E.W.S Tri-Logic II Bass Preamp [traced]
- george giblet
- Resistor Ronker
I'm a bit confused about the mid caps.
The 12kHz treble might correspond to the 1k treble resistor.
The mid frequency specs for the Xotic Basses are the same as the EWS Trilogic II pedal.
The treble is different.
Bass XJ-1 (upto 2009 with switches on back)
Bass XJ-1T (2009/2010 and beyond, switches on front)
SW1: "Mid switch", +/-12dB @ 400Hz/800Hz
SW2: "Bright switch", +/-18dB @ 6kHz/12kHz
However Nikifena mentioned the basses had mid caps 47n and 100n.
I have this feeling the mid frequencies might have got moved on the EWS pedal but the printed specs were not?
I have no specs for the original Xotic Tri-logic pedal.
Anyway From what I can work out the models around are:
1) Xotic "Tri-logic Bass Preamp". (From <= 2006 upto 2011?)
Wide box pedal. Black.
2) Early model Xotic Bass XJ-1: sames specs as XJ-1T except switches on the back. trimpot on back. (From ???? to about 2009)
3) Later model XJ-1T. Toggle switches on front. Trimpot? (From 2009/2010 and beyond)
4) EWS Tri-logic II. Black (From 2011 to 2015).
5) EWS Tri-logic III. Grey/Silver Hammertone (2015 to now).
Bass freq switch. Treble Freq Switch. Mid freq Control.
The 12kHz treble might correspond to the 1k treble resistor.
The mid frequency specs for the Xotic Basses are the same as the EWS Trilogic II pedal.
The treble is different.
Bass XJ-1 (upto 2009 with switches on back)
Bass XJ-1T (2009/2010 and beyond, switches on front)
SW1: "Mid switch", +/-12dB @ 400Hz/800Hz
SW2: "Bright switch", +/-18dB @ 6kHz/12kHz
However Nikifena mentioned the basses had mid caps 47n and 100n.
I have this feeling the mid frequencies might have got moved on the EWS pedal but the printed specs were not?
I have no specs for the original Xotic Tri-logic pedal.
Anyway From what I can work out the models around are:
1) Xotic "Tri-logic Bass Preamp". (From <= 2006 upto 2011?)
Wide box pedal. Black.
2) Early model Xotic Bass XJ-1: sames specs as XJ-1T except switches on the back. trimpot on back. (From ???? to about 2009)
3) Later model XJ-1T. Toggle switches on front. Trimpot? (From 2009/2010 and beyond)
4) EWS Tri-logic II. Black (From 2011 to 2015).
5) EWS Tri-logic III. Grey/Silver Hammertone (2015 to now).
Bass freq switch. Treble Freq Switch. Mid freq Control.
- george giblet
- Resistor Ronker
EWS Trilogic II
Update V1.0 2018_12_02 to V1.1 2018_12_03
The other Xotic products do tend to use 50kB pots.
So I suspect this is correct.
Issues:
1) Not happy about 1nF cap. It has a black dot like a value small cap.
2) What to do about the 1k0 vs 1k8 treble cap issue.
3) Not happy about mid caps
4) The NE5532 opamp current draw looks too high for the current
consumption spec. Possibly RC4557D
--------------------------------------------------------
Bass: +/- 13.5dB @ 90Hz (Mid switch HI)
--------------------------------------------------------
1) 1n treble cap. I can see a black top on the cap
which would imply NPO/COG and small value.
It is quite possible it is 100pF like the 100pF NPO/COG input cap.
*** Chicago Mike (p1), Image 015, we can see this cap in 100pF
Also,OrionManMatt (p3) Handdrawn overlay shows 100pF
So clearly it *is* 100pF
2) Treble Resistor
After changing the 1nF cap to a 100pF cap we can revisit the
esponse specs and the 1k8 vs 1k0 treble treble resistor issue.
1k8: Treble: +/- 13dB @ 10kHz ; This now agrees with the Tri-logic II specs.
1k0: Treble: +/- 16.9dB @ 10kHz
The response is *very* close to the Xotic BB Tone control
when the Treble caps are doubled. Which *might*
be what is done in the Bass version Xotic BB.
3) Mid caps:
OrionManMatt (p4), it fairly clear on the mid cap
high-mid side: 473k
low-mid side: 154k
These are clearly correct, at least for his version of the
board, with the 1k0 treble cap.
Chicago Mike (p1) remembered on of the mid caps was 47nF.
The other cap is unknown.
Nikifena p6. On the Xotic Bass.
Mids 47n and 100n; maybe no 2.4k on mids(?)
Conclusion:
The hi mid-cap is probably 47nF.
The low mid-cap is probably 150n on the version with the 1.0k treble resistor.
The low mid-cap might could be 100n or 150n on the version with the 1.8k treble resistor.
The mid frequencies don't match-up with the published mid frequencies.
47nF: +/- 8dB @ 1.3kHz
100nF: +/- 9.3dB @ 520Hz
150nF: +/- 10.2dB @ 360Hz
4) The Opamp might be an RC4559.
Other's have speculated this part for Xotic Pedals.
Update V1.0 2018_12_02 to V1.1 2018_12_03
The other Xotic products do tend to use 50kB pots.
So I suspect this is correct.
Issues:
1) Not happy about 1nF cap. It has a black dot like a value small cap.
2) What to do about the 1k0 vs 1k8 treble cap issue.
3) Not happy about mid caps
4) The NE5532 opamp current draw looks too high for the current
consumption spec. Possibly RC4557D
--------------------------------------------------------
Bass: +/- 13.5dB @ 90Hz (Mid switch HI)
--------------------------------------------------------
1) 1n treble cap. I can see a black top on the cap
which would imply NPO/COG and small value.
It is quite possible it is 100pF like the 100pF NPO/COG input cap.
*** Chicago Mike (p1), Image 015, we can see this cap in 100pF
Also,OrionManMatt (p3) Handdrawn overlay shows 100pF
So clearly it *is* 100pF
2) Treble Resistor
After changing the 1nF cap to a 100pF cap we can revisit the
esponse specs and the 1k8 vs 1k0 treble treble resistor issue.
1k8: Treble: +/- 13dB @ 10kHz ; This now agrees with the Tri-logic II specs.
1k0: Treble: +/- 16.9dB @ 10kHz
The response is *very* close to the Xotic BB Tone control
when the Treble caps are doubled. Which *might*
be what is done in the Bass version Xotic BB.
3) Mid caps:
OrionManMatt (p4), it fairly clear on the mid cap
high-mid side: 473k
low-mid side: 154k
These are clearly correct, at least for his version of the
board, with the 1k0 treble cap.
Chicago Mike (p1) remembered on of the mid caps was 47nF.
The other cap is unknown.
Nikifena p6. On the Xotic Bass.
Mids 47n and 100n; maybe no 2.4k on mids(?)
Conclusion:
The hi mid-cap is probably 47nF.
The low mid-cap is probably 150n on the version with the 1.0k treble resistor.
The low mid-cap might could be 100n or 150n on the version with the 1.8k treble resistor.
The mid frequencies don't match-up with the published mid frequencies.
47nF: +/- 8dB @ 1.3kHz
100nF: +/- 9.3dB @ 520Hz
150nF: +/- 10.2dB @ 360Hz
4) The Opamp might be an RC4559.
Other's have speculated this part for Xotic Pedals.
- george giblet
- Resistor Ronker
I've been looking at thing too long.
I just came back to check it and I realized the 100pF I mentioned is actually across the other part of the opamp!!! What a dilweed
Ignore the thing about 1nF cap and the treble control spec update.
I'm surprised the specs line-up better with the smaller feedback cap on the tone control.
So how do we know the 1nF cap is 1nF?
EDIT
OK I can see where it came from, OrionManMatt's (p3) Handdrawn overlay.
So it must be correct?
I just came back to check it and I realized the 100pF I mentioned is actually across the other part of the opamp!!! What a dilweed
Ignore the thing about 1nF cap and the treble control spec update.
I'm surprised the specs line-up better with the smaller feedback cap on the tone control.
So how do we know the 1nF cap is 1nF?
EDIT
OK I can see where it came from, OrionManMatt's (p3) Handdrawn overlay.
So it must be correct?
- george giblet
- Resistor Ronker
OK I've fix up the mistakes and regenerated the performance specs.
Can't go any further without more pics or info.
One thing I can add is the Xotic XJ-1T bass looks like it uses the same PCB as the EWS pedal.
The switches and mid-caps are mounted on a second board which is wired to the main board.
Can't go any further without more pics or info.
One thing I can add is the Xotic XJ-1T bass looks like it uses the same PCB as the EWS pedal.
The switches and mid-caps are mounted on a second board which is wired to the main board.
- george giblet
- Resistor Ronker
I found a pic of an Xotic bass which had a large square PCB but still had the switches on the back (not the two toggle switches on the front). It had 100kB pots for the BMT controls! It also had two 8-pin opamps. I could not see a MOSFET.
So this thing is a big mess in terms of versions!
That bass had the same board as the original Xotic-tri-logic(1) pedal.
Maybe the square board with the two opamps is an old version and the smaller rectangular board with the MOSFET is a new version. That might explain "Tri-logic" preamp vs. "Tri-logic 2"/"Tri-logic II".
So this thing is a big mess in terms of versions!
That bass had the same board as the original Xotic-tri-logic(1) pedal.
Maybe the square board with the two opamps is an old version and the smaller rectangular board with the MOSFET is a new version. That might explain "Tri-logic" preamp vs. "Tri-logic 2"/"Tri-logic II".
- chicago_mike
- Tube Twister
HI George!
The larger Tri-Logic is the older version. The II version is the same used in the Xotic Basses , but now with the III version out they may have updated the preamp more.
I have a Tri-Logic II again but it's in storage. I may take it apart fully and take full on gut pics later this month
The larger Tri-Logic is the older version. The II version is the same used in the Xotic Basses , but now with the III version out they may have updated the preamp more.
I have a Tri-Logic II again but it's in storage. I may take it apart fully and take full on gut pics later this month
Skyline FX 2013
- george giblet
- Resistor Ronker
Hi Mike, long time no see! In the past few years I've been going over a lot of your old posts and gut shots.
If you want to check over it that would be great. From what I can remember the hanging items were:
the caps on the mid switch, the values of the pots, the value of the resistor that goes to the wiper on the treble pot (some units seem like 1k0 and others 1k8), and maybe the zener markings.
Thanks for the confirmation. By the time I got to my last post I found a few pics that more or less confirmed the Tri-Logic II was a different beast. After that it made sense. I also notice the Xotic bass docs started quoting Tri-Logic II as well.The larger Tri-Logic is the older version. The II version is the same used in the Xotic Basses , but now with the III version out they may have updated the preamp more.
I have a Tri-Logic II again but it's in storage. I may take it apart fully and take full on gut pics later this month
If you want to check over it that would be great. From what I can remember the hanging items were:
the caps on the mid switch, the values of the pots, the value of the resistor that goes to the wiper on the treble pot (some units seem like 1k0 and others 1k8), and maybe the zener markings.
- chicago_mike
- Tube Twister
I have one of these again since I liked it too much! LOL!
It's in storage but I dont mind taking it out and getting good piccies
I have a few toys I will get good piccies of for the forum.
Just need to get my self organized...LOL!!
Im happy to check over anything too!
It's in storage but I dont mind taking it out and getting good piccies
I have a few toys I will get good piccies of for the forum.
Just need to get my self organized...LOL!!
Im happy to check over anything too!
Skyline FX 2013
- george giblet
- Resistor Ronker
Thanks a lot Mike. You certainty have put up a lot of pic over the years.
(FYI, some time back posted a schem for the Lakland Hanson LH-3 you posted. It's in the Electric Guitar Rewiring forum.)
(FYI, some time back posted a schem for the Lakland Hanson LH-3 you posted. It's in the Electric Guitar Rewiring forum.)
- chicago_mike
- Tube Twister
Im getting a "small" collection of pedals and will get real good pics. I want to make sure I get stuff we dont already have on the forum or if its already on the forum, maybe better pics might help for some pedals.
I used to work at a repair shop and maybe I can use my "contacts" to get official schematics too.
Here to help out if I'm able
I used to work at a repair shop and maybe I can use my "contacts" to get official schematics too.
Here to help out if I'm able
Skyline FX 2013
- jeepe
- Breadboard Brother
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not totally green, but that's all :)
my "level" is about building a big muff... medium complexity :)
I'll never build a DS-2, for example :)
- -
even though I'm a layman to electronics
I'll never build anything without seeing the actual schematics too...
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my all time favorite: Fuzz FAce
it is an always ongoing project..
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I want to end up strumming some strings at the end of the day, whatever the sound
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I'm so sad that this beautiful culture (and freedom movement) is totally ephemeral - Location: Budaspest, Europe
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hi guys,
I wonder what the situation is...?
I hope you are doing fine
guess what, I've just bumped into this... dated of February 2019
this could be it, right?
http://effectslayouts.blogspot.com/2019 ... mp-ii.html
_
I wonder what the situation is...?
I hope you are doing fine
guess what, I've just bumped into this... dated of February 2019
this could be it, right?
http://effectslayouts.blogspot.com/2019 ... mp-ii.html
_
pedal building, tracing and sharing is such a beautiful freedom movement... If only it could be viewed as a future heritage, but it really is ephemeral, as it seems
- modman
- a d m i n
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Please, support freestompboxes.org on Patreon for just 1 pcb per year! Or donate directly through PayPal
- jeepe
- Breadboard Brother
Information
- Posts: 73
- Joined: 10 Jun 2019, 16:48
- Completed builds: I might be at level 2, so to speak..
not totally green, but that's all :)
my "level" is about building a big muff... medium complexity :)
I'll never build a DS-2, for example :)
- -
even though I'm a layman to electronics
I'll never build anything without seeing the actual schematics too...
- -
my all time favorite: Fuzz FAce
it is an always ongoing project..
- -
I want to end up strumming some strings at the end of the day, whatever the sound
- -
I'm so sad that this beautiful culture (and freedom movement) is totally ephemeral - Location: Budaspest, Europe
- Has thanked: 625 times
- Been thanked: 22 times
you're absolutely right -- I didn't by any means want to suggest that it was before this one...modman wrote: ↑19 Jan 2020, 22:53
Source for that was probably viewtopic.php?f=7&t=16263&p=273119#p273119
December 2018
instead, I wanted to point out that activity ended here, and continued there...
last post here: January, first post there: February
pedal building, tracing and sharing is such a beautiful freedom movement... If only it could be viewed as a future heritage, but it really is ephemeral, as it seems
- jeepe
- Breadboard Brother
Information
- Posts: 73
- Joined: 10 Jun 2019, 16:48
- Completed builds: I might be at level 2, so to speak..
not totally green, but that's all :)
my "level" is about building a big muff... medium complexity :)
I'll never build a DS-2, for example :)
- -
even though I'm a layman to electronics
I'll never build anything without seeing the actual schematics too...
- -
my all time favorite: Fuzz FAce
it is an always ongoing project..
- -
I want to end up strumming some strings at the end of the day, whatever the sound
- -
I'm so sad that this beautiful culture (and freedom movement) is totally ephemeral - Location: Budaspest, Europe
- Has thanked: 625 times
- Been thanked: 22 times
hi, I saw this comment of mine today (Dec 29. 2020) and was terrified by the length...
sorry!
I removed it -- since it didn't turn out to be a helpful contribution -- and added it, for the record's sake,
as an attachment... and now it doesn't hurt the topic in either way (I hope)
Peter
sorry!
I removed it -- since it didn't turn out to be a helpful contribution -- and added it, for the record's sake,
as an attachment... and now it doesn't hurt the topic in either way (I hope)
Peter
- Attachments
-
- saved.pdf
- the late LONG comment as a PDF file
- (60.49 KiB) Downloaded 134 times
Last edited by jeepe on 29 Dec 2020, 07:03, edited 1 time in total.
pedal building, tracing and sharing is such a beautiful freedom movement... If only it could be viewed as a future heritage, but it really is ephemeral, as it seems
- george giblet
- Resistor Ronker
I don't have any doubts the schematic I posted on 03 Dec 2018, 23:54 will *work* and even sound OK.
I guess the question is what are the actual values.
- 50kB pots, relatively high level of confidence.
- 1k8 vs 1k0, perhaps slight bias towards the 1k8
- Mid cap of 100n vs 150n, probably the most uncertain part value
I guess the question is what are the actual values.
No photos in the thread resolve these hanging items.08 Jan 2019, 23:46
If you want to check over it that would be great. From what I can remember the hanging items were:
the caps on the mid switch, the values of the pots, the value of the resistor that goes to the wiper on the treble pot (some units seem like 1k0 and others 1k8), and maybe the zener markings.
- 50kB pots, relatively high level of confidence.
- 1k8 vs 1k0, perhaps slight bias towards the 1k8
- Mid cap of 100n vs 150n, probably the most uncertain part value
- The G
- Grease Monkey
I was curious about how different are the two versions:
I attached the Eagle schematics used for drawing, maybe they of some use for someone. Hopefully, there are not too many mistakes in them. Also, in the Eagle schematics I used my custom libraries, so some components might need replacing.
Regarding the final/not final versions, there were two different circuits traced and analysed. How can the second be the completion of the first? Both have their place, so one solution could be to have multiple "traced" links. The current implementation is a phpBB extension for making a topic "solved", which allows for only one "solver" post. It's a definitely a good suggestion and we'll put it on the list. But, since it requires creating a phpBB extension, it might take a while.
I attached the Eagle schematics used for drawing, maybe they of some use for someone. Hopefully, there are not too many mistakes in them. Also, in the Eagle schematics I used my custom libraries, so some components might need replacing.
Regarding the final/not final versions, there were two different circuits traced and analysed. How can the second be the completion of the first? Both have their place, so one solution could be to have multiple "traced" links. The current implementation is a phpBB extension for making a topic "solved", which allows for only one "solver" post. It's a definitely a good suggestion and we'll put it on the list. But, since it requires creating a phpBB extension, it might take a while.
- Attachments
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- ews_trilogic_parametric_johnk.sch
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- ews_trilogic_baxandall_george-giblet.sch
- (164.5 KiB) Downloaded 170 times
- george giblet
- Resistor Ronker
The non-parametric is definitely the one analysed in this thread.Regarding the final/not final versions, there were two different circuits traced and analysed. How can the second be the completion of the first?
I am quite certain John K's parametric version is his own spin on the EWS trilogic III. He basically took the circuit in this thread then appended the parametric equalizer on RG's (Geofex) page, see circuit about half way down,
http://www.geofex.com/Article_Folders/EQs/paramet.htm
The EWS trilogic III has a parametric but it is a semi-parametric (ie. without a Q-control). My feeling is the actual EWS parametric is probably based on a circuit like,
http://i476.photobucket.com/albums/rr13 ... metric.png
or,
viewtopic.php?f=3&t=27398
or perhaps the similar circuit which has an extra opamp.
- The G
- Grease Monkey
george giblet wrote: ↑24 Aug 2020, 06:26 [...] My feeling is the actual EWS parametric is probably based on a circuit like,
http://i476.photobucket.com/albums/rr13 ... metric.png [...]
I hope you don't mind me putting the image here. Hosting sites tend to dissapear ¯\_(ツ)_/¯
- george giblet
- Resistor Ronker
I couldn't see the pic. Here's a screenshot
FWIW, the parametric on the EWS Tri-logic III Bass Preamp is +/-10dB with a frequency range of 250Hz to 3kHz.
The closest match parts are,
C1 = 5n6
C2 = 5n6
which gives +/- 9.5dB and a frequency range of 260Hz to 2.8kHz.
The cap formula on my schematic only holds for +/-15dB.
For the +/- 9.5dB case it is much simpler C1 = C2 = 1/(2*pi*R*f0); where R= pot + series resistance
Remember, we don't know this is the circuit used in the EWS.
FWIW, the parametric on the EWS Tri-logic III Bass Preamp is +/-10dB with a frequency range of 250Hz to 3kHz.
The closest match parts are,
C1 = 5n6
C2 = 5n6
which gives +/- 9.5dB and a frequency range of 260Hz to 2.8kHz.
The cap formula on my schematic only holds for +/-15dB.
For the +/- 9.5dB case it is much simpler C1 = C2 = 1/(2*pi*R*f0); where R= pot + series resistance
Remember, we don't know this is the circuit used in the EWS.
- The G
- Grease Monkey