New Fender "type" amp build suggestions
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Re: New Fender "type" amp build suggestions
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.
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.
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Re: New Fender "type" amp build suggestions
I was wondering about that. These are 1/2w.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’ve got a 1k 3.75w or 3w. Both wirewound.
Will these work?
Attached pics so far.
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Re: New Fender "type" amp build suggestions
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.
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.
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Re: New Fender "type" amp build suggestions
Good stuffYes 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.
Thx
Dave
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Re: New Fender "type" amp build suggestions
These 10uF E caps are bipolar. Do you suggest I remove and replace with standard polarized caps?[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.
Thx
Dave
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Re: New Fender "type" amp build suggestions
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
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
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Re: New Fender "type" amp build suggestions
They should be electrolytic. This is part of the power supply.foreverstrung wrote: ↑Mon 11/17/25 6:51 amThese 10uF E caps are bipolar. Do you suggest I remove and replace with standard polarized caps?[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.
Thx
Dave
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Re: New Fender "type" amp build suggestions
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.foreverstrung wrote: ↑Mon 11/17/25 8:06 pmAnother 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
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Re: New Fender "type" amp build suggestions
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.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.
I’m sure the 450v will be good.
Dave
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Re: New Fender "type" amp build suggestions
450V is overkill and probably kinda huge. I use 10uf 100V caps. 50V is borderline given the bias voltageforeverstrung wrote: ↑Wed 11/19/25 9:29 pmMy 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.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.
I’m sure the 450v will be good.
Dave
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Re: New Fender "type" amp build suggestions
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’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
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Re: New Fender "type" amp build suggestions
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..
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..
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Re: New Fender "type" amp build suggestions
Grounds and shield connections should serve no other purpose.
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Re: New Fender "type" amp build suggestions
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 placementI 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 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
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Re: New Fender "type" amp build suggestions
Better?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..
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Re: New Fender "type" amp build suggestions
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.
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.
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Re: New Fender "type" amp build suggestions
What are your thoughts on this photo?
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Modern Ground Schemes
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Step 1: Remove and discard all JJ tubes.
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Step 1: Remove and discard all JJ tubes.
Step 2: Highlighter test.
Step 3: Use a Voltage Chart from the downloads section to test your voltages.
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Re: New Fender "type" amp build suggestions
Turret needs better solder.What are your thoughts on this photo?
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.
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Re: New Fender "type" amp build suggestions
Which of those solder joints do you think are better? Could the better one be better than it is, or is it good?foreverstrung wrote: ↑Sat 11/22/25 1:23 amTurret needs better solder.What are your thoughts on this photo?
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.
If you can't answer that question confidently, watch the linked soldering videos in my signature.
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'I installed a skylight in my apartment yesterday... The people who live above me are furious.' - Steven Wright
Modern Ground Schemes
Soldering Technique
B+ Voltage Reduction
Amplifier Tools & Parts Info
Troubleshooting Basics:
Step 1: Remove and discard all JJ tubes.
Step 2: Highlighter test.
Step 3: Use a Voltage Chart from the downloads section to test your voltages.
Web Design: flashydragon.com
Guitars / Amps / Effects: JMPGuitars.com
(anti)Social: Facebook · Instagram
Items for Sale
Modern Ground Schemes
Soldering Technique
B+ Voltage Reduction
Amplifier Tools & Parts Info
Troubleshooting Basics:
Step 1: Remove and discard all JJ tubes.
Step 2: Highlighter test.
Step 3: Use a Voltage Chart from the downloads section to test your voltages.
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Re: New Fender "type" amp build suggestions
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 buildWhich 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 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
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