Da Crusher - Champ on steroids - diyAudio
Go Back   Home > Forums > Live Sound > Instruments and Amps

Instruments and Amps Everything that makes music, Especially including instrument amps.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 17th June 2011, 08:56 PM   #1
diyAudio Member
 
Michael Koster's Avatar
 
Join Date: Jan 2008
Location: Eureka, CA
Default Da Crusher - Champ on steroids

Funny how the discussions turn... I just finished the preliminary tweaking and voicing on this 2 stage volume-only amp, which I started building almost 2 years ago. It does cost more than $100 but it's just what I've needed for a small amp.

The idea was to re-do the basic Champ circuit using parts I had on hand; EF804 input, 807 output, 500V power transformer, and a Doberman OPT. It ended up about 2X the output capability of the Champ and I'm using a 12" speaker so I call it Da Crusher.

I switched to a choke input to get about 440V B+ for the 807, which results in a super quiet amp. Just a little EMI buzz with the gain wide open!

I started with values based on the Champ and got really lucky on the voicing first time out. Currently using a 12" 50W ceramic speaker in an open baffle (Fender HRD box) and it sounds nicely balanced. The guitar controls and the second input jack at -6db give me a wide range of tone. It's mostly clean with a nice smooth crunch as I dig into my hot pickup. I can't think of anything constructive to do with the voicing now, but plan to try a low wattage alnico 12" in both open and sealed cabs. I also have an Altec 421 15" I want to try for grins.

Tons of fun!

Michael
Attached Images
File Type: jpg simple807.jpg (70.4 KB, 145 views)
File Type: png crusher807.png (16.1 KB, 144 views)
  Reply With Quote
Old 17th June 2011, 09:11 PM   #2
diyAudio Member
 
Wavebourn's Avatar
 
Join Date: Sep 2006
Location: Pleasant Hill, CA
Send a message via Skype™ to Wavebourn
Nice amp!

I am going to build one using 6N17B and 6P30B tubes.
__________________
The Devil is not so terrible as his math model is!
  Reply With Quote
Old 17th June 2011, 09:14 PM   #3
diyAudio Member
 
firechief's Avatar
 
Join Date: Sep 2008
Location: Near Seattle Wa
I like it! Are you showing all of the windings on the power transformer? If so, where do the filaments connect? I just dont quite get it .
__________________
"You can keep your insurance baby nothing is guaranteed" -Tom Petty
  Reply With Quote
Old 17th June 2011, 10:45 PM   #4
diyAudio Member
 
Michael Koster's Avatar
 
Join Date: Jan 2008
Location: Eureka, CA
Quote:
Originally Posted by firechief View Post
I like it! Are you showing all of the windings on the power transformer? If so, where do the filaments connect? I just dont quite get it .
I pulled some random transformer symbol out of the lib. If someone someday would like to make Eagle parts for some popular Hammond transformers that would be ... just ... great.

There is a 6.3V winding and heater connections which are not shown. I thought that bit was not as important to show. the 6.3V string is simply one side grounded as in the Champ.

Thanks,

Michael
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
the boombox on steroids thread ke4mcl Class D 11 15th May 2009 06:45 AM
Gainclone on steroids sasha Chip Amps 30 23rd January 2006 02:42 PM
Function Generators on steroids for sale NotInTheMafia Swap Meet 1 23rd March 2005 04:54 PM
Old Pioneer on steroids + CDenhancerII Radian Digital Source 0 26th January 2005 02:14 PM


New To Site? Need Help?

All times are GMT. The time now is 09:29 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2