VT Bass Rackmount...

[Fuzzbass]

Over the past year or so I have rarely used my SansAmps-in-parallel rack rig for one reason: I have switched to small lightweight amp plus pedals. I have been meaning to get the VT Bass DI pedal but haven't gotten around to it. Thanks for the reminder!

As for your question about what to pair with your RPM: depends on what you are looking for. I personally give a slight edge to the RBI because the extra bite of the Presence control is especially useful with my tweeterless NV610 -- and it would definitely help give you that Chris Squire brightness.

The VT Rackmount is really cool too, and more versatile overall because of the Character control. That is, with the VTRM you aren't locked into the SansAmp mid scoop. You can dial in scoop if you want by turning Character left of noon (the farther you go, the more scoop you get), but it isn't always there as it is with the BDDI/RBI. I mitigate the RBI scoop by keeping Blend set to around 2 o'clock, and running it in parallel with the RPM further lessens the scoopiness.

 

[Matthew_84]

Over the past year or so I have rarely used my SansAmps-in-parallel rack rig for one reason: I have switched to small lightweight amp plus pedals. I have been meaning to get the VT Bass DI pedal but haven't gotten around to it. Thanks for the reminder!

As for your question about what to pair with your RPM: depends on what you are looking for. I personally give a slight edge to the RBI because the extra bite of the Presence control is especially useful with my tweeterless NV610 -- and it would definitely help give you that Chris Squire brightness.

The VT Rackmount is really cool too, and more versatile overall because of the Character control. That is, with the VTRM you aren't locked into the SansAmp mid scoop. You can dial in scoop if you want by turning Character left of noon (the farther you go, the more scoop you get), but it isn't always there as it is with the BDDI/RBI. I mitigate the RBI scoop by keeping Blend set to around 2 o'clock, and running it in parallel with the RPM further lessens the scoopiness.

Thanks Fuzzbass!

I do think the RBI would get me there as well, whenever I see a clip of someone copping a good Squire tone on YouTube, they always seem to be using a BDDI.

What does the Presence knob on the BDDI/RBI actually do? From what I've read it adds "high end sparkle", which to someone who hasn't used it, makes it sound like a second treble knob. Does it do something else? Like adjusts harmonic overtones or something?

 

[Fuzzbass]

What does the Presence knob on the BDDI/RBI actually do? From what I've read it adds "high end sparkle", which to someone who hasn't used it, makes it sound like a second treble knob. Does it do something else? Like adjusts harmonic overtones or something?

I don't know the frequency spec of the Presence control, but yeah, it's essentially a second treble knob -- low treble, high mid, I think? One difference between Presence and the rest of the EQ on the BDDI/RBI is that Presence is part of the overdrive circuit. So, when Blend is turned all the way off it no longer affects tone, but Treble/Mid/Bass still do. Also, if you crank up Presence it will increase overdrive. Through the NV610 (again, it has no tweeter) I use lot of Presence... meaning set to 11 o'clock, or noon tops -- the other oddity about Presence is that it's boost-only.

 

[Matthew_84]

I don't know the frequency spec of the Presence control, but yeah, it's essentially a second treble knob -- low treble, high mid, I think? One difference between Presence and the rest of the EQ on the BDDI/RBI is that Presence is part of the overdrive circuit. So, when Blend is turned all the way off it no longer affects tone, but Treble/Mid/Bass still do. Also, if you crank up Presence it will increase overdrive. Through the NV610 (again, it has no tweeter) I use lot of Presence... meaning set to 11 o'clock, or noon tops -- the other oddity about Presence is that it's boost-only.

I see. Thanks for your help Fuzzbass!

I'm not sure which one to get yet, but I'm leaning towards the RBI now. I'll do some more research and listen to some clips to figure it out. I appreciate your help.

 

[Matthew_84]

Sorry @Fuzzbass can the 900Hz mid-scoop of the BDDI be tamed/eliminated with the RBI's Mid knob?

IIRC, it's centered around 1kHz, so I'd think it would (for the most part anyway), but thought I'd ask.

Also, was there a way to disable the secondary unit (the RBI/VTRM) so that the RPM was the only unit in the circuit? I'd think you may need to unplug the secondary unit out of the RPM's effect return jack completely, as I'd think flipping the bypass switch, would then blend the RPM with a bypassed, possibly lower output signal from the secondary unit.

Also, out of curiosity, why did you switch to a pedal setup?

Thanks in advance Fuzzbass!

 

[Fuzzbass]

For some reason I thought the BDDI mid scoop was lower, but you could be right. IME the mid control on the RBI does not completely eliminate the scoop, but definitely helps to mitigate it. Of course the sweep mid on the RPM can help a lot too. FWIW, I think scooping (in moderation) can sound great: over the years I have often used Contour or Ultra-Lo or whatever for scoop, then "re-voiced" the mids using whatever mid controls are available. Semi-parametrics such as sweep mid or vari-mid can be especially effective.

