SuperBee
497 posts
Aug 13, 2012
3:04 AM
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Epi valve jr seemed to be all the rage a couple years back, now rarely mentioned. Vht special 6 is the new flavour in favour. Maybe there is nothing left to say about the epi?
It's on my mind though because I just picked one up. $195 including shipping.
It's a version 3 I believe, a 16 ohm 8" eminence speaker, and speaker out jacks for 4 and 8 ohm as well.
I missed the rush first time around, it's taken me this long to find one. I'd actually forgotten I had that search saved.
Anyway, I know there are popular mods. Any thoughts on favourite or essential mods? I haven't plugged it in yet. Think I'll go get it and do a side by side comparison with the Vibro champ xd.
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SuperBee
498 posts
Aug 13, 2012
3:43 AM
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First impression: the Vibro champ xd is MUCH easier to get on with than the valve junior. I messed about trying to get both to around the same volume level. A bit tricky because the VJ just has 1 control, so it just is what it is, but the VCXD has a whole range of gain/volume which changes the sound considerably. I left the onboard effects switched off of course, and just used voice 4, which is the same 'clean blackface' model as the 'clean' channel on the super champ xd.
But, if I lower the gain on the epi and get so control of the tone, maybe it's got potential to be better.
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5F6H
1315 posts
Aug 13, 2012
4:25 AM
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Hi Superbee,
This is how I would start (as well as trying different preamp tubes)...
"Find pin 8 of the 12AX7 socket, it connects to a 2.2K (red/red/red) resistor (R9). This resistor has a 25uf 25v capacitor (C3) in parallel. Clip out this cap. This reduces gain at the 2nd stage of the 12AX7.
Now find pin 3 ofthe 12AX7 socket & repeat the procedure, remove C4 (bypassing R8).
If after doing this the amp has no bite whatsoever, you can replace the 25uf 25v cap at pin 3 by soldering an axial 25uf 25v cap piggy back to the 2.2K resistor, waisted end towards the tube, negative end to ground (use an ohmmeter connected to chassis ground to determine which end of the 2.2K resistor is grounded).
The Epi V Jr has no attenuation to hi frequency as it has no tone pot, in effect the tone control is locked fully up...if you had a tone pot you would almost never run it like this. Take a 0.0047uf 400v axial capacitor (MKT, Mallory or Sprague orange drop style, these have no polarity) and connect one end to the top of the volum pot, the other end goes to ground. A convenient place to fit this cap is in parallel with R7. A larger cap will shunt more highs to ground & make the amp darker, a smaller value cap will be brighter than 0.0047uf."
Usual safety warnings regarding working on high voltage devices apply - if in doubt, DON'T.
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Last Edited by on Aug 13, 2012 4:33 AM
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Baker
236 posts
Aug 13, 2012
5:07 AM
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I own one of these. I bought it as it was a cheap amp to get started on, however I rarely play amplified. I made one mod, which was to swap the pre-amp tube out for a 12ay7 tube, this helped reduce the feedback.
EDIT: See this for a demo of various valves: http://www.modernbluesharmonica.com/board/board_topic/5560960/557365.htm
However, The Lone Wolf company has their recommended mods listed here here: http://lonewolfblues.com/projepimod.html
There is also lots of information available if you try the forum search.
Last Edited by on Aug 13, 2012 5:08 AM
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Piro39
38 posts
Aug 13, 2012
8:50 AM
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Have Ron Landry at Lone Wolf do a harp mod for the amp, you won't regret it.
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HawkeyeKane
1128 posts
Aug 13, 2012
9:01 AM
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I really want a VJ head to convert into a reverb unit with the BitMo modkit. Been itching for a standalone for years, and the BitMo sounds fantastic.
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Hawkeye Kane
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shbamac
208 posts
Aug 13, 2012
10:48 AM
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Hawkeye, I've got a Epi VJ Hot Rod, the one with the built in reverb. Works as a standalone reverb unit. I'd be into sell it if you're interested.
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HawkeyeKane
1129 posts
Aug 13, 2012
11:45 AM
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@shbamac
sent you an email.
