Which make & model bass preamps can appropriately drive a power amp that has 1.4 volts sensitivity?
I'd buy it.
Enjoy the benefits of a premium membership!
Upgrade Account
-
TalkBass has been independent since 1998. Add your voice.
Create a free account to reply to discussions, view embedded media, and browse with fewer display ads.
Join free Log in
Want zero display ads or expanded classifieds tools? Compare plans.
Preamp (pedal) into a power amp
- Thread starter DoctorZeus
- Start date
Which make & model bass preamps can appropriately drive a power amp that has 1.4 volts sensitivity?
I'd buy it.
What does this even mean?
I’m running a Mesa WD 800 preamp into a Mesa WD 800 power amp!
One of my favorite preamps ever is the Broughton Audio Locust Star. It just has strong clean tone, and the EQ arrangement is interesting. I have run it into the effects return of amps several times to good results. Of course it's meant to be a distortion pedal, but its clean tones are a highly overlooked and underrated aspect of it.
I was gonna do this and it was more cost effective for me to just buy a Mesa D350. I keep the SansAmp around as backup.
How?
Even if you know the frequencies an amp cuts and boosts, and even know the amp may cut by 15 db and boosts by only 12 db. Do you know the starting point of the boost or cut already baked in before you start at “flat or noon” ? That is where some of the “secret sauce” lies. The amp companies don’t tell us that.
If it was that simple these kids wouldn't need to develop that amp modeling thing, you would just need frequency plots from all the amps on the market.
Last edited:
Yes! I'm running a Sansamp VT-RM preamp into a Crown XLi 800 power amp. It works and sounds great.
I chose this setup because I'm on a tight budget (new Crown XLi 800 is $350 and used Sansamp VT-RM for $100). I also like the flexibility, for example the Crown can be moved to my home theater system as a sub driver. I can easily swap different preamps to get different tones. Finally, if the preamp or power amp dies I can replace them individually. As a bedroom player I don't care about the extra 6 lbs of weight or the rack.
As has been mentioned, if the preamp signal is weak, it won't drive the power amp to full volume. Basically, you'll want a power amp with 0.775V input sensitivity. Some preamps will have trouble driving a power amp with 1.4V input sensitivity. You may still be able to use a low output preamp or a 1.4V power amp if you run the preamp into something with a higher output signal (equalizer, effects processor, channel strip, etc.) There's some info here that may help:
https://www.sweetwater.com/insync/understanding-signal-levels-audio-gear/
The Crown XLi 800 power amp outputs can be bridged to mono - which, of course, is what we usually want for bass.
The Crown can also accept balanced XLR or unbalanced RCA. The RCA connection is unusual with bass gear, but 1/4" phono / RCA adaptors are cheap and easy to find.
You should verify the power amp's minimum speaker load is compatible with your speakers.
People have been running this type of setup for many, many years. It's proven to work well if you use a preamp (or something after the preamp) with solid output signal into a power amp with low (0.775V) input sensitivity.
I chose this setup because I'm on a tight budget (new Crown XLi 800 is $350 and used Sansamp VT-RM for $100). I also like the flexibility, for example the Crown can be moved to my home theater system as a sub driver. I can easily swap different preamps to get different tones. Finally, if the preamp or power amp dies I can replace them individually. As a bedroom player I don't care about the extra 6 lbs of weight or the rack.
As has been mentioned, if the preamp signal is weak, it won't drive the power amp to full volume. Basically, you'll want a power amp with 0.775V input sensitivity. Some preamps will have trouble driving a power amp with 1.4V input sensitivity. You may still be able to use a low output preamp or a 1.4V power amp if you run the preamp into something with a higher output signal (equalizer, effects processor, channel strip, etc.) There's some info here that may help:
https://www.sweetwater.com/insync/understanding-signal-levels-audio-gear/
The Crown XLi 800 power amp outputs can be bridged to mono - which, of course, is what we usually want for bass.
The Crown can also accept balanced XLR or unbalanced RCA. The RCA connection is unusual with bass gear, but 1/4" phono / RCA adaptors are cheap and easy to find.
You should verify the power amp's minimum speaker load is compatible with your speakers.
People have been running this type of setup for many, many years. It's proven to work well if you use a preamp (or something after the preamp) with solid output signal into a power amp with low (0.775V) input sensitivity.
)
Yeah, SansAmp into Power Amp works great.
Citizen’s bass player (Eric Hamm) is doing that, SansAmp (rack version though) into Power Amp, although he used to use the pedal version for a while too.
