Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => PC Express and JSchem - Schematics and Layout diagrams => Topic started by: tubenit on September 30, 2008, 08:21:56 am

Title: Champ D'Lite
Post by: tubenit on September 30, 2008, 08:21:56 am

I have enjoyed the quasi-sorta D'Lite preamp without the extra gain stages alot in my "Blues Amp."  It has one of the
warmest clean tones I've ever heard.  And using the PAB (pre-amp boost) & the NFB switch can get it into some great
overdrive.

In light of that, I thought I'd try to draw up that same preamp into a Champ style power section to have a 3-4 watt version.

I have NOT built this amp.  It's just an idea at this stage.  Check for errors.  I don't know if this should have another coupling cap after the effects loop going into the next gain stage?

With respect, Tubenit

Title: Re: Champ D'Lite
Post by: Bruspeed on September 25, 2009, 01:21:18 pm

I've taken a great interest in this idea, and just modified your layout to make more sense to a real noob such as myself. No offense intended, It just makes more sense to me when I can see the big picture.  :wink:
Basically I just added a bit more card for the power supply filtering and potentiometer designations and what I think are the correct locations for the heater connections. Anyone ever get around to building this?

Thanks, Chris.

Title: Re: Champ D'Lite
Post by: tubenit on September 25, 2009, 06:29:43 pm

You did a nice job on the layout additions.  Thanks!  If you ever build it, please let us know how it sounds.

With respect, Tubenit

Title: Re: Champ D'Lite
Post by: Bruspeed on September 25, 2009, 07:31:57 pm

Thanks for the response tubenit!! I do have a few questions before I start ordering the bits and pieces. I have not built anything like this before and was curious what you thought the dimensions of the board would/should be? Do you believe it would fit in a blackface Champ style chassis? I want to build my very own mini pigy-back rig  :grin: I will order the board from Hoffman, and I feel eyelets seem easier. Orange drops for signal, and still undecided on power caps. As well as metal film resistors throughout. Any input?

Title: Re: Champ D'Lite
Post by: tubenit on September 26, 2009, 06:15:01 am

Well, for illustration purposes, using a tag/terminal strip board & your layout ......... you'd need 20 paralleled tags. However, you'll need small filter caps to get them on a board (meaning actual phsical size). WeberVST has some.

However, if you build a board from Hoffman, you should be able to make things even smaller plus they would be sturdier as the tag boards are pretty flimsy, IMO.

http://s28.photobucket.com/albums/c216/tubenit/?action=view&current=cabopenchassisbackspeakerreverbtank.jpg

My 56T reverb has 22 tags being used and I used a 18w style chassis that I cut the width down to 18.5"  Look up the dimensions of a Champ type chassis and compare those.  If you used stand up PT & OT, maybe you could make it pretty small. I think the 56T board was around 12" x 2.25" ?

So it's in a cab about the size of a Princeton Reverb or Deluxe 5E3.

Now ....... since you're wanting to build a head and have it be a piggy back. Turret Boards carries a blank chassis that is 12.5" x 6.5" x 2.5.  I'm thinking you could possibly make that work if you used a stand up PT and OT & build a smaller board using Hoffman materials. Hoffman doesn't carry blank amp chassis.

http://www.turretboards.com/


Orange Drops and metal film sound good to me.

Hope that helps some.   Remember this isn't a proven design. As far as I know, no one has built one?

With respect, Tubenit

Title: Re: Champ D'Lite
Post by: Fresh_Start on September 27, 2009, 09:03:08 am

Kyestone Electronics makes single strips of turrets and boards with 2 rows of turrets in different sizes.  Here's one page from their catalog:
http://www.keyelco.com/pdfs/M55p132.pdf (Mouser carries some of these)

Antique Electronic Supply also sells similar pre-made double-row boards.

Just a thought for prototyping & small builds.

Chip

Title: Re: Champ D'Lite
Post by: Bruspeed on September 30, 2009, 11:53:32 pm

What audible difference is there in the hammond 125cse and 125dse? Thanks!

Title: Re: Champ D'Lite
Post by: Bruspeed on October 06, 2009, 08:40:03 pm

Should there be a connection between pin 1 on V1 and the 100k resistor and the tone stack? I'm not entirely sure what V1 is cascading to. I see V1-a flows into V1-b, but then after that I'm not sure where the signal goes?  Sorry If this is dumb. I ordered a bunch of stuff hoping to tackle this project soon!

Title: Re: Champ D'Lite
Post by: sluckey on October 07, 2009, 07:18:26 am

Quote

Should there be a connection between pin 1 on V1 and the 100k resistor and the tone stack?

Yes. See redlined drawing.

Title: Re: Champ D'Lite
Post by: Bruspeed on October 07, 2009, 10:05:31 am

As of 10/25 This is a working layout and schematic.  :wink: :grin:

Bruspeed redid this amp and turned it into what he referred to as a Mini-D

Tubenit