I own a Pensa J-4 custom and I am currently experiencing problems with the second pre-amp installed in October of this year. Is this something electronic,environmental,or what? This is not something that I should be experiencing with a Bass that I paid in excess of $3000 for. I can now begin to see why most Bass players are switching back to passive electronics and choosing basses that are more moderately priced.
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Two Pre-amps gone bad in less than a year....
- Thread starter jcalo
- Start date
Bingo! That's exactly why I don't own a ton of hot rodded active basses.
A whole bunch of people will likely extol the virtues of active electronics and they will have very good reasons but for me - simplicity and reliability are at the top of the list. I personally think passives sound better too.
edwinhurwitz
Supporting Member
Weird. I've never had a preamp go out on me. Except for some weird one that I built when my skills were pretty poor.
Edwin
Edwin
It's a bit of a blanket statement to say that because you've had two bad experiences with the same preamp. Maybe it's something to do with the construction of that certain preamp that is causing problems?
People go passive because there's no need to go active most of the time. IMO, there's great usefulness for both active and passive.
People go passive because there's no need to go active most of the time. IMO, there's great usefulness for both active and passive.
Hi.
From pure engineering viewpoint, active circuit can be anything from a simple single transistor buffer/driver to a complex pack of OP amps.
Your problem description sounds a lot like a certain component failing, a capacitor or an OP-amp.
I don't like active electronics as my first encounters (in the 80's) weren't all that great. I'd bet good money that things have improved a bit since then
. Actives doesn't offer me any advantages over passives either so my only active player is active just because I don't have any other BEAD strungable bass at the moment.
Just my 0.02
Sam
From pure engineering viewpoint, active circuit can be anything from a simple single transistor buffer/driver to a complex pack of OP amps.
Your problem description sounds a lot like a certain component failing, a capacitor or an OP-amp.
I don't like active electronics as my first encounters (in the 80's) weren't all that great. I'd bet good money that things have improved a bit since then
. Actives doesn't offer me any advantages over passives either so my only active player is active just because I don't have any other BEAD strungable bass at the moment. Just my 0.02
Sam
If by "most bass players" you mean some people you know then you are right, but i don't see that happening everywere.
Both active and passive have pros and cons so it's up to each one to choose what's better for themselves.
CrashClint
I Play Bass therefore I Am
Have you been using the same Amp or DI both times the preamp failed? There could be an issue with phantom power leaking back on DI or maybe something is feeding back though your preamp. I have never had a preamp fail on me and I have been playing active electronics since 1988 when I got my first Kramer Specter.
Contact Pensa and see if anyone else is having this issue.
Contact Pensa and see if anyone else is having this issue.
In response to Crash Clint. You're making me evaluate the situation more closely. I don't know if this has anything to do with it however, I have noticed that after I play through my partners old crate PA head that Yes, the pre amp does start going bad or giving static.I usually play it through my Hartke 3500 but when we play low volume,instrumental gigs, I just go through his PA head high Impedence jack.Could there possibly be a Phantom leak there which in turn puts a strain on the pre-amp?
The PA should not be capable of supplying phantom power to the high impedance input. Now it could be leaking DC from somewhere and that would be easy enough to check with a volt meter and a 1/4" cable.
I'll ask the obvious - you did try a new fresh battery right.
In my stable there are both passive and active basses. They both have their place. I generally prefer passive but have the actives there if I need 'em... never say never, eh ?
I'll ask the obvious - you did try a new fresh battery right.
In my stable there are both passive and active basses. They both have their place. I generally prefer passive but have the actives there if I need 'em... never say never, eh ?
You can't see music
At least, not without chemical enhancement
Sorry, I couldn't resist.
Hi.
The dying battery with its decreasing voltage and decreasing dynamic power supplying capability raises the noise floor of the OP amp and usually diminish the hum cancelling capability (if dealing with Lo-Z pickups). Also the pre starts clipping earlier and the freq. response suffers, first with lows obviously.
If the problem occurs on a specific amp there could also just be an impedance mismatch. Active pres should however be immune to that.
As for people switching back to passives, perhaps it's just that at the moment the preference is towards the classic rock sound with an tube amp so passive will do the same job without the battery. All transformer coupled amps have a "inbuilt" Hi-pass filter in around 40 Hz so boosting lows much doesn't really get you anywhere tonewise.
Regards
Sam
The dying battery with its decreasing voltage and decreasing dynamic power supplying capability raises the noise floor of the OP amp and usually diminish the hum cancelling capability (if dealing with Lo-Z pickups). Also the pre starts clipping earlier and the freq. response suffers, first with lows obviously.
If the problem occurs on a specific amp there could also just be an impedance mismatch. Active pres should however be immune to that.
As for people switching back to passives, perhaps it's just that at the moment the preference is towards the classic rock sound with an tube amp so passive will do the same job without the battery. All transformer coupled amps have a "inbuilt" Hi-pass filter in around 40 Hz so boosting lows much doesn't really get you anywhere tonewise
.Regards
Sam
- Feb 2, 2001
- 12,719
- 1,291
- Disclosures
- Builder: Valenti Basses
When and how does the bass make the static noise?
-If you leave the bass plugged in with the amp on, does the static start out of nowhere?
-Does it happen:
...when you adjust the knobs?
...when you move the bass around?
...when you mess with the input jack?
Where do you store the bass?
Does the bass have a Battery compartment similar to this:
[Invalid or Expired Link Removed]
- Feb 2, 2001
- 12,719
- 1,291
- Disclosures
- Builder: Valenti Basses
I think it may the the battery compartment. Sometimes. The battery loses connection with the terminals of the battery compartment causing static noises. What I've done is add a piece of foam on the cover. You should try with a folded up piece of paper or folded thin cardboard (matchbook cover) to add some pressure so the battery keeps a good connection with the terminals.