P.S. As for my gear switch: in short, I got a boutique amp (expensive) that I really love. It's the Studio 1200 by Reiner Amplification: 1200 watt Class D power section, all-tube preamp with 5-band inductive EQ. It's fairly small, weighs just 13 pounds, is transparent when set flat. The advantage for me is tonal variety. In addition to having that transparent base tone that works as is for my classic rock/R&B gigs, I can use a variety of OD pedals for my hard rock gigs: I can change them up from gig to gig, or switch between different OD pedals within the same gig. Of course pedals have disadvantages: additional set-up time, and a certain amount of stage clutter. Worst of all is OD pedal GAS. Life was definitely simpler with the Tech21 rack rig: easy gear setup, easy to dial in one great tone that would work all gig long instead of tweaking multiple pedals for multiple tones (and it can definitely be a challenge to get that high-gain distortion to have the same volume as no or low distortion).

 

[Matthew_84]

For some reason I thought the BDDI mid scoop was lower, but you could be right. IME the mid control on the RBI does not completely eliminate the scoop, but definitely helps to mitigate it. Of course the sweep mid on the RPM can help a lot too. FWIW, I think scooping (in moderation) can sound great: over the years I have often used Contour or Ultra-Lo or whatever for scoop, then "re-voiced" the mids using whatever mid controls are available. Semi-parametrics such as sweep mid or vari-mid can be especially effective.

P.S. As for my gear switch: in short, I got a boutique amp (expensive) that I really love. It's the Studio 1200 by Reiner Amplification: 1200 watt Class D power section, all-tube preamp with 5-band inductive EQ. It's fairly small, weighs just 13 pounds, is transparent when set flat. The advantage for me is tonal variety. In addition to having that transparent base tone that works as is for my classic rock/R&B gigs, I can use a variety of OD pedals for my hard rock gigs: I can change them up from gig to gig, or switch between different OD pedals within the same gig. Of course pedals have disadvantages: additional set-up time, and a certain amount of stage clutter. Worst of all is OD pedal GAS. Life was definitely simpler with the Tech21 rack rig: easy gear setup, easy to dial in one great tone that would work all gig long instead of tweaking multiple pedals for multiple tones (and it can definitely be a challenge to get that high-gain distortion to have the same volume as no or low distortion).

Thanks Fuzzbass!

That really helps me out. I'm not a gigging musician, but if I was, I'd go with a pedal setup as well.

I'm aiming at writing my own, instrumental 70's style Prog Rock (Rush, Yes, Crimson, ELP, etc), and recording them at home. That's why I'm aiming for a Squire/Lee tone, and want to get there relatively cheap with the least amount of gear needed. I do think I need one clean and one dirty channel with separate EQ's to really get there though, so that's why this is so intriguing. I already have a cab, power amp, and an RPM so I'm pretty much there.

I was wondering that it could be difficult to blend the two Rackmounts to a perfect balance while also keeping the overall output at a good level.

Also, I hear you about the pedal GAS! I had spent some time researching how to do this with the least amount of pedals, but realized I needed at least three to do it right. Then I started thinking about adding volume, tuner, chorus, flanger, and reverb pedals, and realized the cost and need was way above my purpose and I need to just keep things simple... But that's me, I'm a bit of a minimalist. I get uncomfortable when I have too much gear. I once had two fretted basses and one fretless, and it actually drove me nuts. I sold one of the fretted basses at a stupid low price just to get rid of it quickly.

 

[Fuzzbass]

I was wondering that it could be difficult to blend the two Rackmounts to a perfect balance while also keeping the overall output at a good level.

Here is how to combine a pair of Tech21 rackmount preamps, from the mad scientist who built my bass head. I assembled an RBI/RPM rack rig based on JGR's approach and it's amazing: I used it as my go-to bass rig for 5+ years. I've also done VT Rackmount plus RPM, and that was cool too. I don't recall whether I ever tried RBI plus VT Rackmount, but of course they could be combined in parallel as well.

The parallel config is more complicated than running in series or footswitching from one to the other, but IMHO it's definitely the best way to get the best of both worlds.

 

[tech21nyc]

I don't know the frequency spec of the Presence control, but yeah, it's essentially a second treble knob -- low treble, high mid, I think? One difference between Presence and the rest of the EQ on the BDDI/RBI is that Presence is part of the overdrive circuit.

The Presence control frequency is around 3kHz and you are correct it is part of the SansAmp circuit. It is emulating the presence control on a vintage tube amp. As for the mid-scoop on the Bass Driver circuit this will usually be exacerbated when running into the front end of another amp unless that amp is set flat. Most amp's have a pre-eq shape that often has a midrange dip.

 

[Matthew_84]

Great. Thanks guys.

I decided on the RBI as I think it will pair the best with an RPM for my purposes.

The VTRM sounds like a great unit and likely the most versatile one. If I were to only have one as my preamp it would be this one, but I think an RPM in parallel with an RBI will give me what I'm looking for.

