Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: bclemons76 on September 30, 2020, 05:16:32 am
-
I got a Vaporizer in a trade and, though I like the cosmetics, I don't care for the sound of it, even after some mods and speakers. I'd like to gut it and use the Pro Junior conversion kit. It looks like they would work, but by the schematic (I haven't opened it back up since I did some mods) the PT has an extra set of secondaries compared to the Pro Junior. Is that a problem? Will I need a new PT? I don't mind losing reverb and plan to add a cut control in it's place.
-
post the schematic n we can "see", but extra wires is very seldom a problem, coming up short on wires is usually a problem
-
Hopefully, this works
-
It looks like you have two 12A_7's and two EL84's. So, it seems reasonable to do a Pro Jr if you like the tone of those.
OR …………. if you wanted something more Marshallish ………….. you could do something like this 18w Minimalist idea using a mosfet cathode follower. Then use either the more traditional master vol (pre LTPI) or a PPIMV master volume. NOT saying you "should" do this, just offering another consideration. You could even add a passive FX loop between the tone stack and the LTPI.
With respect, Tubenit
-
+1
does look like a "good fit", a good sound :dontknow:
the "third" set of winding's looks like it could be used as fixed bias tap. the '84 doesn't need as much.
-
Since you state not liking the sound of your amp, I suggest that you make sure that the dislike is not a dislike of the sound of EL84s.
I convinced myself that I would like EL84 guitar amps because I love them in Hi Fi audio equipment. Turns out I just like big bottles better for guitar amps. To reach this conclusion I built a Spitfire, a Carmen Ghia, an 18W TMB, an 18W Lite, and an AC-15 Lite - the last two using Sluckey's excellent documentation of his builds. Slow learner, eh? If you do like EL84s, I think the Spitfire is a fine amp, although I had to remove the bright cap to save my ears (Tinnitus). Of course you could enlarge the tube socket holes for octals. Regardless, that PCB circuit looks a nightmare, so you will be on to better things.
-
^somewhat agree with bmccowan^
(But I personally like EL84s in a Vox AC15 or AC30, or TW Rocket or Liverpool, Or Matchless DC30 etc, but prefer big bottle output tubes most of the rest of the time)
But if you use 6V6s instead of EL84s, you'll save 620mA heater current on the PT, allowing space for 2 extra 12A_7s - and then the sky's the limit
-
you're one tube short to get over the line :icon_biggrin:
If you want a challenge, make the 9 pin PA tubes 8 pin, add a 9 pin up front, plexi-vox'sh-anything but what it already is amp
-
I've come to be not so much a fan of EL84s .. love 6V6 and bigger but soon I will embark on building Sluckeys Dual Lite..
-
I've come to be not so much a fan of EL84s .. love 6V6 and bigger but soon I will embark on building Sluckeys Dual Lite..
Well you could always build a dual lite with 6V6s, 6L6s, or any other big bottle, as in his American Dual Lite.
-
I've played a few el84 amps, I liked the Vox AC15, Kustom Defender, and Peavey Classic 20. I didn't like the Mesa Subway Rocket. It just seems way too stiff. Moreso than my red stripe Bandit. I'm thinking I might be happier with a little SE amp.
-
little SE amp
So now you are not thinking those transformers, eh?
-
The PT will be fine for a champ, which "champ" will determine if the OT can be used
-
I'm aware that you can use a push-pull OT for single ended amps, but never thought it was a good choice? And I was wondering if you had decided to save the PT for another project as it'll be rated for more amps than you need, and you likely won't be using that bias tap if you go small SE, but you could. You have lots of options!
-
I'm going to sell the vaporizer and build an Alamo Challenger clone. I miss the original I stupidly sold 10 years ago.
-
Nice - Since you were talking transformers, you may want to look at the set Classic tone has for 5W Valco circuits. They are in the vintage voltage range. I used them to rewire a gutted SE GA-5 and they worked out well.
Sell? - It might be more fun to vaporize it.
-
:laugh: