Rocket Build: Transformer Technical Questions

[TimDude]

So I'm putting together a parts list for building a Trainwreck Rocket. A lot of the transformers recommended on this site seem to be decommissioned, so I'm going with transformers that I can order right off the shelf. However, I have questions on the wiring.

It seems like if you're building a Trainwreck, the ClassicTone 30W Power Supply is one of the only options on the market if you want to buy off the shelf. http://www.triodeelectronics.com/40-18065.html
The documentation for this transformer is here: http://www.classictone.net/40-18065.pdf

My next string of questions with this transformer is with regards to how it should be wired. These questions are with regards to the layout from the "Documents" forum attached at the bottom of this post for convenience.

Question 1: I will not use the 300V windings, correct? I'm supposed to take those and simply shrink-wrap them and hide them, correct?
Question 2: The green/yellow wires are my 260V going to pins 4 and 6 of my rectifier, correct?
Question 3: The two Black wires coming out of "PT 1" hole are the 120V, correct?
Question 4: The two wires going to pins 2 and 8 of the rectifier are the 5V wires, correct?
Question 5: The two Brown wires coming out of "PT 2" hole are the 6.3V wires, correct?
Question 6: On the layout document, there are two wires, Brown/White and the Yellow/Red, coming to ground. Which two wires would those be on my transformer documentation? I'm thinking it would be the Red/Yellow 0V in the secondary winding, and it would be the White wire down in the 6.3V section. Am I correct, or am I dreaming on this one?

I do have a question or two on the output transformer as well. First, I'm considering going with the A470, it seems to be a common recommendation. http://triodeelectronics.com/noname.html and documentation here: http://www.triodeel.com/pdf/a470sdiag.pdf
Question 7: If this output transformer is 4.3k Ohm, why does it have BLU/WHT-BLU and GRN/WHT-GRN? Do I disregard the GRN/WHT-GRN?

I'm also thinking I should consider the Classic Tone 40-18080 transformer here: http://www.classictone.net/40-18080.html and documentation here: http://www.classictone.net/40-18080.pdf
This output transformer is $30 cheaper. It also has the option to go for 4.3k Ohm or 6.6k Ohm.
Question 8: I'm curious if anyone has any experience with this output transformer or can compare it to the A470. Should I save the $30, or should I splurge and get the more expensive output transformer?

Lastly, the choke. Apparently this is the only thing to get, unless I'm mistaken, the Hammond 158L. https://www.mouser.com/ProductDetail/Ha ... SoVuCNw%3D
Question 9: is there another choke I should look into?

Thanks in advance for answering any or all of these questions,
Tim

[2tone]

the Green and Green/White are the screen grid for ultralinear type operation. You can tape them off. That's what is on my original Dyna 470 OT..

[TimDude]

the Green and Green/White are the screen grid for ultralinear type operation. You can tape them off. That's what is on my original Dyna 470 OT..

That's what I was thinking. Thanks!

[M Fowler]

The A470 OT is a great transformer but yes it costs more. Edcor, Mercury, and Pacific makes them too.

Doesn't Merren make Trainwreck transformers too.

The Hammond 158L choke is perfect choice.

Mark

[Mark]

Merren doesn't make Trainwreck transformers anymore as he doesn't have the materials and it would be too expensive to buy them for a couple of transformers.

As far as using the Classictone power transformer goes, I used one in my Rocket build and they are physically larger than other transformers (Heyboer), found I have a rail voltage of 315VDC. 300VDC is the ideal value as the EL-84's run at 100% at this voltage.

The screen grid comments in the layout should come with a caution, 1K screen grid resistors means less bass. Many people have increased the screen resistors to 220 ohms and 270 ohms and gotten good tone.

[norburybrook]

Also, don't worry to much about transformer positions if you use larger ones, i.e. keeping to the original positioning. I've made rockets and express amps and always had to mount transformers like the Komet amps in a line with the choke in the middle.


regarding bass on the rocket......... it has plenty in it's default state, you'll find yourself turning the bass knob down most of the time.


M

[TimDude]

Thanks for all of the responses.