Author Topic: F1X hiss (Read 162 times)

Bradley Young · « **on:** October 22, 2007, 08:16:30 PM »

My newly acquired F1-X seems to be the culprit in some rather pronounced hissing (although I'll say that I'm hypersensitive).

Bass plugged or unplugged, it hisses (seems to be more when plugged in, haven't had a chance to change the battery on my bass). Flipping the deep switch makes it more pronounced. The master volume, obviously, controls the hissing as well.

I have another tube, which I might try, if anyone thinks it might help.

Basically, I'm looking for an understanding about what causes hissing, since I'm a pretty decent troubleshooter.

I didn't really have a chance to do a full control/experiment breakdown, but any hints would be appreciated.

David Houck · « **Reply #1 on:** October 22, 2007, 09:54:29 PM »

I found this, but it addresses hum rather than hiss. Still, checking the capacitors might be a good place to start.

hieronymous · « **Reply #2 on:** October 22, 2007, 11:30:09 PM »

How do you have controls set? My understanding is that flat is with the bass & treble at 2, and the midrange on 10. Normally one might expect having all the controls at 5 to be flat, but treble on 5 would be a significant boost. May not be the problem, but just thought I'd suggest it.

Bradley Young · « **Reply #3 on:** October 29, 2007, 07:02:15 PM »

Additional troubleshooting info:

Hisses with a passive bass connected. Volume has no effect.

Active bass (my Epic) hissing is volume dependent. Don't know if this is an Epic problem, but it was dead silent with just the Superfilter. I put a new battery in.

Help!

Bradley Young · « **Reply #4 on:** December 26, 2007, 03:36:03 PM »

Still hissing away, and the new symptom is that it will have a sudden jump in volume occasionally. It sounds like it switches from passive to active inputs or something.

Any thoughts?

David Houck · « **Reply #5 on:** December 26, 2007, 04:27:32 PM »

Inspect the connections around both inputs for any loose solder joints or any components that looked burned.

jbybj · « **Reply #6 on:** December 27, 2007, 11:38:43 AM »

One of the techs at my work will routinely resolder joints even if they look o.k., and has frequent success with that. In your first post you mentioned another tube, but I don't see any follow up on that tact. I would suggest forgetting about the other used tube laying around, and go plop down $15 on a new Groove tube gold series, see if that helps. Good luck.

Bradley Young · « **Reply #7 on:** December 27, 2007, 02:49:01 PM »

Swapped tubes, and tried different wires, seems to have sorted itself (from the wiring change). Didn't have much time to really look at it, but it seems fixed for now.

Bradley

David Houck · « **Reply #8 on:** December 27, 2007, 05:22:58 PM »

Cool!