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

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alexradium
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Post by alexradium »

OrionManMatt wrote:I wouldn't mind finding out how to change the lows to 40, highs to 4k. :-)
i wouldn't touch the bass,there is plenty of gain on 40Hz,just 3 dB less than 20Hz.
For treble try substituting the 1k res on the wiper with a 3.3k ohm,maybe test it with a switch to get the difference.
IMHO this preamp has a too wide Q for every band,enhancing with bass or treble means that the mid band band gets influenced too.

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chicago_mike
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Post by chicago_mike »

finally etching this sucker. A couple actually. good to have a few of these around.

Now onto 40hz and 4khz.

Guess what..if you want boost only on those frequencies..Cough(Sadowsky!!)Cough!!! :mrgreen:

then use a Starzguitarz preamp schematic...Or...Bartolini TCT preamp schematic..OR....Fender tube preamp...ANY model. Remove the midrange pot and put in its place a 6k8 resistor

Use .1 and .047uf caps for bass and mids. say a 300pf or so for treble. You can expirement here with MANY values. My boss likes to replace those origional values with .033 glass/oil caps in fenders.

Theres a fet based sadowsky preamp around here me thinks. :D

Oh, off topic, if you guys ever get the chance to do a cruise ship gig for 2 months, or 3..no longer though..go ahead and do it. its pretty cool. you get paid to see the world. :D
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Post by bluetube »

chicago_mike wrote:finally etching this sucker. A couple actually. good to have a few of these around.

Now onto 40hz and 4khz.

Guess what..if you want boost only on those frequencies..Cough(Sadowsky!!)Cough!!! :mrgreen:

then use a Starzguitarz preamp schematic...Or...Bartolini TCT preamp schematic..OR....Fender tube preamp...ANY model. Remove the midrange pot and put in its place a 6k8 resistor

Use .1 and .047uf caps for bass and mids. say a 300pf or so for treble. You can expirement here with MANY values. My boss likes to replace those origional values with .033 glass/oil caps in fenders.

Theres a fet based sadowsky preamp around here me thinks. :D

Oh, off topic, if you guys ever get the chance to do a cruise ship gig for 2 months, or 3..no longer though..go ahead and do it. its pretty cool. you get paid to see the world. :D
Mike, I reviewed my layout yesterday and did it on another software today to verify. I saw a lot of errors on the EQ portion. :slap: :oops: :slap: :oops:

Sorry bro. I hope you haven't gone too far on the build yet? My apologies for wasted resources if so. I'd post the corrected yet still "unverified" project file if you like?

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Post by bluetube »

Uhm... Couldn't sleep. :horsey: :horsey: :horsey:

After reviewing whatnot material I had on the the subject, turns out my recent eagle adaptation was wrong. I corrected it and now matches the EPCB file. I blame rosin for this. :lol: :lol: :lol:

Still remains to be verified though. Where's the delete button when you need one! :slap: :slap: :slap:

Symbol errors on schematic:
1. V tab before the 1n914??? (supply section) should be V+
2. Insert V on the junction of 1n914???, 100k, and 6.8k (supply section)
3. I'm sure there's more. Anybody care to join the mess? :D :D :D

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chicago_mike
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Post by chicago_mike »

Well....

At least it means I dont need to populate these pcbs...



less work for me!!!! :horsey: :horsey:

All is good home slice. Let me know when you think the layout is cool. :D
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Post by bluetube »

chicago_mike wrote:Well....

At least it means I dont need to populate these pcbs...



less work for me!!!! :horsey: :horsey:

All is good home slice. Let me know when you think the layout is cool. :D
Oops, forgot to mention that the layout checks out on paper. As per revisited verification, it's a go. I hope? :D

I messed up the eagle adaptation that led to me doubt the initial layout. Sorry If I can't offer any assurance other than, proceed with caution? Be the brave soldier Mike? Maybe try populating A board? :D :D :D

The passive/active selector part is still missing tho. You might have to brew something up for that.

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chicago_mike
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Post by chicago_mike »

bluetube wrote:
chicago_mike wrote:Well....

At least it means I dont need to populate these pcbs...



less work for me!!!! :horsey: :horsey:

All is good home slice. Let me know when you think the layout is cool. :D
Oops, forgot to mention that the layout checks out on paper. As per revisited verification, it's a go. I hope? :D

I messed up the eagle adaptation that led to me doubt the initial layout. Sorry If I can't offer any assurance other than, proceed with caution? Be the brave soldier Mike? Maybe try populating A board? :D :D :D

The passive/active selector part is still missing tho. You might have to brew something up for that.

These might go into basses. So the active / passive I wont need. The gain pot will become a trimmer. :D
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Post by Drzeus »

Wheres biffas components?
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OrionManMatt
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Post by OrionManMatt »

chicago_mike wrote:finally etching this sucker. A couple actually. good to have a few of these around.

Now onto 40hz and 4khz.

Guess what..if you want boost only on those frequencies..Cough(Sadowsky!!)Cough!!! :mrgreen:

then use a Starzguitarz preamp schematic...Or...Bartolini TCT preamp schematic..OR....Fender tube preamp...ANY model. Remove the midrange pot and put in its place a 6k8 resistor

Use .1 and .047uf caps for bass and mids. say a 300pf or so for treble. You can expirement here with MANY values. My boss likes to replace those origional values with .033 glass/oil caps in fenders.

Theres a fet based sadowsky preamp around here me thinks. :D

Oh, off topic, if you guys ever get the chance to do a cruise ship gig for 2 months, or 3..no longer though..go ahead and do it. its pretty cool. you get paid to see the world. :D
Feel free to build me one (or two? ha) and I'll send you my Tri-Logic, because I think my Sadowsky pre/DI is toast... I'm getting some sort of weird noise.

Do we need me to double-check anything on my Tri-Logic? I've still got it disassembled.

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Post by chicago_mike »

Oh don't send me anything. I am moving to Italy!! :horsey:

Long story.

Just take as good piccies of anything you think we may need. :)
Mid range switch..active/passive switch...

double check the trace side pcb?
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Post by bluetube »

chicago_mike wrote:Oh don't send me anything. I am moving to Italy!! :horsey:

Long story.

Just take as good piccies of anything you think we may need. :)
Mid range switch..active/passive switch...

double check the trace side pcb?
A landscape pix of the trace side? As flat and as square as possible. Just as if it were scanned on a flatbed. And what mike suggested, clear shots of the active/passive switch? Thanks Matt.

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chicago_mike
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Post by chicago_mike »

Need to get new drill bits for my dremel. Otherwise I would have these demo units built.

Hopefully the pcb's do work out. This is a great pedal / preamp. :)

I should know soon and have reports for everybody,. :)
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Post by jmwreck »

chicago_mike wrote:Need to get new drill bits for my dremel. Otherwise I would have these demo units built.

Hopefully the pcb's do work out. This is a great pedal / preamp. :)

I should know soon and have reports for everybody,. :)
I'm interested on the outcome :D

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Post by Peto Smith »

chicago_mike wrote:Need to get new drill bits for my dremel. Otherwise I would have these demo units built.

Hopefully the pcb's do work out. This is a great pedal / preamp. :)

I should know soon and have reports for everybody,. :)
I will come for the update :horsey:

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Post by Frabbio »

Hi guys, i have built this preamp without the baxandall mid control, adding instead a parametric mid control.
Here is the schematic i used, the pedal sounds good, but when i turn it on it has a stuttering problem for abouta half second.
Any ideas on how i can resolve?
Attachments
EWS TRI-logic 2 + parametric mid.png

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Post by Frabbio »

solved, the led caused popping, but on my practice amp it seemed a different problem. So the schematic is verified,i will post the layout soon .

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Post by Frabbio »

Here is the layout, dimensions are 6x5 cm.
You can change the mid control frequencies by changing C9 and C10 with different values.
Stock it goes from about 300hz to 1100hz.
Attachments
EWS TRI-logic 2 + parametric mid.png
Layout ews+parametric mid.png
EWS layout 6x5 cm h.jpg

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Post by junkwork »

hmm, is there complete schematic?

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Post by Frabbio »

I'm doing some experiments on my modified circuit, stock it has low volume.
I have put the mid controls before the baxandall and increased the gain, i'll keep you updated because it sounds good and it's very versatile.

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Post by pedalgrinder »

Hang On where is the actual schematic of this pedal there seems to be variations and what people thing yada yada yada but what is the legit trace does anyone have it???????? or is it secret squirel business. I have gone through every page of this thread in detail!!!!! and nothing says this is the actual trace of this pedal so maybe you guys are emailing it between each other or iam totally stupid!. Can someone post the actual legit schematic of this pedal. So we know for sure what it and what is a variation on it. Cause Currently you would have to be a rocket scientist to work it out Cheers :thumbsup
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