2020 Bass PreAmp Shootout

Yeah, just so the terms don’t keep getting jumbled:

SVT - classic Ampeg amp line, not related to these things at all
Tech21 - a company
SansAmp - a product line made by Tech21
SansAmp Bass Driver DI (BDDI) - a specific product in the SansAmp line
VT Bass DI - another specific product in the SansAmp line

and the BDI-21 is specifically a clone of the original SansAmp BDDI v1. The current BDDI v2 sounds a little different and adds a mid control that neither the original nor the BDI-21 have*.

*Unless you’re @terb, who modded his to have one :slight_smile:


All that i get, my confusion was that I thought this VT Bass DI was JUST the SANSAMP by Tech 21 with added character of SVT.
maybe that is not even possible, but this was how I understood it, incorrectly.
I must have misunderstood something you said in the past that led me to think this, I thought when I showed this one time you said, yeah, that is a different version of the SansAmp, which I took to mean that it was the base of a SansAmp with some added features.
Oh well, but now I want one, I just figured I had most of it in the BDI-21 and was just missing some ad ons to it.

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How does it compare to what you remember about the Ampeg SCR-DI?


It adds much more character than the SCR-DI, and also has nice sounding, usable overdrive, which the SCR-DI did not (IMO anyway). It’s also much smaller. However it does not have that awesome amethyst-colored LED :slight_smile:


Ahh I see why you were confused. Nah, SansAmp is not a specific product, it’s a product line by Tech21 with a bunch of products in it:

In fact you might want to check out their Steve Harris thing.

A lot of people also like their Para Driver DI because of the parametric mid control.


Yes, this was the confusion, I thought that VT DI was part of the SansAmp line, this is why I thought it was one of their like “New” sans amp products. That is the key of the confusion. And I see how it would have further confused you when I kept calling it SVT instead of VT/DI, but I got it clear now, I am familiar with SansAmp line, now more than ever since I now know this is not in that line.
I will prob get one if a deal shows up.


They’ve also got a Geddy Lee… just saying (and that’s about all I can contribute!)


The VT Bass DI is in the SansAmp line. But a lot of those products are very, very different.

like, this thing:


is also in the SansAmp line. There’s a lot of different stuff in there, including Geddy Lee rack units.


Ok, just another mis-read, got it now


Another case of product marketing confusing things :slight_smile:


To come full circle, today after swapping pedals and PSUs around to play with the new ones, amusingly my ground loop is gone :slight_smile:

But I guess “swapping pedals and PSUs around” is pretty much the definition of how you track down and fix ground loops anyway, so at least I have that.


ground loops are super common in stereo systems, and a million audiophile get one and usually wind up blaming the manufacturer of their equipment for “bad wiring” which has almost nothing to do with ground loops at all. but a million things are now made with “star grounding” which audiophiles believe is the cure for it (it isn’t). probably the leaders in the field is jensen transformers which actually published a bunch of white papers that you can get on their site that describes what causes ground loops, and how to diagnose and fix them. the funny thing is on stereo forums everytime i would point people in that direction they would promptly ignore it and go right on with talking about star grounding bla bla bla. for me, the simplest thing is to make sure all your equipment goes into the same wall outlet, this usually helps.



Yeah, I have them all going on to the same power strip, even. Well there are two power strips, but one is plugged in to the other one.

Japan is weird in that they don’t believe in a separate gound wire here except for high voltage things. Almost all wall plugs are two prong (with fault interruptors for safety).

Don’t get me started, this is no end of frustration. I’ve actually run my own ground wiring down from my air conditioner just to get a common ground.


unfortunately why so many people use cheater plugs. which causes firemen to have heart attacks.


I’m amazed there aren’t tons of electrical fires here.


These are full power amp heads, not just preamps. I’ll go ahead and answer here and feel free to move this to a more appropriate thread. There’s some overlap since the TH tone section is available in preamp form without the power stage.


They both have the identical IcePower module, but the Tone Hammer is rated at 350 and the DG is rated at 500. Go figure. So, the digital stage is top notch studio quality in both.

This DG has effects send/return while the TH requires you to step up a power level higher in the range to get a send/return.

Both have DI.

Annoyingly, the front panel Mute pushbutton on the DG is upstream of the FX Return, so it doesn’t work if you have pedals in the loop. I like using that button when I’m re-patching stuff around.

The DG has the Vintage Microtubes and the B3K pedals built-in, so those speak for themselves and provide a huge range of adjustment. The overdrive section also has that vintage/modern kind of filter knob which is brighter or mellower, very similar to the tone knob on a P-bass. The amp has fewer knobs than the discrete pedals do, but I don’t think they oversimplified anything that I’m having a problem with.

It’s possible to get gritty and breakup sounds out of the TH, but it’s not an isolated section with off/on switch like the DG. The TH knobs are interactive with each other and change the quality of the distortion. The DG applies distortion to whatever tone is on the input of the amp and all its tone control (other than the vintage/modern knob) are downstream of the distortion.

