The Tone God "Tubulent" power-tube drive/tone box, incomplete review

So here's the deal: the Tubulent that they sent me for review is an early unit, that has a technical issue we are working to resolve. Specifically, when connecting it to a computer audio interface, there is a conflict between the ground planes, causing electronic noise (a high-pitched whistle/whine sound) to enter the audio path. So I can't record clips without that noise.

They acknowledged the issue, and that alone gets props from me, because (as I note in my blog) way too often a manufacturer will deny any such noise problem could exist! Beyond that, they have already made some improvements to current-production units, and they are looking into other ways to solve the problem by improving the design of the power path inside the unit.

I thought trying a different power supply, a transformer-based one instead of the switch-mode laptop supply they provided, would fix the issue, but no dice--same noise.

So basically I'll probably have to send this unit back to them, and wait until they have solved this problem completely, before posting any demo clips.

FTR, the noise I'm talking about does not occur audibly when connecting the Tubulent to my amps, or mixer, or headphone amp. So for most people, in most applications other than direct recording, it's a non issue. I suppose a passive transformer DI box might fix the direct recording noise, but I don't happen to have a passive DI right now. My active DI's are not helping.

Of course you'd want me to describe the tone in words, the way I do in my compressor reviews, but every time I try to write something down about this thing it just doesn't read right, and I know it does not effectively communicate what I'm hearing, the way a simple audio clip would. Here's the best I can do with describing it in words, for now:

At low gain it does a lovely job of warming up the signal and giving it some tonal "body". At medium gain it distorts nicely and with good dynamic response, also giving some of the desired inherent compression people like from tube amps. The "damp" control interacts with the input gain control to dial in a wide range of where it starts to clip, and how much, so it's not hard to set your "sweet spot".

The "sag" control adjusts the way it drops power to the tubes in reaction to your signal spikes, the way a full tube amp does. This gives kind of a subtle grunting, swinging quality that does add an amplike feel to your note envelope. With the sag control turned down, the clipping sounds to me just like regular preamp-tube clipping, same as you'd get from a tube overdrive pedal that didn't have the power section and load. The higher the gain, the more I thought that (preamp distortion tone).

Overall, the tone is really rich and full, with no loss of lows. Personally I like the lower-gain tone much better than the higher-gain distortion side of things, at least when using the Tubulent by itself into a clean mixer/amplification channel. In that context the distortion was too buzzy and nasal for me.

At higher input gain it has enough output to directly drive a PA-style power amp, but at lower gain it does not--so if you want the more clean/warm/fat end of things into such an amp, you'd have to add another device with gain, like an EQ, compressor, or another preamp.

The one EQ knob is great for boosting the lows or boosting the highs, but it does not cut highs the way you might expect from a "tilting" EQ like the one on the Diamond Comp. But as with almost all other tube drive devices, you have to roll off the highs (for example by using a cab with 15's and no tweeter) if you want the clipping distortion to sound good.

So here's an interesting dilemma: The Tone God specifically stated they wanted this device to be purely a tube gain stage, not a full-functioned preamp, and they succeeded! But in order to use the device and have it sound good, I had to add extra gear: an EQ to roll off the highs, and if I wanted to record I'd need a passive DI box, and if I want to drive a power amp I'd need a second gain stage, and if I want all three of those things I've got quite a lot of planning to do.

As you can see from the pic, the form factor is awkward--it won't fit on a pedalboard or in a rack, although if you have a deep-enough rack case you could stuff the Tubulent in back behind your amp. I imagine this unit being most at home sitting beside a recording desk, much like a REDDI or other tone-specific DI box.



The construction quality looks nice, and communication with The Tone God has been entirely positive and constructive.

Presumably we will eventually work out the noise deal, and I will update this thread with clips at that time. No promises on when that might happen, though.

If you can make it fit into your rig somehow, I do really like and recommend it for the warm/fat not-so-distorted end of the tubey tone range, as an effect to be run into the main instrument input of a regular solid-state bass amp.