Dallas Arbiter - Tremface

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Re: Dallas Arbiter - Tremface

Postby Xplorer » 28 Sep 2011, 23:45

thanks RG ,

well,first:

i'm thinkng of buildin this version
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Re: Dallas Arbiter - Tremface

Postby Xplorer » 28 Sep 2011, 23:58

Now : thanks because i didn't know what to do with Cx, i didn't understand that it was an unknown value. it wasn't measured ? i guess i missed something. should i pick any value or remove it ?

then, if i look at the schematic of the corrected trem face ( but still original i guess ) , i don't understand the layout of the original trem face.
some values are missing in one R5 , R7 isn't in the other one .

i can't remember which version i tried last year but i though i did it right but i certainly did it wrong somewhere, and i maybe didn't look close enough to your presentation but i just expected something simple and complete.
where is Q1 ? ah ok, it's for the buffered version. i maybe had some more questions, i just can't remember right now.
any advice about the best range for Q2 and Q3 please ?

i'll breadboard it and come back once it's done, so i'll maybe figure it out and finaly be smart enough lol. i'm not a pro builder ...
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Re: Dallas Arbiter - Tremface

Postby R.G. » 29 Sep 2011, 02:31

As I mentioned, give me a list of questions and I'll go do the research on it. As the dates on the article show, I wrote that nearly ten years ago.
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Re: Dallas Arbiter - Tremface

Postby Xplorer » 29 Sep 2011, 03:02

ok

- should i follow the schematic or the layout ( for the original corrected version, not the advanced one yet ) ? as they're different from each other.
-why these differences ?
-as CX is unknown , what should i do : remove it or put an x value cap ?
-what is the best hfe range for Q2 and Q3 ? cause mine are maybe out of specs but i don't know what's required.
-that's all for now, and i'll try with this start, on a breadboard.

and i'd like to thank for your work on the univibe, it's gonna help me to build a nice clone.

thanks !
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Re: Dallas Arbiter - Tremface

Postby Xplorer » 29 Sep 2011, 23:12

Wow ! R.G ! you rock even more than i thought !
http://www.diystompboxes.com/smfforum/i ... c=77451.80


lot of suspense , and a master at work with a lot of patience, congratulation ! i'm very impressed.

i'll try not to repeat the same mistakes.
i'd have some questions :

- please R.G , should i follow this layout i've re posted here, or the one with the millenium bypass ?
from many threads i've seen quite quickly, is this corrected layout taking in consideration what you maybe wanted to change or correct , since you started ? or should i watch and note everything you've said, that could differ from this layout, on the forums ?

- i don't have the same transistors. in this layout version there are two transistors : a bf244b and a bc184c or a 2n3904. those i have from last year for my first attempt are a 2n3904 measured 161 hfe , a 2n5460 and a 2n5485 ( can't remember why ) . so i guess i tried the millenium bypass layout version, with three transistors. will that work, if it's not a bf244b but these ?

- i'll leave CX out of the circuit.

-i'll wire it like on the layout, and with a usual wire.

-when i'll finish and get it working, i'll post some pictures of my build, related to what layout i used, and indications if it can help, cause some pictures can tell a lot than some words sometimes.

-this trem face seems to have been a problem to quite a few, including me, so i hope that i'm not gonna have these difficult times like Toddy !
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Re: Dallas Arbiter - Tremface

Postby R.G. » 30 Sep 2011, 01:20

Xplorer wrote:- please R.G , should i follow this layout i've re posted here, or the one with the millenium bypass ?

Use the simplest one. The one posted here should work. The millenium is good, but it adds a layer of complexity. 3PDT switches used to be over $20 each, but they're cheap now.

I recommend building it on a breadboard first if you are not skilled with PCBs.

from many threads i've seen quite quickly, is this corrected layout taking in consideration what you maybe wanted to change or correct , since you started ? or should i watch and note everything you've said, that could differ from this layout, on the forums ?

I'll trace it out again, but I believe that this layout reflects the correct original circuit.

