Transformer orientation and suggestions.

[nanchangbob]

I finally received all my transformers from James in Taiwan. They were a pleasure to deal with.

My chassis has holes cut in the back for IE and binding posts. I rotated the back piece so I can have the amps sit as a mirror image to each other.

I'm looking at two possibilities now. But I am open to suggestions and advice. The one I like the most is with the Power transformer in the front with the leakage from front to back and the choke behind it in the corner. I was going to point it the same way. The output transformer is on the right side with the leakage pointing towards the output tubes. On the Uniamp board the heaters are along the front of the PCB against the front wall.

The other option I was thinking of was the Choke in the front and PT in the rear with the same orientation.

I'm waiting for the vent plates I ordered for the KT88's I'm ready to start making holes. Any advice you might provide is appreciated.

[richwalters]

You don't show a ruler, but one can get some idea on chassis and transformer size by the "valve holder" pinout.
The problem with encapsulated transformers is knowing which quatrant the internal iron and the core lay. Rule: Keep the mains transformer & choke proximity furthest away from the inputs, as the choke has a gapped core and will radiate a smoothing hum field.
Is it a Steel chassis ?

richy

[nanchangbob]

The chassis are aluminum. The inner dimensions are 400mm long, 295 deep and 75mm tall or 15.75" by 11.6 by 3". The iron is as follows:

6255H F OT 106mm by 80mm
9610 PT 122mm by 122mm
10-200S ch 90mm by 65mm

I can tell the orientation of the PT and OT from the drawings on the website °í·s¹q¤l¤u·~ªÑ¥÷¦³**¤½¥q

I need to write and verify the chokes orientation inside box. Thanks for your response Richy

[palmas]

Originally Posted by nanchangbob

The chassis are aluminum. The inner dimensions are 400mm long, 295 deep and 75mm tall or 15.75" by 11.6 by 3". The iron is as follows:

6255H F OT 106mm by 80mm
9610 PT 122mm by 122mm
10-200S ch 90mm by 65mm

I can tell the orientation of the PT and OT from the drawings on the website °í·s¹q¤l¤u·~ªÑ¥÷¦³**¤½¥q

I need to write and verify the chokes orientation inside box. Thanks for your response Richy

Sorry, but the choke is a PSU filter choke?

[nanchangbob]

Yes it is a power supply filter choke.

Here is a third option which places the output transformer next to the choke. The input is isolated on the far right side towards the back. The heater input is still along the front panel. Comments?

[palmas]

I would separate the PSU from the audio paret as much as possible.
As you need access to the back plate for signal input, signal output and ac supply, I would separate using one side for PSU and the other for the amp.
The PSU trandformer would be near the back to avoid having 230V AC running inside the case.
As you need to transport the signal input to the front (do you? for volume control?) I would also place the output tr on the back so that the wires will solder directly to the binding posts.

This would be my aproach but only placing all on top of the box you get the notion if it will work OK, also estetically

When I make monoblocks I use the back for PSU and the front for the amp, but use input and output on the sides, front part of the box.

[palmas]

here goes a drft of my first aproach

[nanchangbob]

Your draft looks like my option 2 in the first post except for the output tubes. I have them to the left of the transformer. The OT and board are 240mm together. My board is 295 deep and my vent plates I'm putting on are 65mm. I couldn't put the vent plates on if I put the output tubes in front of the OT.

[palmas]

Originally Posted by nanchangbob

Your draft looks like my option 2 in the first post except for the output tubes. I have them to the left of the transformer. The OT and board are 240mm together. My board is 295 deep and my vent plates I'm putting on are 65mm. I couldn't put the vent plates on if I put the output tubes in front of the OT.

From the picture it looked as if you could just squeese that on! even if in some part the PCB will get bellow the power tubes.
If not, tried to place one power tube each side of the output tr?

Nice box, Can I buy one similar?

[nanchangbob]

I should have the plates for the output tubes early next week. I may be able to slide the tube plates over the PCB? I take a look when they get here.

As far as the box goes. I'm working in China and I found the seller on the Chinese ebay/taobao. I would be happy to send you the link. They have it in silver and black. I paid $65 each here in China. I thought that was a bit high but it fit my needs. If your really interested I could inquire about shipping. I can speak the language ok but I can't read or write.