Epiphone Valve Junior Mods

Discussion in 'The Squawk Box' started by Batman, Mar 3, 2012.

  1. Tailgate77478

    Tailgate77478 Junior Member

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    FINAL UPDATE. Seems to be working fine, and I re-attached C2 to the MV pot. I think it has to do with the fact I didn't use shielded wiring for these knobs (I de-soldered the OEM volume mount/wires and wired directly to the board as I needed a longer length to position it in the Gain position). I moved the dressed wires toward the chassis and things seem mostly OK now. Sort of weird. There is a constant hum when I have both the Gain and Master Volume up 3/4 each or so...not sure if there's any real way to get rid of that ambient hum or not. It's not annoying, just that "guitar amp hum."

    I also think the Gain pot may need to be swapped out. I have noticed that when moving it in a full sweep that there is an area between 3/4th and 7/8ths of full throttle where an ultra high pitch noise shows up, then disappears before and after. Wondering if that's just the pot itself? It's an Alpha pot, so not a high-end CTS or anything. Also wondering if I should buy a 47pF silver mica cap to put on there. You think that might help in any way (have seen others do that)?

    Overall, VERY HAPPY with the amp. I just can't believe this little thing is pumping out this much volume through a 1x12...IT'S REALLY, REALLY LOUD! WHAT??? I SAID...... Would certainly love to hear it in a 2x12.

    THANKS AGAIN BATMAN for this thread, and for the replies on my issues. I can't wait to do this again to another EVJ head when I can find one cheap enough, maybe go for a more Marshally sound. I certainly have plenty of spare parts. Heck, I should put together a quick "cheap build kit" for someone else so they don't have to source everything like I did. I know the name-brand kits out there are certainly overpriced!!!!
     
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  2. slidejob

    slidejob Junior Member

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    Love these amps!!

    2 6V6, 1 EL84

    IMG_0188.jpg
     
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  3. TWANG

    TWANG Senior Member

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    sorry I missed this.Congrats!
     
  4. zaphodbb

    zaphodbb Junior Member

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    Hi Batman / TWANG

    I've re-read this thread three times to try and distill all of the information into one document for me to mod my Vjr head - one thing though, any chance of showing the Cathode bypass mod again?
    Post #45 no longer has the picture :-(

    Great article :)
     
  5. DimiPana

    DimiPana Junior Member

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    Hi, thanks for the opportunity to join this community; much obliged to all for your valuable input about modding an EVJ.

    I recently purchased such a combo amp (expected to arrive on Tuesday 1/5). The seller claimed it was "old stock" that was practically still in its original box with all tags and marketing "stuff" intact. All that aside, the important thing is should be an untouched amp so an excellent candidate for modding. I'm keeping my fingers crossed, people will say pretty much anything to make a sale.

    Anyway, while waiting for the EVJ to come, I 'd like to post some initial questions; I'd highly appreciate your feedback whenever you find a free moment:

    1. The serial number is shown in the attached (and some more) picture(s). Do you know what version I got? Is it V1 , V2 or V3 ? And which one is the best to have as a modding platfom? What is -overall- your thoughts about the version I got (what ever that may be)?

    2. I paid $120 for it and although at times I'd seen some lower prices for a head and some combos, I feel for a like-new unused EVJ this is a decent price. Plus, when I was ready to buy, I spent about a week searching all over the internet and this was the best price I could find for a combo of this condition. What is your opinion. Paid too much , too little, or a fair price? Be frank, it really doesn't matter now, it is what it is, right?

    3. Even though I have read all 10 pages of this thread many times, (some pages at least 2-3 times, a few even more) I will second zaphodbb in what he says about how to "distill all the information into ONE document". I have to admit, at times I find the numerous questions and replies a bit confusing. So, I am trying to put together a document with all the mods suggested by the experts in this thread, in a step by step sequence, that hopefully will make modding the EVJ a bit easier. Anyway this is a work in progress but I will certainly post back in due time.

    Thank you -all- in advance for your feedback! I'm looking forward to our future discussions.

    (Also, some of the links posted in this thread are no longer active (especially the one about safety). Is there a chance to fix that, thanks again!
     

    Attached Files:

  6. slidejob

    slidejob Junior Member

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    You have a version 3 which is best for an EL84 mod. I find the 6V6 is a much nastier mod to these amps. Enclosed vid of 6V6 EVJ & 4 string CBG.

    https://www.youtube.com/watch?v=tfbrX3ZvOEA
     
  7. DimiPana

    DimiPana Junior Member

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    Thank you for your reply slidejob

    I liked your video, well done. When you say "EL84 mod" are you strictly referring to what power tube works best with the EVJ or there is more to it? And by "more to it" I mean is there any documentation that I can read bout it?

    Thanks again!

    :)
     
  8. slidejob

    slidejob Junior Member

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    Thanks man! Yep, the EL84 is the stock power tube for EVJ. This is the best thread out there for that mod. IIRC most of the info is in the first couple of pages of this thread. Once you get the amp, expose the circuit board, & start reading the thread it will start to make sense to you. These guys did a great job of documenting the mods. The 6V6 mod is easy, but requires additional parts. Take your time & have fun, these little amps kick butt!!
     
  9. MartijnRGS

    MartijnRGS Junior Member

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    Quick question over here, I ordered an allan bradley carbon composition resistor for R4 (100K 1W 5%) and it measured a bit high at 110K (seller stated already that the 5% was more like 10% due to bad storing condition a few years back). My question is, how would it affect my tone with a 110K at R4 and can it hurt? It's not ideal but would take to long to get another one since this is for a friend that goes abroad for quite some time. The stock resistor measures 99,8K so almost dead on 100K.
     
  10. squinta

    squinta Junior Member

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    It seems the 470K resistor is connected to the wiper and the input, not the pot ground ...! Can you show a better picture?
    Thanks.
     

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