Faulty preamp or other explanation???

[jcalo]

Is there a specific reason why any bass guitar would go through preamps i.e.two in less than one year? Is it a faulty preamp or something in the connection that would allow this to happen on such a frequent basis.How long are they supposed to last?This is very frustrating to the point where I have considered giving up on a bass that I really love playing.

[PDavyduck]

a little more explanation. what do you mean by "go through" preamps?

is it eating them??

[bongomania]

Basses simply do not "go through preamps". A preamp will last decades if it doesn't get broken by the user or fail due to cheap/poor construction.

What bass, which preamps?

[T-Bird]

Hi.

+1 to the above.

If You mean what I think you mean, the preamps stop passing signal through or stop being "active"?

Determined by whom?
Yourself, or the friendly music store employee who want's to sell you something?

Some Chinese preamps eat batteries like crazy, but will usually last as long as people toss them away.

Help us help Yourself, give us a bit more information.

Regards
Sam

[jcalo]

It's not that they stop working completely.After about an hour of playing,I begin to hear what is similar to white noise or the sound that you would hear between radio stations.From what I have experienced on my last preamp, that sound continues to get louder over time. This is a Pensa J-4 custom.An expensive Bass,but maybe cheap preamps which I do not know brand name.Sorry

[bongomania]

Have you tried a new battery? Have you tried contacting Pensa?

[jcalo]

New battery does not make a difference. I will contact Pensa however I'm becoming a little gun shy and extremely frustrated with this Bass.I may need to consider going with a more reliable preamp,but I'd like to really figure out why this is happening.

[T-Bird]

Hi.

+1 for contacting the manufacturer, if this is a common thing on a certain pre amp mfg. run, they know about it and are more than likely willing to help.

Noise floor rising is usually traced to a dried up or faulty electrolytic condenser. Also some OP-amps tend to get noisier when they warm up. Is the pre amp design discrete or OP-amp based? Ie. is there three legged transistors (FETs) or multi legged packages (spiders, bugs, whatever people want to call them )

Are the pickups active or just the preamp?

Does this happen with headphones as well, or just with one amp? Could it be the caps in Your amp?

Regards
Sam

[mikezimmerman]

The other thing to look at: does this happen wherever you're playing, or only at home? For instance, I've noticed that I get something that sounds like radio when I touch the controls on my basses when playing at home, but never at gigs or practices. Turns out I have a neighbor who's a ham radio operator...

If it's only happening in one place, it could be something like local electromagnetic interference, or problems with the wiring/power, etc.

Mike

[jcalo]

I don't know if it's three legged or multi legged. The noise will occur in any location and happens with a variety of different amps. I'm liking the explanation of a faulty batch of preamps that may be notorious for this type of thing. I'll be contacting the manufacturer.

[dmusic148]

Originally Posted by jcalo

I'm liking the explanation of a faulty batch of preamps that may be notorious for this type of thing.

Unusual, but it happens.

[Suhr]

Originally Posted by jcalo

Is there a specific reason why any bass guitar would go through preamps i.e.two in less than one year? Is it a faulty preamp or something in the connection that would allow this to happen on such a frequent basis.How long are they supposed to last?This is very frustrating to the point where I have considered giving up on a bass that I really love playing.

Static shock
Many discrete circuits have no protection from static
Second issue could be DC on the amplifiers input
A well design preamp should last forever and have internal protection against these hazards
Now I see it could be my design since it is a Pensa the only issue could be contruction since I have nothing to do with that.

I designed the original Pensa Preamps in the 80's and gave them directions on how to make them but I have no idea what they have been doing with the circuit since the last 20 years.
I would be happy to fix the preamp for free and see what is wrong and why it isnt working if you send it to me and IF it is still my design.
I have never had any problems with the units I have made. They will last a lifetime.
you can reach me at our website email
www.suhrguitars.com
or PM me here

[Steveaux]

Originally Posted by Suhr

Static shock
Many discrete circuits have no protection from static
Second issue could be DC on the amplifiers input
A well design preamp should last forever and have internal protection against these hazards
Now I see it could be my design since it is a Pensa the only issue could be contruction since I have nothing to do with that.

I designed the original Pensa Preamps in the 80's and gave them directions on how to make them but I have no idea what they have been doing with the circuit since the last 20 years.
I would be happy to fix the preamp for free and see what is wrong and why it isnt working if you send it to me and IF it is still my design.
I have never had any problems with the units I have made. They will last a lifetime.
you can reach me at our website email
www.suhrguitars.com
or PM me here

There is nothing more honorable than a man who takes pride in and stands behind his work.

I doff my cap.

[depalm]

Originally Posted by Steveaux

There is nothing more honorable than a man who takes pride in and stands behind his work.

I doff my cap.

Well said.