What's up with the 'Gain' on the SL2? Help requested!

  • Thread starter Thread starter rlord1974
  • Start date Start date
rlord1974":1b6vqujd said:
Wow, it seems this problem is more widespread than originally thought. Did you try changing the input tube in your head to see if that would fix the problem? Just wondering, as I have not had time yet this week to try that on my M4. I have tried swapping out all of the tubes in the SL2 module itself, and that has not solved the problem.

Anyways, I hope we can find a solution. You can see from the above comments that some guys can run their Channel B gain over 12 noon without encountering this issue - even with humbuckers!!!
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No, haven't tried changing the input tube. Which tube is the input tube on both the M4 and the MOD50? I don't know which one I would need to change.
 
rlord1974":t564go40 said:
rlord1974":t564go40 said:
Unfortunately, I don't have any recording gear, so I can't do it..... :aww:
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Jeez, now I'm quoting myself!

I just had a thought - maybe I can take a short clip using the movie mode on my Canon Digital Elph camera. Does anyone know if I could post such a clip for free on Photobucket, or does Photobucket only allow you to upload still pictures? :confused:
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Why would you put it on Photobucket? Just record the clip and email it directly to Bruce.
 
bbaug14":1e4rzjwz said:
Why would you put it on Photobucket? Just record the clip and email it directly to Bruce.
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I want to post it here so others can hear the exact issue I am having and see if it is in fact the same issue they're having.

I will email it to Bruce as well.
 
RockStarNick":2g19r0t1 said:
Were the modules modded in any way?

When I was experimenting with cap swapping, if you used a cap that was physically too large in the spots right next to the bass and mid pots, it would cause major oscillation squeal. (Other cap spots were fine though, oddly enough).

Didn't happen with the stock xicon or similar caps.

There shouldn't be any of these modules floating around, at least not done by ME. The only person I did that mod for was Aeroic, and we promptly swapped them back.
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My EG3/4 was modded by Bruce & Frank. Quite a while back. It was to be really a EG3/3 so to speak as I liked the EQ on the old 3 better.
 
bbaug14":2ka0esin said:
rlord1974":2ka0esin said:
Wow, it seems this problem is more widespread than originally thought. Did you try changing the input tube in your head to see if that would fix the problem? Just wondering, as I have not had time yet this week to try that on my M4. I have tried swapping out all of the tubes in the SL2 module itself, and that has not solved the problem.

Anyways, I hope we can find a solution. You can see from the above comments that some guys can run their Channel B gain over 12 noon without encountering this issue - even with humbuckers!!!
Click to expand...

No, haven't tried changing the input tube. Which tube is the input tube on both the M4 and the MOD50? I don't know which one I would need to change.
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The V1 input tube is the one closest to the guitar input jack on the front of the M4, MOD50/100.

This tube for the V1 position is great http://thetubestore.com/tungsol12ax7.html
 
Okay, thanks. I've changed those tube (that tube) before but I was trouble shooting a different problem. I never checked to see if it would solve the uncontrolled feedback problem as well. My gut tells me this isn't going to work, but it's worth a shot.
 
bbaug14":1rnch9pm said:
Okay, thanks. I've changed those tube (that tube) before but I was trouble shooting a different problem. I never checked to see if it would solve the uncontrolled feedback problem as well. My gut tells me this isn't going to work, but it's worth a shot.
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You try changing the input tube? Any update?.....
 
bbaug14":2t0i0pfj said:
anyone have an update on this?
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I'll do my best to get a clip recorded this weekend......I'm just pulling 15 hour days at work recently, so time has been TIGHT!!
 
I just wanted to come back to this and say I am not having issues any more. I had some old (very old ... 1960's) Tung Sol 5881s in there. After I took them out I have a whole new amp. Much cleaner livlier and way less microphonics. Cranking the gain with humbuggies up to 2 and 3 o'clock. No real serious issues.
 
You do realize changing power tubes should not have any effect on this squealing. I still need to hear it from someone, please.

Need to determine if it is a microphonic issue or an oscillation. No one answered if the frequency of the squeal changes as you move around with the guitar. Also, does the frequency of the squeal change as you turn the guitar volume knob up/down?

Really do need to hear a demo of this.
 
bruce egnater":3ezd465t said:
You do realize changing power tubes should not have any effect on this squealing. I still need to hear it from someone, please.
.
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:confused: Really? Even if they had gone michrophonic?
 
Yes. Power tubes do not get microphonic like a preamp tube. Also, the squealing certainly is related to the gain of the SL2 which really would have nothing to do with the power tubes. As an experiment, is it possible for you to put the old power tubes back in and see if the problem comes back?
 
Hey Bruce, thanks for the info. I always learn something for you. To clarify my problem was a little different than the original post from "rlord1974". Perhaps he will chime back into his post here. I was experiencing a little squawking from my EG3/4 at higher gain settings.
 
bruce egnater":36ls03ch said:
I still need to hear it from someone, please.

Need to determine if it is a microphonic issue or an oscillation. No one answered if the frequency of the squeal changes as you move around with the guitar. Also, does the frequency of the squeal change as you turn the guitar volume knob up/down?

Really do need to hear a demo of this.
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Sorry, Bruce. I have been super busy recently.

I'll try to get a short clip recorded with my digital camera tomorrow. What email address can I send the file to?

Cheers,

Rob :thumbsup:
 
Update:

I just emailed Bruce the below. Hopefully I'll hear back shortly.

Well, I have yet to record anything, but I can tell you this: It only occurs when my guitar volume knob is above 5 (half). Also, the squealing is loudest when the guitar volume knob is at 10 (full), but the pitch of the squealing gets higher as I roll the volume knob back from 10 towards 5. The frequency and overall problem does not seem to change when I move around with the guitar.

Does the above help at all, or do you still need to hear a clip?
 
Rob - I had a problem like this with my M4, and had been talking to Bruce about sending it in. After poking around inside and putting the cover back on, the problem went away. But then I hit the Ground Lift switch by mistake, and lo and behold, the squealing/feedback was back! Did toggling the switch affect the "hum" normally associated with the Ground Lift switch? Yes. But it was hard to hear over the squealing. For the life of me, I can't understand how this would affect squealing and feedback, but trust me - it did! :confused: I'm just curious if toggling your ground lift switch has any effect . . .
 
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