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Hawkeye Kane
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SuperBee
499 posts
Aug 13, 2012
2:39 PM
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I've been looking at randy's mods, also the 'alnicomagnet' kit. Also the forum search as I know it's all been done. There is quite a lot of water between those fish though.
The whole Idea of buying the epi is to get hands on with the soldering iron. 5F6H, as always thank you for your suggestion.
I only use these little amps at home, or for private jamming. And the Fender is great for that job. I don't really want to mess with that as a first up mod. I got the epi because I know there has been a lot of work done with them.
From memory I think the alnicomagnet mods involve fitting a standby, tone pot, fuse for the power supply and dropping the voltage on the preamp. Has anyone here done this? Randy's idea I think is similiar to what Mark suggests above, reducing the second stage gain.
Sorry, babbling a bit, on the phone and gotta get ready for work.
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HawkeyeKane
1130 posts
Aug 13, 2012
2:51 PM
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I agree with SuperBee. The VJ is a fantastic modding amp. I'm assuming that this is the model that shbamac is talking about. But is this an aftermarket modification or did Epiphone actually produce these themselves?
Epiphone Valve Junior Hot Rod Amplifier Head
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Hawkeye Kane
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arnenym
71 posts
Aug 13, 2012
2:55 PM
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I've had 3 of them you can do whatever you want with them. Here you find turret boards to make them to a 6V6 or even a 6L6 amp.
http://www.turretboards.com/guitar_amplifier_parts_epiphone_valve_junior.html
Now i have 2 left and i still find some new ideas to try on them. One is a Single 6L6 and the other is a parallell 6V6 amp.. yummi yummi....
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SuperBee
503 posts
Aug 15, 2012
4:43 AM
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thanks to all contributors!
just bumping this for one last try then ill go away and decide what to do; has anyone tried the alnicomagnet mod kit?
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isaacullah
2115 posts
Aug 15, 2012
6:01 AM
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While I have not done the alnicomagnet mod, I HAVE done all the Lone Wolf mode and can tell you that they make a significant improvement. I've also fooled around with different tube values and brands as well as speaker cabs (I have the head version), and can tell you that these also have a significant effect on the final tone. Easiest ingress to modification are tube/speaker swaps, and the right combo of these things will probably get you where you want to go. you'll have to try a lot, though, so if you have a buddy with tons of old tubes lying around, that's the best way to try them out (that's what I did). For me, the best combo was an EHX preamplifier tube, and a NOS JJ power amp tube. Imo, the only "soldering iron" mod that is absolutely necessary (note that term!) is the high cut tone control. other mods definitely bring something to the table, but may not be necessary with the "right" tube and speaker combo for your mic and playing style.
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SuperBee
504 posts
Aug 16, 2012
1:50 AM
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Thank you Isaac. Ok, thats all, I'll mull it over and see what I come up with. Thanks again everyone for your input. I have a little box of weber 8" speakers I think I'll plug it into for a 1st thing, also a 5751 that I'll swap into it. Then I'll think about the tone circuit and gain reduction, or vice versa.
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LIP RIPPER
617 posts
Aug 16, 2012
3:32 AM
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What Isaac said; and my amp is on ebay right now starting at $80. Head unit only
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SuperBee
506 posts
Aug 16, 2012
4:22 AM
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Too much postage for me I reckon LR. I did see one head on eBay, a bit more than 80 , up to 175 I think.
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SuperBee
514 posts
Aug 19, 2012
7:31 AM
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I loaded a cab with 2 x 8" weber 8A100 speakers. For a while I plugged the iPod into the VJ, and the VJ into this twin 8" cab. It's a 4 ohm cab. The VJ combo is loaded with the 16ohm eminence speaker. I have another cab with a single 8", 8ohm ceramic speaker. That's a closed back, ported cab. The twin cab is open back, as is the combo of course.
My VJ has 4, 8, and 16 ohm outputs, so I tried them all with all these speakers. The fullest musical reproduction came from the no-name ceramic in the old home audio cab. By far the thinnest, least bass response came from the twin cab. Or was it just a reduction in volume? I've noticed I get less feedback given an equal setting on the volume. Is that because Of the 2 speakers, or are the 8A100s relatively low sensitivity?
