Tech21 SansAmp RBI + Samson Servo 300

[DoctorNop]

Hi!

For a new project, I plan to switch to a rack setup, my idea is:
Use a Tech21 SansAmp RBI as a preamp into a Samson Servo 300 as a power amp. With this, for gig with a sound guy I can plug my Tech21 direct into the FOH, and for other gig or rehearsal without FOH, I'll play this setup as a normal head.
I have some questions.

First of all, I never played a Tech21 in "bass head replacement" setup. It always was as a preamp into a head, or as a DI. But for rehearsals or gig without FOH, does the RBI produce a good sound alone? not too weak? The lack of head is a problem?

The Servo 300 is a Power Amp used for PA and can be bridged in mono to deliver 300w. But I'm not sure if this bridged mode can be plug into a 4x10 bass cab in 8ohm, with a speaker cable. Each informations I see about it mention the red and black cable for PA, but never the simple speaker cable into a bass speaker. Any idea about the way it works?

Thank you for your help!

 

[blubass]

FWIW, I used a Tech21 Landmark 300 head for a while. My issue with it, was that it never sounded like a Sansamp in front of an amp, nor did it sound like a Sansamp into a recording interface. It lacked what I love about the sansamp for live purposes.

This is definitely something you should try out before you buy if you have the means. Best of luck!

 

[grouse789]

I thought the RBI and the RPM were designed as preamps. Meaning they aren't meant to be put in from of an already existing head, unless it is a power amp only.
Of course you can run one into the input of an amp, but yu are changing the amps "color" with another "color".
Good luck. I ran/run a tech21 VT pedal straight into a QSC power amp. Works fine, sounds great.

 

[Masher88]

The Sansamp RBI is a bass preamp. It is designed to be ran in front of a power amp like the Samson Servo. So, yeah, you'll be ok. It'll sound great, in fact. The RBI has been a "bass staple" for a long time because it is a great unit. And, it doesn't cost an arm and a leg. The only "weakness" that you may or may not perceive would come from not enough wattage from your amp (depends on the band setting for what constitutes "not enough watts") or a wimpy speaker cabinet. The preamp itself wouldn't be the issue. You didn't say what cab you are using.

Running it in front of a full fledged bass amp is redundant. Not that it won't work, but it's like grouse789 said: You are "adding color onto an existing color". Meaning that a bass amp consists of 2 sections: The preamp (tone shaping) and the power amp (increases volume)....The RBI is a tone shaping device. You put one tone shaping device in front of another one that existed inside the full fledged bass amp already*.

*Sometimes this could be needed if the full fledged bass amp itself has very limited or just lousy controls, but it'd be best to leave the tone shaping on that amp flat and use the RBI as your main tone shaper.

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I believe what you are talking about is: in order to bridge the amp, you have to either use a banana plug or bare wire ends to attach to the speaker connections on back of the amp and the other end of the cable is a regular 1/4" (guitar type cable)connector to a cabinet. (yes, guys I know there are Neutrix conns etc...but I'm trying to be simplistic here).

The "Red and Black" cables you mentioned are referring to the bare wire method of attaching to the power amp. It's exactly like connecting the speakers to your home stereo....the color codes are to keep the polarity (+ or -) correct.

 

[DoctorNop]

Thank you for your answers !

I know that the T21 is a preamp first, but around me I never had the chance to hear it played like this. It always was in a DI or (for the T21 sansamp bass driver pedal) as a pedal. But if you tell me that's it's pretty good as a standalone, it's perfect !

For the Samson the bridge mode still a bit obscur for me. I know (in the big lines) how works these cables in a home studio for example, but what kind of cable should I use to plug these in a Bass Cab ? For "normal head" with 1/4 output, we plug a specific 1/4 speaker cable (bigger and more resistant). But with this kind of Power Amp, a simple "+/-" to 1/4 is ok ?

sorry, it's not always easy to speak about this kind of stuff in a non-native language..

 

[Das Jugghead]

I run two RBI Sansamps with a Crown XLS 1000 in my rack. As Masher88 alluded to the weak link in this setup could be your amplifier depending on the setting of where you are playing; rehearsal, club venue, or private practice. I have found my current set-up to be adequate for two out of those three but find myself wanting better volume in live settings. I am planning to upgrade my Crown XLS 1000 to something at least twice as powerful at some point this year.

