Mods for my 2204 build - switchable JEL and #34?

  • Thread starter Thread starter ledvedder
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The one on the right is fine but the one going across the tube to pin 1 id have it approach the pin more vertically and like an upside down U

And yes protect the leads since they will have B+ on them.

Could be fine as is but better to approach the pin from above with a little hook on it to solder than horizontally.

Also you’re going to need to bend it to be away from those heater wires. Use pliers to properly fit it up and over the grid and cathode and to also add the hook on the end.

It will buzz badly as shown now since it’s leaning up against the heater wiring
 
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glpg80 said:
The one on the right is fine but the one going across the tube to pin 1 id have it approach the pin more vertically and like an upside down U

And yes protect the leads since they will have B+ on them.
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Or should I pull them back close to the terminal strip and run wires to the pins? Sort of like this.
86cfdd0d-ce69-44d7-b869-06899cf62ec4.png
 
I’m not a fan of that method. I don’t like leaving the other side of the resistors in the air like that. With the current method they won’t move once soldered to the pins and to the terminal strip tangs.
 
You’re pulling AC current for two stages out of phase from the same B+ wire. If you do that pull two seperate wires from the B+ node and feed each resistor separately.

Long story short wires have series inductance and you’re going to get odd high frequency responses with only one wire from the same node.

You also have 350V within arcing distance of the chassis. That’s the other reason I don’t like that method - the resistors aren’t being held by solder on both sides to something solid.
 
I like this instead. Each resistor lead is solders to something solid. You can also protect the leads with heat shrink.

Pull two seperate B+ wires for each plate resistor here as well.

56CFCFBB-30A6-4968-9FA0-8D7A3DDD57B1.jpeg
 
glpg80 said:
You’re pulling AC current for two stages out of phase from the same B+ wire. If you do that pull two seperate wires from the B+ node and feed each resistor separately.

Long story short wires have series inductance and you’re going to get odd high frequency responses with only one wire from the same node.

You also have 350V within arcing distance of the chassis. That’s the other reason I don’t like that method - the resistors aren’t being held by solder on both sides to something solid.
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Got it! I didn't realize I couldn't pull both from the same B+ wire. OK, I'll run the resistors from the tag strip up and over to the pins.

Again, thanks for all your help with this. I'm sure I'm being a real pita 😂
 
glpg80 said:
I like this instead. Each resistor lead is solders to something solid. You can also protect the leads with heat shrink.

Pull two seperate B+ wires for each plate resistor here as well.

View attachment 133831
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So run the B+ wires directly to the plate pins? Or through the plate resistors first, then to the pins?
 
ledvedder said:
Got it! I didn't realize I couldn't pull both from the same B+ wire. OK, I'll run the resistors from the tag strip up and over to the pins.

Again, thanks for all your help with this. I'm sure I'm being a real pita 😂
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Nah man I love this! You’re killing it doing all of this in one night. I can tell you’re excited. You’ll have to share a clip with us.

You’re getting close. Don’t forget to double check all wiring after you get it done and then post voltages here of all pins so we can make sure it’s good.
 
glpg80 said:
Nah man I love this! You’re killing it doing all of this in one night. I can tell you’re excited. You’ll have to share a clip with us.

You’re getting close. Don’t forget to double check all wiring after you get it done and then post voltages here of all pins so we can make sure it’s good.
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Yeah man! This is what's become my "wild Friday nights". 😂
 
Each wire can carry an AC current independent of the other. Yes their fields can couple when twisted but it’s far less of an impact than pulling two different out of phase AC currents through the same wire. It will at least function as intended.
 
ledvedder said:
What are the 2 sets of wire coming off the left side? Shouldn't the wires going to the 0.022 and 0.047 caps come off their respective plate pins?
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Oh those are just grid and cathode wires snd then I also drew your heater wires.
 
Wow, this is a lot of intricate work! I hope I like it lol. Do you know of any decent clips of any 800's modded like this?
 
ledvedder said:
Wow, this is a lot of intricate work! I hope I like it lol. Do you know of any decent clips of any 800's modded like this?
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Yes. My Laney GH100S 😎

It’s very similar. Some other tonal tweaks but similar concept.

Aldrich mods are like this as well. You’ll have on that order of gain if not a bit less.
 
ledvedder said:
Wow, this is a lot of intricate work! I hope I like it lol. Do you know of any decent clips of any 800's modded like this?
Click to expand...
That’s what’s cool about PTP amps. Don’t like it then you can always take it out without worrying about ruining traces.

I wouldn’t put you through this complexity if I knew it’s what you’re searching with the stacking of mods you wanted.
 
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