Newbie builds Cornet 2

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Hazzard

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Newbie builds Cornet 2
« on: 10 Jan 2013, 06:23 pm »
I've ordered the Cornet 2 kit, and I'm beginning to order parts.  Couple of questions, and I hope they haven't been asked too often before:

I can't find the IN5821 diodes -- Digikey no longer seems to carry them.  Source/substitute?

Likewise the red/green LED.

And I do want to add a power switch to my Cornet, probably at the back so I don't have to run AC past low-level signals.  Any hints/tips on this?

poty

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Re: Newbie builds Cornet 2
« Reply #1 on: 11 Jan 2013, 07:50 pm »
http://www.digikey.com/product-detail/en/1N5821-T/1N5821DICT-ND/190683http://www.digikey.com/scripts/dksearch/dksus.dll?FV=fff40008%2Cfff801b9%2C94007b&vendor=0&mnonly=0&newproducts=0&ptm=0&fid=0&quantity=0&PV319=593&stock=1You can easily rewire the input connections to adopt backside switch, but if you ask the question - it is probably better to begin with stock version.

bregez

Re: Newbie builds Cornet 2
« Reply #2 on: 11 Jan 2013, 08:01 pm »

And I do want to add a power switch to my Cornet, probably at the back so I don't have to run AC past low-level signals.  Any hints/tips on this?

The IEC module has a switch built in it.
http://www.digikey.com/product-detail/en/10CS1/CCM1647-ND/379678
Those heat sinks on the board should shield the AC from the low-level inputs.

Hazzard

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Re: Newbie builds Cornet 2
« Reply #3 on: 11 Jan 2013, 09:40 pm »
Many thanks!  Yeah, I just discovered the AC input has a built-in switch. (D'oh!) On the positive side, a dip into my collection of old tubes turned up a set of NOS black-plate 12AX7s and some JAN Philips 12AU7s -- at least I won't have to shop for those.

bregez

Re: Newbie builds Cornet 2
« Reply #4 on: 11 Jan 2013, 10:48 pm »


Likewise the red/green LED.



Digikey Part #    754-1548-ND may be a substitute.  I just looked at the data sheet and it seems the main difference is the replacement LED's red will be brighter.  There is also a small difference in the red forward voltage ( Discontinued= 1.85V, Replacement= 1.95V).  It's worth a shot for $0.36

Discontinued LED data sheet====  http://www.mouser.com/ds/2/216/WP59SRSGW-CC-48011.pdf
Replacement LED data sheet====  http://www.mouser.com/ds/2/216/WP59SURKSGW-78133.pdf

Hazzard

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Re: Newbie builds Cornet 2
« Reply #5 on: 12 Jan 2013, 02:05 pm »
Thanks very much, bregez -- that helps.  I realized one reason I couldn't source those parts through Newark is that I'm ordering through their Canadian site -- for some reason they don't stock them, though the US site seems to.  I can find the diodes I need at Mouser, too, I think.

While I wait for the printed circuit board to arrive I've been scrounging through my parts box.  Found a couple of very nice unused (now discontinued) Hovland MusiCaps (1.0 uf, 400 v) that might work as output couplers, if they fit.

Hazzard

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Re: Newbie builds Cornet 2
« Reply #6 on: 30 Jan 2013, 01:27 pm »
Finished!  And what a great project.  It was a pleasure to get out the drill press and soldering iron and work on it.  Needless to say, I'm incredibly impressed with the sound.  I'll try to attach a photo here, but you can see more pictures at http://s1304.beta.photobucket.com/user/AdamHazzard/media/DSC03584_zps555d1619.jpg.html?sort=3&o=3





Hazzard

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Re: Newbie builds Cornet 2
« Reply #7 on: 30 Jan 2013, 03:48 pm »
Okay, one more picture.  I was happy with the metalwork on this project, since the only power tool I have is a drill.  I was well-stocked with Greenlee punches, but cutting out the rectangular opening with a nibbler was -- well, time-consuming.


galyons

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Re: Newbie builds Cornet 2
« Reply #8 on: 30 Jan 2013, 04:35 pm »
Well done! Congratulations!
Cheers,
Geary

jostber

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Re: Newbie builds Cornet 2
« Reply #9 on: 30 Jan 2013, 04:36 pm »
That's a nice looking Cornet! Thanks for posting.

WireNut

Re: Newbie builds Cornet 2
« Reply #10 on: 30 Jan 2013, 06:03 pm »
 Awesome job. Only took 20 days from the original post.  :thumb:
 
 Did you have any hum issues at all ?
  Any problems with the manual ?

 Steve
 

Hazzard

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Re: Newbie builds Cornet 2
« Reply #11 on: 30 Jan 2013, 06:11 pm »
No hum issues at all.  I was careful to grind off a little of the anodized finish where the chassis parts made contact, to make sure the entire case was grounded, and I was careful with wire placement, not that that was much of an issue.  I made sure the transformer case had a ground path to the chassis, too.  In my system -- which uses Lowthers -- it's dead quiet

The manual was fine, given that I've had some experience with electronics.  It's not a project I would give to a rank beginner, but the Hagerman site makes it clear that you do need some experience.

WireNut

Re: Newbie builds Cornet 2
« Reply #12 on: 30 Jan 2013, 06:35 pm »
 
 What was your approx total cost to build (with or without tubes) ?
 
 Thanks,
 Steve
 

Hazzard

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Re: Newbie builds Cornet 2
« Reply #13 on: 30 Jan 2013, 06:40 pm »
I raided my parts box for some of this, including the tubes, but I probably spent between five and six hundred dollars all told.  I'm wincing at the thought of opening my credit card bill, but it's an absolute bargain for this kind of performance.

WireNut

Re: Newbie builds Cornet 2
« Reply #14 on: 30 Jan 2013, 06:48 pm »

 A close-up pic of the rear where the wires past thru the board to the RCA's would be awesome.
« Last Edit: 30 Jan 2013, 10:55 pm by WireNut »

WireNut

Re: Newbie builds Cornet 2
« Reply #15 on: 31 Jan 2013, 08:20 am »
I was well-stocked with Greenlee punches.

Hi Hazzard,

I will need to buy some Greenlee punches. What sizes do I need to purchase?

Thanks,
Steve

Hazzard

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Re: Newbie builds Cornet 2
« Reply #16 on: 31 Jan 2013, 04:59 pm »
I used 1 3/8" for the opening for the 5Y3 and a 1 1/8" for the 12AX7s and 12AU7.  For the holes under the transformer I used a .75" -- a little larger than specified, but it works, and that was the punch I had. 

smitkoku

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Re: Newbie builds Cornet 2
« Reply #17 on: 2 Feb 2013, 12:29 am »
Looks great Hazzard.  That's what I love about these kits, you can get performance that you would have to pay >3x as much to get in a commercial product.   :thumb:

Then there is the pride factor....you can't put a price on that!!! :eyebrows: