madbeanpedals::forum

General => Open Discussion => Topic started by: wretched on January 01, 2014, 09:52:42 PM

Title: Looking for amp simulator pedals
Post by: wretched on January 01, 2014, 09:52:42 PM
Does anyone know of any good amp sim pedal clones? I think Joyo makes a few. I already have something for tweed.
Title: Re: Looking for amp simulator pedals
Post by: jimilee on January 01, 2014, 09:59:08 PM
Like the chunk chunk? I believe bean also has an ac30 too.
Title: Re: Looking for amp simulator pedals
Post by: wretched on January 01, 2014, 10:06:11 PM
Yep like the Chunk Chunk. I am just putting that one together now hope to have it going after the weekend. As for the AC30, is that the "daytripper" ?
Title: Re: Looking for amp simulator pedals
Post by: jimilee on January 01, 2014, 11:30:02 PM
Yep
Title: Re: Looking for amp simulator pedals
Post by: wretched on January 03, 2014, 07:41:12 PM
I see Tech 21 made a few. I ended up getting BlackBird and Plexi Drive PCB boards. I also have a Tweedy Bird and Professor Tweed in the works

Any one know of any others?
Title: Re: Looking for amp simulator pedals
Post by: midwayfair on January 03, 2014, 07:45:06 PM
Quote from: wretched on January 03, 2014, 07:41:12 PM
Any one know of any others?

Almost everything by Runoff Groove is at least good. But for now, build the Azabache and Supreaux Deux for low-gain type stuff, and the Thor for higher gain. Thomas_H has PCBs for a bunch of ROG circuits
Title: Re: Looking for amp simulator pedals
Post by: wretched on January 03, 2014, 08:29:22 PM
Thanks I grabbed all 3. This should keep me busy for a while.
Title: Re: Looking for amp simulator pedals
Post by: wretched on January 08, 2014, 04:36:48 PM
First off GREAT demos, I looked these PCBs up on YouTube.  I am getting ready to place an order and wondering if a 20k Trimmer would be okay in place of the 25k trimmers the Thor and Azabache are asking for?
Title: Re: Looking for amp simulator pedals
Post by: midwayfair on January 08, 2014, 04:41:40 PM
Quote from: wretched on January 08, 2014, 04:36:48 PM
First off GREAT demos, I looked these PCBs up on YouTube.  I am getting ready to place an order and wondering if a 20k Trimmer would be okay in place of the 25k trimmers the Thor and Azabache are asking for?

"Most likely."

FETs are like delicate little snowflakes, and the biasing can be precise in Runoff Groove builds. However, there is a bell curve to the expected drain values required to properly bias the FETs. Runoff Groove's design philosophy indicates that one should use a trim pot twice the size of the expected value when building with FETzer valves. If you're building with a J201, you can expect the drain value to be a touch over 10K -- which means a 20K will actually get pretty close right in the dead center, but some super incredible outlier could require a larger trim pot. In other words, 20K is just fine for the Azabache for sure, but I thought you'd like to know the why of it. :)

I can't speak regarding the Thor, I haven't built that one, only breadboarded it. Marshalls just aren't my thing.
Title: Re: Looking for amp simulator pedals
Post by: wretched on January 08, 2014, 05:26:35 PM
a little off topic, but could I use a trim pot in place of a resistor on a board. I have read that I could just use the middle and one ends as a lead. I only ask because I have to Bias some j201's for some other builds that I have been putting off. If this would work I could build the circuit and then use the trim pot to find the resistor I need.
Title: Re: Looking for amp simulator pedals
Post by: midwayfair on January 08, 2014, 05:54:32 PM
Quote from: wretched on January 08, 2014, 05:26:35 PM
a little off topic, but could I use a trim pot in place of a resistor on a board. I have read that I could just use the middle and one ends as a lead. I only ask because I have to Bias some j201's for some other builds that I have been putting off. If this would work I could build the circuit and then use the trim pot to find the resistor I need.

Yes, of course. But most builds with FETs use trimpots unless the biasing isn't critical.
Title: Re: Looking for amp simulator pedals
Post by: wretched on January 09, 2014, 05:43:06 AM
They are a couple from Chi Boy The tweedy and Black Bird from the looks of them they are great, but I have to sort through the j201s I picked up from SmallBear.
Title: Re: Looking for amp simulator pedals
Post by: aeroemi on January 09, 2014, 08:29:20 AM
Quote from: midwayfair on January 03, 2014, 07:45:06 PM
Quote from: wretched on January 03, 2014, 07:41:12 PM
Any one know of any others?

Almost everything by Runoff Groove is at least good. But for now, build the Azabache and Supreaux Deux for low-gain type stuff, and the Thor for higher gain. Thomas_H has PCBs for a bunch of ROG circuits




... Cool... Where could i get the Thor schematic?



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Title: Re: Looking for amp simulator pedals
Post by: kothoma on January 09, 2014, 08:34:33 AM
Quote from: aeroemi on January 09, 2014, 08:29:20 AM
Quote from: midwayfair on January 03, 2014, 07:45:06 PM
Quote from: wretched on January 03, 2014, 07:41:12 PM
Any one know of any others?

Almost everything by Runoff Groove is at least good. But for now, build the Azabache and Supreaux Deux for low-gain type stuff, and the Thor for higher gain. Thomas_H has PCBs for a bunch of ROG circuits

... Cool... Where could i get the Thor schematic?

google
http://www.runoffgroove.com/thor.html
(and also build instructions for http://diy.thcustom.com/shop/rog-thor-modified-v1-2-pcb/ )