The Amp Garage

Great build and documentation--thank you! I sprung for a Hammond 269ex PT, and will build this Firefly design. My chassis has an 8-pin socket for tube rectifier 5u4gb. I'd like to use this instead of the diode rectifier. What are the ramifications of this? Will the voltage drop lower than with the d...

I'm gutting the Packard Bell chassis and turning it into a Matchless Lightning clone. The chassis is compact (11 x 7 x 1.5"), so I'm keeping the 4-section capacitor can on top to maximize space inside for a custom turret board. I'm not going to put this inside a cabinet--I'm going to build it with t...

The Lightning breaks up too earlier compared to the Spitfire. Is that, "It breaks up too early," or, "It breaks up earlier, too, which is cool."? I see you built a Lightning recently, Mark. I think I'll start a new thread, and hopefully you can help me when I have questions. In fact, I feel a quest...

Decided to strip the chassis and build a Lightning clone. Anyone want to make an offer on the PT and OTs before I auction them off? $80?

I'm still most interested in making a Spitfire clone. Ceriatone offers PT, OT and choke for $90, but add $100 for shipping! Can y'all spec Hammond or other replacements for OT and PT, and choke? I can't find details of the choke in any of the FIVE layouts and schematics I found! And there's too many...

If you want to rebuild the amp rather than eBaying it, how much are you willing to invest in the project? And how loud would you want it to be? I would invest one or two hundred dollars, if necessary. But this is going to be a studio amp, and will probably never play with a band. So low to moderate...

Since this is a stereo amp, why not keep that part of the equation and build 2 x 18w Marshall type amp? Great idea, Tom. In fact, I own a 2x12 cab that is switchable from mono 4 ohms to stereo 8 ohms per side. I usually run a Line 6 X3 Live in front, so stereo effects are available. And that meets ...

Do you guys have a feeling that the PT and OTs are worth keeping? If so, I like the idea of using 6V6 power tubes.

Anything more I can investigate to help make this decision?

Best Spitfire diagram I found is the Ceriatone one: http://www.ceriatone.com/images/layoutP ... iatone.jpg

First question: The spec'd PT delivers 290 vac, but mine read 348 vac (per leg). With my existing PT, are we going to get the 352vac spec'd at B+?

This looks like a good choice: Matchless Spitfire clone: http://www.turretboards.com/guitar_amplifier_kits_matchless_spitfire.html diagram: http://www.diyguitarist.com/Schematics/SpitfireSchematic.bmp I can get a turret board here: http://www.turretboards.com/circuit_boards_matchless_style.htm What ...

Check out the AX84 HO: http://www.ax84.com/hioctane.html This plan uses 2x 12ax7 and one EL84. Has the benefit of lots of supporting materials and explanation. The biggest hurdle for me will be understanding the variables I'm throwing into the equation: the existing PT, OTs, and tube rectifier. This...

Currently, I have a Blackheart BH5H Little Giant. This is 5 watts, switchable to 3w, one 12ax7 and one EL84. I put in the three-way tone stack mod, and run a modded RAT distortion in front. I couldn't be happier with this $170 amp! My other amp is a Mesa Boogie Mark IV head, which covers a lot of gr...

I think he's checking the OT, putting the 5.57AC into the primary. So with .187 on the secondary, that's would be about 30/1 turns ratio. Assuming an 8-ohm load, that's around 7K3 primary impedance. Pretty close to the 8K book value for a pair of EL84s. Does the other OT test the same? Yes, the oth...

Phil, isn't this correct for an OT? It's supposed to convert the high voltage, low current signal from the power tubes to low voltage, high current required to drive the speakers.

Why do you expect the voltage to rise?

First photo shows 5 vac output from PT jumpered with white and yellow gator clips to input winding of OT. Red center tap is not connected to anything. Red and black gators run to the multimeter, which shows 5.57 vac. [img:1024:768]http://www.monkeymatic.com/pub/ebay/packardbell9.jpg[/img] Now multim...