Riffster Posted October 6, 2008 Share Posted October 6, 2008 So I am thinking about replacing the output transformer on my Epi Junior V2 head with a hammond. I read somewhere that the V2 stock transformer would work well in one of those Fender champ 600 since the impedance is close to the 7K a champ uses with its 6V6 tube. Any truth to this? would it be a direct drop in in the champ? I am after the 4/8/16 ohm taps... Link to comment Share on other sites More sharing options...
tunghaichuan Posted October 6, 2008 Share Posted October 6, 2008 So I am thinking about replacing the output transformer on my Epi Junior V2 head with a hammond. I read somewhere that the V2 stock transformer would work well in one of those Fender champ 600 since the impedance is close to the 7K a champ uses with its 6V6 tube. Any truth to this? would it be a direct drop in in the champ? I am after the 4/8/16 ohm taps... The 7.5K primary on the stock V2 VJ is a better match for a 6V6 than an EL84. I would speculate that it was probably a champ OT to begin with. I believe the mounting centers match as well so the VJ OT should bolt right up without any modifications to the chassis. Thanks for the idea. I was considering replacing the stock Champ 600 OT with another, and it didn't even occur to me to use the V2 VJ OT. tung Link to comment Share on other sites More sharing options...
Riffster Posted October 6, 2008 Author Share Posted October 6, 2008 I was thinking about making the champ into a head since I have a cab with an 8 ohm speaker and the VJ CAb with the lady luck but the 4 ohm output was stopping me and the upgrade kits are more than I want to spend. I figure replacing the OT on my Epiphone head and using it in the champ would be great. My knowledge on this subject is limited. I see that the OT for a fender champ has a 7k impedance, what would be the effect of using the Epi at 7.5K. Would anything else need to be changed? would it work just fine? Link to comment Share on other sites More sharing options...
tunghaichuan Posted October 6, 2008 Share Posted October 6, 2008 My knowledge on this subject is limited. I see that the OT for a fender champ has a 7k impedance' date=' what would be the effect of using the Epi at 7.5K. Would anything else need to be changed? would it work just fine?[/quote'] Sorry, that didn't come out the way I intended. What I meant to say was: I doubt anybody (me included) would be able tell the difference between a 7.5k ohm OT and a 7K OT, all other things being equal. 500 ohms is negligible. I used a V2 7.5K OT in a circuit using a 6AQ5A, which is a 7-pin version of the 6V6 with some of the ratings being lower. I don't see any reason why it wouldn't work. With the V2 VJ OT, you might be able to put a rotary switch in the Champ and have selectable impedances which would be very cool. Then you could use the stock speaker in a pinch or connect the amp to a larger speaker cabinet. tung Link to comment Share on other sites More sharing options...
tunghaichuan Posted October 7, 2008 Share Posted October 7, 2008 Update: Just checked a V2 VJ OT against a Champion 600 chassis. The stock OT is slightly smaller than the VJ OT. Also, the stock OT is very close to the 6V6 tube, almost touching it. It looks like the VJ OT will fit but just barely. I will have to unbolt the stock OT and mount the VJ OT in the chassis to see if it fits okay. It may not work with a 6V6 with a larger diameter, such as the JJ 6V6S. More later. tung Link to comment Share on other sites More sharing options...
