Rocktron - Austin Gold Overdrive

allesz · Post by **allesz** » 23 Oct 2009, 15:18

After a lot of web search I gave up to find the schematic of the rocktron austin gold, it's a overdrive I really like, and use a lot. sadly it is not made super strong.

I posted in this forum the request for a schemo.... but I had no answer

I finally, without searching for it

http://www.aronnelson.com/gallery/main. ... d.gif.html

Now I want to understand why I like it's sound so much

RnFR · Post by **RnFR** » 23 Oct 2009, 20:43

moved to modern folder.

Nikifena · Post by **Nikifena** » 24 Oct 2009, 09:36

and the schematics.. again

allesz · Post by **allesz** » 24 Oct 2009, 17:52

I just completely love you

allesz · Post by **allesz** » 26 Oct 2009, 09:40

I found the pcb too: http://www.aronnelson.com/gallery/main. ... t.gif.html

Post by **audioguy** » 28 Oct 2009, 19:44

From what I remember Mark had trouble with that layout... said it didnt sound quite right.

allesz · Post by **allesz** » 29 Oct 2009, 14:57

Yes, it is is true. Mark M. said he had some problem on the output.
Anyway, I don't want to rebuild or clone completely the austin gold, but just get the secret of it sound. The prebass is, to my ears, a fine tone shaping device (from TS to bass heavy drive sounds).
I would like to put it in some upcoming project. I would like to mimic the tone of the pedal with transistors (will it be possible?)

Bernardduur · Post by **Bernardduur** » 01 Nov 2009, 15:19

Anyone knows if the schematic is verified? All I'm getting is a tremolo effect

celadine · Post by **celadine** » 01 Nov 2009, 23:22

The output looks funny. Perhaps some bypass switching components (fets, etc.) were eliminated from the schematic, while others were left behind. (Speaking from experience...

)

<edit> Bernard - did you use FET opamps? They might not like this circuit.

KHELSTROM · Post by **KHELSTROM** » 20 Aug 2010, 19:40

Wow, this thing has a lot of power filtering.

infisus · Post by **infisus** » 21 Aug 2010, 00:52

This is my first post. Thank you for all the info here.

Tha Austin Gold is one of my favoite pedals. I also traced it and believe the schematic above is correct. But the bypass part is omitted. The "old" rocktron pedals use 4066 analog switch IC to do the bypass part. (The "new" ones use sth like the BOSS.)

To my knowledge, when using analog switches to trun on/off audio signals, the 2 sides of the switch should be bisaed to the same level. Also a cap in one side of the analog switch. All these parts are for avoiding the "pop" sound.

I am talking about the C7/R8/R10/C8. I do not want to take my Austin Gold apart again. But I pretty sure there is a analog switch between C7 R8 & R10 C8, in series with R9. Of course, some parts have other duties except for the bypass.

Tone wise, the 4066 method is better than BOSS in my book.

yongki · Post by **yongki** » 15 Feb 2012, 19:37

Schematic from rocktron austin gold
http://www.4shared.com/office/kbWwLEOy/austingold.html

jonasx26 · Post by **jonasx26** » 15 Feb 2012, 20:42

My trace from photos uploaded on this forum. Seems to match the pdf-schem.

mirosol · Post by **mirosol** » 13 Nov 2012, 15:32

For the Jonas' schematic, there seems to be something wrong with the connections for vcc2 and ground.

For the PDF schematic, that 22µ coming from drive pot through 620R needs to be reversed. I just finished Mark F's layout, and it's now verified, with that cap reversed. This means that the PDF schematic should also be considered as verified - after that cap has been reversed. It's negative to ground...

IvIark · Post by **IvIark** » 13 Nov 2012, 15:48

Excellent, which makes this verified then

jonasx26 · Post by **jonasx26** » 15 Nov 2012, 11:34

mirosol wrote:It's negative to ground...

Yes. Negative to ground, if ground is a lower voltage than whatever is connected to the other side of the cap..
In my schematic both sides of the capacitor are essentially at the same 4.5V bias. So there is no correct orientation.

The 22µ cap can be connected to either 4.5V or 0V. Won't change the sound, AC signals don't care that much what "ground" is..
Connecting it to ground instead of VCC/2 is better. And makes polarity way easier. Negative to ground.

Victor Nery · Post by **Victor Nery** » 19 Dec 2018, 16:25

Greetings,

I've got one here for repairing. The capacitor in series with 620r is 22u and it is oriented with + side to vcc or gnd (didn't check if it's ground or vcc but it is oriented reversed from the way we usually see). CIs are JRC5532DD, HD14016BP (instead of 40106N) and HD14584BP (instead of 4016N). Apart from that, the schematic posted by Jonas Sjöberg is accurate and all the connections match. The version I had at hand used smd resistors and capacitors. I Could check only the electrolytic caps and the values he posted are correct.

Thanks everybody.

jonasx26 · Post by **jonasx26** » 24 Dec 2018, 02:27

Victor Nery wrote:Greetings,

I've got one here for repairing. The capacitor in series with 620r is 22u and it is oriented with + side to vcc or gnd (didn't check if it's ground or vcc but it is oriented reversed from the way we usually see). CIs are JRC5532DD, HD14016BP (instead of 40106N) and HD14584BP (instead of 4016N). Apart from that, the schematic posted by Jonas Sjöberg is accurate and all the connections match. The version I had at hand used smd resistors and capacitors. I Could check only the electrolytic caps and the values he posted are correct.

Thanks everybody.

Hey! Thanks for the verification. Happy holidays!

Rocktron - Austin Gold Overdrive [schematic]