audiofreakme Posted January 1, 2007 Share Posted January 1, 2007 Thanx for the reply Ric-step by step for you maybe! I'm long on solder exp. a little light on the electrical theory. I know tubes have sreens, grids and plates, but sometimes I forget which is which. Its the "You may have to break a trace on the printed circuit board to disconnect the screen supply" and "Can't remember just how it's set up" that worries me. It's those mights, maybes and not sures that send people or their amps to the ER! I could do all of the mods discused here because I can see how they're done. I mean adding a cap to the circuit via a switch is easy with pics! This is a bit more involved. So if anyone has done this, can you post the pics or Ric may have to open her up again!! I haven't modded my head yet at all, but thinking about the brite, imp, gain and standby switches-although I'm only using this head as the right channel, fx only singnal from my TC Electronics G-system, the left goes to my main amp a Fuchs 30W 2X10 combo-which gets the left channel of the effects into its parallel effects loop+ the dry guitar sound as I plug the guitar into the amp directly. The VJ drives a Fuchs 1X12 cab with an Emmienece Red Coat speaker. The combo's 10's are also Emminence Red Coats. So the VJ's tone is not really an issue-it can be changed via the eq in the G-system. So yes I use a $99 head with a $1500 fx processor and a $3000 combo! The great thing about America is, you can cheap out when you have the money, and spend the money you don't have! Link to comment Share on other sites More sharing options...
audiofreakme Posted January 1, 2007 Share Posted January 1, 2007 btw- a 2/3 reduction in power is even better! Link to comment Share on other sites More sharing options...
Rock Soldier Posted January 1, 2007 Share Posted January 1, 2007 I hear you. I'm running my VJ Head through a cabinet that cost 4 times what the head did. As far as mods go though sorry I can't help. Like you I can solder just fine but my experience and electrical theory (at least with amps ... I can wire a house) is lacking. Fortunately for me the VJ Head sounds great like it is. The most tempting thing about the mods is the fact that some of these instructions make me say ..... Hey! I could do that! A.K.A. TRGuitar Link to comment Share on other sites More sharing options...
audiofreakme Posted January 1, 2007 Share Posted January 1, 2007 I might have you beat: the hardest part for me would def. be drilling the holes in a nice neat line! but some of these mods ARE easy-in particular, all of tone mods & stand by switch. I did swap the stock 12AX7 for either a Brimar or Mullard 12AX7 and that helped a bit. Those are expensive British bottles I had left over from a tube change on another amp. I can tell you that a very simple circuit like this, or most other single ended amps- benefit from better tubes, input cables, speaker cables, and to a lesser extent, power cords. Those are all no solder tweeks to try. After all is said and done, trust your ears. Link to comment Share on other sites More sharing options...
Ricochet Posted January 1, 2007 Share Posted January 1, 2007 Honestly I'm not blowing you off, audiofreakme, but I've got a lot of other stuff I need to be doing and am not likely to come up with a step by step illustrated how-to for a triode switch on a VJ. If I wanted one on my amp I'd do it and take pictures, but I'm happy with it as is. I do understand your hesitancy to undertake something new and unfamiliar. But it's really important to be able to look at a schematic, look at the physical circuitry in front of you, identify componentry and trace out the circuitry in the wiring and board traces you have. When you can understand how it's laid out and what the stuff does, that's when you're ready to make changes. There are several versions of the VJ out there, and my early combo might not be laid out quite the same as your VJ. A picture with "Snip here" and "Solder here" is not a sufficient basis for working on your circuitry. I've said this before, but IMO the VJ is just what it needs to be as it comes from the factory and needs no modification. Its simplicity is its soul. If you're primarily wanting to get experience with amp modding and building, it's not a bad place to start, though its use of a printed circuit board is a great handicap. A better approach would be to build an amp from one of those kits like a Champ clone or an AX-84, so you understand what's what and what it does, then experiment with changing a part here and a part there to see what its effect is. "A cheerful heart is good medicine." Link to comment Share on other sites More sharing options...
audiofreakme Posted January 1, 2007 Share Posted January 1, 2007 I've built SET 300B based amps before, as well as Graymark kits in the early seventies, but they had instructions-so this wouldn't be a starting point for me. Actually, "snip here, solder here"is all I need. I'm not interested in breadoarding things anymore-just what works-I'll leave the why they do for people who wrote the books! So if anyone has put a 1/2 2/3 power switch in a VJ head pleae let me know Link to comment Share on other sites More sharing options...
Ricochet Posted January 1, 2007 Share Posted January 1, 2007 Try here: http://valvejunior.com/ "A cheerful heart is good medicine." Link to comment Share on other sites More sharing options...
Junior 1 Posted January 4, 2007 Share Posted January 4, 2007 Just wondering if anyone has put a 10 inch speaker in the VJ combo? I like that cab size, but would like to hear it with a 10. Link to comment Share on other sites More sharing options...
Ol Boy Rivers Posted January 5, 2007 Share Posted January 5, 2007 I didn't put it into a combo, But I play with a g10-d 10inch marshall cabinet with the head. It sounds great. Never trouble trouble till' trouble troubles you. Link to comment Share on other sites More sharing options...
