HeadCase. Similar to Rat but 4558 chip .. Soundclip Added April 12

Melanhead · February 06, 2006, 09:16:39 AM

Well I finished it up this weekend ... Just for fun, I wanted to make a Rat type circuit using a 4558 and no transistors ... I also wanted to make it a bit smoother with less mushy bottom end ... this is the result ... I love it! ...Soundclips to follow, when I have a moment to box it up

comments ?

http://aronnelson.com/gallery/melanhead/HeadCaset

http://aronnelson.com/gallery/melanhead/HeadCase_layout

enjoy ...

The layout was verified by me this weekend but I tweaked it since to make it a bit smaller ... should be fine though.

Pix:

http://aronnelson.com/gallery/melanhead/HeadcaseWeb
http://aronnelson.com/gallery/melanhead/HeadcaseInside

Soundclip added April 12/06:

man my Strings are dead! ... Marshall sorta clean then Marshall and Headcase ... Enjoy!

http://users.eastlink.ca/~melanhead/MP3/HeadcaseMarshall.mp3

Steben · February 06, 2006, 09:19:19 AM

Why not use a smaller level pot after the few-ohmic 4558 buffer? Even 1k would work... 10k is common. less noise and above all less treble loss if there is a low impedance thing after it etc...

How did you come up with "HeadCase"?

Melanhead · February 06, 2006, 09:33:54 AM

Quote from: Steben on February 06, 2006, 09:19:19 AM
Why not use a smaller level pot after the few-ohmic 4558 buffer? Even 1k would work... 10k is common. less noise and above all less treble loss if there is a low impedance thing after it etc...

How did you come up with "HeadCase"?

Interesting ... I could try that, ... worth a shot just for fun, thanks! ...

HeadCase ... well I just liked the name, as it's part of my nickname or could pertain to a female/male with a distorted mind or it's could be the box or case that the circuit is in. lots of meanings!

WGTP · February 06, 2006, 03:25:56 PM

Nice. I have drawn up several designs like that, but I can't keep myself from sticking a second set of diodes in the second op amp to make a dual clipper.

Melanhead · February 06, 2006, 03:34:07 PM

yup! ... I have the same problem but so far I haven't liked the outcome

... I'm keeping things simple and getting good results.

Melanhead · February 08, 2006, 12:13:39 PM

now with inside and outside pix ...

MartyMart · February 08, 2006, 12:31:16 PM

Nice graphics there Mr Melan

And a nice little layout too, I might add .... hey, did you see my layout for
the Tech 21 XXL ? ( in my layouts gallery above )
I've just been recording with it, and it ROCKS !! the band loved the sound

Peace,
Marty.

Melanhead · February 08, 2006, 12:39:54 PM

Quote from: MartyMart on February 08, 2006, 12:31:16 PM
Nice graphics there Mr Melan
And a nice little layout too, I might add .... hey, did you see my layout for
the Tech 21 XXL ? ( in my layouts gallery above )
I've just been recording with it, and it ROCKS !! the band loved the sound

Peace,
Marty.

Thanx!

Yup saw the XXL when you posted ... I think I even replied but can't remeber

I may have to build it soon ... I love building the easier tone shaping pedals

wampcat1 · April 10, 2006, 10:14:54 AM

Not the exact schemo, but I'm going for the same thing. Rat type tone with a 4558. So far:
http://www.indyguitarist.com/soundclips2/rat_vs_4558-rat-emu.mp3

I'm using the exact schem as the rat except using a rc4558 and using the second half of the opamp as the buffer like Mr. Melan did here.

Getting a little closer anyway to the tone.

Xavier · April 10, 2006, 12:22:28 PM

Melanhead, any news regarding your sound samples?

I've completed the Chaos but I'm afraid it's too raspy for my tastes. Can you elaborate a little bit about the sound differences with the Rat? I'm also concerned about the dull low end and fuzzyness of the Rat.

What about the bass response?

Thanks in advance

Melanhead · April 10, 2006, 01:54:51 PM

Quote from: Xavier on April 10, 2006, 12:22:28 PM
Melanhead, any news regarding your sound samples?

I've completed the Chaos but I'm afraid it's too raspy for my tastes. Can you elaborate a little bit about the sound differences with the Rat? I'm also concerned about the dull low end and fuzzyness of the Rat.

What about the bass response?

Thanks in advance

Bass reponse is quite a bit "tighter" ... all I can say is it's not as mushy sounding. I have the same issues with the Rat as you... My intention were to illiminate these issues but maintain the same sorta tone .... It has a bit less gain than a Rat but not much less

it's also cleans up better when the gain is down, more of an overdrive than the Rat in that sense.

I'll see if I can get some time to do some clips this week, I'm recording a solo for friend with it anyways ...

Xavier · April 11, 2006, 03:33:21 AM

I'm going for it. I'll build it today , as I'm pretty sure it will sound good. We seem to have the same tone tastes. Must be the age

Melanhead · April 11, 2006, 07:29:11 AM

Quote from: Xavier on April 11, 2006, 03:33:21 AM
I'm going for it. I'll build it today , as I'm pretty sure it will sound good. We seem to have the same tone tastes. Must be the age

maybe ears too

I think you'll like it ... for sure!

WGTP · April 11, 2006, 09:24:47 AM

Just a suggestion. C4 at .68uF controlls bass and gain. The input cap C1 .022uF also controls bass. Try making C4 1uF and C1 much smaller like .001uF. By varying the 2, you can tune the bass as desired.

tungngruv · April 11, 2006, 09:30:54 AM

I will say this, I built the Headcase days ago and it rocks!! I did sub a .47 cap instead of the .68 and it sounds fine. I use it with an I banez 7 string (Air Norton and Tone Zone) into a 79' Marshall JMP MK2 and it sounds huge, easily getting pick squeels and controlled feedback. I know it's supposed to be a Rat knock off but it sounds very different to my ears. Very cool build!

Melanhead · April 11, 2006, 10:00:49 AM

Quote from: WGTP on April 11, 2006, 09:24:47 AM
Just a suggestion. C4 at .68uF controlls bass and gain. The input cap C1 .022uF also controls bass. Try making C4 1uF and C1 much smaller like .001uF. By varying the 2, you can tune the bass as desired.

Yup ... I did that though with just C4 ... The bass response for me is perfect now but a great suggestion for the tweakers, I have allready tweaked this thing too much

... but then again I'm sure I'll add to it later. Maybe some switchable diode combi, boost mode etc ... Just no time right now. House reno's are calling

tungngruv · April 11, 2006, 10:14:06 AM

I was thinking about Jack Ormans idea where you put a pot in front of the diodes to control the amount of clipping there. I think he called it a "warp" or "saturation" control. It's in his lab notebook. I remember playing a Rat once that I built that had an on/off/on switch and taking the diodes completley out had a pretty good sound also.

WGTP · April 11, 2006, 10:24:50 AM

I have Jack's Warp control on a rebuilt Rat. It is a 10K pot that pans between a Ge and LED. The other diode is an SI. Definitely recommended.

WGTP · April 11, 2006, 12:11:32 PM

Another thought/question. Would the TS Tone control work for the second op amp?

Melanhead · April 11, 2006, 12:32:21 PM

Quote from: WGTP on April 11, 2006, 12:11:32 PM
Another thought/question. Would the TS Tone control work for the second op amp?

Probably would although I tend to avoid it, taking it outa my TS clone in favor of a filter...

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HeadCase. Similar to Rat but 4558 chip .. Soundclip Added April 12