Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: tubenit on April 18, 2017, 04:16:56 pm
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Am I seeing the B+ to the tremolo correctly on this? Seems like the voltage is going thru a .01 and a .02 cap prior to getting to the plates of the tremolo 12AX7? Seems to be a very different way of doing this IF I am seeing this correctly?
Does the way I drew this look right to you guys?
Compare with original Fender scheamtic here: http://el34world.com/charts/Schematics/files/fender/Fender_TREMOLUX_5E9A.pdf (http://el34world.com/charts/Schematics/files/fender/Fender_TREMOLUX_5E9A.pdf)
with respect, Tubenit
EDIT: HBP's response below was an incorrectly drawn schematic which I've deleted from this post.
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The drawing is missing a direct connection from pin 6 of the trem oscillator to pin 2 of the trem buffer. It is also missing a connection from pin 1 of the trem buffer to B+. 5E9-A schematic (http://el34world.com/charts/Schematics/files/fender/Fender_TREMOLUX_5E9A.pdf)
Fender's drawing of the schematic is reflective of how the socket was wired. The trem buffer is a cathode follower, with a direct connection from plate to B+. The 220kΩ was wired across the socket to the plate of the trem oscillator, to be its plate load. And of course the direct wire from the oscillator's plate to the follower's grid.
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Hey Brian, Thanks for the help as always! Once I read your comments a couple of times, a light went on. I think Fender really drew the schematic in an odd manner compared to other tremolos like the 6G9-A. While there are some differences & similarities in those two tremolo schematics, I think the actual drawing of the 5E9-A was really hard to follow. Thanks for sorting that out for me! I appreciate it.
Any more errors?
You've played or owned one of these haven't you? What did you think of it?
And what about the 10M resistor in the schematic, is that some type of local negative feedback?
With respect, Jeff aka Tubenit
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And what about the 10M resistor in the schematic
That's like a kickstart for the tremolo oscillator. That oscillator can be slow to start when stepping on the footswitch, maybe even take a couple seconds to start wobbling. The spike from the B+ thru that 10M helps get the oscillator running faster. Kinda like a quick slap! It's very annoying to step on a trem footswitch and not have instant trem effect.
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Any more errors?
I think everything else on the schematic is correct.
You've played or owned one of these haven't you? What did you think of it?
I used to own a 5E9 Tremolux. Dumbest (amp) thing I ever did was sell it.
If you're looking to build one for yourself, I'd recommend going with the large-sized cabinet they used for most of these: 20" x 22" x 10". It seems to add to the depth of sound for this amp. You might also consider being open to dropping the coupling caps to 0.022µF based on listening tests. Just like the 5E3, 0.1µF can get too woolly, especially when the output section is distorting.
The trem is excellent on these, as it only has to overcome the relatively small bias at the cathodes of the paraphase inverter. Very deep & swampy.
The paraphase also seemed to give a richer sound, probably by adding a bit of distortion before the output tubes. I definitely thought it sounded more complex than my 5E3 copy.
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+1 HBP but my temolux was a '63 black face. I had the piggyback 2x10" but then aquired a bassman 2x12" to go with it. It was my "stack" growing up in and past high school. Then gave it up for a JCM800 2204 half stack w/ 6550's
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If these help and you would like any close-ups,let me know. I have noticed over the years that layouts and wiring practice don't necessarily go hand in hand with the tweed era Fenders. Or send me your email and I send you high res shots.
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Very nice bangy!
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Thanks JoJoKeo
I am a sucker for the tweed circuits. Fingers, guitar, cord, amp, speaker(s) - with as little in between seems to work for my dinosaur-axx.
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Hi there. I have one at home that I built using the larger sized cabinet (the Pro-sized). It's loaded with the correct stiff and a vintage speaker and it's been my favourite amp for three years now. It's the amp I gig with. It's portable, not too heavy and sounds great. All you need with it is a clean boost or TS and you're good to go. I even got rid of my reverb pedal though I could deal with it now, sometimes.
Great amp and I've built all the tweed line except the Twin so far! :m7
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Hi Jeff, I just listened to some youtube videos--what a great amp! I think I'll convert my vibrolux/Deluxe to that circuit. Your schematic makes more sense to my brain than the Fender one. I noticed two differences. There is one 220k and one 270k bias resistor on yours. Intentional? Also, the 100pf cap between the PI plates is .001uf on yours.
Thanks for the ideas!
--Craig
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Great amp and I've built all the tweed line except the Twin so far!
Did you build a 5G9 tweed tremolux?
If so what do you think of it?
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Your schematic makes more sense to my brain than the Fender one. I noticed two differences. There is one 220k and one 270k bias resistor on yours. Intentional? Also, the 100pf cap between the PI plates is .001uf on yours.
I simply tried to redraw the Fender schematic so I would reference the original Fender schematic.
With respect, Tubenit