Another Cornet II started...

pretzel_logic60 · « **on:** 20 Feb 2009, 10:12 pm »

These Hagerman kits seem to be very popular projects but judging from all the great reviews well deserved. I have been using a Cornet I now for a few years and never did any upgrades after the original build. I did use sonicaps in the signal path but that was about the only change I did different from stock. I've always been very satisfied with my original Cornet but wanted to give this new one a go.

I've actually had the boards for both the Piccolo and Cornet 2 for several months but after buying a new house and finally getting settled in it was time to tackle both these projects. I knew going in it really should be a fairly easy build considering how easy the first Cornet went. But I wanted to make some major upgrades and after doing a lot of reading on here and at the AA I decided it was time to get down to ordering parts.

I want to thank Jim, "tubesforever" for being very very helpful in getting me on the right path and explaining some things. I'm no pro at reading schematics, have a little knowledge but only enough to get into trouble. So after several e-mails I was ready to begin gathering parts. I'm certainly not taking this as far as Jim has, he seems like the ultimate tweaker and though I may make some changes down the road I'm sure I'll be very happy with what I have to start with.

I was able to get all the resistors, tube sockets, the electrolytics and a few other parts soldered to the board last night and this morning. I'm using Kiwame 2 watt resistors, a few stock electrolytics but Panasonics in a couple areas. In the signal path will be mostly Dynamicaps, a couple oversized Mundorf SIO, as well as some Russian K40y9 for the RIAA phase that Jim had extras of and is selling me.

This should be a very fun project though fitting some of these capacitors in will take some thought. But after seeing what some others have done I don't think I'll have many problems. I am still waiting on a few parts including the Lansing case. The one I ordered which was different than the spec case was out of stock so I had to change that up a little. I also am going with a separate switch/AC input and want to mount the power switch on top of the case.

I'll try to post some pictures as well...

Brian

tubesforever · « **Reply #1 on:** 22 Feb 2009, 07:59 am »

Thanks for the kind words Brian. I am really looking forward to your build. I seem to learn one thing or another from every kit that is constructed and posted here at the hagtech site.

I hope your build goes smoothly!

Cheers!

pretzel_logic60 · « **Reply #2 on:** 22 Feb 2009, 08:11 pm »

Here is a pic of my Cornet board mostly complete. I am still waiting on a few parts and have to order a couple more as well, I destroyed 2 of the transistors, forgot to mount them to the heat sinks before soldering them in and doing it after was next to impossible. I may end up going to a larger case as well than the stock unit, it will be a tight fit otherwise. So far so good though, only have a couple solder joints that didn't take to well and will redo those.

I thought I had run out of heat shrink and that's why the Mundorf SIO's are sitting on the bench instead of installed. I found some more this morning and may get back to soldering this evening. Hopefully the picture works...

pas · « **Reply #3 on:** 22 Feb 2009, 09:11 pm »

I'm asuming that your putting heatshrink on the exposed wires of the caps. Why?

pretzel_logic60 · « **Reply #4 on:** 22 Feb 2009, 10:26 pm »

The reason for the heat shrink is the caps are hanging off the board somewhat and I don't want any chances of something coming in contact with them. With the stock case it will be a tight fit and I may go with something wider. The Mundorfs will definitely get the heat shrink but again just as a precaution.

Brian

hagtech · « **Reply #5 on:** 22 Feb 2009, 11:27 pm »

Quote

I'm asuming that your putting heatshrink on the exposed wires of the caps. Why?

I agree. Heat shrink makes a shitty dielectric. All that money into expensive caps with primo dielectric, and you then parallel such with heat shrink? Use teflon tubing instead. Yeah, this is minor and we're nitpicking, but then again, we be perfectionists, right?

jh

pretzel_logic60 · « **Reply #6 on:** 22 Feb 2009, 11:38 pm »

I bought this stuff a few years ago and am 95% positive it's a teflon shrink tubing and I know it's not the regular crap that's out there. I had 2 different types, one was just a colored batch and the other the teflon. This stuff is pretty thick and if I remember the other was fairly typical of a hardware store heat shrink.

Brian

pretzel_logic60 · « **Reply #7 on:** 24 Feb 2009, 02:54 pm »

After searching for the rest of my heat shrink I came across what is left of the teflon tubing, it's been a few years since I used it and what I have on the cap leads is not the teflon.

I'm wondering how much of an effect the regular heat shrink will have, I could easily remove the stuff. I was only using it as a protective measure and really for no other reason.

I'm hoping to get back to work on this tonight or tomorrow.

Brian

tubesforever · « **Reply #8 on:** 24 Feb 2009, 06:13 pm »

I would use the teflon if it works ok. Most of mine is thicker wall stuff, generally it does not allow for the kind of bends I need to keep components in contact with the circuit board. I have used shrink on my Hagermans and they sound delicious. I bet the teflon would be as good or better sounding but it will not be night and day different.

Why not leave it in place for now. At least on the side closest to the case work. Safety first. If your teflon stuff is flexible enough you can remove the 4 caps, use the teflon and solder them back in place.

Cheers!

PatOMalley · « **Reply #9 on:** 26 Feb 2009, 10:08 pm »

Those caps .... I am going to use Jantzen crosscaps at C206 and C200. The length dimension is 24mm which I think will fit fine.
Thing is that those electrolytics are bypassed with foils then those are bypassed with another foil. Choose the best final cap for bypass and you can cheap out or buy-to-fit for the ones at C206 and C200. The choice for electrolytics in that section mean even less as they are bypassed. But I am choosing Panasonic ECG ED long life jobbies;cheap though.

