[L0rdGwyn]

Busy day. Marking up the chassis and finalizing the layout took a big chunk of time. Jamming quite a bit inside, so the measurements needed to be exact.

Nearly finished drilling as well, just need to use a step bit to drill some holes for the wires to pass from the transformers. Wanted to finish, but it is 10° F right now! It was time to come inside. The cold keeps the drill bits nice and cool though

Otherwise, drilling is done. Tomorrow I will add the wiring holes, strip some of the anodization off for grounding and the transformer shield connection, then start mounting the components. Should have everything mounted by the end of the day tomorrow.

 

[L0rdGwyn]

Made some major progress today. Thought I was going to just be doing a wee bit of drilling and mounting the components, but I had a little surprise...

I realized the panels of this chassis were not electrically connected due to the anodization. The hardware does not link the metal panels the way it is constructed. This is a safety issue in addition to not providing adequate shielding from the outside environment, so I had a little project on my hands.

First finished my drilling, then went to work on the chassis with my Dremel. Had to grind away the anodization on the hardware contact points to link the four side panels, then use a wire brush attachment to remove the anodization on the corners of both the top and bottom panels, AND the corners of the side panels. This allows a metal-to-metal connection so the entire chassis is now groundable. An absolute PITA, but it had to be done.



With the drilling done and my grounding issue resolved, the prepwork for the chassis was finally complete (back panel was on backwards in this photo ).



Last thing I did today was mount the major components. Not everything is in there, but the major stuff is. I'll have to take the chokes back out to wire them, but I wanted to see how everything fit together. Good news, this is starting to resemble a tube amplifier.

Here are some pics of the interior:



And a little teaser of what the amp is going to look like when complete:



So far so good, really like how it is looking. Next thing will be to mount the final minor components, then start wiring! Probably will take it easy tomorrow, been at it non-stop for two days

 

[mordy]

Wishing you good luck with a home run on the first try!

 

[L0rdGwyn]

Wishing you good luck with a home run on the first try!

Thanks, mordy. So far all of my planning has payed off, let's hope that continues! I've invested a lot in this amp, so it better sound good (I think it will ).

 

[2359glenn]

Nice job!!!
Now the fun of wiring it.
Looks like it will be done next week

 

[leftside]

Looking really good. Makes me appreciate the fine work that Mischa and Glenn do even more.

 

[L0rdGwyn]

Nice job!!!
Now the fun of wiring it.
Looks like it will be done next week

Yes, the wiring is going to be interesting. Unfortunately, it won't be completely done until early March, K&K didn't have my output transformers, they are on the way. Should be here in the next two weeks, but with everything else done, will be very simple to drop them in

 

[Tjj226 Angel]

Jesus those clarity caps are a LOT bigger than I would have guessed.

So far so good though. You lay out your stuff a hell of a lot better than I do, so Im sure you will be successful. : )

 

[L0rdGwyn]

Between last night and this morning, I finished wiring the tube heaters. Not trivial given the oddball tubes that are going in this amp. Thankfully, as I've thought about it, this project is going to get easier as I go, should be over the hump on extremely tedious tasks now

Here is the mains transformer wired. All of the wire is PTFE insulated silver-plated copper, all twisted with a hand drill. I ended up adding some voltage dropping resistors for the power tubes. I opted to solder them directly onto the transformer heater pins, only dissipating 0.25W a piece and are rated for 5W. One less thing to mount in a crowded amp and I can keep a better twist up to the heater pins without resistors in the way.



Here is a mess of mains and heater wires after mounting the transformer. Chokes were removed for more working room and to get the heater wiring into the corners of the amp.



Here is the result. For my layout, I had originally wanted to keep all of the AC wiring on one side of the amp, and the major signal wiring on the opposite side. I couldn't justify sending heater wiring across the middle of the amplifier for the right output tube, so it is on the signal wiring side. I am using shielded wire for the inputs, so shouldn't cause any hum issues. If it does, can always move it later, I may reconsider.



Here are some of the dropping resistors, the set on the left (yellow wiring) drops the 5.9V winding down to 5V for use of 5Z3 rectifiers. The set on the right (green wiring) drops the other 5.9V winding down to 4V for the driver tubes. Note that it is center-tapped with a pair of 100ohm resistors. I wasn't originally going to use any chassis-mount resistors, but decided I needed to dissipate some of heat into the chassis since it has essentially no airflow. Together they are dissipating about 5W, with thermal compound in between the resistors and the chassis wall.



And here is the rectifier socket. This combination socket from Yamamoto allows the use of 5V UX4-base rectifiers (for my purposes, 5Z3), as well as European 4V B4-base rectifiers (U18/20, FW4/500, 45-IU, etc.), which will be what I use primarily. A pair of 0.2ohm resistors drops the voltage down from 5V to 4V for the B4 filament pins.



I originally wasn't going to post any finished-product-looking photos of the amp until it was actually done, but what the heck, it looks pretty cool!

In these photos are a Marconi-Osram U18/20 rectifier, Marconi-Osram CV399 driver (military MH4), and Sylvania 6A5G output tubes.



And as promised, it can use 5V 5Z3 rectifiers as well. Here is a Fivre 5Z3.



That's all for now, we'll see if I have the energy to get started on the power supply today, that is the next step

 

[Zachik]

Looks great, and the workmanship of the wiring - I would say it is Glenn level (which I think is a big compliment)!!

