Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: theundeadelvis on July 05, 2010, 11:36:52 am
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So I found a Musical Power Supplies output transformer I ordered a while back, and I'm trying to think of something to build with it. I also have a 17.5" X 6.5" chassis drilled for 6 tubes that I'd like to use up too. Any suggestions of a cool build that could use these? Preferably something simple to keep the price down (since it's a spare parts build). Thanks!
Here are the transformer's specs from their site:
25W to 40W PP guitar amplifier circuits using 6L6 pair or EL84/6V6 Quad power tubes into 4200/3300 Ohm inputs with 4,8 & 16 Ohm Outputs
Also usable 8400/6600 Ohms to 8,16,32 Ohms output
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If your chassis is pre-drilled for 6x novals you may build a nice quad EL84 + 2x 12AX7 (two sections for gain and tone shaping, two for the PI) 30-watt something amp - a Maz GT clone or a Stang Ray (pentode front end) could be a great base to start with. Or a similar amp with 6V6GT's if you've got 4x larger holes (or can enlarge existing ones). Or a PP with reverb and lots of goodies, Texas Raptor- or Little Wing-style (just two very nice designs from some of our most creative members). Or a PP with reverb and overdrive. Or something else.
It all depends on your building skills and tone preferences...
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I'm taking it all 6 are 9 pin.. Vox AC15/30: http://www.el34world.com/Hoffman/images/AC30Old.gif
Matchless Lightning: http://www.freeinfosociety.com/electronics/schematics/audio/matchlesslightning.pdf
As FYL suggested.. a 4 EL84 power section with a 2 tube preamp: http://www.el34world.com/projects/images/StoutOld.gif
Classic 18W TMB: https://taweber.powweb.com/store/6m18tmb_schem.jpg
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That MPS output transformer works well with a quad of EL84's - 30 watts output...
(http://i497.photobucket.com/albums/rr333/valvetone/verve/faceplate.jpg)
Or a pair of EL34's in a Trainwreck themed amp - also 30 watts...
(http://i497.photobucket.com/albums/rr333/valvetone/tramwreck/front.jpg)
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In that last photo is that toroidal transformer from the company Antek by chance?
Regards,
D.
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Thanks for all the suggestions!
Daryl - What is the first amp in your pictures? I love a simple three knob amp.
I've considered the Vox and the 36 watt Marshall.
MPS also says they would work for a Tremolux, Vibroverb, or a Vibrolux, and these have peaked my interest too. I've built a number of blackface Deluxe Reverbs (w/bias trem) and some 5E3's, but I have no experience with any of the those three.
edit-Vibroverb is out. Forgot about how many tubes that guy would have. Although, I have room where I could add at least one more tube if needed.
Any opinions on the Tremolux and Vibrolux?
Thanks guys!
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In that last photo is that toroidal transformer from the company Antek by chance?
No. It's sold by Altronics an Australian electronics retailer. http://www.altronics.com.au/index.asp?area=item&id=MC5337
I use the 37+37 volt secondaries in series, through a voltage quadrupler rectifier/filter to produce a DC output of about 400 volts. The 12+12 and 15+15 secondaries are series wired and rectified for the fixed bias supply. The small conventional transformer next to the toroid powers the heaters. The high cost in Australia of "real" transformers for valve amplifiers makes these sort of workarounds necessary.
What is the first amp in your pictures? I love a simple three knob amp.
There is a construction description here: http://www.guitargear.net.au/discussion/index.php?topic=23445.0
The preamp is very similar to that used in the 5-watt amp I described here: http://www.el34world.com/Forum/index.php?topic=9027.0
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I love a simple three knob amp.
Gain, tone, master. Plenty of possibilities...