[CButterworth]

I finally threw together some pictures and posted them on my website.  The url is:

http://homepage.mac.com/butterworthfam/AudioDIY

Last night, I performed a little bit of tube rolling with the 12AX7s.  This is what I noticed.

1. My stock tubes were Tung-Sol 12AX7 new production.  These sounded good in comparison with my very cheap solid-state phono.  The bass was strong and solid, highs were clear, etc.  In other words the Cornet2 sounded great.

2. I swapped these for old Telefunken 12AX7s.  They are not matched and the sections are possibly not balanced.  However, in terms of sonic clarity, they beat the Tung-Sols. The highs were cleaner and crisper, but not harsh.  The bass initially sounded weaker, but really it was less boomy.  My wife described the Tung-Sols as muddy in comparison with the Telefunken.

3. Old, used GE and an old used Amperex (Bugle Boy) 12AX7s.  Both made in Gt. Britain by Mullard, and probably of the same era.  Anyway, we liked these the best.  Where the Telefunken was a little shy in the bass, the "Mullards" were warm smooth, but not boomy like the Tung Sols.  The highs weren't as crisp as the Telefunken, but still exceptionally clear.

Anyway, I am not going to go into a great deal of detail on the tubes, as I am unskilled in this sort of thing.  We used the original vinyl of I-Robot by Alan Parsons for our comparisons.

I describe on my webpage that the 12AU7 is the input tube and the 12AX7s the output tubes.  Is this really the case, or the best way to describe their roles in the Cornet2.

Finally, my website is under construction and I'll be adding more photos and diagrams.

Regards,
Charlie

[ecir38]

Charlie, your chassis came out great

[amandarae]

Very Nice!

[bluesky]

Hi

Fantastic wood finish and remarkably I too have something similar underway with a Clarinet, Cornet and Aksa 55N+ for the amp.  I have opted for the Lansing chassis at least for a while but do wish to explore some wood and polished aluminium chassis ideas in the future.

Can you tell me a source for that Maple, I guess it wouldn't cost too much to send to Australia given the relatively small amount involved.

Bluesky 

[JohnR]

Beautiful! Looks like waves in water.

[poseidonsvoice]

Absolutely gorgeous. I love quilted maple (see my gallery).

Excellent, congrats!   

Anand.

[CButterworth]

Bluesky,

I purchased the quited maple at my local woodworking store - Woodworkers Source (www.woodworkerssource.com).  I went through their supply and picked out the straightest piece and had then cut and edge it.  This added around $15 to the cost, but it saved me having to "true" the edges.

They do ship, and I expect that wood for something like a Cornet2, which I made larger than the regular chassis, will cost less that $60US.

Right now, my AKSA is in a Hammond enclosure.  After seeing the Cornet2, my wife asked whether the AKSA could be housed in a quilted maple chassis.  I may do this, but what I'll do to save cost is to use a quilted maple front with regular maple sides and back.  The AKSA sits on a shelf with a shelf above, so the sides are not really visible.  I also need to check with Hugh about chassis dimensions for the LifeForce, as I want to upgrade in the future, and may need to upgrade the AKSA PSU accordingly (in the 55N, the PSU has no upgrade, does the N+ include PSU upgrade?).

Regards,
Charlie

[Bill Epstein]

The chassis really is gorgeous! Congratulations!

I'm mulling over what power supply to use for my own dual-octal Aikido, also with 4-6SN7's. The Cornet PSU seems pretty good and I have a schematic John sent which uses a power tranny I have on hand. Do I see 2 power transformers on yours, true dual mono? Willing to share the schematic?

[bluesky]

Hi Charlie

Thanks for the info on the Maple.

And yes, the N+ upgrade includes the higher specced power supply caps.  Although I am thinking of trying the Vishay MKT1822's as bypass caps as well in my Aksa N+ and in a couple of positions in the Cornet, these have been given a good rap from some Audiocircle members and at less than a dollar for most values seems like worth trying to squeeze a bit more performance without breaking the bank.  Compared to the cost of the teflon caps that some others shout about I think these are worth a try, well for someone on my budget anyway.

Bluesky

[CButterworth]

Bluesky,

I'll have to find out about the higher specced caps for the AKSA 55N.  I expect that they'll allow a little more slam and better transients.

Maybe, I need to make a post to the Aspen forum and see if Hugh is willing to part with this information.  I really respect Hugh's designs, products and support.  If the better caps are supplied with the LifeForce upgrade, then I would be willing simpy to have him give details of any extra space that they require.
As for bypass caps, which cap numbers are these on the Cornet2.  I spent a considerable sum of money on upgrade caps for the Cornet2.

Thanks,
Charlie