Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: dwp on June 25, 2011, 02:39:42 am
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I have a 5F4 Tweed Super Chassis and Cab I want to turn in to a 2X10/6L6 Tweed Deluxe. I would like to populate the chassis controls, has anyone got a layout or schematic for such an animal? Or is this just not appropriate for the 5E3? I want the Deluxe grind, priority one. If not valid for such controls, button covers may be my best option?
Opinions, advice, options always appreciated.
thanks in advance, dwp
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I've done this and was looking for the "member gallery pictures" thread but can't seem to find it?
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Jojo, it's under "media".
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Thanks John. I learn something new everyday. This is just recently done, no wonder. I should maybe change my notifications?
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DWP, here's what I've done w/ mine. I wasn't too enthralled w/ a 5E3 chassis I came accross and being a one trick pony somebody screwed up making it from a kit and why I got it so cheaply. The iron will support 6l6gc's if wanted so I decided to scrap the whole thing since it wasn't vintage. I re-designed & built the whole thing using the board, chassis, and iron. The other stuff wasn't worth keeping. Two pp pots in the unused inputs are treb/bass, then pre-amp vol, ppimv, & switchable presence where the old tone pot was. The treb/bass controls are on pp pots for V1 & V2 ran series/parallel and tone stack bypass respectively. I've repaired a broken fuse holder (happened at recent gig :cussing: - Murphy's Law wouldn't you know it) and while it was out to repair I tweaked a few things speaker & voicing-wise and haven't since updated the schematic except handwritten notes on a hard copy I hand drew. Not sure if this is the kind of thing for what you're looking for or not?
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jojokeo,
Very nice. Very nice indeed. You always come up with nice little twists for a more versatile amp.
Hey do I spy a nice looking bench top drill press?
Brad :icon_biggrin:
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It sounds like it would be a great amp... but I doubt it would sound much like a Deluxe. 6L6's, treble, bass, presence, all would subract from the Deluxe sound. That being said, it would have it's own voice and it should be great. I know you're dealing with an existing chassis so this probably won't be much help, but your best bet for a more powerful 5E3 (I'm assuming that's the point of the 6L6's) is to build a stock amp with 4 - 6V6's. The tone controls will suck gain and the 5E3 has no feedback loop so a presence is not really possible... unless you add one. If you do, scratch more of the raw sound this amp makes.
I'm betting this isn't much help, but it is my honest opinion. Hopefully, it'll help you decide what you want to do.
Dave
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HotBluePlates (who is my amp building mentor) brought his 5E3 Deluxe over one time and I compared it with my Carolina Blues Special. There were some similarites & differences.
So in light of that, here is simply an idea to consider given some of the parameters you suggested. The NFB could be switchable.
I like the James Tone stack. Check out how much you can shape the tone. http://www.duncanamps.com/tsc/ (http://www.duncanamps.com/tsc/)
With respect, Tubenit
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is great help BB, thanks. I conclude the same then, 5E3 is simplicity. I was also missing another major plus of the Tweed Deluxe, portability. 1X12 easy to grab and go. Rather than live with the control plate defficiency mounting the 5E3 in the 5F4 chassis......am going to put a single channel AB763 with no mid, MV then use presence for reverb pot. Easy add, the 4th tube, controls align, that takes care of my mod-the-super jones. Can wait it out, next buy out, 5E3.
Thanks again, dwp
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It sounds like it would be a great amp... but I doubt it would sound much like a Deluxe. 6L6's, treble, bass, presence, all would subract from the Deluxe sound. That being said, it would have it's own voice and it should be great. I know you're dealing with an existing chassis so this probably won't be much help, but your best bet for a more powerful 5E3 (I'm assuming that's the point of the 6L6's) is to build a stock amp with 4 - 6V6's. The tone controls will suck gain and the 5E3 has no feedback loop so a presence is not really possible... unless you add one.
I don't run 6l6s in this just that it can if ever wanted. The pi isn't concertina as it's a long tail but when the amp is run v1 in parallel w/ the tone stack bypassed it sounds insane w/ the presence ingauged or not. The clarity and touch sensitivy w/ the strings through your fingers really brings out the tone in any guitar and speaker combo used that is up there w/ anything I've ever played. When set this way, everyone that's played it gets a big smile on their face. But, the amp has much more than this too.
The mods I've done are basically using the same schematic but w/ different values in some critical areas which really made the final differences stand out.
*edit - wow, I can see some Bozo mistakes from a couple years ago w/ this as I haven't looked at it in a long time. The presence hs no swtich, the heaters don't show 100r resistors or going to the right place, the pi's load resistors are reversed, etc...sorry.
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"I don't run 6l6s in this just that it can if ever wanted."
Sure, I was going by the original post:
"I want to turn in to a 2X10/6L6 Tweed Deluxe"
Like I said, I'm quite certain amp dwp first proposed would be sweet, I just don't know how much like a 5E3 (as he indicated he wants) it would sound.
Personally, I prefer a 5F6a preamp with an AB763, 6V6 (BF Deluxe) power amp... but cathode biased.
Dave
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When I read your post's title, I immediately though, "5F4, 5E5, etc."
You can't have presence without a feedback loop, which will knock down rawness somewhat. The 6L6's and fixed bias will have more authority and volume than cathode biased 6V6's. It's also hard to add a more elaborate tone circuit to the 5E3 without taking away some gain (the stock control doesn't knock down the whole signal, as much as one end or the other).
That said, you can build a typical 5F4 and add a bypass for the tone circuit. Tubenit didn't mention that the other amp I always brought over to his place for jamming was a 5F4 copy. I eventually added a tonestack bypass switch in the presence pot location, because I almost never turned up the presence (my guitars tended to be bright enough for me).
The tone circuit bypass is fairly simple. There is already a 0.1uF coupling cap leading from the cathode follower into the tone circuit. We will utilize it. On the side opposite the cathode follower, we will run a wire to the bypass switch, and another from the other side of the switch to the grid of the next stage. There is a 220k resistor to ground that will be used as the ground reference for the stage after the bypass switch. See the schematic posted, knowing that it shows a closed bypass switch (i.e., a straight piece of wire).
The layout shows the points I added the 2 bits of wire, and a poorly-drawn switch. My switch was really in the presence pot hole. I'd be hesitant to run it long distances to some other location, just because there is already a fairly big loop of wire from the cathode follower to the next stage through the bypass switch. Big loops of wire increase the chance of picking up hum and buzz, as well as for creating oscillation if you add gain stages.
I'd also recommend using an adjustable fixed bias circuit, as you could probably drop in 6V6's (especially modern JJ 6V6's) if you keep an eye on dissipation.