EHX - Hot Tubes CMOS overdrive - Nano

After my former post people asked me about the Nano version of the EHX Hot Tubes CMOS Overdrive pedal. Prior to this I already published the schematic at Freestompboxes.org.

 

 

This pedal is a smaller version of his bigger (older) brother. Next to the smaller footprint of the pedal it can now be run with a 9V DC adapter and is True Bypass.

The circuit

Looking at the schematic you can spot that the unit is close, but not exactly, a copy of the original. The parts are most SMD; only some caps are the big thru-hole versions.

Some parts are updated (like a rev log gain potmeter), soms parts were changed. It looks and feels pretty solid.

The Sound

Biggest question: do they sound alike? And the answer is no AND yes. 

No; they don't sound alike. The orginal has a depth to it the Nano can't surpass. The original sounds richer, deeper and more 'natural' when compared to the Nano that can sound really flat at certain positions. Sure, they can't be tested at the same knob settings; the gain knob (for example) is a rev log taper. Yet you can get close to a similar setting in which you hear the difference.

BUT

Yes; these differences are pretty small. I do believe that at certain settings (for example a gig) you can't tell one from the other.

The verdict

The EHX Hot Tubes Nano is a great version of the original 1979 Big Box version if you are not looking for a deeper, more natural sound. It has the basic sound of a CMOS overdrive pedal colored by the Hot Tubes design. It works very well on both guitar or bass and makes the sound really stand out and rock! I like it a lot but yes, do prefer the original over it.

(MODs?)

For those suggesting to mod this unit: I tried. If you take the filter frequencies into account and try to add the values of the original without removing too much of the original design, it still doesn't get to the sounds of the original. Still too 'flat'. Well, I tried!