Anyway, playing harp rather than an iPod through them, they improve the VJ quite a lot. Then I also swapped a 12AU7 into the preamp and to my surprise the amp sounds pretty good. Now I can turn the volume to about 2 o'clock although that's maybe a little too distorted. What surprised me was that the thing actually still had some bite. I expected it to be totally wimpy with the AU tube. That's why that tube is hanging around still; I've never found a use for it. This amp though...
So now I think, with the lower gain preamp tube and the twin webers, the VJ maybe has the edge over the 5watt Fender.
Tube swap was a little tricky. I removed the 8! screws holding the back on, but it still wouldn't budge. I decided it was glued on, and that was correct. Once I levered part of it free I was able to gradually unstick it but it was a bit of a worry. Stuck down tight. Seems an odd thing to do. Would have been easy to damage the tolex or worse, break the back panel. I think there are another bunch of screws in that panel, holding the grate in place. anyway, that's been fun. I thought about trying a jj el84 or another vintage 6bq5 but my heart wasn't in it really. 1 thing at a time. That tube is very tight in the socket anyway. Lazy. In fact, I'm going to bed.
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Last Edited by on Aug 19, 2012 7:44 AM
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isaacullah
2116 posts
Aug 19, 2012
10:43 AM
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Do try the JJ EL84. I have found it makes a big difference in the overall warmth of the tone. The 12AU7 actually does some of what the Lone Wolf mods do: it lowers the gain of the preamp stages. This means it takes more "umph" before you get any crunch from the preamp stage, and so preamp overdrive starts to happen at a relatively louder volume level than with the 12AX7 tube. This allows you to push a louder signal into the power amp stage before you start to experience feedback. FYI, if you have a low-Z mic, you will likely find that the 12AX7 tube will sound better with that mic than the 12AU7, which will sound pretty wimpy. The "Hi/Lo input" Lone Wolf mod basically sets a two different input impedances (one on each input jack) so you can use both types of mics without having to switch tubes.
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=========== I S A A C ===========
View my videos on YouTube!
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Visit my reverb nation page!
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SuperBee
539 posts
Sep 04, 2012
6:39 AM
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Mark, I've been reading over your suggestion above. I haven't pulled amp out yet, just about to. Where you suggest removing C4, and then replacing it if the result is too severe, is the replacement simply restoring things the way they were before snipping out C4?
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5F6H
1335 posts
Sep 04, 2012
7:09 AM
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Hi Superbee, yes, that's the idea
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SuperBee
562 posts
Sep 10, 2012
11:02 PM
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Finally pulled the chassis out. And managed to extract the el84. Seemed like it was glued onto the socket! Its where someones been heavy handed with the silicon and its run through onto the valve socket. And cooked a bit it seems.
Better find that schematic.
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Last Edited by on Sep 11, 2012 2:38 AM
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TheATL
49 posts
Sep 11, 2012
1:49 PM
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I got one of these and have done all of Randy's lone wolf mods. I really like the way it came out. Does not bite at all and has great tone.
There are a few errors on Randy's documentation, although overall, he has done a FANTASTIC job with pictures and all. (Thank you Randy - I have been meaning to offer to help update your docs for all the help you gave me over the phone on this). I put the Weber speaker in it as well, and that was a Good Thing.
Let me know if I can help.
Last Edited by on Sep 11, 2012 1:53 PM
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SuperBee
567 posts
Sep 11, 2012
3:47 PM
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Thanks. Yes, I thought i noticed some inconsistencies in the schematic, but im not very experienced with reading them. But the photos seem good. I have the circuit board he has photographed for his option 2 mod. I gather you've done option 1? My black board at first glance is not so easy to follow the traces but I have not seriously set out to do anything yet. Still studying, surveying the ground for my first move. I don't appear to have the same circuit Mark refers to above; not the same component values anyway. I think I'll upgrade my soldering iron before I dig in. Interested TheATL. I probably need all the help I can get
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