Additionally, in terms of being able to hear oneself, I have found that a lack of wattage can be compensated for to some degree by tilting the cabinet so that it is aimed at your chest rather than your ankles. The caveat with this is that it may end up bouncing your sound off the ceiling of the room you are in - this results in rhythm guitarists insisting that you turn down but drummers seem to really like it.

This is one of the more recent cabinet stands I made to angle the speakers up at my chest rather than the floor. The wider stance made it a bit more stable. I also fabricated a better stand to hold the rack in place. The one pictured was just a place holder while I designed the final stand for the rack.

This picture was one of the earlier versions of my rig and one of the first stands I made to angle the cabinet and this worked nicely at rehearsal where I did not have to move it around much but as you can see was not very stable.

 

[DoctorNop]

The XLS1000 is 700w bridged that's it? And you need twice of it?
I was a bit worried about the 300w of the Samson Servo, but I can't at the moment put too much on the Power Amp part.
Our band is a trio + singer, in a "Tool kind of bass tone". And I am, very very present in the mix. You think the 300w of the Samson isn't enough (for gig without FOH and Rehearsals)?

This cab is 300w, but your PA is like 700w if bridged? I think i'm lost in your signal chain

 

[Das Jugghead]

The XLS1000 is 700w bridged that's it? And you need twice of it?

Indeed it is 700 watts bridged at 8 ohms. I have a pair of Hartke VX 410 cabinets that I respeakered after I blew them up at an outdoor gig that are each now running 500 watts at 2 ohms. I have never run bridged even though that would be an option for driving one cabinet. I also have a 610 that I built with 100 watt speakers wired in threes. Channel one of the Crown runs one set and channel two drives the other set. Depending on situation I use either the 610, the two 410's, or just one 410.

I was a bit worried about the 300w of the Samson Servo, but I can't at the moment put too much on the Power Amp part.

I needed a power amp and bought the Crown XLS 1000 on sale at GC but in retrospect I wish I had saved my money and done a little more research before buying this one. Don't get me wrong, it is a great amp and I have zero issues or complaints with it; I just want the extra wattage to be able to drive whatever speaker arrangement I end up with at any given point in the future. The Crown XLS 2502 should fit the bill:

Crown XLS 2502

Our band is a trio + singer, in a "Tool kind of bass tone". And I am, very very present in the mix. You think the 300w of the Samson isn't enough (for gig without FOH and Rehearsals)?

The band sounds very cool - I really love the Tool sound. Those are some hellified shoes to fill. I have always had issues with hearing myself onstage so maybe my problem will be solved with some IEM's. I have never played a gig where my stage rig doubled as the sound system as we have always had FOH. As I said above my current rig is just fine for rehearsals. In fact, most of the time at rehearsal I back myself into a corner with my rig facing me which seems to work fairly well.

This cab is 300w, but your PA is like 700w if bridged? I think i'm lost in your signal chain

I think if all you are running is one cabinet the Crown XLS 1000 is plenty powerful enough. I may be wrong (someone please chime in to correct me) but I have always been told I should have roughly twice the amp wattage as I have in cabinet wattage. I do not run the volume at 100%.

Signal chain?
Bass > Boss TU3 tuner > Boss NS2 noise suppressor > Radial Bones ABY
Radial Bones ABY output A > RBI > Channel one of EQ > Channel one of Crown > Cabinet
Radial Bones ABY output A > RBI > Channel two of EQ > Channel two of Crown > Cabinet

 

[Masher88]

DasJugghead is running some kind of weird setup. I have no clue why he is running 2 Sansamp RBI's. Possibly splitting his bass signal for 2 separate sounds...but only having 1 cabinet confuses me. Maybe he can expand on that. It's definitely not a needed thing and won't make you any "louder".

What I don't see is a compressor. Maybe he has a pedal compressor? That is one of the most important pieces of equipment in a bass rig, though.

