Fender FR-12 preamp mod : The Hissterectomy

[Beexter]

There is an unresolved issue with the FRs though. If you plug in a 1/4 jack for input it will have a low level hum. Balanced, unbalanced, whatever. It has a small ground loop hum using the 1/4 input. It will do this on a stock pre or a V2.

Could this be a region specific issue? I'm in the UK so have the AC line frequency in the FM9 set to 50Hz.
My FM9 is connected to the FR-10 from Out 1 (L) with a single , standard 1/4 jack cable (not even a humbuster) and I'm not hearing any hum, even with the FR-10 volume maxed.
It is, of course, quite possible that my hearing is shot!

 

[WKSmith]

Could this be a region specific issue? I'm in the UK so have the AC line frequency in the FM9 set to 50Hz.
My FM9 is connected to the FR-10 from Out 1 (L) with a single , standard 1/4 jack cable (not even a humbuster) and I'm not hearing any hum, even with the FR-10 volume maxed.
It is, of course, quite possible that my hearing is shot!

It's possible the power supply is different. When you take it apart, get a pic of the power supply board and its revision date for me please.

It is a very quiet hum. If the FR is hissing it is not really noticeable. It was only when The V2 killed off the hiss that it became evident.

 

[ballhawk]

What if the source is 1/4 in. trs cable with xlr going in to the FR10? will that be ok?

 

[WKSmith]

What if the source is 1/4 in. trs cable with xlr going in to the FR10? will that be ok?

Still hums with a balanced TRS.

On that combo FR input jack.. TRS should be wired to exactly match the xlr on the FR pin to pin. But it is not wired that way.

Simply plugging in a 1/4" plug of any kind activates the hum.

Bizarre

 

[ballhawk]

Simply plugging in a 1/4" plug of any kind activates the hum.

Thanks for the info. Very disappointing. Looks like we are out of luck.

 

[WKSmith]

Thanks for the info. Very disappointing. Looks like we are out of luck.

Xlr to trs into the FR hums
Trs to xlr into the FRxlr input is fine

 

[ballhawk]

Trs to xlr into the FRxlr input is fine

Good!

That's what I can do. I didn't do a good job of explaining my 1st question.

 

[Patzag]

As a note, on the FM9, TRS to TRS into FR10 hums at such a low level that it's unnoticeable. Unless you crank the level on the FR10 to "stadium" levels. What is absolutely unusable at any level is a TS cable into the FR10.

 

[pima1234]

Maybe my ears are getting the best of me, or maybe the standard hiss level is just too high, but I don't notice a hum. Right now, I'm running out from the Ethos Clean Fusion Deluxe into a Lehle P-Split iii and out to my FR-10s.

 

[sick pickle]

Ingesting to see both the FR10 and 12 on Pearl Jams recent Howard stern performance.

 

[200man]

View attachment 139416

Ingesting to see both the FR10 and 12 on Pearl Jams recent Howard stern performance.

what are those mics pointing into the tubes ?

 

[usphotographer]

what are those mics pointing into the tubes ?

I believe those are acoustic Bass tube traps which reduces reverberation in a room by absorbing certain frequencies within a given spectrum normally custom designed for that specific room although those look somewhat home made. I'm assuming those condenser mics are recapturing some of those frequencies and throwing it back to the mixing board but I'm not sure on that. Looking at the photo again, the condenser mics may just be capturing the rooms overall ambient sounds over the drums and may not be pointed down the tubes. Can't really tell because the photo is taken from front view instead of side view.

 

[WKSmith]

Looks like a standard drum overhead pair of condensers on booms.. swung back out of the way for a cymbal change or some other reason.

 

[WallyG3]

I think they're just lights. The mics aren't near them, just an optical illusion.

 

[pima1234]

We are all above the level of Pearl Jam now! (The V2s are coming, baby!)

 

[WKSmith]

And Saturday is My 17th annual 39th birthday

I am beyond exited about these V2s!!
the birthday ..not so much. But I hear there will be margaritas.

 

[usphotographer]

I think they're just lights. The mics aren't near them, just an optical illusion.

You are most likely correct on all accounts. Thought they might just be lights as I've never seen bass traps that looked that janky but thought it might be a homemade trap! LOL

 

[usphotographer]

Well if it makes you feel better, you are only 4 months and 14 days older than me! Happy Birthday! Take the day off and enjoy yourself with a fine 1968 wine!

 

[ballhawk]

I am beyond exited about these V2s!!
the birthday ..not so much. But I hear there will be margaritas.

Happy Birthday you whippersnapper I saw my 17th annual 39th birthday 15 years ago (that's some kind of funky math )

Just remember, there's only one way not to get older!

 

[200man]

You are most likely correct on all accounts. Thought they might just be lights as I've never seen bass traps that looked that janky but thought it might be a homemade trap! LOL

Yeah, they are definitely overheads, but it is a good optical illusion.