Another Cornet 2 ... HAS ARRIVED!

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G E

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Another Cornet 2 ... HAS ARRIVED!
« on: 18 Feb 2013, 01:31 am »
So..... I have pretty much finished up the parts sourcing for my Cornet 2 build.  Funny, Jim's sale on the Classic Cornet board got me thinking about a new project and after reading through the forums decided to go with the Cornet 2 version.

Interesting to go through all the threads and learn about the various approaches... very educational.  Here is my pending edition:

Lansing enclosure.  Thought about a custom wood case and metal top but got over that.
Auricaps as Jim indicates as an upgrade
I am going with the PC board mounted RCA jacks to eliminate wiring issues.  I looked for gold plated PC board versions but the hole configuration is unique to the part spec'd by Jim
Resistors as spec'd.
Tube sockets - non gold plated per some recommendation on the boards
Tubes.  I spent some money here on NOS, I figured this has great impact on sonic signature.  I have Bendix 6106, Mullard, Amperex, RCA BlackPlate ( a really old one from the late 1940's) and a couple others that escape me at the moment that will arrive this week.  Vintage Tube Service, Andy Bowman.  Very enjoyable interaction with him.
I also got a Hakko 888 soldering station.  Nice upgrade from a real basic RS 2 setting station.  I might end up with a drill press as well.  They are really handy to have.

I hope to get started this coming weekend. 

Looking forward to it!
« Last Edit: 19 May 2013, 05:43 pm by G E »

G E

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Re: Another Cornet 2 coming....
« Reply #1 on: 4 Mar 2013, 03:09 pm »
Checked in all my parts yesterday.  Everything is as ordered.

A question on the Hammond transformer and the internal ground wire.  If I remove the screws from the four corners to extend it to the internal star ground, what is the risk of the plates separating?  What about the risk of the transformer buzzing after I do this?

G E

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Re: Another Cornet 2 coming....
« Reply #2 on: 19 Mar 2013, 03:40 am »
I finally started the project this weekend.  Installed the sockets, straightforward enough once I figured out the dimple on the octal socket lined up to the little "o" on the silk- screened side.  Tried to make sure the contacts inside the ceramic body of the socket was aligned fairly well with the holes.  Also soldered in all the contacts for the transformer wiring.  It was a bit of a challenge to get them in reasonably straight so it didn't look all snaggledy-tooth.  Perhaps I am too picky about this stuff, but it has always paid off in the end.

There was a bit of a delay when I had to swap out my new Hakko FX-888 soldering station.  It had a loud and very annoying hum.  If I pressed lightly on the cover of the power supply case it would quiet completely.  I thought about rigging up something to dampen it but decided just to swap it out.  This is a nice solder station, much better than the RS junk I'd been using.

G E

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Re: Another Cornet 2 coming....
« Reply #3 on: 13 May 2013, 08:38 pm »
Long journey nearing its end!  In a way it is kinda sad to come to the end of the parts bag.  So full of goodies at the beginning and now it just has a few parts from ordering extras (just in case parts) and the rubber feet.

Last night I crimped on the terminal connectors, put in tubes (my test kit with new Sovtek rectifier, and  Electro Harmonix 12AU7 and  ancient JJ 12AX7 tubes I had laying around.  No smoke, no exploding caps, red LED tuned green after 10-15 seconds.  Voltage within 1-2% spec on the high side.  Excellent.  Heater voltage around 6.39

Replaced the Sovtek with my nos Bendix 6106.  Voltages in 1-2% range of spec but on the low side.  Heater voltage settled in at 6.42 so I will work on R223 values before putting in my nos 12AU7 and 12AX7 tubes.  With the Bendix it took perhaps twice as long for the LED to turn green.  At first I wondered if I got a dud.  It is certainly a more robust tube, weighs a good bit more and the elements inside look more substantial.  And they are straight, not tilted somewhat like the Sovtek.

Have not listened to it yet, will do so when I dial in the heater element voltage.  I am looking forward to that moment.


