endofanera wrote:japmn wrote:Thanks, that was what I was hoping to hear. I have a few random 12AX7s doing nothing somewhere around the house. I'll pop one in and cross my fingers.The reverb driver on a Super Reverb is a 12AT7 or a 12AU7 as I recall. It may not be a 12AX7 on your Epiphone either. I imagine it will likely work with a 12AX7 if so, but the verb may be slightly distorted. I dont know.I have heard they are the same tube (and that the AT7 is just less gainy) and can be substituted with minimal change in sound. Maybe bullshit. I don't really know much about tubes.What about 12AD7's They are said to be low hum / Non-microphonic versions of a 12ax7.Has anyone ever used those? They sound like good replacements for reverb tubes.Edit: Doesn't really matter. Teh preamp tubes in the Epiphone are 6EU7's and a 6C4.On the schematic it looks like signal passes through Valve 2 (6EU7) through the reverb knob, into the tank, and then through Valve 3 (6C4). Am I right in thinking Valve 3 is the one I need to take a look at here?

Last night I was playing through my 63 Epiphone Pathfinder with the reverb on. After a while it started to get a very high pitched feedback loop in the reverb itself. If I turned the knob down, It would gradually fade away. It only stayed gone if I turned off the Reverb with the foot switch.I have run into this reverb feedback in my Quad Reverb once upon a time but it just went away. What causes this... tube? How can I fix it? I cannot record until it is fixed.

endofanera wrote:japmn wrote:Last night I was playing through my 63 Epiphone Pathfinder with the reverb on. After a while it started to get a very high pitched feedback loop in the reverb itself. If I turned the knob down, It would gradually fade away. It only stayed gone if I turned off the Reverb with the foot switch.I have run into this reverb feedback in my Quad Reverb once upon a time but it just went away. What causes this... tube? How can I fix it? I cannot record until it is fixed.Usually it's a microphonic reverb driver tube. Replacing the tube will cure it if so.If you turn up the verb and tap on the preamp tubes with a pencil eraser or chopstick or something you can usually find the one that's microphonic.Thanks, that was what I was hoping to hear. I have a few random 12AX7s doing nothing somewhere around the house. I'll pop one in and cross my fingers.

A 150' coil of RG59/U Broadcast Video cable just fell into my lap. It looks almost just like guitar cable. I need to make a shit load of guitar cables and interconnects for 3 pedal boards. These are this cables specs:Dielectric Material = Gas Injected FoamNominal O.D. = 0.242Nominal Impedance = 75.0 ohmsNominal Capacitance = 16.5 pf/ftNominal Velocity Of Propagation = 82%Shield Cover = 67% Braid, 100% FoilAttenuation (dB/100ft)I don't know what most of that means. would this cable be suitable for guitar/instrument cable?

eliya wrote:Is there any way I can fix it? Maybe I should take advantage of that and upgrade to and wide LCD screen.I'd guess a faulty electrolytic cap in the PSU since it failed on power-up and continues to do so. But... CRTs can be dangerous to work on, it will be a hassle, and you may as well get a nice cheap LCD.

endofanera wrote:The difference in gain is the only thing Ive noticed from swapping those types of tubes. 12AX7s seem to be highest gain of the ones Ive encountered.Another major difference is the plate impedance (output impedance) which is important depending on what load impedances you are driving. I'm guessing reverb tanks may tend to present a heavier load in general.Japmn - looks like V3, yes, assuming that's your problem. Try tapping it with a plastic pen or something and see if it rings with the reverb up.

endofanera wrote:japmn wrote:endofanera wrote:japmn wrote:Thanks, that was what I was hoping to hear. I have a few random 12AX7s doing nothing somewhere around the house. I'll pop one in and cross my fingers.The reverb driver on a Super Reverb is a 12AT7 or a 12AU7 as I recall. It may not be a 12AX7 on your Epiphone either. I imagine it will likely work with a 12AX7 if so, but the verb may be slightly distorted. I dont know.I have heard they are the same tube (and that the AT7 is just less gainy) and can be substituted with minimal change in sound. Maybe bullshit. I don't really know much about tubes.What about 12AD7's They are said to be "low hum / Non-microphonic" versions of a 12ax7.Has anyone ever used those? They sound like good replacements for reverb tubes.The difference in gain is the only thing Ive noticed from swapping those types of tubes. 12AX7s seem to be highest gain of the ones Ive encountered.Ive never used a 12AD7.Low hum/ low-microphonic version of the 12AX7 is the 7025. Another option is the 5751, which is almost identical to the 7025 but is slightly lower gain, and may have a more heavy-duty filament implementation. Never heard anything about the 12AD7.

eliya wrote:Alright so I bought an LCD monitor and it's pretty cool. It has analog and digital input, my card supports both, so I plugged in to the digital since I never done it before.What are the differences between the digital and analog source/outputs? Like, what are the main differences/benefits?Also, this monitor has a little buzz/hum, it's nothing too loud but I don't know if this is supposed to be like that, should I go back and replace it or save my time and use it?LCD monitors shouldn't have any kind of buzz/hum. Are there speakers built into it, and are they turned all the way up but is the audio cable on the monitor not plugged into anything? Otherwise it's probably bad.

Oh and the digital connection to your monitor is better. There really aren't any benefits to using the analog connection, it's just there so that you can connect the monitor to a computer that only has a VGA output.

tbone wrote:eliya wrote:Alright so I bought an LCD monitor and it's pretty cool. It has analog and digital input, my card supports both, so I plugged in to the digital since I never done it before.What are the differences between the digital and analog source/outputs? Like, what are the main differences/benefits?Also, this monitor has a little buzz/hum, it's nothing too loud but I don't know if this is supposed to be like that, should I go back and replace it or save my time and use it?LCD monitors shouldn't have any kind of buzz/hum. Are there speakers built into it, and are they turned all the way up but is the audio cable on the monitor not plugged into anything? Otherwise it's probably bad.Nope, no built in speakers.I'll take it back to the store, thanks!