Mike Pope Flexcore - White Noise Level?

Modulus1906 · #1 12-02-2012, 10:07 PM

Folks,

Just wanted to know whether anybody is experiencing any "hissing" with the preamp when in active mode. For example, with the treble set flat, there is an audible hiss that I don't recall being present when the preamp was first installed. Even if I turn the treble or the master volume all the way down, the hiss is still present and seems "fixed" at the same volume. Also, it's not as prevalent when I run the pre passive, but still more noticeable than my other basses in active mode. Is it indeed possible for idle hissing to get worse over time and what things should I have checked? Thanks

thepontif · #2 12-03-2012, 04:00 PM

It's weird. There when passive too?

SGD Lutherie · #3 12-03-2012, 06:04 PM

Is it hiss, or is it a high pitched buzz?

Modulus1906 · #4 12-03-2012, 06:53 PM

Quote:

Originally Posted by SGD Lutherie

Is it hiss, or is it a high pitched buzz?

It's hiss just as if you would drag out saying"hissssssss". Some of it is inherent in my amp and is, therefore, present with all of my basses, but I do notice it's louder when I plug in the bass with the Flexcore in it. To test, I assessed the amp's natural noise level (EBS TD650-pretty low noise). Then, I plugged in my stock Yamaha bass and the noise level was pretty much the same as the amp itself, so the Yamaha is not really contributing any noise. Then, I plugged in the bass with the Flexcore and the noise level in active was higher than the amp itself. Either I'm imagining things or it's louder since the preamp was first installed. It's not intolerable but noticeable. Thepontif, in passive mode, the hiss seems to be at the same level as the amp itself, so I'd say there is not an issue in passive. Thanks

masmasbasso · #5 12-05-2012, 07:44 PM

I've never had that issue.

bassbenj · #6 12-05-2012, 08:41 PM

Quote:

Originally Posted by Modulus1906

It's hiss just as if you would drag out saying"hissssssss". Some of it is inherent in my amp and is, therefore, present with all of my basses, but I do notice it's louder when I plug in the bass with the Flexcore in it. To test, I assessed the amp's natural noise level (EBS TD650-pretty low noise). Then, I plugged in my stock Yamaha bass and the noise level was pretty much the same as the amp itself, so the Yamaha is not really contributing any noise. Then, I plugged in the bass with the Flexcore and the noise level in active was higher than the amp itself. Either I'm imagining things or it's louder since the preamp was first installed. It's not intolerable but noticeable. Thepontif, in passive mode, the hiss seems to be at the same level as the amp itself, so I'd say there is not an issue in passive. Thanks

So this is about what is expected. The Flexcore is hissing. It is certainly common for preamps to develop probems over time or just have a problem start at a later date. Problems can range from hiss to dead. Semiconductor parts have a natural hiss level that varies from unit to unit that is usually determined by chance when it's manufactured, but it is also common for parts to develop hiss later as well. Cheap preamps are made by just taking parts from the bin so some will be much more noisy than others. Quality preamps usually use parts selected for low noise levels (which cost more) so they are all pretty much the same...unless a part goes bad.

I presume the Flexcore is potted which means that the fix is to replace the whole unit. Flexcore should have a hiss specification, which if your pre is exeeding it, they should send you a new one under warranty.

Got2SadowskyNYC · #7 12-05-2012, 08:43 PM

Email Mike through his website. Nice fella. He'll get back to you.

thepontif · #8 12-06-2012, 11:22 AM

Quote:

Originally Posted by Modulus1906

It's hiss just as if you would drag out saying"hissssssss". Some of it is inherent in my amp and is, therefore, present with all of my basses, but I do notice it's louder when I plug in the bass with the Flexcore in it. To test, I assessed the amp's natural noise level (EBS TD650-pretty low noise). Then, I plugged in my stock Yamaha bass and the noise level was pretty much the same as the amp itself, so the Yamaha is not really contributing any noise. Then, I plugged in the bass with the Flexcore and the noise level in active was higher than the amp itself. Either I'm imagining things or it's louder since the preamp was first installed. It's not intolerable but noticeable. Thepontif, in passive mode, the hiss seems to be at the same level as the amp itself, so I'd say there is not an issue in passive. Thanks

Send me an email at Mike@MikePopejazz.com and I will take care of you. It shouldn't be hissing like that. This is a very rare occurrence. I'm betting its the ground driver, but can't say for sure.

Got2SadowskyNYC · #9 12-06-2012, 11:58 AM

What did I say. Mike Pope stand up Guy.

Weshunter413 · #10 12-07-2012, 06:17 AM

I've had the same problem with mine. And it's was brand new. It was not like a normal buzz or hiss that comes from boosting frequencies but it would still have the noise when the treble was off and even when the volume control was off. The only thing that stopped it was to switch to passive mode. Complete silence then. I just stayed in passive all the time because of the sound and sold it a few weeks later since I never really used it. Just weird

Modulus1906 · #11 12-07-2012, 01:43 PM

Quote:

Originally Posted by thepontif

Send me an email at Mike@MikePopejazz.com and I will take care of you. It shouldn't be hissing like that. This is a very rare occurrence. I'm betting its the ground driver, but can't say for sure.

OK, I just sent you a note. Thank you!

testing1two · #12 12-07-2012, 02:11 PM

Quote:

Originally Posted by Weshunter413

I've had the same problem with mine. And it's was brand new. It was not like a normal buzz or hiss that comes from boosting frequencies but it would still have the noise when the treble was off and even when the volume control was off. The only thing that stopped it was to switch to passive mode. Complete silence then. I just stayed in passive all the time because of the sound and sold it a few weeks later since I never really used it. Just weird

did you sell it to the OP?

Modulus1906 · #13 12-07-2012, 03:36 PM

Quote:

Originally Posted by testing1two

did you sell it to the OP?

No, I bought mine new.

Munjibunga · #14 12-10-2012, 04:10 PM

Quote:

Originally Posted by bassbenj

So this is about what is expected. The Flexcore is hissing. It is certainly common for preamps to develop probems over time or just have a problem start at a later date. Problems can range from hiss to dead. Semiconductor parts have a natural hiss level that varies from unit to unit that is usually determined by chance when it's manufactured, but it is also common for parts to develop hiss later as well. Cheap preamps are made by just taking parts from the bin so some will be much more noisy than others. Quality preamps usually use parts selected for low noise levels (which cost more) so they are all pretty much the same...unless a part goes bad.

I presume the Flexcore is potted which means that the fix is to replace the whole unit. Flexcore should have a hiss specification, which if your pre is exeeding it, they should send you a new one under warranty.

Actually, the Flex Core is modular, so it's likely you'd only have to replace one pot and its attached circuitboard. It would take a little bit of troubleshooting to determine which one.

Munjibunga · #15 12-10-2012, 11:28 PM

OK, I checked the Flex Core in my Sadowsky Metro UV70, and there's slightly more hiss in in active over passive. So I checked my Foderas - same difference. So I checked my LeCompte (OBP-3) - same. Then I checked My Fender Am Deluxe Jazz Plus V - same. When I feel like digging out a bunch of the others, I'll check them, but I'm getting the feeling that a little hiss is the nature of the beast with active pickups. None of the hiss I'm hearing would be detectable in a gigging situation. I don't even hear it on the recordings I did with my trio a couple weeks ago.

thepontif · #16 12-11-2012, 06:53 PM

Quote:

Originally Posted by Modulus1906

No, I bought mine new.

Hey, I have boards here that I want to send you but I don't have your address. You sent an address without a ZIP Code so I don't know where to send the stuff. So hit me with an email as soon as you can so that I can get these things out and get you up and running again.

dmusic148 · #17 12-11-2012, 07:17 PM

Quote:

Originally Posted by thepontif

Hey, I have boards here that I want to send you but I don't have your address. You sent an address without a ZIP Code so I don't know where to send the stuff. So hit me with an email as soon as you can so that I can get these things out and get you up and running again.

This.......... is very impressive customer service. Well done Sir.
You may just become the next Larry Hartke.

thepontif · #18 12-11-2012, 08:15 PM

Quote:

Originally Posted by dmusic148

This.......... is very impressive customer service. Well done Sir.
You may just become the next Larry Hartke.

No matter what, I'll always be better looking :-)

Weshunter413 · #19 12-13-2012, 05:30 PM

I may have to buy another one if that was just a freak thing. I did love the control with it.

Modulus1906 · #20 12-13-2012, 07:38 PM

Quote:

Originally Posted by thepontif

Hey, I have boards here that I want to send you but I don't have your address. You sent an address without a ZIP Code so I don't know where to send the stuff. So hit me with an email as soon as you can so that I can get these things out and get you up and running again.

Thanks Mike. I sent you the wrong city and no zip. Not sure what I was thinking, but I just sent you an email with the corrections. Thanks