Turbo Rat

I've been offered the chance to get a Turbo Rat for a good price, should I go for it?

I've just splashed out on the Neunaber Stereo WET I've wanted for the past 12 months so I'm not sure I can justify it but on the other hand I have been wanting to try out a Rat for a while and this is a good deal.

Does it have that classic Rat sound that everybody around here loves so much?

Thom Yorke's heavy use of one during the 90s is what sparked my interest but I'm not 100%. :confused:

It's is a good sounding pedal, but it is not the traditional Rat sound. The Turbos use LEDs for clipping rather than the LM308. This was probably done to reduce costs when the chip became a bit too expensive. That said, a lot of builders use LEDs in their makes and a lot of mod guys add them after the fact. For example, the MXR Custom Badass '78 Distortion has a switch to add the LED clipping. Typically, LEDs have a tube like grit to them. Plus, changing the color of the LED can modify the tone if you are so inclined.

^^ Don't think the LED clipping has anything to do with the LM308 (or any chip). Rather it means that LED diodes are used instead of a stock Rat's silicon diodes.The result with the LED's is less compression (to me , less density of the distortion, and more clean signal maintained, and more volume.

My point is that regardless of chip, diodes are being used to clip the signal (BTW, I am just re-gurgitating what I have read over time from 11 Gauge)

I have a GFS Brownie Classic w/LM308 chip and it has 3 modes- LED clipping (Turbo), silicon diode (stock) and no diodes (cleanest and loudest, relative to the same Volume/Gain knob positions of the other modes)

I use "Turbo" setting when I want the Brownie to behave more like an OD, as the breakup and open-ness (keeping a clean signal) are very controllable, dynamic; really shines in this mode. When I want to go into thicker distortion with sustain and more compression- I switch to "stock" and turn up! "Turbo Rat" is different, but a great sound.

^^ Don't think the LED clipping has anything to do with the LM308 (or any chip). Rather it means that LED diodes are used instead of a stock Rat's silicon diodes.

:oops: I did leave out the silicon diodes thing. Sorry.

^^ What the hell do I really know? Nothing. But I'm trying!

All I know is once you find a Rat (or clone) the search is over- time to just play!:wink:

I have the Mouse. The LED mode doesn't get as crunchy or fuzzy but is a very usable tone. I love it for adding clean dirt. ¿Wait, clean dirt? I confused myself.

I have a rat clone with the LM308 chip and a switch to go from clean boast , led, mosfet, and silicon diodes. (also has a mid scoop switch), The silicon diode gives my pedal the most compressed sound out of the bunch. The Led is much louder and less compressed. Like Chiogtr4x I use that mode to when I want a more OD sound and much more dynamic sound. When I want more distortion and fattness I go to the mosfet setting which is a little more meatier than the silicon but a little less compressed as well.

^^ These multi-mode "Rats" (Rat/Turbo, Mouse/Brownie etc.) are IMO great OD/distortion factories, once you work with them, get to know what you can do...
I used mine last night (noisy-ass, but fun rehearsal) in Turbo (LED) mode, at moderate Drive- working up songs from Pink Floyd's DSOTM- very fun!

I went for it in the end, I just couldn't pass up such a good deal.

I will post my thoughts when I've played around with it a bit.

I went for it in the end, I just couldn't pass up such a good deal.

I will post my thoughts when I've played around with it a bit.

This is all subjective stuff here, it all comes down to the kind of music you play, and how you incorporate distortion/OD (and the pedals than create it) into your sound.

I'm a blues/old classic rock/R&B guy and up until a few years ago (thanks TDPRI!), I just associated a "Rat" as a hair band rock/metal pedal (and let's be honest, it was always marketted that way), and I play neither- never though I would get Allman Brothers/Eagles/Stones -style distortion out of my Rat clone- 'till I tried!:wink:

^^ Don't think the LED clipping has anything to do with the LM308 (or any chip). Rather it means that LED diodes are used instead of a stock Rat's silicon diodes.The result with the LED's is less compression (to me , less density of the distortion, and more clean signal maintained, and more volume.)

