Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Stankfut on December 19, 2013, 11:30:59 am
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Hey y'all! I'm about to embark on a new build, and I am looking for design input. I have a Hammond 270DX and a Hammond 125E, so it will have either a 2 X 6v6 or 2 X EL84 output section, beyond that I haven't got a clue! What I want is a "modern" amp, high gain with lots of grit that can also scream with rich harmonics without being fuzzy or buzzy. I want it to be tight but not stiff. I also want it to have a crisp pick attack, the last time I tried a high gain amp, the attack was too mushy. I figure I'll use diode rectification, although I am going to wire an 8 pin socket to have options. I'm also leaning toward a master volume to keep it all under control. I'm hoping you guys can point me in the right direction. Thanks!
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Maybe Soldano Astroverb or Atomic 16:
http://www.el34world.com/charts/Schematics/files/soldano/soldano_atomic16.pdf (http://www.el34world.com/charts/Schematics/files/soldano/soldano_atomic16.pdf)
http://www.el34world.com/charts/Schematics/files/soldano/soldano_astroverb_16.pdf (http://www.el34world.com/charts/Schematics/files/soldano/soldano_astroverb_16.pdf)
MasterThatGear! - Soldano Astroverb 16 1x12 Combo (Part 1) (http://www.youtube.com/watch?v=GNux56sD6Ug#)
The most modern distortion setting comes at about 10:20,,,,so don't get bored and shut it off early
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Here are some ideas for high gain monsters that clean up well: The OD Chan. Bogner Ecstacy. Very Marshally sound but able to get that wailing Jeff Beck howl also.
http://www.el34world.com/charts/Schematics/files/Misc/bogner_ecstacy.pdf (http://www.el34world.com/charts/Schematics/files/Misc/bogner_ecstacy.pdf)
Or, the The Triple Giant.
http://www.el34world.com/charts/Schematics/files/Misc/bogner_triplegiant_preamp.pdf (http://www.el34world.com/charts/Schematics/files/Misc/bogner_triplegiant_preamp.pdf)
Silverfox.
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I just converted one of my amps to a Daisycutter. The attached schematic is from AX84. There is a very good youtube video about the DC 10, which is a single ended Daisycutter with an EL34 output. The values are shown, and they are different in some places than the schematic. I followed more closely the values in the video.
My amp also has 2 EL84 in cathode bias/push-pull. The DC also has three gain stages like the Atomic 16.
If you want a gigging amp that also does cleaner tones then I would add another gain stage before the cathodyne, otherwise the EL84 are not pushed enough when the gain control is set low. With a long tail pair PI this amp is going to be very loud though - I know because I tried both in that amp. If you go long tail consider a PPIMV.
Cheers Stephan
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I must say that Soldano demo video is very good.
Cheers Stephan
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Yeah,I'm kinda sold on the Soldano :icon_biggrin:
The Bogner really doesn't do it for me so much. The high gain stuff is a little too much. I know it can be tamed, but the Soldano seems much better to my ears. Not really looking for much clean, just a ridiculous amp to bang around on. There are a few additions I may want to make, I'm going to do some research and post back here.
Thanks again!
Steve
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Links to vids: Push-Pull EL84, 12BH7 Preamp, 12AY7 PI Cranked 002 (http://www.youtube.com/watch?v=N3EFrHD9aS0#ws) 1x12 guitar cabinet (oversized) (http://www.youtube.com/watch?v=98C2pHo52Nk#ws) of a daisycutter I built last year.
I am not a high gain player so I swapped out the 12ax7's for a 12bh7 and 12ay7. With 12ax7's it's easily into marshall territory. I was using a Tele (single coils) for both vids. Here's one with humbuckers, 12ax7's and much better playing than my own: Phaez Daisycutter 14w EL84+6V6 *voxy to brown sound* (http://www.youtube.com/watch?v=BguBjk55xpc#)
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Okay, here's a few questions!
I would like to add an effects loop like the one Ed Chambley used for his Princeton, thread here: http://www.el34world.com/Forum/index.php?topic=14317.0. (http://www.el34world.com/Forum/index.php?topic=14317.0.) Will that design still work with this circuit? The reverb tank in the schematic is a short tank with a 10 ohm input, not sure which transformer to use. Would it be possible to use a long tank and Fender style transformer, even though the driver is not paralleled? I'm not really concerned about a small footprint, I learned my lesson the hard way :icon_biggrin:
This build is still a ways out, but thanks your help!
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I would like to add an effects loop...........
This build is still a ways out, but thanks your help!
Since you've got some time.....also take a look at tubenit's one tube active effects loop.....here's his latest amp with it in there:
http://www.el34world.com/Forum/index.php?topic=16447.0 (http://www.el34world.com/Forum/index.php?topic=16447.0)
I think this would be a cool addition to that soldano....
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I've actually been thinking of adding that loop, and I think I will, but i am wary of "scope creep" setting in, making this thing more complicated that it needs to be. Next question is if this PT has enough juice for the extra tube?
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Next question is if this PT has enough juice for the extra tube?
