|
Post by splawndude on Jul 12, 2016 19:16:22 GMT -5
No idea....but he may not have had a chance to respond again yet as he is super busy.
About the only thing I could think of to try that would be related would be to run the amp at half power (drop impedance down one step) and then start running the power tubes in pairs to see if you can get the problem to go away.
Pull the outer 2 - play Swap inner pair with outer pair you just pulled - play Interchange remaining in different combinations - play
If one of those combinations holds firm as good with no volume drop then you may find a bad one through process of elimination. That would be valuable even with a new quad of tubes coming because you 'could' use those as spare tubes.
|
|
|
Post by gtrjunior on Jul 12, 2016 19:29:27 GMT -5
I'm emailing with him now....a new problem has reared its ugly head....ugh. I thought of doing the half power thing too but the problem is I can't "make" the symptoms happen....they either happen or don't.
|
|
|
Post by gtrjunior on Jul 12, 2016 20:03:15 GMT -5
I'm completely f'in frustrated...grrrr
|
|
|
Post by cipher on Jul 12, 2016 20:55:26 GMT -5
Bummer. Hope you get this all sorted man.
|
|
|
Post by splawndude on Jul 12, 2016 21:26:24 GMT -5
Take a deep breath.
What other EL34s do you have access too?
Remove all pedals and effects from the mix.
Test all tubes again with a pencil with your cab separated as far apart as you can.
You got new power tubes coming soon right?
|
|
|
Post by gtrjunior on Jul 13, 2016 4:33:30 GMT -5
So last night I'm playing and after about 15 min this happens: vimeo.com/174489767Keep in mind there's no delay or reverb on the amp. I was thinking maybe it's the floyd's springs rattling but this guitar has noiseless springs in it. So I plugged in the Les paul just to check but it still does it. I unplug everything from the loop(Mxr 10 band eq and an ISP G-string noise gate.) the noise stops. Scott says it must be something in the loop causing it. But these pedals have been in the loop for weeks with absolutely no problems. If I have pedals on the loop and hit the loop bypass, it emits a high pitched squealing. The volume knob is able to raise or lower the volume big the squeal (preamp section?). And there was about a 25% volume drop and it sounds very trebly, like you have a wah pedal on and are stepping in the toe down position. Splawndude: To answer your question. I have a set of New issue Mullard el34 that my amp tech said weren't close enough matched to bias in my 50w Marshall. I think he's incorrect because I bought them as a matched set and they biased up in my JVM. I took them out of the JVM and put Ruby's in instead. Only because I didn't like them in that amp. I kept them to have as spares. vimeo.com/174491067All the tubes "look" fine. There is m visual indication of red plating or a busted filament. This video is after the amp had been on for at least 20-30 min. Edit: now that I look again...the first tube on the left seem to not be glowing as brightly and the second one is glowing more that the last 2....no idea if that means anything. It is slight differences...
|
|
|
Post by gtrjunior on Jul 13, 2016 4:41:31 GMT -5
Bias probe is scheduled to be delivered Thursday.
|
|
|
Post by splawndude on Jul 13, 2016 8:55:44 GMT -5
Funky sh!t man. I wouldn't worry about the varying glow of the tubes. They won't all glow the same anyway. I didn't see anything that would alert me. That clinking sound in your video is weird though. I wouldn't immediately suspect a power tube based on that. I wonder if the loop PCB is f**ked up? I would still try the half power power tube swaps I mentioned earlier. And this sound is intermittent? Swapping preamp tubes around does nothing? (I'm not an amp tech)
|
|
|
Post by gtrjunior on Jul 13, 2016 9:53:20 GMT -5
Last night is the first time it happened...ill have to play with preamp tubes and see...I haven't done that. All the preamp tubes are NOS that I put in so who knows...they all worked and sounded great up until that noise last night...
|
|
|
Post by gtrjunior on Jul 13, 2016 9:55:39 GMT -5
Here is another video I sent Scott this morning...haven't heard back since then. Never mind my Rhode Island accent...lol vimeo.com/174530066
|
|
|
Post by splawndude on Jul 13, 2016 12:00:46 GMT -5
OK - so this is a new problem?
These are just some random thoughts/suggestions I have (again, not a tech here):
-If the guitar volume is turned up but just sitting there 'unmuted' the pickups might be picking up noise. Do that again, but hold guitar or maybe mute stings or turn guitar volume down.
-Also plug guitar directly into effects 'Return' and see what happens.
-Take noise gate and EQ out of there - we want to isolate things as closely as possible. You don't need those things in there.
-Turn the amp gain down
-Try the clean channel
-Take those cylinders off the preamp tubes and leave them off (for now anyway)
-Seems you have a microphonic preamp tube or a bad loop. Kind of hard to say because I'm not there and not sure what is plugged in when.
|
|
|
Post by gtrjunior on Jul 13, 2016 12:10:29 GMT -5
So the squealing is something that I heard for the first time last night, however I've never turned off the loop with something running in it so.... the guitar in the video was plugged in but the volume knob was off.
I'll try the other suggestions but I also had another idea... If I use a 6" patch cable and "jump" the fx loop and it makes that noise when I disengage the loop, may be a problem in the loops pcb board. At least I would be able to isolate that it either is or isn't a pedal causing it....
There is a possibility of a microphonic preamp...I just think it's strange that the squeal only shows up with the loop disengaged and only if something is plugged into the loop. If I take the pedals out of the loop....no squeal.
|
|
|
Post by splawndude on Jul 13, 2016 12:10:59 GMT -5
Question:
At the 1:00 mark on your video you say 'If I unplug' the noise goes away but it is not clear to me what you are unplugging.
You also say, I think, at the beginning of the video that your guitar is plugged into the Gate then EQ then effects loop? Are you plugged into the front of the amp?
|
|
|
Post by splawndude on Jul 13, 2016 12:17:16 GMT -5
So the squealing is something that I heard for the first time last night, however I've never turned off the loop with something running in it so.... the guitar in the video was plugged in but the volume knob was off. I'll try the other suggestions but I also had another idea... If I use a 6" patch cable and "jump" the fx loop and it makes that noise when I disengage the loop, may be a problem in the loops pcb board. At least I would be able to isolate that it either is or isn't a pedal causing it.... There is a possibility of a microphonic preamp...I just think it's strange that the squeal only shows up with the loop disengaged and only if something is plugged into the loop. If I take the pedals out of the loop....no squeal. Just saw this: Yes, try the patch cable and then also guitar into FX Return
|
|
|
Post by gtrjunior on Jul 13, 2016 12:48:18 GMT -5
So the guitar into fx send basically bypasses the preamp section, right? And just to clarify I plug into the fx send and not return...in an earlier post you said plug into the fx"in" which i take to mean the return jack...since the send is an output. Pls correct me if I'm misunderstanding you...my head is swimming with technical jargon right now. Lol
|
|