[mingles]

I'd like to hear from people who built the kit using the Hammond chassis which is quite a bit smaller in height than the Lansing (3.47" versus 2.0"). I'll be using 1uF Mundorf SIO for C208 which are 1.22 inches tall. Has anyone else used large caps and squeezed them into the Hammond? Am I asking for trouble?

I'd also like to hear what folks think about relocating the transformer to a separate external box and using a shielded umbilical cord to attach the cabling. The Cole phono stage uses a similar design:

http://mysite.verizon.net/vze22yzp/id28.html

Ideally, I'd like to put a pair of Cinemags in the chassis. Jim has said you can't do this without getting a lot of hum, but if the tranny isn't anywhere near the SUTs, I'm wondering if it could work. Any thoughts?

thanks!
Mark

[standman]

Hello Mark,  I may not be able to help on this much but I have the standard cornet that was modded when I received it. Huge Mundorf caps-etc. Had to shim the bottom to get the cover on. Anyway I've had this thought as well as far as relocating the tranny. I've had some trouble with the 270 BX doing a little buzzing due to excessive ac line voltage I understand, and wanted to upgrade the tranny as well. I've been fairly happy with the modded Cornet however would like to try and take it a little further if I can before totally upgrading to a new one.  My understanding of electronics is very limited but I have a desire to learn and this may be a good place to start. 

[Eric H]

While it might not be impossible to use the 2" Hammond chassis it's a whole lot easier to use the 3" Hammond chassis...  trust me!

[mingles]

I'm sure the Lansing case is easier to use, but I'm not convinced it's worth $80 extra bucks. I'm pretty good at carpentry and metal work. I'm not planning to do anything fancy like Tubesforever did with banks of bypass caps. I just want to be sure the Mundorfs fit in the Hammond chassis without too much trouble.

Any other thoughts on relocating the tranny? The cabling will carry some noise in and out the back of the unit, but it has to be less than having the tranny sitting on top. I wonder if it will be quiet enough to put a pair of SUTs in there.

-Mark

[Brinkman]

Any Cornet2 building is years away for me, but I wouldn't feel so dead-set on marrying my SUTs to any one single phono preamp; it seems counter-intuitive as far as component auditioning/upgrading goes.

But if you're really set on it, I would home-brew a wooden chassis. Especially if I was good at carpentry (which I'm not). You could extend the chassis by one of the dimensions of the Power tranny, install it upside down inside the chassis, and effectively create a sub-chassis by putting up a wall between it and the SUTs. You could then line this sub-chassis with Texas Instruments RF/LF foil.

Regardless, it just seems like a PITA to drag around a stray power transformer (and not be able to use anything but your specific MC), like in the event you or a friend wanted to hear the Cornet2 in said friend's system. Besides, if one were to purchase/make an multi-tapped SUT, one would have access to the knobs that adjust the gain and loading, as well as the option of not using it at all.

Best,
Brinkman

[hagtech]

The CineMags should go right next to the input tubes.  NOWHERE near the high voltage wires in the power supply!

jh

[mingles]

Brinkman, thanks for the comments.

I wouldn't feel so dead-set on marrying my SUTs to any one single phono preamp; it seems counter-intuitive as far as component auditioning/upgrading goes.

I agree, but if I put the SUTs inside they won't be hard wired into the circuit. I'll have a switch that toggles between MM and MC. The only reason I'm thinking about putting them inside is to eliminate an extra set of ICs in front of the phono stage. Maybe I'm making too much of this, but the cartridge signal is already very tiny. In theory, less wire will change it less. And good ICs aren't cheap.

it just seems like a PITA to drag around a stray power transformer

I agree, but I'm planning to use a DIN to disconnect the tranny.

(and not be able to use anything but your specific MC), like in the event you or a friend wanted to hear the Cornet2 in said friend's system. Besides, if one were to purchase/make an multi-tapped SUT, one would have access to the knobs that adjust the gain and loading, as well as the option of not using it at all.

If I put the SUTs inside, all of these things will be adjustable via toggle switches in the back.

[mingles]

The CineMags should go right next to the input tubes.  NOWHERE near the high voltage wires in the power supply!

