems in moist or damp environments, fire hazard,… but Leo has done that for decades and his amps are statistically among the most reliable amps ever. An amp would have to deal with a lot of other issues when used regularly in moist environments.
Small remark of your build: you’ve gone through a lot of hassle to ground the shields of the wires coming from the MV pot. I would have bolted a solder lug under the nut of the turret board that is between the coupling caps of the PI to the power tube grids. Just for the looks maybe..

I noticed you used cloth wire. I seriously considered it. The last few builds I used PVC high temp wire. It was great to work with. I've got those effortless wire strippers so it's ok. This tefzel wire was tough. Not any more so to strip, but placement
I noticed you used the standoff bolt/nut to ground the MV shielded wire ground. I wanted it to look clean. Yours absolutely does, but If I tried to ground at that point, I though my build would look sloppy, so I grounded this way. I'll revisit this decision.
On the layout drawing you have a terminal strip in front of V3 and I'm not sure exactly why but I wired it just like you have it regardless. Maybe it'll become clear later.
Thx
Dave

Small remark of your build: you’ve gone through a lot of hassle to ground the shields of the wires coming from the MV pot. I would have bolted a solder lug under the nut of the turret board that is between the coupling caps of the PI to the power tube grids. Just for the looks maybe..

Better?

I’ve got it about finished up. I did not ad the vibrato pedal jack yet. I will tho, but for now, I’m going to check all my wire, connections caps and resistors for proper positioning and values ( tho I’ve been doing this each day before starting )
I hardwired the power cord. Just because. I put a 1A 250v slow blow fuse on the turret board and a 2A 250v slow blow in the mains.
If you guys see something, please say something.

What are your thoughts on this photo?

What are your thoughts on this photo?

Turret needs better solder.
I’m going to go thru the entire project. Check all connections, wired locations correct. Resistor n cap values correct. Lots of cleaning up still. Def not calling it ready to power up yet.

foreverstrung wrote: ↑

Sat 11/22/25 1:23 am

What are your thoughts on this photo?

Turret needs better solder.
I’m going to go thru the entire project. Check all connections, wired locations correct. Resistor n cap values correct. Lots of cleaning up still. Def not calling it ready to power up yet.

Which of those solder joints do you think are better? Could the better one be better than it is, or is it good?

If you can't answer that question confidently, watch the linked soldering videos in my signature.

Which of those solder joints do you think are better? Could the better one be better than it is, or is it good?

If you can't answer that question confidently, watch the linked soldering videos in my signature

I’m not making any excuses, but I do appreciate those videos Josh. I honestly watch them as a refresher before every build. I def did this time too as this was my first turret build
I know the one turret was short on solder and the other fat on solder. Both were poor connections. I never did say either were 100% acceptable. However it’s one thing to add and another to remove. At least for me.
I’m half blind tho I do use magnifying lights.
So here now, my intention was to go thru n clean up all the connections. Slow n steady wins the race.
Dave