Alesis X2

Electrical mods
Mechanical mods


I do not work for Alesis, nor ever have. I have no affiliation with Alesis. I do not claim to be any type of expert on their products nor do I repair their products for money, nor do I sell the information that I collect. Any donations I receive are used to pay for bandwidth and to keep this information online. All of the information I have collected has been freely given to me or it is my own work. Iím just a happy X2 owner and have spent years trying to find as much information about them as possible, especially as the consoles wear out and the original information is lost to time.

You can donate to via Paypal if you find the information in this website useful and would like to help keep it online.

What this is:
This is hopefully going to be the most complete site for Alesis X2 technical information anywhere on the internet. I've literally received hundreds of emails from all over the world responding to my forum threads on GroupDIY, Gearslutz, and others. I have tried my best to answer these emails but there have been so many that I haven't been able to keep up with them all, especially those that have multiple questions and replies. I just can't keep everyone and their console questions/problems straight and it takes me too much time to go back and look at emails and messages that I keep finding myself lacking at things I need to be doing, like working :) .

What I can offer through this site:
I can put everything I know or have on this site. If it's not here, I don't know it or have it. I'll try to write up all the problems I've had and all the mods I've done. I have a portion of the schematic scanned and will likely post that too. I've been asked many times about modification kits or if I will offer modification or repair services. I've thought about it and I don't think I could offer either of these on a regular basis although I can probably accommodate some work like modifying a channel for you to use as your template to modify your own, etc. If you feel that you need help after reading this website, email me at The parts you'll need to fix 99% of the problems are readily available from various websites like Digikey, Mouser, Farnell, etc. Some of the more rare parts like the Nichicon ES capacitors are still available from smaller websites like Handmade Electronics ( ).

What I can't offer through this site:
Warranty on my information. I put all this information on this site without ANY warranty implied at all. All of this information is accurate to the best of my knowledge though. If you don't think you can complete the mods without help or you don't understand what I'm talking about, it's best to find a tech who can do them for you, or just enjoy your console as-is. In it's stock form, it's really not a bad console at all. Some of these mods have considerable risk and can damage your console much more than you think.

My journey with the console:
I purchased an Alesis X2 console sometime in 2002 after an extensive search for some kind of recording console with 24 inputs. What really hooked me was the fact that the console came with the ability to remove single channels. The second thing was that it had fully parametric mid-band eq sections. The third thing was that it was designed for studio usage, which meant that it could be used inline with recorders instead of having to switch input connectors and so forth.

Not a whole lot of information was available about these consoles other than they were discontinued for some time and not that many were ever made. I actually happened upon them by luck. I was browsing an audio DIY forum and happened to mention looking at consoles when a reply from a fellow forum member mentioned the Alesis X2, which to that point, I had never heard of before. I had cash in-hand for a mackie 8 bus or a cheap Ghost although I wasn't extremely happy with the experiences I had with them at the time, but I was willing to deal with them in order to move up from a tiny little mackie mixer I had been using for years. I read the X2 manual I found online and liked what I saw yet could not find an X2 for sale anywhere. I soon figured that I might just be out of luck until one day I found one on EBAY. Looking back I think it was a little high in price but the seller promised that it was in full working order, unlike most X2 consoles at the time. I was sold and purchased the console without seeing or hearing it at all. At the same time I purchased a Tascam MX2424, which at the time was also a hot-ish item. Had I known the MX2424's reputation for being a fickle machine when I purchased it, I would have bought something else. That's a story for another time though.

