Hoffman Amplifiers Tube Amplifier Forum
Other Stuff => Effects => Topic started by: Dynaflow on April 10, 2009, 08:08:05 am
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Does anyone have a shematic or layout of a easy a-b-y box? Since its going to just switch two channels in the same amp I'd presume that I don't need a transformer isolated type? I'm just going to use it to switch from channel to channel on my TMB18 watter, heck I'd rarely combine the channels so even just a-b would be fine. Any help would be appreciated.
Regards,
Dyna
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if i remember this weekend i'll crack open my morley a/b/y and sketch it for you. i opened it before and it's pretty simple, probably just what you need.
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Thanks much, appreciated. Yeah a simple passive switcher is all I need. Thanks.
Regards,
Dyna
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TWO OPTIONS (http://www.singlecoil.com/docs/aby.pdf). One with LEDs, and one without.
Gabriel
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Thanks Gabe, I'll go look at that stuff, much appreciated.
Regards,
Dyna
Edit: Thanks thats exactly what I need. Thanks again.
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FWIW the morley is very similar to G's schematic w/ leds.
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Hey Dyna,
Please forgive me if this obvious. But...I have seen a bunch of dual channel 18 watt variants that use the flying switch at the input jacks to "choose" the channel. The typical JCM-800 approach. I don't think that a simple a/b/y switch will do what you want if your's is this type.
Just thought that I would mention it.
Keep on rockin!
Dave O.
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Nope, different than what I have. I have two separate inputs, one for the clean channel and one for the TMB channel. I've played these before with my 90 Lucille with stereo output jacks. Use the clean channel on the neck pickup and the bridge pickup gets the TMB channel for lead use. It sounds great, what is REALLY cool though is combine both pickups/channels, really thick. I've just got to get another stomp switch and I'll have the stuff to do the switch. In the meantime, the stereo setup with Lucille works the treat.
Regards,
Dyna
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Sound like a really sweet set-up!
Any chance that you could share/direct me to your 18W TMB schematic? Is it a Ceriatone type?
I have taken an interest in building one of Sluckey's Plexi/JCM800 plans but don't want the full 50W of the 2 X EL34 power amp.
Maybe mate the pre-amp section to the TMB 18W power section. Any thoughts on that?
I have never owned an EL34 amp but own a Mesa Boogie DC3 with 4 X EL84 which is less than inspiring.
TIA,
Dave O.
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Dave,
I used Weber's layout, although truly between ceriatone, weber and those available at 18watt.com theres not much difference, slight differences but not huge. That might be pretty cool using Sluckey's preamp on a el84 output depends on if you like el84's or not. The tmb18 cops the mid-range sound of the Marshall and combines it with some chime that I really like not unlike a Vox. It might also be cool to use a EF86 or maybe the 5879 the guys are using in the Hoso56 here too, if you like that sort of grind. I play mainly rhythm in our band, but do get my lead chops in and these little el84 amps really cut through pretty well for what I do.
The weber version of the TMB is Here:
https://taweber.powweb.com/store/6m18tmb_schem.jpg
https://taweber.powweb.com/store/6m18tmb_layout.jpg
My power section is a tad different because my cap can was only 2 sections, so I just added another 22 uf which I glued to the bottom of the chassis just to get a bit more filtering. It looks something like 32-32-22 now and I use the copper cap as a replacement for the ez81 (which amounts to a 61 ohm 10 watt resistor and two big diodes I know because I've had it apart :D ). I'm using a 270fx hammond and deluxe reverb OT which seems to work real good, nothings getting hot so I guess I did something right for a change. :D
Regards,
Dyna