WireNut

Re: Another Cornet 2 coming....
« Reply #4 on: 13 May 2013, 08:58 pm »
Sounds good. What did you use to make the holes in the cabinet for the tubes, punches, drill press, milling machine  :?:

 

G E

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Re: Another Cornet 2 coming....
« Reply #5 on: 13 May 2013, 09:13 pm »
Sounds good. What did you use to make the holes in the cabinet for the tubes, punches, drill press, milling machine  :?:

I used a hand drill. I have an extensive bits kit which helped. I picked up a step bit and used it for the tube openings. One thing I did was to cover the top plate with painters blue tape and use a compass to accurately mark the circle. Good thing because the hole got off center and I had to work the drill a bit to get the hole right.  Seeing the circumference line was a life saver.  A drill press would have been handy. They all turned out round and I cleaned up with a dremel tool.

The receptacle opening on the back was done by drilling lots of holes and using a hand file to clean up. Paying attention in shop class 40 years ago has paid off.

G E

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Re: Another Cornet 2 ... HAS ARRIVED!
« Reply #6 on: 19 May 2013, 06:03 pm »
I updated the name of this thread to reflect the successful launch of my newly completed Cornet 2.

Before putting it into my system, I hooked it up to my headphone amp (original SOHA design by Alex Cavelli, a hybrid tube/opamp design I built a few years ago), checked for hum and and channel balance.  I then replaced my Bugle with the Cornet 2.  What was the first record I played?  Imperial Bedroom / Elvis Costello, US Columbia first pressing.  This is a very nice recording, great music, some of the cuts have an enormous 3D sound stage.  Also played Zappa Waka Jawaka/Hot Rats, Genesis Lamb Lies Down, Lou Reed Blue Mask, and a couple others.  All are US first pressings that I picked up, "back in the day".

Black silence, liquid sound, micro dynamics amazing, the nuances of the recording come out.  A great match with my Grado Reference Sonata (high output version).

Tubes used: Bendix 6106, pair of Amperex 12AX7 (early 60's), RCA 12AU7 (late 40's early 50's).  I have a couple more - RCA 12AX7 (late 40's early 50's), Mullard 12AU7, and an Amperex 12AU7 Bugle Boy now in the SOHA headphone amp.  Looking forward to rolling tubes.  BTW, I got my tubes from Vintage Tube Services - Andy is proprietor - and he grades his tubes for suitability for use with MC or MM or line stage preamps.  His tubes may fetch a slight premium but you know what you are getting.  And he is a lot of fun to talk to. This unit is pretty much stock except for Auricap capacitors.  I put my "upgrade money" into the great old tubes.

The Bugle has served me well, but as others have observed, this is in another league.

I still have a couple little things to do with the case before it is officially done, but it is making music now.

Well done Mr. James Hagerman!

WireNut

Re: Another Cornet 2 ... HAS ARRIVED!
« Reply #7 on: 19 May 2013, 06:11 pm »
   

       Lets see some pics  :o

G E

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Re: Another Cornet 2 ... HAS ARRIVED!
« Reply #8 on: 19 May 2013, 06:18 pm »
   

       Lets see some pics  :o

Will try to post a little later, I have a couple of the PC board when it was well along.  I have an idea or two for enhancing the case work and will takes pics when it is complete.  Stay tuned.

G E

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Re: Another Cornet 2 ... HAS ARRIVED!
« Reply #9 on: 11 Aug 2013, 04:40 pm »
An update on my Cornet2:

This is an amazing phono preamp.  The past 4 weekends I have not listened to *any* digitally sourced music - no CDs, no DVD-As, no SACDs.  Just vinyl bliss.

A while back I played some well produced SACDs after spinning records and it just sounded kinda dead.  Yes, it was quieter, better dynamics and all that, but something was missing.

I just picked up a new phono cable that will run from turntable to Cornet2 (morrow PH4) but haven't installed it yet.  I have to modify my turntable - add RCA jacks, its phone cable is captive.

I have a number of NOS tubes to roll.  My current line up is Bendix 6106 rectifier, Amperex Bugle Boy 12AU7, Amperex Bugle Boy 12AX7 in v200, and Amperex early 60's vintage in v201.  I also have some RCA blackplates and they are lots of fun, too.  Somewhat warmer presentation.

My build is stock with the Auricap upgrades.