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DIY Stompboxes => Building your own stompbox => Topic started by: dubs on January 15, 2004, 10:25:50 AM

Title: Interesting Bass headphone amp...
Post by: dubs on January 15, 2004, 10:25:50 AM
Apparently bass players have raved how transparent and fantastic it sounds. loved to have a shot a making one myself. Anyone up to making a pcb layout?
www.cafewalter.com
Perhaps I could email the seller see if he sells kits...

(http://www.cafewalter.com/ha1/graphics/ha1_349x199.jpg)

(http://www.cafewalter.com/ha1/graphics/inside_345x302.jpg)

(http://www.cafewalter.com/ha1/graphics/ha1_schematic.gif)
Title: Looks pretty Sanzzie..
Post by: petemoore on January 15, 2004, 10:34:44 AM
I'm sure it could be modded though...lol
 If the schematic's good I don't see why not.
Title: Interesting Bass headphone amp...
Post by: Robin on January 15, 2004, 10:59:07 AM
Wow, I'm impressed. Interesting layout, Burr Brown preamp, three dedicated inputs, separate power amps and all. This guy sounds like a humble member of our little club. Worth checking out the site.

Rob
Title: Interesting Bass headphone amp...
Post by: Jason Stout on January 15, 2004, 03:06:56 PM
Thanks for the link!
Title: Interesting Bass headphone amp...
Post by: Tubebass on January 15, 2004, 03:22:49 PM
I built one of these on perf. I used 5532 opamps, 2n3904/3906, and used a MAX 1044 charge pump converter to get -9v. It seems to work fine, though I haven't actually listened to it yet....just looked at its output on a scope.
Title: Interesting Bass headphone amp...
Post by: Joep on January 15, 2004, 05:49:39 PM
cool, can you share your layout?

thanks,

Joep
Title: Layout? We don't need no steenking layout!
Post by: Tubebass on January 15, 2004, 05:58:32 PM
Sorry, I don't really have a layout as such. When it comes to perf I just start jammin' parts in there and keep going till it's done. I have great admiration for those folks who do all the pre-planning before a build, but my brain just doesn't seem to work that way :oops:
Title: Re: Interesting Bass headphone amp...
Post by: mnats on January 21, 2004, 07:06:29 AM
Quote from: dubsAnyone up to making a pcb layout?

I've taken the bait:

http://www.geocities.com/m_natsume/ha_1.html
Title: Interesting Bass headphone amp...
Post by: dubs on January 21, 2004, 06:12:38 PM
Very nice work! Thanks for doing that! Maybe you could also post jpeg/gif of the layouts for those that don't use PCB express?
Title: Interesting Bass headphone amp...
Post by: mnats on January 21, 2004, 10:24:37 PM
Quote from: dubsVery nice work! Thanks for doing that! Maybe you could also post jpeg/gif of the layouts for those that don't use PCB express?

Good idea. I've done it.
Title: Errors in layout?
Post by: dubs on January 22, 2004, 11:08:44 PM
Thanks for that.
Comparing schematic to layout, I think perhaps there's some errors/alterations needed:
- layout  has R6 connected to c4, is this common ground point and be linked to ground?
- Is that soldering point b/w c6 and c5 that isn't  connected to anything be connected b/w the two resistors and be labelled j3?  
- point b/w r27 & r28 be labelled j4
- point b/w r17 & r18 be labelled j4


I ain't no electronics whizz, so apologies if I'm wrong..
Title: Re: Errors in layout?
Post by: mnats on January 23, 2004, 01:04:07 AM
Quote from: dubsThanks for that.
Comparing schematic to layout, I think perhaps there's some errors/alterations needed:
- layout  has R6 connected to c4, is this common ground point and be linked to ground?
- Is that soldering point b/w c6 and c5 that isn't  connected to anything be connected b/w the two resistors and be labelled j3?  
- point b/w r27 & r28 be labelled j4
- point b/w r17 & r18 be labelled j4


Sorry, I did it in just a couple of hours in between putting up 40 metres of fence!

R6 & C4 ARE connected to ground.

Similarly C6 & C5 are too connected to ground - perhaps there is a problem with the .pcb file or you are using a different version of the software?

The pad between R27 & R28, R17 & R18 are the right and left outputs respectively.

What I did miss was a connection for the pad between R5 & R6 which is the tuner output.

I noticed my .gif for the PCB wasn't very good and contains the same error. I'll go back and correct it sometime soon.
Title: Interesting Bass headphone amp...
Post by: dubs on January 23, 2004, 08:36:07 AM
Yeah sorry after I looked at the schematic after posting I realised r6 & c4 are to the ground. Doh!!

I only looked at the gif  files. Thanks I appreciate your hard work. Now I need to find where I can get some OPA134P IC's in Australia....
Title: Interesting Bass headphone amp...
Post by: mnats on January 24, 2004, 06:52:31 AM
Quote from: dubsYeah sorry after I looked at the schematic after posting I realised r6 & c4 are to the ground. Doh!!

I went back, made the correction and refined the pcb and the gif files.

Quote from: dubsI only looked at the gif  files. Thanks I appreciate your hard work. Now I need to find where I can get some OPA134P IC's in Australia....

I've got a few OPA2134P (duals) but I can't see any reason why you couldn't use other single opamps. Check Doug Self's site for some ideas http://www.dself.dsl.pipex.com/ampins/webbop/opamp.htm
Title: Interesting Bass headphone amp...
Post by: SirPoonga on November 20, 2004, 11:00:45 PM
http://www.geocities.com/m_natsume/ha_1.html

This looks cool.  Could someone explain to me where on the PCB you are suppose to hook up the battery or batteries?
Title: Interesting Bass headphone amp...
Post by: Paul Perry (Frostwave) on November 21, 2004, 05:17:51 AM
Quote from: dubs. Now I need to find where I can get some OPA134P IC's in Australia....

Farnell (Australia) has them at $4.07 each.
Title: Interesting Bass headphone amp...
Post by: melkaone on November 21, 2004, 10:38:07 AM
yeah! another bass project!! :D
could be useful for my talkbox (if i don't blow the horn driver) :D
Title: Interesting Bass headphone amp...
Post by: SirPoonga on November 21, 2004, 08:21:50 PM
ok, I am still confused on the batteries.  Where do they hook up in the pcb I linked.  How do you hook up two batteries so they "turn on" when you insert the jack?