Riptide Posted October 26, 2013 Share Posted October 26, 2013 So I'm trying to get some more volume out of my Epiphone Valve Junior without it starting to break up. I'm looking at either using a 12au7 or a harder El84 like 7-10 (right now I'm running a 12ax7 and an El84 rated at 5) What do you all think the best option is? Thanks! Link to comment Share on other sites More sharing options...
surfpup Posted October 27, 2013 Share Posted October 27, 2013 I don't really think you can do what you want to do. If you drop the gain value of the preamp tube, you also drop the overall volume. So while it may not break up as early according to the knob with a 12AU7, it will be much quieter at a given knob setting. Thus you will have to dial it to 80% to get what would have been 50% with the 12AX7 and vice versa. You might investigate a resistor mod on that circuit board instead. It's simple and very moddable. Another thought, add another VJ and run them in stereo. I did this for a while and it sounded pretty good. Link to comment Share on other sites More sharing options...
Riptide Posted October 27, 2013 Author Share Posted October 27, 2013 I don't really think you can do what you want to do. If you drop the gain value of the preamp tube, you also drop the overall volume. So while it may not break up as early according to the knob with a 12AU7, it will be much quieter at a given knob setting. Thus you will have to dial it to 80% to get what would have been 50% with the 12AX7 and vice versa. You might investigate a resistor mod on that circuit board instead. It's simple and very moddable. Another thought, add another VJ and run them in stereo. I did this for a while and it sounded pretty good. Okay thanks for the reply. And getting a output tube with a higher rating (or whatever you call it) won't work either? Link to comment Share on other sites More sharing options...
Karloff Posted October 27, 2013 Share Posted October 27, 2013 check out www.thetubestore.com Link to comment Share on other sites More sharing options...
surfpup Posted October 27, 2013 Share Posted October 27, 2013 Okay thanks for the reply. And getting a output tube with a higher rating (or whatever you call it) won't work either? I don't think so. There is a new EL84 that breaks up earlier (the EL844) but this is the opposite of what you want. While some versions of the tube may remain a bit cleaner at a given plate voltage, the differences will be minor I think. You are just not going to get clean volume out of one EL84. Link to comment Share on other sites More sharing options...
Riptide Posted October 27, 2013 Author Share Posted October 27, 2013 I don't think so. There is a new EL84 that breaks up earlier (the EL844) but this is the opposite of what you want. While some versions of the tube may remain a bit cleaner at a given plate voltage, the differences will be minor I think. You are just not going to get clean volume out of one EL84. Okay thanks for your help! Is there a certain brand you suggest? Link to comment Share on other sites More sharing options...
surfpup Posted October 27, 2013 Share Posted October 27, 2013 I use these guys a lot. They have great reviews (start by reading those) and I'm sure they would be happy to field your questions as well. http://www.thetubestore.com/EL84-6BQ5-Tube-Types Link to comment Share on other sites More sharing options...
Riptide Posted October 27, 2013 Author Share Posted October 27, 2013 Okay cool! Yeah I checked out that site after Karloff suggested it :) Link to comment Share on other sites More sharing options...
Bender 4 Life Posted October 27, 2013 Share Posted October 27, 2013 what Surf says is true about total volume loss, but if it's really tone you're concerned about, 12au7=ecc82, which is what i've swapped the preamp section to (from 12ax7/ecc83) in both my Blackstar HT5 & Blues Jr, to solve that exact issue. couldn't be happier....tone is smoother, with more volume before noticible breakup. there's also a 12at7/ecc81 that's supposed to be even lower gain yet.....I was just looking at them online when I read your post. Link to comment Share on other sites More sharing options...
surfpup Posted October 27, 2013 Share Posted October 27, 2013 there's also a 12at7/ecc81 that's supposed to be even lower gain yet.....I was just looking at them online when I read your post. Actually the 12AT7/ECC81 is actually quite a bit higher than the 12AU7. Think of the 12AX7 as 100%. Then the 12AT7 in about 60% and the 12AU7 less than 20% of the 12AX7 gain. There is also a 5751 which hangs around 75% on 12AX7 gain. Link to comment Share on other sites More sharing options...
Jeff-7 Posted October 27, 2013 Share Posted October 27, 2013 Could part of the early breakup be the speaker? Maybe try looking into a higher efficiency speaker, or some modifications to take out some of the clipping. Link to comment Share on other sites More sharing options...
Bender 4 Life Posted October 27, 2013 Share Posted October 27, 2013 Actually the 12AT7/ECC81 is actually quite a bit higher than the 12AU7. Think of the 12AX7 as 100%. Then the 12AT7 in about 60% and the 12AU7 less than 20% of the 12AX7 gain. There is also a 5751 which hangs around 75% on 12AX7 gain. just last night I was looking on "Tube-Depot" pricing wavy glass Mullard ecc82s....i'm running 3 of them in a Blues Jr.(scavenged from an older amp).....when I saw them priced at $299.95 EACH I almost wet myself. time to pull those bad boys & sell them......nah, they sound too good. Link to comment Share on other sites More sharing options...
