ABY for channel switching

Discussion in 'Effects, Pedals, Strings & Things' started by kingink, Aug 25, 2005.

  1. kingink

    kingink Gold Supporting Member

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    I want to get an ABY pedal for channel switching on my SF Bassman head. Can I get away with a Morely or Whirlwind, or should I spend a little more for a Startouch, Loooper, Loop–master, etc.? I've heard the Morely has issues, like tone-sucking and popping, but I'm not sure if those are amp switching or channel switching issues.

    Thank you,

    David
     
  2. Loop-Master

    Loop-Master Member

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    That is Morley switching issues. :)
     
  3. Kiwi

    Kiwi Silver Supporting Member

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    Yeah, the Morley gives you a click when you switch.

    The Whirlwind is silent.

    - K
     
  4. fr8_trane

    fr8_trane Member

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    After some research I would say the startouch is probably the highest quality for the money followed by the loooper and loop-master stuff. Passive a/b pedals apparently have grounding issues that make them questionable for switching between separate amps but they should work flawlessly and quietly for switching channels on a single amp. I'll probably go with the loop-master for my SF bassman.
     
  5. kingink

    kingink Gold Supporting Member

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    Yeah, my understanding is that you need isolation transformers for amp switchers.

    FR8, have you modded the bass channel of your Bassman at all? I'm messing around with it these days.

    Thanks for the comments everyone. Keep 'em coming if you got 'em.

    David
     
  6. fr8_trane

    fr8_trane Member

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    I modded the bass channel to bypass the tone controls but it provides WAY too much gain to be useful. At this point I'm 99% sure that I'm going to have David Allen perform his bassman mod so I can have BF and pseudo tweed/plexi with an A/B switch. The A&B option might yield some tasty in between sounds. If you are handy with a soldering iron I would suggest modding the bass channel tone stack caps to more GTR friendly values (check the tweed and blonde bassmen for ideas) and adding a 25K mid pot where the ext. spkr jack is. I did this with my Deluxe Reverb and it makes a 1 trick pony into a versatile channel switcher.
     
  7. UconnJack

    UconnJack Supporting Member

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    I had Mr. Allen modify my 67 Bassman and couldn't be happier. I'm using a simple A/B Loooper Box to channel switch. Zero issues.
     
  8. fr8_trane

    fr8_trane Member

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    Uconn jack,
    If you are familliar with the tweed or blonde bassman how does Allen's bass channel stack up. There is a clip of a goosed (EQ pedal in front) '59 bassman RI floating around HC that sounds like a cranked Marshall (I'm talking EVH). If I can get something similar out of the Allen mod I'm sold.
     
  9. kingink

    kingink Gold Supporting Member

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    Thanks for the info, Uconn Jack. I've heard lots of good stuff about the Allen mod.

    FR8_Trane, I pulled the cap that's across the plate resistor of one of the 12AX7s on the bass channel to make the bass channel less foggy and dark. Then I replaced the .1 and .047 caps in the tone stack with .022s. This is sort of Marshally/mid bite tone and cool, but now I want to try to do the tweed sort of thing and put the .1 and.047 back, change the 330pf cap in the tone stack to 250pf, and change the slope resistor from 100K to 56K. I'm also trying to find out how to turn the deep switch into a mid-boost switch.

    Anyway, I really like blending the channels with a jumper cable, no matter what the bass channel sounds like, which is why I'm interested in an ABY box. Switching between them will be cool, but I don't want to lose the blending option.

    Thanks again for the info.
     
  10. erksin

    erksin Member

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    I own a Startouch ST-2 A/B/Y - it's a fantastic box. Incredilbly well-built, silent switching, totally pro in every aspect. Tony has an amazing level of customer service as well. Highly recommended!
     
  11. UconnJack

    UconnJack Supporting Member

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    Hey Guys,

    I don't think the Bassman compares to the tweeds. The "guitar" channel is more like a blackface super reverb now. Definately more in the Blackface camp. At least that's how it sounds to me. It's clean up to about 6 before it starts to break up.. It get's throaty after that (in a great way). The "Bass" channel is entirely different. It has a very mid range quality to it. But it gives up the goods very early (around 2), and can get real crunchy. It's been described as an early plexi?!? Alot of classic rock tones in here. With the A/B box, this amp covers alot of ground.

    Interesting question regarding the Bassman vs the Tweed amps as I'm looking for my next amp and have been wondering the same thing. I've been going back and forth between something blackface or something tweed. Leaning Bassman LTD or Blues Deluxe right now.
     
  12. fr8_trane

    fr8_trane Member

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    The blues/hotrod deluxe & deville are based on the tweed Bassman circuit but I don't think they sound very tweedy. The clean channel is very clean (and very good) and the OD is harsh. Its more of a hybrid BF sound. I have heard alot of raves about the Bassman LTD recently. Here is the clip I was referring to and a couple others. Its an LTD boosted by a Boss GE-7 eq pedal (at least thats what the poster claims).

    http://www.jasonjosephphotography.com/richvc1.mp3
    (Amp on 6)

    http://www.soundclick.com/bands/3/jpec_music.htm
    (click on "discohign". Amp and boost maxed)

    http://www.jasonjosephphotography.com/digi3a1.mp3
    (lo gain)

    Putting those bigger caps back will shift the EQ curve into the mud. The stock BF bass channel is completely useless for GTR in my opininion and I would avoid modding the amp back to those values. The classic tweed/plexi tone stack is 250pf, .02uf, .02uf. Its a good place to start. The blonde bassmans had 1000pf treble cap on the bass channel which gave those amps a characteristic midrange emphasis which alot of folks like. In fact the most common way to add a midboost to the SF bassman is to wire the "deep" switch to add a 500pf or 750pf cap in parallel with the treble cap. The tweed bassman also had a 25k mid pot which is a great mod for any BF/SF amp IMO. Cranking the mid pot in this case gives you more gain and a more aggressive tone. Keep in mind that none of these mods will give you a truly accurate tweed/plexi sound because the 2 circuits are much different than just component values.
     

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