WE91A Clone - Iron Fest

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I got all the parts together for a WE91A clone. I have been talking to Raymond Koonce of Time Bandit Audio about the project and gave me some useful info on sourcing parts and construction.
It's going to be all Hammond irons (there are 9) with NOS RCA 5692s and JJ 300Bs. Good for around 8-9 wpc. I am going to powercoat the 17x10x3 hammond chassis and iron bells in apple candy red. Hopefully I can fit eveything in the chassis:


http://bp0.blogger.com/_i08-ibvZ150/R89YkcCGe4I/AAAAAAAAAsU/WZzx3h_Fq8w/s1600-h/S5033052.JPG

[parabellum]

heheh you just wanna powdercoat something. I'd rather grab some spray and paint it. Painted an aluminum chassis once for a preamp and it looked so good I surprised even myself with the paint job quality.

Good luck with it.

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Powdercoating easy and cheap. Great finish in no time, instead of putting in hours of painting, clearcoating, sanding, etc. More power to you if you're an expert at spray painting, but I am not. Besides, I'd rather concentrate on actual construction of the amp.

[parabellum]

actually i never tried before that and thats why i was so surprised to see it come out so well :)

I'm interested to see how yours turns out, i love powdercoat finish too.

[EWBrown]

Holy moly, batman... THat's impressive and is going to weigh a ton Yellow_Light_Colorz_PDT_08

/ed B in NH

[Brik]

Impressive hardware, indeed! I cannot wait to see the completed project.

WFIW, I am building a stereo KT88 pp amp on a Hammond 17x10x2 steel chassis. With all the iron on, the chassis visibly sags from the weight of all the transformers and a choke. I had to devise a reinforcement L-beam under the chassis a la Ed's suggestions.

/b

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Yes, the Hammond chassis I am using isn't the most robust thing in the world. With 35 lbs irons on top, I might get some sags too. I am putting in 9 x 7 12 ga aluminium plate underneath to fasten those oil caps, which I hope will help reinforce the top plate a little. I also have some metal strips to use as support if I can find room for them. Mounting those open frame trannies on the strips is always an option. BTW, I really like the look of 1626SEAs. I wish all Hammond Irons had the same finish on their bells like these ones instead of varnish.

[SteveH]

Got chokes ?
Yellow_Light_Colorz_PDT_01

[EWBrown]

I've used angle stock, usually 3/4 inch aluminum (about 1/16 - 1/8 inch thickness) and it can really stiffen up a saggy chassis.

it's better than viagra :o Yellow_Light_Colorz_PDT_09 Yellow_Light_Colorz_PDT_04 Yellow_Light_Colorz_PDT_08

/ed B in NH

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Ed,
Where can I get those angle stocks? I went to Home Depot to look for 'em, but to no avail. What section in hardware stores can I get find them? Thanks. -Min

[ecir38]

Min, Which schematic are you using?

[EWBrown]

I've usually just pulled the angle stock out of the scrap bin at work, when it occasionally appears... Sometimes I dumpster dive at the local town dump, they have a semi-trailer siized metal dumpster - though the dumpmasters usually give me some "crap" they don't actually tell me not to do so. Over the years, I've become a pretty good scrounger / vulture Yellow_Light_Colorz_PDT_05

Any sheet metal fabrication shop and most smaller (Ace, True Value, etc)hardware stores should have it available. The metal shops probably toss away short pieces. Big box stores like Lowe's or Home Despot probably won't have this angle stock, they want to sell big expensive stuff...

If you look in SorenJ's third photo of his amp on pre-bay, there is a good example of how I use the angle stock, across the centerline of the chassis.


/ed B in NH

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Brad,

Min, Which schematic are you using?

Click on "schematic" on Robert Koonce's 300B amp site (http://www.timebanditaudio.com/james300b/James300B.htm). This is his take on venerable WE91A. There is also a link to the WE91A article on Sound Practices magazine. The author (Joe Roberts) is obviously biased in favor of SE amps, but it's a good read nonetheless.

There is True Value around the corner, so I will try there. I gave my exit seminar for my degree to a bunch of first year grads and semi-interested/awake professors yesterday, so I will finally have some free time to work on this project. Yes, I definitely have my priority straight. Yellow_Light_Colorz_PDT_16

[Slartibartfast]

BTW, I really like the look of 1626SEAs. I wish all Hammond Irons had the same finish on their bells like these ones instead of varnish.

Yes the varnish finish scratches so easily! What is the finish on the 1626SEA tranny?

[EWBrown]

It looks like Black Oxide or perhaps black powder-coating.

/ed B in NH