E.W.S Tri-Logic II Bass Preamp  [traced]

General documentation, gut shot, schematic links, ongoing circuit tracing, deep thoughts ... all about boutique stompboxes.
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chicago_mike
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Post by chicago_mike »

lots of things have happened. Good, and bad...

Here is an offer of peace...
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more
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more
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more to come
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Post by chicago_mike »

I do not know how close or far these are ...

Schematic wise.

Mid shift on pedal is 400hz low , 800hz high
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Post by quaternotetriplet »

:applause: :slap: mad props to you my friend.

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Post by quaternotetriplet »

chicago_mike wrote:I do not know how close or far these are ...

Schematic wise.

Mid shift on pedal is 400hz low , 800hz high
i dont see those switch on the schem? :horsey:

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Post by chicago_mike »

Those scematics are just ones I found over the net.

I don't have the pedal anymore, but I do have more pics I can post.
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Post by quaternotetriplet »

i hope someone can trace this.. this one is a nice preamp.

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Post by pedalgrinder »

so i can see ok op amp more than likely dual one bs170 did you write down the cap values? then all we have to do is follow the colour code for the resistors and could maybe make a black and white pic out of a pic of the trace side of the board. Just some thoughts i had with it. More pics please Chicago Mike i reckon this one is possibly traceable. thanks
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Post by pedalgrinder »

the caps on the switch need to be identified also did you catch what they were by chance?
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Post by chicago_mike »

I'll see what more pics I have.

The midrange frequencies are advertised as 400 and 800hz

So, if this follows the 3-band active baxandall, a little math :scratch: :hmmm: :?: :slap: might tell us what values.

But I think they were 015 and 033.. :whappen:

Wish I still had this pedal.



EDIT:

One of the MID caps is a .047

Oh, where do I get such pots and blue caps???
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Post by pedalgrinder »

as long as you know the values any pot will be fine the numbers on the blue caps are no different to the numbering scheme of green caps and i gaurantee you would sound no different. so yeah all we need is purely the numbers on the caps then any other caps can be used without making the pedal sound bad in anyway. Sure you could sit here and argue oh this cap sounds slightly bettter than that one. I say shove that theory up your arse. i've used green caps always they sound fine to my ears.
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Post by chicago_mike »

Oh, I'm not concerned about that. I like the fact they are small. :D

I just wonder where I can purchase the smaller sized pots and those little blue caps. I dont see easily see them around.

I will be uploading the rest of the pics I have today. Also, I'll make some trace images b&w and also try layering.

Whats cool is this is also the same circuit used in the Xotic series of basses.
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Post by pedalgrinder »

how did you get your hands on the pedal in the first place is there any chance you could grab it back just to write down the cap values or pot values by chance? Tracing the circuit shouldn't be over difficult but cap values certainly make a difference and i really couldn't be bothered sitting there with a calculator hoping to get the maths correct. Thought it was worth a shot to ask.
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Post by chicago_mike »

I sold it like 9 months ago. :(

I do have more pictures I have to post. The pots are 50KB. One of the caps on the midrange switch is a 473 (047). So we only have that and maybe the tantalum to get?

I should have the rest of the pics here later tonight. :)
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Post by bs_ane »

Has anyone schematic from this preamp??

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Post by chicago_mike »

That's what we are working on. :D

I installed windows 8 last night and forgot to edit the rest of my pics of this preamp. I'll post everything I got in a few.

The preamp is rather simple, but very musical.
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Post by chicago_mike »

:popcorn:
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:popcorn:
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