Blog | FXdoctor Custom Effects | Custom guitar effects and modifications

Shin-ei Uni-Vibe Controller (Part 2)

Posted on June 20, 2018 by Joshua

A few years back we created a Shin-ei Uni-Vibe Expression Pedal as a replacement for the original controller which can be hard to find. The Uni-Vibe requires a controller to adjust the rate and for bypass so if the controller goes missing or is damaged then the Uni-Vibe is useless. The one picture above offers the same functionality but in a smaller 2.5″ x 4.5″ package that’s designed to be activated by hand rather than with your foot.

Edited to add: check out Part 3 for another variation on this device.

Posted in Custom Shop | Leave a comment

NE5554N Substitutes

Posted on June 17, 2018 by Joshua

As a company that repairs vintage electronics we often run into the problem of finding quality replacements for discontinued ICs. Third-party companies will often make reproductions for popular chips but for the less common chips we’re on our own to find a suitable replacement. The NE5554N is a dual polarity voltage regulator used in older EHX pedals like the Micro Synthesizer and Memory Man. We made a PCB replacement using surface mount voltage regulators and utilize the PCB as a heatsink. This provides better heat dissipation as the stock chip (and suitable replacements) will heat up under use. These boards are NOT for sale; we exclusively use them in our repairs.

Posted in Modifications | Leave a comment

Tap Tempo

Posted on February 22, 2017 by Joshua

This tap tempo footswitch controller was designed to display the tempo that was most recently tapped. This project was a fun experiment into the Adafruit Trinket world but will not become a product that we sell. All credit for the code goes to Phillip Burgess and his project page can be found here if you’d like to build your own or get more information on how the circuit works.

Some interesting parts of this project include how to interface a tap tempo footswitch with another delay pedal. The problem being that some delay pedals will average together your inputs and other pedals will simply take the time between the last two inputs. The tempo displayed will be 100% correct to what was entered but your pedal may actually be at a different rate depending on how it interprets your inputs. Other considerations include how practical is this? At the end of the day it’s a fun toy, but I’m not sure if knowing the tempo is going to matter for most applications.

And some general tech specs: 125B enclosure, soft touch foot switch, 9V DC input at around 20-50mA of power usage, two ¼” jacks to control two delay pedals and the option to add as many outputs as needed. For any DIYers I strongly recommend going slow and hand filing the cutout for the screen as it was by far the most time consuming part of the project.

Posted in Custom Shop, Prototype | Tagged tap tempo, trinket | Leave a comment

ISP Beta Bass Preamp Pedal

Posted on February 20, 2017 by Joshua

A customer sent in this feature-rich ISP Beta Bass because it has a footswitchable distortion but oddly enough no volume control. The addition of a volume control allows us to boost or cut the distortion section so the user no longer needs to compromise gain and volume levels. After the mod the distortion section can also work as a clean boost.

Posted in Uncategorized | Leave a comment

EHX Small Clone Mix Mod

Posted on November 5, 2015 by Joshua

One of the great things about the large EHX casings is that there is plenty of room to add knobs on the pedal. This pedal was one of our own to experiment on. Our mix knob has been popular on flanger and phaser pedals so we decided to add it to this chorus pedal. Chorus is simply a dry signal mixed with a pitch shifted (vibrato) signal so this mix control allows you to make the chorus effect a bit more subtle by mixing in some clean guitar or more intense by mixing in more of the vibrato sound. Turning the knob entirely clockwise will give a full vibrato effect.

We added a Depth Knob which affects how wide the LFO sweeps.Since adding a Depth knob makes the Depth switch redundant, we decided to rewire it as an Intensity Switch. When pushed up the pedal is at it’s stock tone, when slid down it is a more subtle shimmer effect.

Other mods include a Volume knob to help the pedal boost the signal an appropriate amount and a Boss style barrel jack to replace the stock ⅛” phone jack. Overall a very versatile pedal with an entirely analog circuit path which should cover a wide variety of tones.

Posted in Custom Shop, Modifications | Leave a comment

“The Tripel” – Big Muff, Pro Co Rat, Tubescreamer all in one enclosure

Posted on November 4, 2015 by Joshua

In a previous post we combined a Pro Co Rate and EHX Big Muff into one enclosure with a few modifications. We decided to take this one step further and add both a Rat and a Tubescreamer into this USA Big Muff for an even more versatile sound. We didn’t want to dramatically change the tone of each effect but we did decide to go with some minor tweaks on each circuit.

Big Muff: We added our “Body Knob” to adjust the lower midrange and help the pedal sit well in the mix. We also moved the stock LED right next to the footswitch so it would match the layout of the added footswitches. This pedal already had true bypass so we didn’t need to change the switch but we did install a “Boss style” barrel jack to make it easier to power.

Ibanez Tubescreamer TS-9: For the TS-9 we converted the pedal to true bypass and simply replaced the stock IC with a socket and a JRC4558D as it should have had from the factory.

Pro Co Rat: While I think this pedal needs a bass boost we decided against putting that modification in as that may muddy up the Big Muff which is located down the signal path. We simply removed the stock chip and installed the LM308N and left the rest of the audio path unchanged.

This has been a great way to utilize the empty space in the cavernous Big Muff enclosure and make a convenient, all-in-one distortion pedal to cover a wide variety of tones.

Posted in Favorites, Rehousings | Leave a comment

Shin-ei Uni-Vibe Expression Pedal

Posted on August 24, 2015 by Joshua

We always like to see vintage pedals in here and this is definitely one of the holy grails. The Shin-ei Uni-Vibe is the original uni-vibe pedal which has inspired clones for decades since its inception as a portable device to emulate a Leslie spinning speaker.

This pedal was in for basic servicing but the important goal was to build a replacement expression pedal since the main unit does not have a Speed knob or a bypass switch rendering the main unit useless. Our replacement expression pedal unit uses a custom 5-pin DIN cable to connect to the main unit so the rate can be adjusted while playing.

The interesting part of this project was that in order to copy the original expression pedal we needed to install a bypass switch in the heel. Most people are familiar with a wah pedal which is activated by pressing down firmly with your toes. While this works great for a wah pedal it can sound bizarre on a univibe as you would need to turn the rate to full speed (toe down) in the process of hitting the switch. By placing the bypass switch in the heel (rocked back) position it allows for a seamless transition from the slowest setting to the bypassed tone with almost no effort.

This project was a custom build but we are always able to recreate similar expression pedals as a direct replacement for the original Uni-Vibe expression pedal.

Posted in Custom Shop | Leave a comment

Ibanez UE-300 Multi Effects Rehousing

Posted on March 1, 2015 by Joshua

The Ibanez UE-300 is a relic from the 1980s when multi effects were becoming popular but predates the popularity of digital effects. This unit has an all analog signal path with a compressor, overdrive (tubescreamer), and chorus all built into one unit with a master bypass switch and effects loop. The pedal sounds great but after thirty years the hardware is a bit tired. This rehousing narrows the pedal by almost two inches and also provides the opportunity to install soft-touch footswitches, all new jacks, a bypass switch for the effects loop, and convert the pedal to run on DC instead of 110V AC. This ended up being a big project but the end result should provide years of reliable service and sounds great!

Posted in Rehousings | Leave a comment

Custom wah base plates

Posted on January 25, 2015 by Main

We’ve had quite a few requests to put modulation and delay pedals into a wah pedal casing. The problem is that in order to hit the bypass switch you need to rock the treadle forward which means you lose the setting you were currently at. This add on plate allows a box to be mounted to the side for a bypass switch and a status LED (not yet installed in the above photo).