MXR EVH 5150 Overdrive

Post by **modman** » 16 Nov 2015, 11:21

Could we stop guessing and start tracing?
Please somebody provide a gut shot...
We also have this to look at ....

alexradium · Post by **alexradium** » 16 Nov 2015, 14:47

FuzzMonkey wrote:This looks interesting considering EVH is famous for saying he never used any sort of distortion / overdrive pedal.

well,maybe he didn't use distortion pedals,for sure he boosted his plexis with graphic eqs,echoplexes and whatnot,all of this means nothing when a company signs a good check with several zeros for your pocket,be it MXR,Peavey.Fender,Kramer,Dunlop,you name it.
Just add another Lambo in the garage.

FuzzMonkey · Post by **FuzzMonkey** » 17 Nov 2015, 22:39

modman wrote:Could we stop guessing and start tracing?
Please somebody provide a gut shot...
We also have this to look at ....

I've been searching for a gutshot but no luck yet.

J0K3RX · Post by **J0K3RX** » 18 Nov 2015, 00:45

This should be in the "Requests Folder" topic....

Ice-9 · Post by **Ice-9** » 18 Nov 2015, 20:40

I love this description from one shops website.

EVH© 5150™ Overdrive joins hand-adjusted multi-stage MOSFETs with a full complement of controls to deliver overdriven tube-like tones and exceptional sonic flexibility through a wide variety of amps and speaker cabinets

What does hand adjusted MOSFET mean? trimmers ? selected? selected value resistors ? is there any need to do this with MOSFETS ?

MoonWatcher · Post by **MoonWatcher** » 18 Nov 2015, 21:40

Ice-9 wrote:What does hand adjusted MOSFET mean? trimmers ? selected? selected value resistors ? is there any need to do this with MOSFETS ?

It means nothing without actual relevant details.

I would say there's no need to do this with mosfets, especially with a device that's designed to distort, and is primarily pre- and post-eq shaped within that distortion.

But Dunlop or other pedal companies would probably say absolutely yes, hand adjustment is necessary. Many mosfets have higher thermal noise characteristics than other types of transistors, but this pedal has a noise gate. So there's no hand adjustment (which I would take to mean selection) for lower noise.

And sorting for gains on a mass production scale makes no sense, unless it's being used as some sort of angle to justify raising the price a bit. Remember that if you sell something made in large numbers, and you figure out a way to raise the price even just a little bit (even just 5USD$) for what is basically zero impact on labor times, any company would probably go for that.

I think at least one newer Dunlop pedal uses power mosfets, unless I'm getting them mixed up with another big company (like Digitech/DOD)? Maybe hand adjusted means they are doing something with the heat sink? There would be no sonic advantage, but it could still be spun as a marketing ruse.

Dirk_Hendrik · Post by **Dirk_Hendrik** » 20 Nov 2015, 09:33

modman wrote:Could we stop guessing and start tracing?
Please somebody provide a gut shot...
We also have this to look at ....

J0K3RX wrote:This should be in the "Requests Folder" topic....

And as well,
When did 13-in-a-dozen-MXR become "boohteek".

tschrama · Post by **tschrama** » 20 Nov 2015, 09:36

I find the clips so far pretty good! Eager to have a look at the guts and help tracing

J0K3RX · Post by **J0K3RX** » 21 Nov 2015, 02:28

Ryan Bruce layin it down!

56335130 · Post by **56335130** » 11 Jan 2016, 08:26

J0K3RX wrote:Of course Ola... His sound actually sounds a bit different on this one which is rare, because usually everything he plays sound the same..

I want to hear it directly into a power amp damn-it!

Agree everything the same PART

vikingz · Post by **vikingz** » 11 Jan 2016, 23:27

Way too much gain....

J0K3RX · Post by **J0K3RX** » 12 Jan 2016, 04:20

vikingz wrote:Way too much gain....

NEVER!!!

jaybeemusic · Post by **jaybeemusic** » 20 Jan 2016, 01:59

Here ya go guys... I can't trace for shit...and this is only a loaner pedal... so I can't really disassemble it...

I will leave it to you guys to determine what pix are decent. It's all SMD... and it looks like some of the transistors are sanded off.

Perhaps someone can stitch them together to make a really big photo.

https://s302.photobucket.com/user/jaybe ... 50%20Pedal

MoonWatcher · Post by **MoonWatcher** » 22 Jan 2016, 18:25

jaybeemusic wrote:It's all SMD... and it looks like some of the transistors are sanded off.

I see at least 2 trimpots, possibly 3. And there could be more. At least two are in proximity of transistors. If they are truly mosfets like MXR claims, then I guess those trimpots might connect to the sources. But if they are jfets, I'd think they'd connect to the drains.

I didn't bother to try and zoom in on the transistors for part numbers - I honestly don't care that much.

I was also looking at resistor values in proximity to some of the transistors, and it looks like straightforward values of the usual suspects - 10k, 1M, 100k, and then smaller values like 390r and so on - I'm guessing the small resistors are attaching to either the sources or emitters. Some values looked like they could indicate a Big Muff stage, as silly as that sounds.

I would think that some of the op amps are for uses like as initial boost stages, or primarily for EQ shaping. Many of the transistors could be used with the op amps for gyrators, I would think.

Even if component values are sanded off, we can figure out the basics with the DIP8 devices - I'm assuming pin 4 connects to ground, and pin 8 connects to a source voltage.

I also thought I saw a pair of anti-parallel diodes that would most likely be used for clipping. There are other 3-terminal diodes that I'd think could be also used for clipping purposes.

Overall, what I see just looks to be on the overly complex side, as what I guess would be needed to mimic the amount of distortion and EQ characteristics of a 5150 amplifier. Whether or not that is done with op amps or transistors is probably somewhat trivial or academic, given the amount of gain - as long as the op amp stages aren't latching up, it's really hard clipping, after all.

xaaxaa · Post by **xaaxaa** » 02 May 2016, 12:18

No news concerning the tracing, even after 4 months?
Gut shots aren't enough with SMD, not to mention some markings have been acid removed, someone needs to personally test the values of the components .

J0K3RX · Post by **J0K3RX** » 02 May 2016, 14:15

xaaxaa wrote:someone needs to personally test the values of the components.

See if jaybeemusic will send you the pedal for analysis

I don't think any of the parts have had the markings removed with acid... You could be right but it's probably a combination of camera lighting, image quality and small amounts of flux residue on some of the parts.. Hitting it with a tooth brush and some denatured alcohol may reveal the markings... But, you are correct, it's an impossible task without the pedal in the hands of somebody who is willing to get the part values and that means some parts will need to be isolated/removed to get the correct readings..

So, don't lose any sleep over it..

Ice-9 · Post by **Ice-9** » 05 May 2016, 22:15

xaaxaa wrote:No news concerning the tracing, even after 4 months?
Gut shots aren't enough with SMD, not to mention some markings have been acid removed, someone needs to personally test the values of the components .

Yes, you are welcome to personally test the values yourself and post your results, it would make a great 3rd post for you.