F-1X Microphonic problems

[joetruscott]

Hi guys,
 
I recently just bought a F-1X and the sound is amazing and I love it but I seem to be having a major problem when playing. The rig seems to pick up noise from external sources so if I tap the front it's noticabley sounding through the amp.  
 
When I first power up the rig isn't subject to pick up any noise but after he's all warmed up he starts picking up the noises. It's coming out of all of the outputs, including the XLR.  
 
I'm running a Crest CA-12 Stereo Poweramp with SWR Golliath III and Son Of Bertha and i'm going out the full range into the power amp or using the crossover.  
 
I checked cetain aspects like the power rating, a new groove tube and grounding but had no luck. Can anyone give me a litle much needed, appreciated help.  
 
Thanks

[adriaan]

Tubes can be microphonic - but you've already changed the tube, so that would be two tubes in a row, and that's not really likely.

[David Houck]

Does it happen with different instruments?
Does it happen with different instrument cables?
 
If it's in a rack, take it out of the rack and isolate it from the other components and see if that has any effect.
 
Go to the FAQ section of this forum and read the F-1X section, especially the note about jumper settings.

[811952]

I had a rack that did the same thing.  I finally isolated a bad XLR connector between components.  Swapping that out solved the problem.
John

[joetruscott]

Hey all,
 
Thanks for all the quick replies.
 
This happens even if there are no instruments or leads connected and I tap the front of the unit. I've tried it with a different power amp and speaker and it is definatly the source. The jumpers have been checked and are in the correct position.  
 
Maybe like john said theres something with the compnents wrong. Tonight (as I don't have the unit with me until practice) I will try the contact cleaning on the jack sockets as i haven't tried that yet and if this doesn't solve it, it may have to go to, alembic or a technician.
 
Anymore help would be amazing.
 
(Message edited by joetruscott on September 20, 2005)

[palembic]

Something stupid.
Tweak Peaks got a F1-X and DS-5R and Power amp + some other stuff not important here.
I noticed a significant differance in tone when the F1-X is hurther away from the Power Amp.
So the DS5-R is always between the F1-X and the power amp.
 
Paul TOBO

[xlrogue6]

Try an Electro Harmonics 12AX7--they are in my experience less microphonic than any other current production tube.  You don't specify which Groove Tube you installed, but it is not uncommon for new production tubes to be microphonic out of the box.

[bassdr]

Two suggestions- 1) I recently retubed my F1-X with an NOS GE tube from the late 60's- WOW! 2) Look at and possibly resolder all the solder joints you can see- I was having some wierd noises and they went away when I did that.  I also was not enamored with the sound of the Groove Tube compared to the GE- looking at them, the GE is built much beefier.  My 2 cents, Michael (Flame Koa Essence)

[joetruscott]

 
 
(Message edited by joetruscott on September 23, 2005)

[joetruscott]

Hey,
I finally fixed my F-1X by doing what the alebic people said fixes most of the F-1X's problems. I found it hard to believe that inserting and removing the jack 30ish times would be able to cure what sounded like a grounding or component problem but i'd like to thank all of you for the good advice.
 
P.S I love my new groove tube in the preamp. Compared to the old slovak one it had in it (Even though slovak and GT were made by the same people) but it has a nice little bump in the upper mids which gives it a nice vintage sound while still having the F-1X clarity. I can't wait until it ages abit.
 
Thanks All
 
(Message edited by joetruscott on September 23, 2005)

[David Houck]

Congrats!!

[worldfamousandy]

I have had to exersize my output jacks a couple times, as well. That's a funny part of our maintenance routines as Alembic owners!