Riptide Posted October 27, 2013 Author Share Posted October 27, 2013 what Surf says is true about total volume loss, but if it's really tone you're concerned about, 12au7=ecc82, which is what i've swapped the preamp section to (from 12ax7/ecc83) in both my Blackstar HT5 & Blues Jr, to solve that exact issue. couldn't be happier....tone is smoother, with more volume before noticible breakup. there's also a 12at7/ecc81 that's supposed to be even lower gain yet.....I was just looking at them online when I read your post. Noted. Thanks! Could part of the early breakup be the speaker? Maybe try looking into a higher efficiency speaker, or some modifications to take out some of the clipping. I don't think so, the speaker has a pretty high rating and my amp isn't turned up that loud. Link to comment Share on other sites More sharing options...
fredcapo Posted October 28, 2013 Share Posted October 28, 2013 Noted. Thanks! I don't think so, the speaker has a pretty high rating and my amp isn't turned up that loud. The advice about the speaker is right on... He s talking about efficiency rating not wattage. If it the stock speaker it likely is not the most efficient. Check with a speaker expert... Link to comment Share on other sites More sharing options...
Reiska666 Posted October 28, 2013 Share Posted October 28, 2013 useful link for tube comparison... http://www.thetubestore.com/Gain-Factor Link to comment Share on other sites More sharing options...
Bender 4 Life Posted October 29, 2013 Share Posted October 29, 2013 dunno how you did it Reiska666, but your avitar is the tubes that I was pithing m'self over!! or, is that the Mullard "Black Sable" that nets, $599.99 each? Link to comment Share on other sites More sharing options...
vangoghsear Posted October 29, 2013 Share Posted October 29, 2013 +1 on the speaker efficiency comment. I have a Traynor 40 watt that was refitted from a 30 watt Celestion to a 100 Watt Celestion to give more clean headroom. I've also used the 8 ohm speaker output from my Epi Valve Junior to a 200 watt PA speaker and got tons of clear headroom, but it was too sterile, not being a guitar speaker. Link to comment Share on other sites More sharing options...
Riptide Posted October 30, 2013 Author Share Posted October 30, 2013 Well you tell me. "Thank you for your inquiry. Eminence and Epiphone engineers collaborated to develop the Lady Luck speaker specifically for the new line of Epiphone Amplifiers. The development and testing of this speaker has been in process for about two years. The speaker is a 16 ohm model and is rated for 70 watts RMS. Each speaker sports a custom Epiphone/Eminence finish in Mustard Yellow along with the Lady Luck label on the back. The speaker has a stamped steel frame, a front rear sealing gasket, a 34 oz magnet, 1.75" voice coil, a full paper cone with paper edge, and a cloth dust cap. This speaker has a sensitivity of 99dB and a useable frequency range from 80Hz-5kHz. It has a very smooth response from the low-end through the mid range. It also has a very nice top end sparkle. The speaker was engineered to exhibit very warm, and smooth break-up modes. The tonality of the amp is such that very little tonal coloration from the speaker was desired. Consequently, the speaker was engineered to provide a subtle, yet effective compliment to the amplifier." Strangely the speakers sounds really close to a Greenback. Link to comment Share on other sites More sharing options...
Riptide Posted October 30, 2013 Author Share Posted October 30, 2013 It's the sensitivity that determines how early the speaker breaks up, right? Link to comment Share on other sites More sharing options...
badbluesplayer Posted October 30, 2013 Share Posted October 30, 2013 You can try a harder output tube - with a high rating. But you're beating your head against the wall if you're trying to get much more volume out of that amp. You can try a bigger speaker, but bigger speakers usually give you a more wimpy tone. A 12 inch speaker is pretty big for a 5 w amp. I'd try a hard output tube. There's no sense messing with the preamp tubes. That won't fix your problem. Sticking a 12AT7 in there is just like having a 12ax7 and turning down the volume some. Link to comment Share on other sites More sharing options...
Riptide Posted October 30, 2013 Author Share Posted October 30, 2013 You can try a harder output tube - with a high rating. But you're beating your head against the wall if you're trying to get much more volume out of that amp. You can try a bigger speaker, but bigger speakers usually give you a more wimpy tone. A 12 inch speaker is pretty big for a 5 w amp. I'd try a hard output tube. There's no sense messing with the preamp tubes. That won't fix your problem. Sticking a 12AT7 in there is just like having a 12ax7 and turning down the volume some. Thanks, that's what people have been telling me. I only turn it up to like 10 or 11 o'clock so that's why I was asking if I could get anymore clean head room. They keep on asking me for some more volume at my church... awesome right? EDIT:: I think I just need to get another amp. Link to comment Share on other sites More sharing options...
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