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SOHA II Builders Thread - Page 50

post #736 of 1687
Thread Starter 
Correct.
Dr. Cavalli gained notoriety with his first DIY amplifier projects. His success has blossomed into Cavalli Audio, a world leader in amplifier design.
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post #737 of 1687
Quote:
Originally Posted by adamus View Post
have you guys seen the 'red light district amp' on the diyforums. could you not replace the 18v zener with a smallish led array (3x3 grid?).
Are you talking about this?
SYclotron Audio ยป The Red Light District

If not, got a link?
post #738 of 1687
yes indeed.

Been thinking more about the idea, and its dont think it will ever be a runner. To drop 18v you'll need at least 10 led's by which time you will will have 10 lots of dynamic resistance, circa 40 ohms. This is greater than the zener.

concept born.... concept deemed worthless.
post #739 of 1687
oops.
post #740 of 1687

Schottky Rectifiers?

Today I received the last parts to build my SOHA_II. The resistors and E12-diodes are already stuffed, the rest to follow soon.

Now I have some schottky diodes at hand (MBR1100, 1 A 100V) and I think they could be a nice upgrade over the UF4004 for the +/- 15 V supply (D1P-D4P).

Anyone already tested different diodes? What do you think?

Chris
post #741 of 1687
Thread Starter 
Don't see any reason why not.
Dr. Cavalli gained notoriety with his first DIY amplifier projects. His success has blossomed into Cavalli Audio, a world leader in amplifier design.
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post #742 of 1687
almost there on the sohaII I am building. Power supply checks out fine. Just waiting on a an order for the E12 parts. hopefully the suggested farnell relay should be ok.

having not followed th whole thread, are the step by step instructions for initial setup still ok considering the PS revision?
post #743 of 1687
Thread Starter 
Yes, they should be correct.
Dr. Cavalli gained notoriety with his first DIY amplifier projects. His success has blossomed into Cavalli Audio, a world leader in amplifier design.
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post #744 of 1687
Thread Starter 
That is, the ones on the website should be correct.
Dr. Cavalli gained notoriety with his first DIY amplifier projects. His success has blossomed into Cavalli Audio, a world leader in amplifier design.
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post #745 of 1687
I'm happy this was posted as I'm almost to that point on my build. I assume that the proper setup is somewhere in this thread.
post #746 of 1687
Thread Starter 
It could be, but the easiest place to find what you need is here:

Cavalli Audio
Dr. Cavalli gained notoriety with his first DIY amplifier projects. His success has blossomed into Cavalli Audio, a world leader in amplifier design.
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post #747 of 1687
Sorry, I misinterpreted the posts at the end of a long day at work. I was already intending to use your site thanks.
post #748 of 1687
Im built a 2 box version of this amp - transformer and switch in one box and amp in a separate box connected with a neutrik 5 pin plug. I have a little noise, especially with the Dennon D2000 plugged in. How should grounding be done on a 2 box solution? powere box grounded to its own case and amp board grounded thru a standoff at the star ground point? Any other way or better way? Also have wires hooked upo for tube leds - could that have extra noise?
post #749 of 1687
Ok, after about a month of guests and traveling I am finally able to get back to my SOHA II. I was looking at the place to solder the ICE and I noticed that (in addition to lifting the pad on pin #8, which is not connected to anything) the pad on pin #1 is starting to lift on the top of the board (maybe also on pin #2). Everything looks ok on the bottom of the board. I have attached a picture. Is this going to be a problem? I would rather find out now and get a new board than to wait until the end and find out the amp doesn't work. At this point, I have only added the resistors and two of the IC sockets so it wouldn't be such a big deal to start over (the waiting would be a little annoying though).

I have to admit that I am a bit OC sometimes and *feel* that I want to start over with a nice new perfect board but maybe that is a ridiculous. [If I had second board and second set of resistors, I would start over.]





Also, my board seems a bit warped. I didn't notice this before. Should I be worried? I am wondering if this is another reason to get a new board.




Thanks!

Quote:
Originally Posted by shellylh View Post
I soldered the opamp socket in backwards in the SOHA II and, afraid that may lead to me putting the opamp in backwards in the future, I desoldered it. However, it took a lot of work/heat and in the process and I lifted one of the pads on the top side of the board. The pad on the bottom side of the board looks intact so I think I should be ok. Will this be ok?

Also, I can no longer fit the (new) socket into the holes. I guess I couldn't get all the solder out. Should I try and buy a new socket with thinner leads or do something else? I am afraid if I try more desoldering, I will just lifts more pads off the board and will have to start from scratch. At this point, I just have the resistors in place (I have been pretty busy) so it wouldn't be the end of the world to start over. Sigh...
post #750 of 1687
Thread Starter 
Edit: Ahh. My original text referred to the wrong amp. On this amp none of the pads are grounded so if the traces are solidly connected to the pads on the bottom of the board you are ok.
Dr. Cavalli gained notoriety with his first DIY amplifier projects. His success has blossomed into Cavalli Audio, a world leader in amplifier design.
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