 

[John D Harris]

The Presence control frequency is around 3kHz and you are correct it is part of the SansAmp circuit. It is emulating the presence control on a vintage tube amp. As for the mid-scoop on the Bass Driver circuit this will usually be exacerbated when running into the front end of another amp unless that amp is set flat. Most amp's have a pre-eq shape that often has a midrange dip.

"Most amp's have a pre-eq shape that often has a midrange dip."
IMO - bad assumption!
Jeez!

 

[crguti]

I got a 2nd VTRM and I checked the internal jumpers. Each jumper comes with a mark on the pcb surface specifying the stock position.

View attachment 2439344

I'm quoting myself here.
The mark on the PCB means that the jumpers MUST be empty. So from left to right, jumper#1 to the left, jumper#2-3 to the right (exactly the opposite of the above picture).

 

[gilthethrill]

Thought I'd share this with everyone in this thread. I asked Tech21 why the VT bass Rackmount did not have a switch to turn on and off the speaker simulation, here is the reply which in my opinion makes total sense:

Thanks for your inquiry. It's all about the timeline...

SansAmps never had defeatable speaker simulation... it was always an integral part of our "sound" and would add a professional studio quality "focus", even when it went through real guitar and bass speakers.

In the original Character Series pedals, you couldn't defeat it. And it was around that time that we started working on the VT Bass Rack (which, like the RBI and RPM bass preamps before it, would always have the simulation in the circuit). Then, we started reading posts on the forums saying there were a number of players who wouldn't even TRY a SansAmp because of that, so we added the defeat switch to the second generation of the Character Series, and soon after, the VT Bass DI. But the layout of the VT Bass Rack was already done.

 

[Kro]

Seeing is still how this thread is still the bible for info about VTRM jumper positions, I'm resurrecting it.

I've read through this entire thread and searched through it for info on the jumpers many many times, but there are inconsistencies and some responses to questions that aren't quite as clear as they could be.

For the record, @tech21nyc is this the stock jumper setting for these units? Asking because this is not how it came to me as I bought it used (from Canada... who in this thread's was it ).

 

[crguti]

Seeing is still how this thread is still the bible for info about VTRM jumper positions, I'm resurrecting it.

I've read through this entire thread and searched through it for info on the jumpers many many times, but there are inconsistencies and some responses to questions that aren't quite as clear as they could be.

For the record, @tech21nyc is this the stock jumper setting for these units? Asking because this is not how it came to me as I bought it used (from Canada... who in this thread's was it ).

It looks like it has been mod. I can see that some of the components have been re-soldered. AFAIR the jumpers seem to be in the correct position.

@Kro Can you take a picture of the transformer? I misconnected mine and now it doesn't work so I would like to compare it. Thanks.

 

[Kro]

@Kro Can you take a picture of the transformer? I misconnected mine and now it doesn't work so I would like to compare it. Thanks.

Apologies, but I closed it up and integrated it back into my rack not long after I took those shots, and I didn't have any pictures of the transformer I'm afraid. If I do open it up again I'll send some pictures to you. Perhaps @tech21nyc can help on that front as well as confirming the jumpers in my image above are in the stock (starred) positions.

Though I admit your post above about mods (or repairs) does lead to more questions from me. I do see what you mean with the soldering, and hadn't noticed it before. Tonally, it doesn't seem like anything was modded, but I'd love to know for sure if it was just a repair or a mod. Maybe Tech21 can weigh in on that front as well.

For the record, this is what the various EQ curves look like using the different EQ jumper positions on my unit. @tech21nyc , anything look odd about this that would point to something being changed aside from the jumpers? It does sound good (I've been using it constantly). Note that the starred position for mids doesn't align with the stated stock mid frequency point from post #38. For mine, the starred mid position is the lowest, not middle curve.

 

[Kro]

Better quality shot so that one can actually see the values on the components that appear to have been tinkered with after production:

 

[tech21nyc]

Seeing is still how this thread is still the bible for info about VTRM jumper positions, I'm resurrecting it.

I've read through this entire thread and searched through it for info on the jumpers many many times, but there are inconsistencies and some responses to questions that aren't quite as clear as they could be.

For the record, @tech21nyc is this the stock jumper setting for these units? Asking because this is not how it came to me as I bought it used (from Canada... who in this thread's was it ).
View attachment 4865472

You can see little stars by each jumper. These indicate the stock factory settings.

 

[Kro]

You can see little stars by each jumper. These indicate the stock factory settings.

Thanks, just making sure those stars indicated "filled" vs "blanks".

In terms of the soldering on this board, would you agree it's been modded in some way, or is there a chance it's just a repair, or even might have left Tech 21 like that?

 

[tech21nyc]

Thanks, just making sure those stars indicated "filled" vs "blanks".

In terms of the soldering on this board, would you agree it's been modded in some way, or is there a chance it's just a repair, or even might have left Tech 21 like that?

I have no idea. We would need to see which REV of the board it is. If the unit works and sounds good I wouldn't worry about it.