Go Back   Home > Forums > Amplifiers > Chip Amps

Chip Amps Amplifiers based on integrated circuits

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 15th March 2007, 04:34 AM   #1
diyAudio Member
 
Join Date: Jun 2002
Location: El Dorado Hills, CA
Send a message via AIM to Hewie Send a message via Yahoo to Hewie
Default How long did it take to complete your first GC?

Well, I wouldn't call it "complete", but it's close, and it only took 3 years, and that doesn't include the time researching and ordering parts. So here it is: a basic LM3875 inverted GC, ala Nuuk. With exception of two Black Gate Caps and a couple of resistors, all the parts, including the case materials, are from the local surplus shops. For the time being, I'm just running it in my shop off a cheap CDP with a passive vol. and cheap speakers, but I'm really impressed so far. Dead quiet and <20mV DC output. In hindsight, I wish I had sourced the components a little more carefully. Maybe I'll rebuild it with quality components.

Here's the first channel in May 04:
Click the image to open in full size.


And the second channel was added in Aug 04:
Click the image to open in full size.

I spent some time listening in my shop with a portable CD player and realized this had some real potential. It took a couple years popping into the machine shop on lunch breaks to put together a case:
Click the image to open in full size.

And here is the result with the passive pre:
Click the image to open in full size.

Is it complete...well, not really. I 'd still like to remove the dykem, buff the scratches out of the aluminum, build a new bottom since it's a little like swiss cheese after moving parts around and counter-bore the SHCS on the face plate. I guess that's next years project.

Dave

PS Thanks for the help of the board members along the way.
  Reply With Quote
Old 15th March 2007, 04:47 AM   #2
Nordic is offline Nordic  South Africa
diyAudio Member
 
Nordic's Avatar
 
Join Date: Sep 2005
Looks very nice!

Those exposed fuses bother me though, can't say I've never been shocked by them... Have a look around, I found some nice round case mount ones the other day for a few cents each, they have screw cap on the outside...
  Reply With Quote
Old 15th March 2007, 05:02 AM   #3
renfrow is offline renfrow  United States
diyAudio Member
 
renfrow's Avatar
 
Join Date: May 2005
Location: Salt Lake City, Utah, USA
I must say that looks mighty tasty! I've got a kit waiting for me to get time to put together. Two sets of speakers and moving are currently ahead of it, though .

Tom.
__________________
Now, we can do this the hard way, or... well, actually there's just the hard way.
-- Buffy Summers (Buffy the Vampire Slayer)
  Reply With Quote
Old 15th March 2007, 07:42 PM   #4
diyAudio Member
 
Join Date: Jun 2002
Location: El Dorado Hills, CA
Send a message via AIM to Hewie Send a message via Yahoo to Hewie
Quote:
Originally posted by Nordic
Looks very nice!

Those exposed fuses bother me though, can't say I've never been shocked by them.
Nordic-
The primary AC fuse is mounted in an enclosed holder just above the IEC power socket, the exposed fuses are on the low voltage DC legs. I plan on removing the low voltage fuses once I'm sure everything is working properly, but I don't think they pose any danger.

Thanks for looking,
Dave
  Reply With Quote
Old 16th March 2007, 05:13 PM   #5
lgreen is offline lgreen  United States
diyAudio Member
 
lgreen's Avatar
 
Join Date: May 2003
Location: San Diego, USA
Default I likey!

Looks nice, you sound like me. A lot of my projects take multiple years to make. But the truth is you are never quite done, are you?
__________________
Retired from DIY (2010) but still lurking now and again. My DIY audio projects- PartTimeProjects.com.
  Reply With Quote
Old 16th March 2007, 05:52 PM   #6
diyAudio Member
 
Join Date: Mar 2006
Location: Great Yarmouth, UK
I like the case! Did you build this yourself too?
  Reply With Quote
Old 17th March 2007, 05:21 AM   #7
diyAudio Member
 
Join Date: Jun 2002
Location: El Dorado Hills, CA
Send a message via AIM to Hewie Send a message via Yahoo to Hewie
Default Re: I likey!

Quote:
Originally posted by lgreen
A lot of my projects take multiple years to make. But the truth is you are never quite done, are you?
And there are two categories of these: 1) the ones I keep tweaking, and 2) the ones my wife reminds me about that really are NOT finished.


Quote:
Originally posted by markiemrboo
I like the case! Did you build this yourself too?
Thanks. Yep. the case is actually what took so long. I sneaked into the machine shop on lunch breaks when I could afford the time. It's pretty much a copy of the work others have done and posted on the galleries.

Dave
  Reply With Quote
Old 17th March 2007, 07:48 AM   #8
diyAudio Member
 
tamasic1's Avatar
 
Join Date: Dec 2006
Default case time

Great looking project! I completely understand about the swiss cheese bottom.
I'll bet for something like a GC the case will always take you far longer to complete than the circuit layout. I used an old computer case (IBM PCjr) and it took me a couple hours every night after work for exactly a week to get everything right. ( I kept changing the internal layout around also) I'm still working on it as I just got the parts to build the AD815 based pre and it also will be housed in the case.
__________________
Tube Amp builders - Getter Done!
  Reply With Quote
Old 17th March 2007, 07:53 AM   #9
diyAudio Member
 
Join Date: Dec 2002
Location: Western Australia
Send a message via MSN to Scribble
Very nice, you should be proud
  Reply With Quote
Old 17th March 2007, 11:16 PM   #10
jduffy is offline jduffy  United States
diyAudio Member
 
jduffy's Avatar
 
Join Date: Oct 2006
I really like to see wood but that's just me. Nice job with it all and hey, you can't rush greatness!
  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
almost complete rv1890 Multi-Way 6 21st February 2006 06:28 PM
Forgot to do this long long time ago chris ma Introductions 2 30th October 2003 10:53 PM
Long output lead or long output transistors leads? which one to pick? chris ma Everything Else 3 6th June 2003 12:06 PM
Amp or Pre-amp Complete kit fcel Solid State 2 19th September 2001 01:53 PM


New To Site? Need Help?

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


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