My rack rig that incorporated an RBI used to be: Korg 1 space rack Tuner -->Sansamp RBI -->DBx 160a Compressor (through the FX loop of the RBI) -->QSC PLX 3002 amp (bridged mono to 4ohms) -->Barefaced Big Twin 2 (2x12" cab)

After running that rig for years (it served me well!)...the RBI started acting weird and making my rig cut out at shows, so I replaced it with a BBE Bmax preamp. It had a compressor in it so I could get rid of the DBx to make my rig smaller. But it was just a 1 knob type that gives you more or less compression at a factory setting. Well, I didn't like the compression...I wanted it to be more user variable. At higher levels I could hear it pumping the bass sound (heavy squash in volume at first, then a long, blooming release of the sound)

Just last week I replaced the BBE with a Presonus Tube Channel Strip---- Studio Channel | PreSonus

The Presonus has a tube in the preamp, a fully adjustable compressor (not just a one knob kind), a semi-parametric EQ (fully parametric for one of the mid EQs). So now, I got rid of the compressor and I'm down to just 3 pieces of gear....Presonus, Tuner, QSC Amp. All in the name of being ultra portable and ultra loud! If only some preamp maker would include a tuner into their design too!!!
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The Crown XLS1000 that DasJugghead has states it should do 1100 watts into 4 ohms when bridged. That should be more than enough power for almost any gig assuming you'll be in the PA syatem. I have no clue what kind of band and loudness levels he needs, though. That's also assuming you run a cab that has a good sensitivity rating to make good use of the wattage.

There are sooooo many variables in play when it comes to getting "loud". You gotta do some research. Even browse through TB here at all the posts about it. It's very involved and technical at times.

This is the kind of cable you'd want for your speaker connection: Amazon.com: Musician's Gear Banana to 1/4" Speaker Cable 14 Gauge 10 ft.: Electronics

 

[Das Jugghead]

DasJugghead is running some kind of weird setup. I have no clue why he is running 2 Sansamp RBI's. Possibly splitting his bass signal for 2 separate sounds...but only having 1 cabinet confuses me. Maybe he can expand on that. It's definitely not a needed thing and won't make you any "louder".

Yes you are correct in that I am running two RBI's in order to have two distinct sounds. At some point I would like to separate my bridge pickup and my neck pickup to run to their own independent output jacks much like a Rickenbacker. I run both of the RBI's into a single 610 cabinet that is wired for two inputs. Each input drives one half of the 610. This was not done to make my rig any louder. I will achieve "louder" with a more powerful amp and more powerful cabinets at some point. Presently I am only using the 610 and am considering selling the 410's locally and just using the 610 for the time being.

What I don't see is a compressor. Maybe he has a pedal compressor? That is one of the most important pieces of equipment in a bass rig, though.

I had a compressor for about a month and while I liked what it did for my sound it did not do what I was told it would help with which was get rid of a hiss ergo the EQ in an attempt to dial out the hiss. Once I get the hiss taken care of I may explore the compressor option again. Unfortunately in order to have a rack mount compressor the EQ would have to go or I would have to upgrade to a larger rack. I may explore the possibility of a compressor pedal at some point.

The Crown XLS1000 that DasJugghead has states it should do 1100 watts into 4 ohms when bridged. That should be more than enough power for almost any gig assuming you'll be in the PA syatem. I have no clue what kind of band and loudness levels he needs, though. That's also assuming you run a cab that has a good sensitivity rating to make good use of the wattage.

I agree if I were running one set of speakers but I am driving two sets hence the use of dual channels rather than bridging.

To the OP I feel as though I have drawn this discussion of your post off course and I apologize. To answer your question yes you can use the RBI in the manner you have described. I recommend you check out a bassist in a live setting who is using the RBI to see if it will meet your needs. Ask lots of questions - most bassists I have met are really cool and happy to talk gear. The Sansamp RBI is not for everyone but for me it got me the sound I was after.

 

[DoctorNop]

No problem, I'm very interested by the subject so it's cool to read other people about that!

All of the answers were helpful, thank you!
Now my only concern is about the 300w PA. My cab can't handle more than 400w at 8ohm, so I don't have many possibilities without busting my bank. What about the thing you said earlier "the PA should be twice powerful than the cab", you mean in the way that a 600w PA should be in a 300w cab? I saw this on other thread one or two times but never really notice it.

 

[blubass]

The servo 300 puts out 300w @ 8ohms.....

