Rockbass Pre-amp Question.

[Dave The Wraith]

I have owned a 2007 Rockbass Vampyre 4 for a while, and recently bought a 2007 Rockbass Streamer LX 5 which I'm in the process of bringing back up to scratch.

I noticed a significant difference in both volume and tone between the two. When I opened up the Streamer to check the battery I noticed the pre-amp set up is completely different to the Vampyre (the Vamp has the guts encased in a resin block whereas the Streamers appears to be two bare PCB's). Also the Streamers blend control and volume are reversed to where they were found on the Vamp - on the Streamer the blend pot is the uppermost one, and on the Vamp its the Volume (plus the blend control selects the neck pickup by turning counter-clockwise, whereas on the Vamp its clockwise).

The two basses appear to be from the same year (Vampyres serial is RB M-047671-S07 and the Streamers is RB J-046682-S07) so were different Preamps used on the Vampyre and Streamer LX models, or has someone fitted an aftermarket pre-amp set up to the streamer?

Only other difference is the Vamp has a J.A.N. III and the Streamer a broken J.A.N. II (soon to be replaced with an ordered J.A.N. III)

Any advice would be great

 

[Narcdor]

Take this with a big grain of salt, from memory the top one looks like the coloursound preamp used in the RockBass line and the bottom looks like a version somewhere along the way of the MEC. The current stock streamers are all passive except for the NT but these are so old I really am guessing. Sorry I couldn’t be more useful!

 

[Dave The Wraith]

Take this with a big grain of salt, from memory the top one looks like the coloursound preamp used in the RockBass line and the bottom looks like a version somewhere along the way of the MEC. The current stock streamers are all passive except for the NT but these are so old I really am guessing. Sorry I couldn’t be more useful!

Any info is useful.. thanks for replying. The top one is my Vampyre (there is a similar unit in the Warwick shop). The second one is the Streamer. I really like the sound of the Vampyre but the streamer is very "muffled" in tone and output (even with a new battery) so I may have to look into getting one similair to the Vampyre pre.

 

[jester]

These are most probably different preamps because of the output, unless it's the pickups (active vs. passive for example).

This knob layout is standard on all Streamers, the front most knob is the pickup blend. I think this is heritage from the old Spector era.

 

[Narcdor]

You should be able to find people selling the top pic coloursound preamp fairly easily, a lot of people with RockBass change out the preamp for something more their flavour. It’s not an expensive preamp but if it works for you check talkbass classifieds they come up there for next to nothing.

But before you change the preamp, the pickups are a factor too, do they both have gold MEC or silver MEC? Preamps are generally designed for active or passive pickups but not both without some fiddling around of the pot values.

 

[Dave The Wraith]

You should be able to find people selling the top pic coloursound preamp fairly easily, a lot of people with RockBass change out the preamp for something more their flavour. It’s not an expensive preamp but if it works for you check talkbass classifieds they come up there for next to nothing.

But before you change the preamp, the pickups are a factor too, do they both have gold MEC or silver MEC? Preamps are generally designed for active or passive pickups but not both without some fiddling around of the pot values.

The pickups are the passive MEC (Silver logo I know they are passive so I guess the Silver logo denotes this) on the Streamer, and Active (though I thought they were passive) with the Gold logo on the Vampyre

 

[Dave The Wraith]

The pickups are the passive MEC (Silver logo I know they are passive so I guess the Silver logo denotes this) on the Streamer, and Active (though I thought they were passive) with the Gold logo on the Vampyre

WARWICK MEC Dynamic Correction J-Bass Pickup, Neck, 4 & 5-String, Lefthand these to be preciset the right hand version)

 

[jester]

The pickups are the passive MEC (Silver logo I know they are passive so I guess the Silver logo denotes this) on the Streamer, and Active (though I thought they were passive) with the Gold logo on the Vampyre

The active MECs will give you much more output compared to the passives, so there you have your culprit. Most preamp designs do not boost signal output, giving you unity gain. In most cases you can use any preamp module you want with any pickup set you want, provided that you use volume and blend pots that have the correct values for the pickups' type.

 

[Dave The Wraith]

The active MECs will give you much more output compared to the passives, so there you have your culprit. Most preamp designs do not boost signal output, giving you unity gain. In most cases you can use any preamp module you want with any pickup set you want, provided that you use volume and blend pots that have the correct values for the pickups' type.

Makes sense - so Im guessing with the Streamer LX it is more of an active EQ rather than pre-amp boost? My other two backup basses (Washburn Axxess XS-4 and XS-5) have passive pickups with switchable active/passive Pre-amps and the output is higher (similair levels to the Vampyre) but they have a simple tone control rather than bass/treble cut/boost

 

[jester]

Makes sense - so Im guessing with the Streamer LX it is more of an active EQ rather than pre-amp boost? My other two backup basses (Washburn Axxess XS-4 and XS-5) have passive pickups with switchable active/passive Pre-amps and the output is higher (similair levels to the Vampyre) but they have a simple tone control rather than bass/treble cut/boost

Both your RockBasses have an EQ preamp that should not boost your signal.

 

[Dave The Wraith]

Both your RockBasses have an EQ preamp that should not boost your signal.

I may have got to the bottom of this. I had a nagging feeling that the wiring looked familiar, and after further investigation the streamer contains an Artec 2 band active eq - I know this as I bought an identical one (which I still jave in a parts box as it was pretty awful - worse output than many of my passive bass's). On comparison they are twins down to wire colours, pot makes, even the "Artec" text on the circuit board. I am guessing the old system failed or was sold and replaced with a cheap ebay Artec model at some point (very well fitted I must say). That or Rockbass were using Artec pre-amps in 2007 (which I highly doubt).

 

[jester]

I may have got to the bottom of this. I had a nagging feeling that the wiring looked familiar, and after further investigation the streamer contains an Artec 2 band active eq - I know this as I bought an identical one (which I still jave in a parts box as it was pretty awful - worse output than many of my passive bass's). On comparison they are twins down to wire colours, pot makes, even the "Artec" text on the circuit board. I am guessing the old system failed or was sold and replaced with a cheap ebay Artec model at some point (very well fitted I must say). That or Rockbass were using Artec pre-amps in 2007 (which I highly doubt).

Is the Streamer the louder one? I think cheap designs tend to boost the signal to at least give you something as a supplement to their mediocre quality.

 

[Dave The Wraith]

Is the Streamer the louder one? I think cheap designs tend to boost the signal to at least give you something as a supplement to their mediocre quality.

No.. the Vampyre is significantly louder. As are both my Washburns. I had an Artec pre-amp briefly due to an issue with the one in my XS-4 but took it out again after a week or so as the output was actually WORSE than all the Passive basses I had at the time (very noticeably so)

 

[Dave The Wraith]

Well I decided to bite the bullet and have ordered one of these direct from Warwick

https://shop.warwick.de/en/Parts+for+Instruments/Parts+for+Basses/Electronics/Active+electronic+for+passive+PUs+Vol-BalMN250K-Treble-Bass

Hopefully it will perform better than the crappy Artec one.