Personally, that’s what I do, SansAmp as my main “amp tone” into every amp’s power amp that I use (practice; live, etc…). Sounds awesome most times.
Citizen’s bass player (Eric Hamm) is doing that, SansAmp (rack version though) into Power Amp, although he used to use the pedal version for a while too.
Personally, that’s what I do, SansAmp as my main “amp tone” into every amp’s power amp that I use (practice; live, etc…). Sounds awesome most times.
20 years ago, on another (formerly very popular) bass forum, the suggested budget friendly, gig worthy rig setup was a SansAmp BDDI->QSC RMX850 power amp->Avatar 4x10 cabinet. I remember that a lot of people took that and ran with it as their setup.
All this talk about the .775 and 1.4 input sensitivities has me questioning future plans. I scored a super deal on two QSC Powerlight 1.8 power amps a couple of years ago that I thought I might use for this application down the road, however, now that I'm looking at the specs, the power amps have a 1.4 input sensitivity. I'm not seeing a correlating spec on GED-2112 I was planning to pair with one of those power amps on whether or not it is .775 or 1.4.
All this talk about the .775 and 1.4 input sensitivities has me questioning future plans. I scored a super deal on two QSC Powerlight 1.8 power amps a couple of years ago that I thought I might use for this application down the road, however, now that I'm looking at the specs, the power amps have a 1.4 input sensitivity. I'm not seeing a correlating spec on GED-2112 I was planning to pair with one of those power amps on whether or not it is .775 or 1.4.
And I forgot to mention, I’m so used to the SansAmp tone being part of my sound for 20+ years that if my band was going on tour and I needed a gigging setup, I’d get the rack SansAmp, a QSC Power Amp, and a 4x10 cab. I’m sure that would be awesome.
But I can’t justify that now so I rely on back line/other people’s amps and go though the power amp input of whichever amp I’m using there and then.
But I can’t justify that now so I rely on back line/other people’s amps and go though the power amp input of whichever amp I’m using there and then.
GED-2112 I was planning to pair with one of those power amps on whether or not it is .775 or 1.4.
According to manual GED-2112 has Unity Gain output which I have read is 0.775 +3dbu
Recently put this SGT-DI [and tiny board] + SAPA rig together that work well together.
How much are you trying to save??
QSC is the way to go - I'd start watching for a used Quilter Bass Block....
When you’re dealing with pedals you’ll have to try things to see what works acceptably with a power amp. You can’t assume that just because it’s a preamp or has a ‘line’ out jack that it’ll work.
Despite what’s often inferred in a pedal’s ad copy or its manual (assuming there is one) many I’ve tried needed to have their output boosted to be used effectively with a power amp. Even if the power amp has a .775V sensitivity setting.
Despite what’s often inferred in a pedal’s ad copy or its manual (assuming there is one) many I’ve tried needed to have their output boosted to be used effectively with a power amp. Even if the power amp has a .775V sensitivity setting.
I've been using a setup like this since last year and it's working great.
I use and Ampeg SGT-DI into a GSS Baby Sumo AmpXlite Power Amp. This power amp is small and delivers what I need for most of my bar gigs. I also have an Aguilar Tone Hammer that I've use as well with good results.
It's a great setup, IMHO.
This thread got real technical real fast. Which is helpful, of course. If I may summarize the literature on this question across the last few years of TB (which I have read with great interest because I have had this very idea myself), this was the answer I synthesized for myself:
Yes, it is a perfectly viable option provided you account for the technical considerations mentioned in this thread. From a practical perspective, the advice seems to come down to the idea of convenience. With a pedalboard and power amp, you will ALWAYS need to bring both. To every gig, every practice, every jam, everything. The benefit to a purpose-built bass head is the simplicity and convenience in those situations where you could get by without the whole rigamarole.
Yes, it is a perfectly viable option provided you account for the technical considerations mentioned in this thread. From a practical perspective, the advice seems to come down to the idea of convenience. With a pedalboard and power amp, you will ALWAYS need to bring both. To every gig, every practice, every jam, everything. The benefit to a purpose-built bass head is the simplicity and convenience in those situations where you could get by without the whole rigamarole.
I have an EDEN WTDI which I used with my Eden WT-1250 power amp until I got my WT-100 Navigator preamp. worked fine.
As for your situation, what will work with your particular power amp,will be based on the amp sensitivity rating rating and the output of your rig (SansAmp or whatever).
