New Komuro 300b dc coupled amp build thread

[Yesterday]

Planning to do a build of this amp and post pics. But here and there also pics of my failures. Often people (including me) just show the end result.

I already did the chassis wooden frame a year ago or so. Needed a power transformer which I took from an old amp. It was already painted in my "house style" But I noticed the "top cover" could be better. So I lightly sanded it after drilling the holes...and thought right. Lets spray on a primer again before painting.


Bad idea. The primer ate into the paint..this pic is after spraying it with some more primer. I used the primer as a paint stripper.

 

[Yesterday]

Far from perfect. But good enough.

 

[Selmerdave]

Following

 

[spantou01]

How did you attach the screen?

 

[zackthedog]

Nice save! I'm a terrible novice at painting metal parts.

 

[Yesterday]

How did you attach the screen?

Wood glue. PVA. Which suprisingly is extremely heat resistant. I was experimenting with coating my crossover with it...and had to resolder a part in. A 400 degrees celcius hot soldering iron did not ignite or burn it...and it would hardly budge.

 

[Yesterday]

Feet for my first ever non bought oak frame. In hindsight it would have been prettier to have them "sunk" even deeper.

 

[Yesterday]

The feet are "ebonized" with the good old vinegar and iron scouring pads solution...Then some blo which makes it even darker. The chassis from leftover wood of a tabletop I used for my open baffle speakers.

 

[Yesterday]

"Say hello to my little friends!" 5kg or 11lb a piece.



The output transformers made by a Dutch winder. MUG transformers. First time using his transformers so time will tell. But he has a good reputation..
Enclosures are aluminium. Painted in my "house style"

 

[Yesterday]

Note to self. Scarface references are soooo 80s. And not appreciated by the AudioKarma folks.

Back to progress:
I like to have little subchassis. It helps "modulerize" and therefore I can make some progress in my cramped little hobby room without having the whole chassis on my desk. Which won't fit.

I use cutouts from other projects sometimes...for example this square bit cut out for a mains transformer.


Above is my work from home desk. Set up to assist in holding the little plate....


I then use the cutout as a drill template where I want it in the main chassis.

The Takman were in my stash taken out of a Baby Huey PP amp's carcass.

 

[Yesterday]

Example how I used the subchassis in my 2a3 amp.

 

[Yesterday]

 

[Selmerdave]

Very nice work, looks like you're going to have a beautiful, beautiful-sounding amp!

 

[Lavane]

Very nice! What is the color of that hammer finish paint? I really like it too.

 

[Yesterday]

 

[Yesterday]

Pimped my Magnequest Abbie chokes. I've actually had the hammerite before. But it did not look good enough with the brass end bells. So I tried the same type off white as in the pics for the body. Not bad. But still not good enough. So I spray painted the brass. And went with hammerite om the body.

 

[Yesterday]

 

[Yesterday]

Sickening. Both off center. One 1.1mm more than the other. But I'm not re-doing. Should be not noticeable once assembled. I'll make it work.

 

[Yesterday]

I am very happy though that I still have some real USA made UX4 sockets with silver connections.

 

[Yesterday]