Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: clarkleach on December 28, 2021, 08:37:46 pm

Title: Turret board spacing
Post by: clarkleach on December 28, 2021, 08:37:46 pm
Is there somewhere I can find the spacing between turrets on the AB763-2 Twin turret board?
It would certainly help in putting together a real BOM.
Title: Re: Turret board spacing
Post by: sluckey on December 28, 2021, 08:40:31 pm
Ask Doug.
Title: Re: Turret board spacing
Post by: EL34 on December 29, 2021, 08:41:26 am
Is there somewhere I can find the spacing between turrets on the AB763-2 Twin turret board?
It would certainly help in putting together a real BOM.

I already have a BOM on the library page for all my boards
https://el34world.com/schematics.htm#Hoffman_AB763_Two_Channel_

And all the parts I stock are in the Parts list page here
https://hoffmanamps.com/MyStore/catalog/PartsListIndex.htm


For a twin you would have to double the screen grid and 1 ohm resistors

Board spacing depends on the parts widths
You can read more here
https://el34world.com/Forum/index.php?topic=22753.msg243271#msg243271


Title: Re: Turret board spacing
Post by: sluckey on December 29, 2021, 09:35:42 am
I measure 0.2969" spacing between the majority of "rows" on Hoffman's AB763 long board. Things like his bias pot are different.

I like to use 5/16" (0.3125") spacing on my layouts. Big components like filter caps need more spacing.
Title: Re: Turret board spacing
Post by: EL34 on December 29, 2021, 09:40:19 am
On all new boards and DIYLC boards, I now like .25 inches as the common spacings


I could go back and shrink my older turret boards by using .25 inch spacing, but that would be a ton of work
Title: Re: Turret board spacing
Post by: sluckey on December 29, 2021, 09:52:31 am
I like your 0.2969" spacing and the story of how that came to be. It's classic. I wouldn't change a thing. Would eyelets even fit a .25" spacing?
Title: Re: Turret board spacing
Post by: acheld on December 29, 2021, 10:26:25 am
OK, I'll bite.   What is the story behind the .2969 spacing?
Title: Re: Turret board spacing
Post by: EL34 on December 29, 2021, 10:53:08 am
I like your 0.2969" spacing and the story of how that came to be. It's classic. I wouldn't change a thing. Would eyelets even fit a .25" spacing?

The eyelets I sell are .20" in diameter, so .25" spacing would work
That would leave .1" gap between them
That's pretty tight, but it would work on my board material
I would not do that on crappy fiberboard though.

My turret lugs have a .155" base, and so .25" would not be tight

Now that I use DIYLC, I don't use exact spacings
.25" is fine for small stuff, but you can lay the exact part on the board and figure out if you need more spacing or not

Here's two carbon comps on .25" spacing using eyelets

Title: Re: Turret board spacing
Post by: EL34 on December 29, 2021, 10:53:54 am
I like your 0.2969" spacing and the story of how that came to be. It's classic. I wouldn't change a thing. Would eyelets even fit a .25" spacing?

I think it is all in the link post up above?
Title: Re: Turret board spacing
Post by: EL34 on December 29, 2021, 11:50:24 am
The spacing thing has been asked a few times over the years


I added all the info into a new post here with images
https://el34world.com/Forum/index.php?topic=28346.0