Still economizing I chose Obbligato coppers for output and RIAA with Russian PIOs in the middle. The Russians have heatshrink on the can, not the leads. As an audiophilke I think I can get away with that one.

tubesforever · « **Reply #10 on:** 27 Feb 2009, 07:31 am »

Since I cannot obtain a Black Gate 47uf 450v electrolytic, I figure the Panasonic ED is the next best choice. It has extremely low esr and has super black background. I also found it to be more smooth and non grainy sounding than the specified Nichicons.

I will state for the record that the specified Nichicons are no slouches. If ED's are hard to come by then Nichicons are definitely the go to pieces.

Pat, I look forward to hearing about your build as it comes along. I have been evaluating 0.47uf K40Y9's in the B+ bypass positions. I have had them there for about a month now and without any teflon. I feel that I am missing out on the dynamics, so I will probably try piggybacking these with FT-3 teflons just to see what happens. I was hoping the K40Y9's would have more depth and space than the Dynamicaps but this test confirms how good these Dynamicaps can sound.

So far the Dynamicaps 1.0uf 435v in parallel with the FT-3 0.10uf 600v teflons have been my favorite mix for the B+ chores.

Happy New Year O'Malley. It's nice to see you posting. Those PRP's look sweet with the Kiwamis mixed in. I plan on using them on my Piccolo that will be powered with the regulated Hagerman Bugle power supply.

PatOMalley · « **Reply #11 on:** 1 Mar 2009, 02:55 am »

Tubes,

Seems like the Russian PIOs are soft on top and using the Teflons as bypass on top might really improve them.
But I wouldn't bypass the Dyanmicaps ...
On my DAC I bypassed some Obbligato's I have with .001uF Russian PIOs which does -something- on top but seems softer. May take 'em out.

tubesforever · « **Reply #12 on:** 1 Mar 2009, 08:03 am »

Pat are you following the 1/10 rule? Basically the bypass should be 1/10 or less than the cap it bypasses. 1/2 to 1/10 seems to sound best to my ears.

I tried some teflon and PIO caps of 0.01 caps bypassing the 1.0 film caps and these were way bright and etched.

PatOMalley · « **Reply #13 on:** 1 Mar 2009, 04:06 pm »

Rules?

I only go by the thumbnail that up to 1uF covers everything, .1uF is a midrange cap, 01uF is top end, 001uF is wispy air.
I have a 4.7uF cap with a .1uF and a .01uF in the DAC, for instance.

I will not be bypassing the 1uF Obbligato at output on the Cornet2, though, and I may remove the Teflon form the Clarinet.
I think doctoring the Russians together makes for a great cap array but the Obbligato's and Jupiters have a character that "is what it is" and bypassing them is sort of like, "why did you spend all that money on an expensive cap to rob it of the sound that you paid for?"

pretzel_logic60 · « **Reply #14 on:** 5 Mar 2009, 01:16 pm »

Well I decided on the Lansing case after all and when it arrived found that the way my board is configured, the Dynamicaps hang over the side edges too far. Of course I already cut the extra length off them

so I either have to purchase 4 more 1uF caps or solder new legs to them to make them fit. I am planning on building the Clarinet at some point and if I'm correct they also use the 1uF caps and it looks like I could make my existing caps fit. So I will probably go ahead and order 4 more caps and while waiting for those work on the Lansing.

Ahhh, live and learn... This kit has been fun regardless when I've had the chance to work on it, it's just taking longer than I'd hoped.

Brian

PatOMalley · « **Reply #15 on:** 5 Mar 2009, 11:11 pm »

pretzel_logic60,

I decided on the Jantzen 1uF caps and they fit perfectly. They are not boutique but since they are bypassed and fit I am happy so far. See the graphic above ..

tubesforever · « **Reply #16 on:** 14 Mar 2009, 06:41 am »

Hey Brian where are you with your build! Its been a while since we've heard anything on the C2.

Cheers!

pretzel_logic60 · « **Reply #17 on:** 18 Mar 2009, 10:47 am »

Hi Jim, unfortunately I had to put off the build for a little bit, got busy with the kids but also had my truck go down on me. Ahh, the joys of being able to do things myself, had to replace wheel bearings and while I was at it ball joints and a few other things.

I just received the replacement caps, the 1uF 425V that I had already installed but found hung over the edge of the board too far, so basically reinstalling those and the board is done. I need to get started on the casework and have been pondering the best way to go about that. I want to use my drill press and I have some scrap laying around so I'm going to make some test holes with and see how things turn out. So other than the casework and final assy I'm about done, thought that doesn't mean it will be done by the weekend.

I'll keep you up to date and hope to do whatever soldering I have left tonight. Oh, one question, and I will look at some of the pics on here. But the wiring for the input/output jacks, I have no idea which is positive and neg though I just briefly was looking at it the other day.

Brian

galyons · « **Reply #18 on:** 18 Mar 2009, 03:56 pm »

Quote from: pretzel_logic60 on 18 Mar 2009, 10:47 am

Oh, one question, and I will look at some of the pics on here. But the wiring for the input/output jacks, I have no idea which is positive and neg though I just briefly was looking at it the other day.

Brian

Brian,
This is from my notes accumulated for building the C2.

The 2 big holes are for mounting tabs, ignore.

The small center hole in the middle is ground.

Looking at the board so the lettering is right-side-up, with the mounting holes at the top, or away from you, the right hole, which is on a line is right, the left one, left.

Hope this helps! Get it done!!

Geary

pretzel_logic60 · « **Reply #19 on:** 19 Mar 2009, 10:58 pm »

Thanks Geary, I had a feeling that's how it was laid out but wasn't sure.

My main thing is this chassis now, I think I'll be best off getting a stepped bit but haven't found one locally. Time to look online again...

Brian