The only important measure of different diode types (at least in something with such massive clipping as a Rat) is their forward voltage - the amount of voltage at which they begin to conduct will determine the clipping characteristics. The lower the forward voltage, the more extreme the alteration to the waveform. The higher the forward voltage, the less extreme. Having a switch that takes the diodes out altogether obviously demonstrates what it sounds like when the chip is completely clipping on its own.

Stock Rat diodes are 1N4148, with a forward voltage of around 600mV. A red LED starts to light up at around 1700mV, or 1.7VDC. So your signal can have a voltage amplitude that is roughly 3X as large before the LED-type diodes start to alter the waveform.

In some pedals, diode substitutions might just give a difference in volume or compression for the most part. But the Rat starts clipping so early (at the chip as well) that the different diode types have a stronger affect on the EQ as well. There is also a filter (not "the filter") in a Rat that is set to around 1500Hz - strong upper mids. But it isn't really emphasized in a linear fashion as the gain is reduced/increased. So the different diode types will cause there to be some differences in interactivity between the controls. You will probably find yourself adjusting the filter/tone control when you change the diode switch setting and altering the gain.

Since the upper mids are so strong, different pickups play a huge role, as well. It is not uncommon to have to re-dial everything in when switching guitars, and some diode types might work better with certain pickup types. IMO, P90's and humbuckers that are "not overwound" (i.e. pretty close to stock Gibson PAF specs) tend to sound good with almost any type of diode. Since Fender-ish single coils let all sorts of higher harmonics thru, things can get to be a little trickier as you up the gain.

The Turbo Rat was one of the earlier LED clipping pedals, and IMO it is pretty cool. Unless you really want the heavier compression that the original 1N4148's provided, the LED's can usually work pretty well.

^^^ Very cool! Thanks for explaining how the different diodes, I guess "influence" the sound coming from the clipped waveform. Funny, how between the pickups and diodes- there is so much science/physics in R&R Guitar!

Funny, how between the pickups and diodes- there is so much science/physics in R&R Guitar!

Not only that, but the chip in the Rat (even the non-LM308N) is a semi-unique beast, which is why the pedal sounds as it does. That's why even with the diodes disabled, it still gets dirty really early on (IMO). Even a 741 chip is a much better choice to use as a "more clean" boost.

But besides the science, it's cool that so much of this stuff is consistent, and it really is simple compared to a lot of other technical stuff (take my word for it).

I just appreciate that folks will let me be the pedal nerd techie geek. It fascinates me, just like someone might choose a certain string gauge, or wound third for certain reasons, just like you might want a Rat with X type diodes for certain reasons.

It's kinda funny that the "parts we can see," like tubes or pickups tend to draw more attention from guitarists. Most know what kind of magnets they have in their pickups, and possibly how they were wound. Many tube amp owners have preferences of tubes, know the importance of getting power tubes properly biased, etc. Bridge saddles, whether or not your Strat has a steel block in it...

...But pedals are like the family car's transmission - lotsa folks either don't know the details, or don't care. The average cost of a diode is probably 60 cents, with ones that are in the Rat being more like 10 cents...and they have as much of an impact on the characteristics as going with a significantly different type of tube would.

So, no one needs to know any engineering or hard math, but just knowing some of the details could help shape your rig just as much as choices in pickups/strings/saddles/tubes/speakers....

The verdict is still out on whether or not I can find a use for it but so far I'm having a lot of fun with it.

I love how squashy and compressed it gets when you really crank the gain and filter controls, it's so slushy and raggedy yet a perfectly usable and musical sound.

I'm glad 11 Gauge has chipped in too. I actually messaged 11 a couple of months ago about which Rat variant would be good to experiment with for a first time Rat user but other purchases came up and I never got round to taking his (very much appreciated) advice.

And here's the obligatory hipstagram NPD shot:

http://a5.sphotos.ak.fbcdn.net/hphotos-ak-ash3/552683_10150986812150000_2117760021_n.jpg

W e l c o m e
to the Rat Pack

You made me want to dig out mine. I got it a bit after they first came out and GC was selling them cheap. I used it a few times and stuck it back in its box. Unfortunately that box is in storage 5,350 miles from where I live now.