So I received the console via freight about a week later. It was a LOT bigger than I had imagined. I built a desk for it and built a rack for the MX2424 and the harddrive bay that I purchased to use with it. I made my own ELCO to TRS cables and set about recording. I found that a number of channels didn't work right. I either had no sound or the meters were lit or I had static, etc. I started simple troubleshooting and found that some of the cables had come loose in shipping and some of the caps were bad. Replacement caps were purchased after consulting the DIY forum. From that point, things changed rapidly. I was bitten by the modification bug and was almost obsessive about the newest and best opamps and capacitors. I found myself changing parts out so much that the PCB traces were falling apart and soon found myself fixing more problems than when I started out. It was a vicious cycle, and one I don't recommend. This is why I am building this informational site on the X2, so that my headaches and money spent helps others before they waste time and money on stuff that doesn't matter. In any case, I tried all of the top opamp contenders, OPA2604, OPA2134, OPA404, OPA627, AD825, etc, etc, etc. Some sounded good, some did not. Most of them created a sound that was OK for single channels but when mixed was impossible to get rid of. This took a long time to recognize and then admit to myself that spending all this money was rather a waste and that the original sound of the console was bland but much more usable in terms of mixing. I also dabbled in forcing opamps into Class-A modes which seemed to add something to the sound but soon exceeded the power supply's ability and burned the cables in the unit. I tried experimenting with DC coupling all the sections which led to a couple worn out pots and a lot of crackle.

I forced myself to take a step back and study what I was doing. I was just following what others were saying on internet forums that I should do. I did some research about audio caps and what other console designs did to make them more transparent in the audio chain. I put sockets in the through-holes for the caps on a number of channels and ran comparisons between about a dozen different caps from a handful of different manufacturers. Iím not going to get into the details but they all have their quirks if you listen hard enough. Actually, for the most part, there arenít that many caps in the audio path in the X2, so itís not that big of a deal. Also, the ďsoundĒ of a cap isnít that big of a deal either. Itís quite overblown in most forums, especially when you have a large number of armchair engineers who havenít actually tried any of them. I spent too much money trying all of them!

I think SSL taught me more about caps than any of the other manufacturers really. Especially when I researched why they used two series caps and biased them with voltage. This is because a series cap that is not biased will give slight distortion. Bipolar caps are supposed to be the fix for this, although they are more expensive. I have not tested this theory but the ES bipolar caps sound good and Iím happy leaving it at that. Now that I had finally picked a cap to use, I could move on.

I was back to the whole ďwhich opamp?Ē question again. From here, I stripped all the opamps from most of the channels and replaced them with sockets. So much soldering ruined a lot of solder pads and traces, which I spent a lot of time fixing unfortunately. I ran pairs of channels with each of these opamps that I settled on due to price/availability: MC33078, MC33079, NE5532, OPA404, OPA2604, OPA4604, OPA2134, OPA4134. It was pretty clear from my testing that the NE5532 channels were less HI-FI sounding but didnít color the sound very much while still retaining good transient detail. The OPA parts sounded more HI-FI but once you record through the channel and then mix back through it, their sound is stuck forever and canít be EQíd out. I also found the OPA404 parts to be shrill in the EQ sections.

I Found the MC33078 and MC33079 to be very good sounding overall. They do have a downside in this console though. As the console was designed around low bandwidth JFET input opamps in the EQ sections, the higher bandwidth BJT input MC33079 can oscillate when used in the EQ section and certain bandwidth settings are used at full gain. Part of this problem is layout; part of it is simply the difference in parts. Experimentation showed that the input currents on the parts played a part in the oscillation as well as the extended bandwidth. Two things helped here. One was to thicken the ground to V4A and V6A to reduce the impedance and the other was adding filter caps in the feedback paths. The caps worked to eliminate all oscillation but reduced the transient response to the point where they sounded no better than the TL084 that were originally present. I elected to do the grounds and just deal with the oscillation when/if it happens.

Dual inline channels
Removable channels
Fully parametric mid-band EQ
Dual faders
Simple audio path
Easy to work on
Cheap parts
Built-in meter bridge
Elco balanced and differential I/O for external recorders
Good system grounding
Fairly low power consumption for a 24 channel console
Well built power supply

Poor power decoupling throughout the console
Newer revisions of PCBs poor quality, both in parts and construction
Connectors prone to tarnishing/corroding
Concentric pots on mid-band EQ prone to physically coming apart.

Now on to the modifications:

Electrical mods
Mechanical mods