Another 100w probably won't do much in the way of adding volume. People have blown speakers using less power than the cab is rated for. Depending on the input sensitivity of the power amp, your best bet is to use what you have before throwing up a bunch of hypothetical that may not even be an issue.

You already have the power amp and cab, so they aren't going anywhere. Decide if the RBI is right for you, pick it up if so, run your rig the way it is, and adjust fire from there.

 

[Garret Wheeler]

Yes you are correct in that I am running two RBI's in order to have two distinct sounds. At some point I would like to separate my bridge pickup and my neck pickup to run to their own independent output jacks much like a Rickenbacker. I run both of the RBI's into a single 610 cabinet that is wired for two inputs. Each input drives one half of the 610. This was not done to make my rig any louder. I will achieve "louder" with a more powerful amp and more powerful cabinets at some point. Presently I am only using the 610 and am considering selling the 410's locally and just using the 610 for the time being.



I had a compressor for about a month and while I liked what it did for my sound it did not do what I was told it would help with which was get rid of a hiss ergo the EQ in an attempt to dial out the hiss. Once I get the hiss taken care of I may explore the compressor option again. Unfortunately in order to have a rack mount compressor the EQ would have to go or I would have to upgrade to a larger rack. I may explore the possibility of a compressor pedal at some point.

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I agree if I were running one set of speakers but I am driving two sets hence the use of dual channels rather than bridging.

To the OP I feel as though I have drawn this discussion of your post off course and I apologize. To answer your question yes you can use the RBI in the manner you have described. I recommend you check out a bassist in a live setting who is using the RBI to see if it will meet your needs. Ask lots of questions - most bassists I have met are really cool and happy to talk gear. The Sansamp RBI is not for everyone but for me it got me the sound I was after.

Hey man, I'm really interested in your rig! This is very similar to a rig I had imagined once in my free time, even the 610 wired in sets of three speakers, except my dream rig was an 810 wired in fours. At first glance I would guess that you have the two Sansamps set to have different levels of grit to blend together? If so, I am even more interested in this setup. Do you have any sound samples?

(Sorry to the OP, I know this is really off topic)

 

[scuzzy]

I see that the xls1000 and the RBI is a great combo for others as well! I've started using it again over my GK mb212, as I prefer the DI on the RBI, plus the 10's don't boom the front row as much as the powerful 2x12.

Our church sound guy loves this preamp. Independent xlr out volume is great.

 

[DWBass]

No problem, I'm very interested by the subject so it's cool to read other people about that!

All of the answers were helpful, thank you!
Now my only concern is about the 300w PA. My cab can't handle more than 400w at 8ohm, so I don't have many possibilities without busting my bank. What about the thing you said earlier "the PA should be twice powerful than the cab", you mean in the way that a 600w PA should be in a 300w cab? I saw this on other thread one or two times but never really notice it.

That 300 watts will be fine unless your band is a very loud one. What cab are you using?

 

[scuzzy]

The XLS1000 is 700w bridged that's it? And you need twice of it?
I was a bit worried about the 300w of the Samson Servo, but I can't at the moment put too much on the Power Amp part.
Our band is a trio + singer, in a "Tool kind of bass tone". And I am, very very present in the mix. You think the 300w of the Samson isn't enough (for gig without FOH and Rehearsals)?

This cab is 300w, but your PA is like 700w if bridged? I think i'm lost in your signal chain

It's 1100 Watts bridged at 4ohms. 700 Watts at 8ohms. I bridge it and run into my 4ohm 2x10 cab. I'm a believer in overpowering my cabs, listen to signs of too much. I don't push them hard. I get very impressive, non-distorted volume from these 2x10's easily cruising with 1100 watts at my disposal. I have the bn10-300x celestion greenbacks. Rated at 300w each. It's a great, lightweight setup.

Matching heads to cabs has its place, but in my opinion, listening to the cab and how it is responding at a given volume will keep you from disaster. If it starts to sound bad, distort, clip, turn it down. As said above, a 100 watt amp clipping can blow a cab that can handle 500watts. The solid state clip damages speakers. Check the amp FAQ's/ sticky's.

 

[deepestend]

I have played this exact amp combo with good results. I'm sure that there are better sounding amps out there, but it's a very dependable setup with lots of options for preamp shaping. Go for it!