I traded an inexpensive guitar I had for a valve jr. combo. I like it. I want to do mods, but have to learn how first. There is just insane amounts of feedback. So, in the meantime I have a mixer. I plug the mic into the mixer, use its equalizer to cut out the high end, and BINGO, no more feedback.
I realize this means that the amp isn't getting my full signal, BUT, until I learn ho to drain a capacitor and solder, this is what I think I'm going to do.
I think there are more threads on this amp on here than any other, by far! If you're not gigging or performing out with it, it'll suffice for now if you just stand or sit far enough away from the amp and vary microphones perhaps, but one very drastic beneficial change you can make is to yank that 12ax7 and replace it with a 12ay7. I posted some vids going thru the tube swaps, and mine stayed with a 12ay7 until I got it modded this past weekend(now it has a 12ax7 again). ---------- Todd L Greene. V.P.
Yeah, I would keep it simple. I just use a digitech pedal now. My guitar player is a tone nut and we swapped many tubes in both the preamp and amp stages..NOS, different brands, different values, the whole nine yards. We also tried vintage alnico speakers, from 10 to 12 inch. In the end, none of it made as much difference as using 2 12 inch speakers instead of one and eq'ing via the digitech pedal. Since then, I've found amp models in the pedal that add to the valve juniors natural tube character to give it that deep growling chicago sax tome I was missing. I found it excels at trumpet simulation right out of the box. Since you playe guitar too, having a digitech pedal can serve you both ways. That's why I decided to try it, I already had one. There is every imaginable harp sound and many you haven't considered in that pedal with that little amp and the right speakers (i have the head, not the combo). I bet the combo would behave just fine too.
The Epi Jr. is a nice little starter amp to be sure. You will enjoy the heck out of it. I owned 3 of them at one time. I always kept one of them stock, so as to be able to see the difference in the mods. It is easy to work on and the pc board is not too wimpy to stand up to many mods. However, I think that hardwired amps are the way to go for many reasons, one of them being that they really are easier work on for modifications. I used a number of different speakers in my Vjrs and thought that for harp, the stock speaker was not too bad. I picked up a Goldtone speaker from Mojo which I liked the most. The Goldtone is also used as the stock speaker in the Gibson Les Paul Jr reissue GA-5. My first choice for a harp speaker in any amp is the Weber Ferromax smooth cone ceramic . For my taste, a delay pedal is all that is needed. I use an MXR Carbon Copy which has true bypass and does not alter the tone. Enjoy your new toy, it is a sweet little amp.
Last Edited by on Mar 18, 2010 9:02 AM
Mine is bone stiock except for the preamp tube. It's some old tube a guy gave me and I broke the EH tube that was in it...lol.
I run a dynamic mic and wireless unit. I have ZERO feedback issues, cupped or open, on stage. In my 10x14 practice studio, I may get some when it's wide open, but I use my food pedal to control volume. I also use a digitech pedal and have eq'd it to my personal taste. Granted, there is less midrange and trebel in there now, and cranking that can induce feedback. i tried it a couple days ago to see. When cupped, it is not an issue though. I suspect a bullet mic would be a problem because I built a mic from a turn signal housing and it is more feedback prone than the cut-down vocal mic I use. I also flattened the mesh ball to within 1/4 inch of the mic element..this puts the harp within 3/8-1/2 inch of the element.
I like mine stock through every speaker combo i've tried, but the 2 12 inch jensens give me a noticeable volume increase and a higher decibel reading of nearly 6 db on the meter over any single speaker I've tried. If you play guitar and have some pedals, try them..it can't hurt.
Mic is samson r21. Do a search on the forum for pictures of it.
Last Edited by on Mar 18, 2010 10:48 AM
Here it is..no feedback and it's pretty darned loud in here. I'm about 4 feet directly in front of the cab and the mic is pointing in the worst possible direction.
Phogi, the valve junior has a built in cap drain circuit. To make sure they fully are drained, turn the amp OFF, but keep the cord plugged in. Wait 10 minutes, then UNPLUG the cord from the wall, and flip the switch "ON". Wait another few minutes. The caps will be drained. I checked this with my multimeter, and confirmed they were totally drained after this procedure. To be safe, you can make a "cap drainer" by soldering an alligator clip to one lead of a ceramic power resistor (something like 10-100k ohms rated for like 50-100 watts). Then solder an insulated wire to the other lead with another alligator clip (insulated too) to the end of that wire. Attach the clip that's on the end of the resistor to the amp chassis (for a solid ground connection), and then clip the other end to the positive leg of the big electrolytic caps in the power supply. You can attach your multimeter in series to monitor the power drain if you want to (put the meter on the DC voltage setting). ---------- ------------------ The magnificent YouTube channel of the internet user known as "isaacullah"
Iv got a valve junior. i haven't touched it in terms of modifying. The only time i get feed back is when im in my bedroom practicing. When i go out gigging it never happens. The bigger the room your in the less feedback. I think tone has more to do with your playing skills than your equipment. i haven't noticed much of a difference in the tone out of all the examples of the mods Ive seen on the forum.
SSAL-Changing the preamp on mine to a 12ay7 before the mods were done cut the gain, therefore I could turn it up more and get more warmth from the amp before feedback, but the overall 'tone' didn't change-the amp was still voiced the same. Now, with the mods, it's got a fatter, more desirable, less midrang-ey and trebly horn-honk tone to it. The capacitors etc. being changed DID change the tone of the amp, but yes, acoustic tone comes from the player. Mic technique makes a huge difference as well, as does being in a small enclosure or playing right next to the amp, or pointing the mic's screen at the speakers. I had played thru some of Randy Landry's project amps(he does them as a hobby, not to sell YET...), and the mods he did to the Epi are similar to what he builds his project amps like, so I knew the difference I would be getting. It's all subjective of course, but I wasn't thrilled with the sounds of the amp pre-mod.
Got pedals, processors, etc laying around that make the Epi or any other amp sound better? Use them. I don't like to fool with all kinds of settings, etc. if I don't have to. I'm not a complete minimalist, but the more things in the chain, the more potential for something to break. It's great that there is more than one way to skin a cat and make a <200$ amp sound good!
I read an article once by Gerald Weber that stated adding more pre amp stages complicated the feedback issue instead of solving it. Keeping that in mind you can understand why MOST Harp players love the sound of single pre amp smaller watt amps and the tone they have. Todd (and by extension Randy) is quite correct that changing the value of the resistors in the pre amp stage and the Filter caps (an amp can never be filtered too much it does nothing but good things) is a better solution then cutting the gain of a pre amp to the power tubes. While cutting the gain will result in less feedback it is doing so by cutting the efficiency of the amp. Besides you never know when you may want to add gain in whatever playing/sound situation you find yourself, so why limit it? ----------
The Original Downtown Philadelphia Fatman... Accept No substitutes!
"It's great that there is more than one way to skin a cat and make a <200$ amp sound good!"
This is simple wisdom.
The same goes for guitar with this amp. Out of the box, it's pretty surprising what you can do with a strat. Or a jazz guitar, or les paul ...tone is in your fingers. The sheer number of variations before you put anything in the chain is very satisfying. Once you add your favorite pedal or modeler, the world is your oyster. I have read all the mods for guitar and just can't hear the need...not for me. I prefer to tinker with my ability and whatever I have on hand for gear.