Tone Section
This is where I can’t say anything meaningful to anyone else. Either the knobs fit to your rig and your playing style and tone choice or they are missing something. They do different things.

Low - DG says 80Hz, TH says 40Hz but it’s super useful. Maybe the DG rolls off at 80 and the TH is centered on 40. I haven’t really checked that close, but they both do what I want this way.

Mid - DG has two mid knobs, each with a frequency choice (250/500 and 1.5k/3k). TH has one midband that is fully sweepable to any mid frequency.

Hi - DG says 5k. TH says 4k.

The TH also has a “Drive” knob that doesn’t apply overdrive; it’s frowny face EQ and eventually boosts the mids. That eventually has the effect of pushing more mids into distortion if “Gain” is up. The knobs on the TH take getting used to. The manual doesn’t explain them, so it takes reading forum threads to figure them out unless you are more patient than me. Clean tone on the TH is with Gain and Drive all the way down. There’s a huge range of Gain where it seems it does almost nothing. Maybe I need to try running hotter or adding a clean boost to get that knob into a better operating range.

Overall, I really like them both. The TH sounds better with the Ibanez 5-string on the GK15 than the DG to me. I can get either one to sound super with the Fender P on the 410.

I’m not trying to cut through a mix or fit to the music on stage. I’m making sounds at home that I want to get lost in and completely enjoy. So, if there’s something in the tone I want to fix, I’m always frustrated by the fixed EQ points. For this reason alone, the sweepable mid is lovely for me. If I were buying again I’d buy the next level up of the TH to have the FX loop. I’d forget the DG because the overdrive section inside is too much of a VCR/TV combo for me. The DG is good for a compact integrated rig that’s more cost effective than buying the amp and pedals separately. It’s too bad they rip you another $100 for the footswitch though.

Dave’s Dream
Of course they never make what I actually want.

  1. I’d like a clean block power stage with no knobs, just an input and a speaker connector.

  2. I’d like a seperate preamp, not in pedal form, in piggyback form over the powerblock that is the tone/drive/gain section from the Tonehammer 350 with the addition of a 2nd fully sweepable mid control. I’d also like the Bandwidth knob to be added to the two mid controls.

Figuring out what all these tailored knobs on music equipment do and then trying to get them to do what I want drives me absolutely bonkers (contour, presence, mojo, bark, growl, drive, gain, boost, bump, thump, rump. etc.). I’m sure for most people on stage these are nice, easy tools that get the job done, are easy to understand and fast to grab. For me in my shed trying to get rid of that one resonant frequency that’s bugging me without destroying the rest of my tone, they are all blunt hammers. Just give me a compressor with Attack/Release/Threshold/Ratio/Soft and I’ll make that one compressor do whatever I want. Just give me a 4-band fully parametric EQ with a shelf filter on the top and HP filter on the bottom and I’ll never need to buy another piece of tone gear again.

They all sound great. They all suck at flexibility. If I ever gig I’ll give you a completely different answer because I’ll probably find out that one of them is the superstar knob. Unfortunately, it only works if gain is set at 3 and drive is set at 7 and you push the mid freq select button 3 times first.


+1 to this. I can think of no one who has covered this topic better.


@DaveT Thanks for the in depth response. I’m going to have to read it a few times to completely absorb it all.

I was expecting something along the lines of…
“You know how they say using a Tone Hammer gives you a big bottom end?”
“They’re right!”
“You can’t get a bottom end bigger than with a Tone Hammer.”

I’ve seen a number of comments like that. Does this match your experience?

I want this also. I have searched high and low for it but there are very few options out there. A boutique option. One from France. And one that a guy builds by order in his garage here in the US. This last one comes in at 500 watts for $250 but it looks like it made out of spare parts from a popcorn machine.

The problem I see with it is you would need to sell it at 50 cents a watt for it to be competitive (and have it not look like popcorn machine leftovers). Otherwise someone can get a used amplifier, only use the power section, and have a built in back up pre-amp.

Then there’s the idea, would any of the amp companies even want this to be successful because of how it would change how amps are sold since it removes the markup they can get for selling one pre+power amp versus two separate units. And that’s just the beginning.

What became the Quilter Labs Bass Block 800 started out as a discussion about what people wanted to answer this need. At some point (without any explanation I could find) Pat Quilter decided to go ahead and build a full amplifier.

This topic gets me fired up because I see such an opportunity to build something I would want but I don’t have the skill set or faculties to make it profitable.

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LOL, clearly I need to work on my review skills. That would make sense to me. Yeah, the Tone Hammer is my favorite so far and I do prefer the big bottom. You do realize that an engineer saying something like that without actually measuring is like overcoming the impulse not to take a breath underwater.

No one will make one for exactly this. The way to be profitable is to be unique and mythical.

The beauty about making something for yourself is you can have things no one will make because they couldn’t be profitable.