Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: GvilleDave on December 28, 2011, 10:11:56 am

Title: Starting My First Amp Build - Some basic questions????
Post by: GvilleDave on December 28, 2011, 10:11:56 am

OK so I have been reading books and studying up, lurking here reading posts etc...  I am getting ready to start wiring the board on my first amp project an I have a very basic (i think) question:  How do I know which direction to position the capacitors that don"t show a + notation on the layout or schematic?

C1, C5, C6, C7, C12, C13, C14, C15, C16, C17, C18

I am building a Marshall 18 watt clone (tremolo) and using the "Richie's Improved" layout and schematic.  I have attached a copy of the layout and schematic for reference.  I know I could have selected a simpler first build but given the time and expense of the build I wanted to build an amp that I really want...

I have found some pictures of similar completed boards online and could use those as a visual guide but that isn't a very sure way to do it...  Besides by asking the folks here I will learn why they are positioned in a partcular direction.

Thanks for the help!

Title: Re: Starting My First Amp Build - Some basic questions????
Post by: TubeGeek on December 28, 2011, 10:23:24 am

C2, C3, C11, C19 are the caps that you need to have correct orientation, they are electrolytic's.  C1, C5, C6, C7, C12, C13, C14, C15, C16, C17, C18...These other caps are not polarized and can be installed either direction.

The +/- side of the cap will be marked on those electrolytics.

The + side will connect to the circuit and the - side of the cap will connect to ground.  It should be clear once you look at it.

Title: Re: Starting My First Amp Build - Some basic questions????
Post by: six el six on December 28, 2011, 10:27:18 am

The electrolytic capacitors on that layout are clearly illustrated. The indented side of the cap is the positive side in those illustrations.

There is a HUGE amount of info on the internet concerning tube electronics.

A gentlemen who is a moderator on this forum has an excellent site with important info on it. Google Paul Ruby Amplifiers.

One of my favorite sites is Aiken Amplification. Very good info. Yes sir indeed.

This suggestion should have probably come first. This site has THE TUBE AMP LIBRARY OF INFORMATION that you can't go wrong with.

Good luck and do not electrocute yourself. It sucks. Trust me.

Title: Re: Starting My First Amp Build - Some basic questions????
Post by: GvilleDave on December 28, 2011, 12:08:06 pm

Thanks for the fast response and the suggested sites.  That should get me going.

Title: Re: Starting My First Amp Build - Some basic questions????
Post by: stingray_65 on December 28, 2011, 12:45:37 pm

Hey Dave!

There is LOTS of info here http://wjoe.com/capacitorinfo.htm (http://wjoe.com/capacitorinfo.htm) on your original post.

Title: Re: Starting My First Amp Build - Some basic questions????
Post by: kagliostro on December 28, 2011, 01:19:19 pm

Here there is an interesting thread started by Tubenit

http://www.el34world.com/Forum/index.php?topic=11427.0 (http://www.el34world.com/Forum/index.php?topic=11427.0)

usually we don't give much care to the orientation of non electrolytic capacitors

and amps are often build without this sophistication

but is a detail that can make the difference

Kagliostro

Title: Re: Starting My First Amp Build - Some basic questions????
Post by: GvilleDave on December 29, 2011, 10:15:38 am

Kagliostro - That is an interesting thread.  Although I don't think I will take the time to make a tester it is interesting to know there can be a difference.  The thread also mentioned that the sozo caps tended to all have the outer foil on the side with the strip and since those are what I am using I will allign them all w/ stripe closest to the ground and go with it...

Thanks for the advise.