cGil Posted October 8, 2008 Share Posted October 8, 2008 6V6's may like 7k OT impedance in Champs, but 6V6's do sound pretty darn exceptional with a 5k Hammond. That 5k impedance is just as wonderful with the el84, which is also supposed to prefer 7.5k OT's best. The deal is, all that tube data was done by engineers with clean, low distortion (bland) audio reproduction in mind. Guitar amps often bend certain rules to get the sweet musical harmonic distortions we crave so much to phatten up our clean tone, as well as those exquisite grinding clipped distortions for our grungy tones. I was thinking about using a scrap 7.5k Vjr OT in the former Crate VC508 I'm rebuilding to run a 6AQ5/EL90. I've still got 4 or 5 of those v1 & v2 OT's in a box, but they just aren't the greatest. So, last night I mounted a 5k VJr OT. I'll probably try the 7.5k OT just to be sure. I could use a 12ohm speaker load on the 8ohm tap to bump the 5k OT up to a 7.5k load at the tube for a slightly more fair comparison of the two OT's, but using a combination of speakers on one OT and not the other would skew the results anyway. I've also got a 6.6k Heyboer and Hammond 125DSE and ESE's to try. However, space is at a premium with this extra small chassis, so I'd like to stick with one of the VJr OT's if I can, or the Heyboer if I gotta. The 6.6k Heyboer with an el84 doesn't quite have the thick and meaty bottom end that the Hammond's have. It's actually closer to the tone spread of the 5.k VJ OT on el84's, but with a little more detail. This OT might be a really good choice for an el84/6V6 amp, especially if you're using the VJr 1x12 cab. Gil... Link to comment Share on other sites More sharing options...
Riffster Posted January 1, 2009 Author Share Posted January 1, 2009 Bringing this post back from the past...well, I did it... I replaced the OT on my V2 with a Hammond and it sounds great, then I used the stock Epi OT on my Champ 600, I made a cabinet for the chassis, I covered it in tweed, shellacqued it and matched it to my groove tubes cabinet (which I also refinished) the cab has a weber blues dog 12". The huge jewel light was replaced by a smaller NOS light and I am adding a switch for something, I have not decided yet the big washer will go, its just that the whole is huge... Handle, rubber feet and impedance selector switch are next. I do wonder how the Hammond would have sounded with the Champ, I should have compared before I installed it on my EVJ. Here are some pics. Now my EVJ and my Champ are blood brothers... Link to comment Share on other sites More sharing options...
Steven Lister Posted January 1, 2009 Share Posted January 1, 2009 Any heat buildup issues using that small enclosure pine wood 600 head-cab w/valves down? 12" Weber Blues Dog choice One of the most under-rated and best blues/rock tone bargains out there. Hit every BLUE NOTE baaaby..., I'm going to play on:-" Link to comment Share on other sites More sharing options...
cGil Posted January 1, 2009 Share Posted January 1, 2009 Sweet looking rig! Nice! Gil... Link to comment Share on other sites More sharing options...
Riffster Posted January 2, 2009 Author Share Posted January 2, 2009 Any heat buildup issues using that small enclosure pine wood 600 head-cab w/valves down? 12" Weber Blues Dog choice One of the most under-rated and best blues/rock tone bargains out there. Hit every BLUE NOTE baaaby...' date=' I'm going to play on:-" [/quote'] No heating issues, the amp stays cool. The doulble aluminim foil tape I applied to the cabinetseems to dissipate the heat well. I also may rotate the OT away from the 6V6. The part that gets warmer is the side with the cicuitry but actually this cabinet has about 1/2" more clearance than the original on that spot. The weber is a nice speaker, this one has no doping so it makes for an interesting sound. Link to comment Share on other sites More sharing options...
Follow It Home Posted January 3, 2009 Share Posted January 3, 2009 that looks awesome! ive always wanted a champ, this just makes me want one more! its funny how the preamp tube is all the way in the corner, and the OT is right next to the 6v6 Link to comment Share on other sites More sharing options...
Riffster Posted January 3, 2009 Author Share Posted January 3, 2009 that looks awesome! ive always wanted a champ, this just makes me want one more! its funny how the preamp tube is all the way in the corner, and the OT is right next to the 6v6[/quote'] Thanks, I do have to say that the tone is better on my EVJ with the Hammond OT. There is a reason for the placement of the OT next to the tube as I found out, I rotated the OT in between the 2 tubes but now I get a slight hum even at no volume. The OT is now sitting too close to the volume wires or something. I will have to figure out something, these amps have some hum anyway so I will try to address it all at the same time. My EVJ has some hum as well but I know how to fix that... Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.