 

[chrisdrop]

Between last night and this morning, I finished wiring the tube heaters. Not trivial given the oddball tubes that are going in this amp. Thankfully, as I've thought about it, this project is going to get easier as I go, should be over the hump on extremely tedious tasks now

Here is the mains transformer wired. All of the wire is PTFE insulated silver-plated copper, all twisted with a hand drill. I ended up adding some voltage dropping resistors for the power tubes. I opted to solder them directly onto the transformer heater pins, only dissipating 0.25W a piece and are rated for 5W. One less thing to mount in a crowded amp and I can keep a better twist up to the heater pins without resistors in the way.



Here is a mess of mains and heater wires after mounting the transformer. Chokes were removed for more working room and to get the heater wiring into the corners of the amp.



Here is the result. For my layout, I had originally wanted to keep all of the AC wiring on one side of the amp, and the major signal wiring on the opposite side. I couldn't justify sending heater wiring across the middle of the amplifier for the right output tube, so it is on the signal wiring side. I am using shielded wire for the inputs, so shouldn't cause any hum issues. If it does, can always move it later, I may reconsider.



Here are some of the dropping resistors, the set on the left (yellow wiring) drops the 5.9V winding down to 5V for use of 5Z3 rectifiers. The set on the right (green wiring) drops the other 5.9V winding down to 4V for the driver tubes. Note that it is center-tapped with a pair of 100ohm resistors. I wasn't originally going to use any chassis-mount resistors, but decided I needed to dissipate some of heat into the chassis since it has essentially no airflow. Together they are dissipating about 5W, with thermal compound in between the resistors and the chassis wall.



And here is the rectifier socket. This combination socket from Yamamoto alows the use of 5V UX4-base rectifiers (for my purposes, 5Z3), as well as European 4V B4-base rectifiers (U18/20, FW4/500, 45-IU, etc.), which will be what I use primarily. A pair of 0.2ohm resistors drops the voltage down from 5V to 4V for the B4 filament pins.



I originally wasn't going to post any finished-product-looking photos of the amp until it was actually done, but what the heck, it looks pretty cool!

In these photos is a Marconi-Osram U18/20 rectifier, Marconi-Osram CV399 driver (military MH4), and Sylvania 6A5G output tubes.



And as promised, it can use 5V 5Z3 rectifiers as well. Here is a Fivre 5Z3.



That's all for now, we'll see if I have the energy to get started on the power supply today, that is the next step

Lookin' good. Very pretty all 'round.

 

[L0rdGwyn]

Thank you gentlemen, much appreciated, gonna keep chugging along. Supposedly I will have a nice sounding tube amp at the end of all this madness, we will see!

 

[leftside]

Going for a two box/chassis solution with external power supply?

 

[L0rdGwyn]

Going for a two box/chassis solution with external power supply?

Not this time around, maybe on a future project! It's all in there, just need to wire it, test it, make sure I am getting the expected voltages. I have some high-wattage dummy resistors to approximate the tube load, so that will tell me things are looking okay before I connect any precious tubes

 

[2359glenn]

Between last night and this morning, I finished wiring the tube heaters. Not trivial given the oddball tubes that are going in this amp. Thankfully, as I've thought about it, this project is going to get easier as I go, should be over the hump on extremely tedious tasks now

Here is the mains transformer wired. All of the wire is PTFE insulated silver-plated copper, all twisted with a hand drill. I ended up adding some voltage dropping resistors for the power tubes. I opted to solder them directly onto the transformer heater pins, only dissipating 0.25W a piece and are rated for 5W. One less thing to mount in a crowded amp and I can keep a better twist up to the heater pins without resistors in the way.



Here is a mess of mains and heater wires after mounting the transformer. Chokes were removed for more working room and to get the heater wiring into the corners of the amp.



Here is the result. For my layout, I had originally wanted to keep all of the AC wiring on one side of the amp, and the major signal wiring on the opposite side. I couldn't justify sending heater wiring across the middle of the amplifier for the right output tube, so it is on the signal wiring side. I am using shielded wire for the inputs, so shouldn't cause any hum issues. If it does, can always move it later, I may reconsider.



Here are some of the dropping resistors, the set on the left (yellow wiring) drops the 5.9V winding down to 5V for use of 5Z3 rectifiers. The set on the right (green wiring) drops the other 5.9V winding down to 4V for the driver tubes. Note that it is center-tapped with a pair of 100ohm resistors. I wasn't originally going to use any chassis-mount resistors, but decided I needed to dissipate some of heat into the chassis since it has essentially no airflow. Together they are dissipating about 5W, with thermal compound in between the resistors and the chassis wall.



And here is the rectifier socket. This combination socket from Yamamoto alows the use of 5V UX4-base rectifiers (for my purposes, 5Z3), as well as European 4V B4-base rectifiers (U18/20, FW4/500, 45-IU, etc.), which will be what I use primarily. A pair of 0.2ohm resistors drops the voltage down from 5V to 4V for the B4 filament pins.



I originally wasn't going to post any finished-product-looking photos of the amp until it was actually done, but what the heck, it looks pretty cool!

In these photos is a Marconi-Osram U18/20 rectifier, Marconi-Osram CV399 driver (military MH4), and Sylvania 6A5G output tubes.



And as promised, it can use 5V 5Z3 rectifiers as well. Here is a Fivre 5Z3.



That's all for now, we'll see if I have the energy to get started on the power supply today, that is the next step

Nice job Keenan