Hi Jim, thanks for that tip! In general, what do you think of relocating the tranny? Would you predict marginal or solid benefits?

[Brinkman]

Mark,

You have obviously put a lot of thought into this, but prior threads here have made me apprehensive about running extra wires down the length of the chassis, getting stray fields from the power supply at each pass. In your case, you have wiring going from the rear inputs to the cinemags up front (per Jim's advice), from the cinemags to the gain switch in the rear and back to the cinemags, then again from the cinemags to a loading switch in the rear, and finally, back to the cinemags.

That's five passes. Per Cinemag.

And I'm concerned about the power supply to the motorized volume pot I'm going to put in my Clarinet!

I think we all feel sick when a fellow DIYer's having having hum or instability problems with their build, especially when it's a Hagerman design. And as educational a hobby it can be when you're forced to troubleshoot, I think it's even better to not have to troubleshoot at all.

Best,
Brinkman

[taskerc]

While it might not be impossible to use the 2" Hammond chassis it's a whole lot easier to use the 3" Hammond chassis...  trust me!

I agree with Eric - for me it was worth the extra cash.  But, I did see a 3" hammond case after I finished my lansing/Cornet2 and started thinking .....

The Lansing case is a really nice case - the hammond just looked and felt so DIY  .....

Now if someone could get some Cornet2 silkscreening going, I would ba a happy guy .........

[hagtech]

Remote placement of the power tranny will help.  The stray magnetic fields emanating from the core and coils can be quite problematic.  Keep in mind you also get the same thing from the long output wires (but not nearly as bad).  The orientation of the coils inside the tranny also makes a difference.  The "spray" goes in a dipole pattern (think large circles all going through center of core).

jh

[mingles]

Jim, I appreciate your thoughts. You've sold me on the idea.

I plan to wrap the umbilical that connects the tranny to the chassis with steel braiding. I don't think this will degrade the power quality, but it should contain some of the emf. If anyone has thoughts to the contrary, let me know.

Brinkman, I appreciate your comments on the Cinemags and troubleshooting. I'm having second thoughts about putting them in the chassis. For what it's worth, if they go in, the switches will be located in the front, so there won't be five passes by the high voltage. But your point is well taken.

I'm still trying to decide which case to get... decisions, decisions.

[Brinkman]

Mark,

I think you're pretty set on building a very utilitarian Cornet2. So I think moving the MC phono inputs to the front and mounting the SUT & associated knobs up front as well would be a good solution. Perhaps LO MC go in the front and MM goes in a separate input in the rear?

As for the transformer, sounds like you got that figured out.
Best of luck!

-Brinkman

[Big Jim]

I love the Hammond chassis and it doesn't look DIY at all if you know what you're doing with a little woodworking, plus I hate black audio components. They look shapeless or devoid of form to me. I have friends who come over and they all thought I'd bought the Cornet2 already built it looks that good. Mine has beautiful oak sides and corner pieces for the front.

Plus the money saved you can put into your BOM list. I built my Cornet2 for just a little over $225 and it sounds amazing. If you're a smart shopper you can put a Cornet2 together that will keep up with preamps costing 5 times as much, easily. In fact I heard a fancy pre that shall remain nameless and I was stunned at how cold it sounded. It was crazy strange because the rest of the system was beautiful, even god forbid when listening to CDs.

Mr. Hagtech has designed a beautiful PCB and kit. I hope more and more people get a chance to build one, and enjoy it. BTW soldering to a PCB as opposed to P2P is dead easy and fast! All my P2P pieces have had one problem or the other no matter how careful I've been. The Cornet2 had no issues and sounded beautiful the first few minutes I fired it up. Stunning!   

[mingles]

Big Jim, can you post a pic of your Cornet? I'd love to see what you've done.

I'd also like to see pictures of other Cornets. I'm still in the planning phase, so I'm looking for ideas and inspiration. I've decided not to use the Hammond or Lansing case. I'm sure it would be easier, but I seem to like difficult projects. I want to build a chassis using wood for the front and sides, and sheet metal for the top, bottom and rear. I have it sketched out, but I need to find a place to buy the metal. Any suggestions? I may just use the Hammond cover plates from AES. I'd have to cut them to size and paint them black.