If you were thinking of doing the Astroverb with reverb and the loop, then you'll exceed the filament capacity of that xfmr (3.4 amps with 6-12AX7s and 2-EL84s)
The Atomic with the loop should be fine, and would actually be 2 less 12AX7s (might not sound like that Astroverb demo though)
If your sold on the Astroverb, you "might" be able to get away with the 3.1 amps on the filament windings, and just insert a passive loop before the PI.....
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either a 2 X 6v6 or 2 X EL84 output section
6V6's will get you there with that PT.
2x6V6 = 2 x .45A = .9A
2x6BQ5= 2 x .76A = 1.52A
1.52A - .9A = .62A freed up heater current, enough for 2x12 _ _ 7.
Brad :icon_biggrin:
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Thanks guys!
Silvergun, I think the Atomic would not really sound the same because, it appears to me, there are two more gain stages.
Brad, that's definitely an option. Wonder how it affects tone to switch to 6V6?
I was kinda going in the direction Silvergun pointed out, run it slightly over current with a passive loop. The active loop would be cool but not critical. Although know that Hammonds are supposed to be overrated, but how far can they be pushed? I'd hate to fry my PT.
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Wonder how it affects tone to switch to 6V6?
Well, some love EL84's/6BQ5's to get a low volume Marshall EL34 type of sound. There's a big 18w/20w Marshall crowd for that sound, distorted, grind, bright/chime.
OTOH, some love 6V6's for a low volume Fender sound, tweed 5E3, tweed Tremolux 5E9A - 5G9, 6G3, Princeton, Deluxe reverb, etc., for a smoother distortion and less bright/grind sound.
It comes down to what kind of music you play.
Brad :icon_biggrin:
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Hey Guys, sorry to hijack this thread. If one were to build the preamp of the Soldano Astroverb 16 (schematic in second post above)without reverb, would the paralleled triode on the first half of the cathode follower be needed? The reason Im asking is I have a 6V6 5F6A head type build and was impressed with the versatility of the Soldano cilp above and was wondering if I could get away with just adding a 6AV6 triode (added gain stage) in front of the existing cathode follower? (and changing the necessary caps and resistors to match the Soldano) Any information is much appreciated. Thanks Punky
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Hey Guys, sorry to hijack this thread. If one were to build the preamp of the Soldano Astroverb 16 (schematic in second post above)without reverb, would the paralleled triode on the first half of the cathode follower be needed? The reason Im asking is I have a 6V6 5F6A head type build and was impressed with the versatility of the Soldano cilp above and was wondering if I could get away with just adding a 6AV6 triode (added gain stage) in front of the existing cathode follower? (and changing the necessary caps and resistors to match the Soldano) Any information is much appreciated. Thanks Punky
Just to clear it up in my head.....do you mean, get rid of V2b and V3a and replace them with a 6AV6?....so you would just be adding that 7 pin socket to your existing build?....and cascading the 2 separate input triodes in the 5F6A?
That's how I'd try to do it........
I think this would make for a good thread and you'd get much more attention if you started a new one....
I think you're idea (if I got it) is fine, and do-able,,,especially since the 6AV6 is a 100mu tube,,,,you'll only be losing the extra % of gain that you'd get by paralleling the 12AX7..........that amp has plenty of gain to "give away" some
:thumbsup:
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Thanks for the reply Silvergun. I guess another question is: What is the purpose of the (paralleled triodes V2b, V3a) driving V3b? To help boost the reverb? I see connection C coming from the return of the reverb circuit going to the grid of V3a, so it looks like a boost for the reverb??? Since Im not going to have reverb my thoughts are eliminate triode V3a using the 5F6a`s original CF and installing a 6AV6 single triode for V2a. .
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What is the purpose of the (paralleled triodes V2b, V3a) driving V3b? To help boost the reverb? I see connection C coming from the return of the reverb circuit going to the grid of V3a, so it looks like a boost for the reverb???
Their not in parallel, they have 2 separate input grid feeds.
Yes the V3a is the second reverb return stage, but V2b/V3a are being used as a mixer by using a single plate R.
Brad :icon_biggrin:
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What is the purpose of the (paralleled triodes V2b, V3a) driving V3b? To help boost the reverb? I see connection C coming from the return of the reverb circuit going to the grid of V3a, so it looks like a boost for the reverb??? Since Im not going to have reverb my thoughts are eliminate triode V3a using the 5F6a`s original CF and installing a 6AV6 single triode for V2a. .
Merlin calls it a common-anode mixer....because the grids are fed from 2 different sources, the 2 triodes will act differently than a standard paralleled triode (where the grids are connected), and amplify separately....and their inputs get mixed together at the output plate of V2b/V3a.
So I see it more as mixing the reverb with the dry signal, with the benefit of higher output current, lower output impedance, and lowered noise floor.......while "boosting" the combined signal.
Since you're not having reverb, maybe one of the big guys can help you re-design the stage to act similarly.....on your new thread :icon_biggrin:
That Willabe fellow types faster than me :sad:
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That Willabe fellow types faster than me :sad:
Hehe, and I can only type with 1 finger. :laugh:
Your answer was a better fuller explanation.
Brad :icon_biggrin: