Cornet C13 and C14 question

pretzel_logic · « **on:** 20 Sep 2003, 03:17 pm »

The instructions call for connecting the negative leads on these caps together to reduce hum. I'm wondering how others have been doing this. I was going to twist splice and solder them together on the solder side. Ok to do or should I just follow Jims directions.

Brian

mgalusha · « **Reply #1 on:** 20 Sep 2003, 04:03 pm »

Here's how I did it.

First I cut the traces around the ground connection for C14. I then installed C13 and C14 taking care not to cut the negative leads from the caps.

I mounted D1 and D3 on the other side of the board with the anodes facing the solder point for C13.

I bent the lead from C14 at 90* so it could be tied to C13. The leads from the diodes were also bent to meet at the negative lead of C13. Basically all of them tie together at the solder point of C13's ground connection.

I got the idea for this after viewing the picture of Jim's premium version. I noticed that D1 and D3 were missing. It followed that they had to on the underside of the PCB.

Hope this helps.

Mike G.

pretzel_logic · « **Reply #2 on:** 20 Sep 2003, 08:49 pm »

Thanks for the reply. I don't want to start cutting traces, I'm still fairly new to this though I'm sure I could make it work, just not sure enough yet. Also not sure exactly what you did but have a good idea. I didn't want to splice the caps on the bottom, seems like it would be tougher than doing on the solder side but am worried about shorting after installation. Once I have more time to look at it maybe it won't be a problem but wanted to see what others have been doing. I just have the resistors in right now but the caps will be next though not tonight, have too many other things to do.

Thanks again,

Brian

mgalusha · « **Reply #3 on:** 20 Sep 2003, 10:59 pm »

Brian,

I understand your reluctance. Here is a closeup picture from the Hagtech site of how to do this above the board.

He has some other tips for improving your Cornet. The can be found on his tips page.

Mike G.

pretzel_logic · « **Reply #4 on:** 21 Sep 2003, 01:25 pm »

Mike, thanks for the pic. I can have a tough time visualizing how something should be without seeing it and I don't think I'll have a problem with that now. Also I went to the tips page, was looking for it on his website but it's not there when I go to his homepage for some reason but got there through your link.

Also, I had e-mailed Jim about which caps to upgrade and he told me go with a high quality 1uf 200v cap for the coupling caps. I still have a tough time reading schematics, at least which part of the circuit is which. Can you tell me which caps these would be? I thought he meant go with high quality .1uf so I upgraded those as well as the rest of them. Now I still don't have the 1uf.

Thanks again,

Brian

mgalusha · « **Reply #5 on:** 21 Sep 2003, 06:03 pm »

Brian,

The 1uF cap replaces the .47uF cap at C6. You will need two. This is the output coupling cap and prevents DC from appearing at the output. This cap is directly in the signal path and I would use a quality cap in this location.

C5 is also a coupling cap and is directly in the signal path. The same thoughts apply as for C6, use a good quality cap.

Mike G.

pretzel_logic · « **Reply #6 on:** 21 Sep 2003, 06:59 pm »

Thanks Mike, I thought the .47 might be it but wasn't sure. I will order a couple 1uf's for that as I need a few caps for my amps. I have all Multicaps except for the electrolytics, also some Auricaps as well. Have all the resistors in but am going to concentrate on the chassis for now.

Brian

mgalusha · « **Reply #7 on:** 22 Sep 2003, 01:22 am »

You're welcome. Let us know how the project turns out. Pictures are always nice.

Mike G.