Zongrilla Posted February 7, 2007 Share Posted February 7, 2007 Howdy all! I've done a fair piece of soldering in my days but never worked on any tube amps. (I've mostly done 9v effects.) I want to go ahead and mod my VJ (head only) but I am unsure of the best way to discharge the filter capacitors such that it doesn't damage me or the PCB. I've seen threads/sites that say make sure and do it but without specifics to this head. Is there any info available on the best/safest way specific to these amps? Thanks in advance! Link to comment Share on other sites More sharing options...
miroslav Posted February 7, 2007 Share Posted February 7, 2007 Ahhh...I think the simplest way is to get a jumper wire that has alligator clips... ...clip one end to the negative leg of the cap...and clip the other to a screw driver...and then touch the screw driver to the metal chassis (while the amp is off, but still plugged in). You bring it to ground and that should drain the cap. You want avoid using your hand/body as the ground connection. You can use a meter to check the caps for any remaining voltage... Maybe someone has a better/safer way...? miroslav - miroslavmusic.com "Just because it happened to you, it doesn't mean it's important." Link to comment Share on other sites More sharing options...
mikesr1963 Posted February 7, 2007 Share Posted February 7, 2007 I have a Valve Jr. Head into a Crate 412 cab and even when I crank it I get little hum; not enough to want dig in and alter it. Link to comment Share on other sites More sharing options...
Junior 1 Posted February 7, 2007 Share Posted February 7, 2007 I have a VJ head and the combo and have been using the head with a 10 inch cab lately. Last night I used the combo with an Ibanez Talman thin line acoustic electric I got for Christmas and the sound was great. I had to listen for the hum! I'm a hobbyist and don't record, so I guess it would make a difference if I did. I have EH tubes in it and have decided that the only other mod I need to make is to stop listening for the hum and just play!!! The hum is gone once the first note is played. That acoustic sounds great through that little amp!!! Link to comment Share on other sites More sharing options...
Ricochet Posted February 8, 2007 Share Posted February 8, 2007 You can discharge caps with a straight jumper wire or screwdriver, but it'll arc badly and burn holes in your connectors and amp parts. Use a jumper with a resistor in it and leave it clipped on a little while. The value of the resistor isn't critical. Something like 1K is a good starting point. "A cheerful heart is good medicine." Link to comment Share on other sites More sharing options...
John213 Posted March 3, 2007 Share Posted March 3, 2007 Hey, how difficult would it be to add a master volume to the VJ? Just so u can get break up of the pre amp valve without having to crank it, as it is still quite loud for bedroom use. I read somewhere that it'd be quite easy. Link to comment Share on other sites More sharing options...
miroslav Posted March 3, 2007 Share Posted March 3, 2007 Here's how I do it with my VJ Heads.... I go over to the cabinet I'm using...and place a basic chair in front of it. (For recording, I already have a mic in front of the cab and between the cab and chair.) Then I go and get 1-2 large quilt comforters and drape them over the chair and the cabinet. The chair creates some space for the speaker to breath in. Then I go over to the VJ Head and turn it up to "11". I can get great break-up...but with less level in the room! That's about the easiest/quickest "mod" you can do. Of course...it only works in a controlled environment... miroslav - miroslavmusic.com "Just because it happened to you, it doesn't mean it's important." Link to comment Share on other sites More sharing options...
Dr. Ellwood Posted March 3, 2007 Share Posted March 3, 2007 Put it in a clothes closet and close the door. http://www.thestringnetwork.com Link to comment Share on other sites More sharing options...
Guitarzan Posted March 4, 2007 Share Posted March 4, 2007 attach two to a curved piece of metal for monster headphones! :grin: http://www.soundclick.com/bands/pagemusic.cfm?bandID=193274 rock it, i will Link to comment Share on other sites More sharing options...
Mooreamps Posted March 4, 2007 Share Posted March 4, 2007 Yes, I did. But, to do it, I had to pull the stock printed circuit card out and replace it with a new pre-amp card and a new power amp card. -g Link to comment Share on other sites More sharing options...
jag327 Posted March 14, 2007 Share Posted March 14, 2007 I've seen mercury magnetics offer replacement trannies and adding a choke for the valve junior. I was thinkin about swapping my trannies for a pair of trannies for an old hammond organ from the 50's or 60s. I also have a 4.0 Henry choke laying around. I believe mercury kit came with a 3.0 henry choke. where in the circuit would a choke be placed? .....if i swapped trannies i would even have a 5 volt tap for a tube rectifier... Link to comment Share on other sites More sharing options...
jag327 Posted March 15, 2007 Share Posted March 15, 2007 One more thing, has anyone raised R10 enough to lower the plate dissipation to 10.7W? I've read that's the 'sweet spot.' I raised it from 220 ohms to 1.41K, incrementally with 470 ohm resistors and got it down to 11.37W. My goal is to 'clean up' the sound a bit. when turned up, it just kinda mushes together. Link to comment Share on other sites More sharing options...
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