- i don't have the same transistors. in this layout version there are two transistors : a bf244b and a bc184c or a 2n3904. those i have from last year for my first attempt are a 2n3904 measured 161 hfe , a 2n5460 and a 2n5485 ( can't remember why ) . so i guess i tried the millenium bypass layout version, with three transistors. will that work, if it's not a bf244b but these ?

Use the 2N3904 and the 2N5485. **CHECK THE PINOUT FOR THE DEVICES YOU HAVE AGAINST THE PINOUT FOR THE DEVICES SPECIFIED**. The 3904 will do reasonably well in that circuit, but it has the base in the middle. If you make a PCB first (and I recommend using a breadboard first to sort these kinds of things out) note well the markings for where C, B, and E are and get the right pins in the right holes. For the 5485, it should work instead of a BF244. But the pinout is different. I think the 5485 is GSD, not DGS like the 244. Check the data sheets for the parts you actually have on line.

- i'll leave CX out of the circuit.

That has worked for others.

-i'll wire it like on the layout, and with a usual wire.

I highly recommend stranded wire, not solid core.

-this trem face seems to have been a problem to quite a few, including me, so i hope that i'm not gonna have these difficult times like Toddy !

Education is what you have left when you've forgotten why you started the project. :D
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Re: Dallas Arbiter - Tremface

Postby Xplorer » 30 Sep 2011, 01:55

fantastic ! thanks R.G .

indeed, i don't have a pcb and i'll simply breadboard it as i planned. i love breadboards :D
then i'll make it solid. later ..

about the fet transistors, yes, except looking at the datasheets, i don't know how to define which is d, which is g, and which is s. and if it has something like a gain range, like the usual transistors ... i don't even know that.

do you think that this 161 gain for the 2n3904 is good ? i perhaps have some others so if there's a better value required for this effect, i should go with it instead ..

"**CHECK THE PINOUT FOR THE DEVICES YOU HAVE AGAINST THE PINOUT FOR THE DEVICES SPECIFIED**. "

i'm not totaly sure to understand the sense of you meant in english, as it's not my first language. i'll check it out. it seems important.


I highly recommend stranded wire, not solid core.

Sure. the solid core broke on toddy's trem face wiring, right ?

Education is what you have left when you've forgotten why you started the project.

ha ha, yes.

i might go with some piher resistors, carbon film, it should sound good.

things are more clear for me now, thanks R.G !
i'll reply once i'll have it built, and i may post pictures, to have things clear.
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Re: Dallas Arbiter - Tremface

Postby theehman » 30 Sep 2011, 03:01

Isn't Cx is just a pair of diodes to prevent overloading the circuit? Seems like I saw that somewhere.
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Re: Dallas Arbiter - Tremface

Postby theehman » 30 Sep 2011, 03:03

theehman wrote:Isn't Cx is just a pair of diodes to prevent overloading the circuit? Seems like I saw that somewhere.


Never mind. It shows that in the first post.
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Re: Dallas Arbiter - Tremface

Postby orpheumlover » 30 Sep 2011, 10:51

Xplorer,
What I found out two years ago when R.G. was helping me get my Trem Face going in the epic saga (over at diysb) were two things:

First, be patient. I am going to crack my Trem Face open on Monday to find out why my box sounds so differently than the original on YouTube. Mine sounds very "boingy" and "swishy" ( a very uneven sine wave) and not as smooth as the original. I will take pictures of my layout for you. I followed the layout from the trace not the schematic.

Second, use the schematic as a reference guide but not as your "road map" for laying your board out. Meaning...you will get lost if you do that. The schematic "as is" is like an old map atlas. Sevearal new streets (suggestions and corrections) have been built since it was made and it may have you put a part in wrong...as it did with one of my errors. There have been many many requests to have a new schematic made of the original because of all of these new ideas and developments in the past three years. This simple circuit has gotten very confusing! When R.G. re-does the schematic I will be the first to send up celebratory fireworks!!

Third, DO NOT USE SOLID CORE WIRES!!! When the box made it to see him in his secret lair in the Lone Star state, R.G.'s discovered that that was main reason my circuit gave me so much trouble. And, two other minor issues that I will not discuss...

I'll be here watching and cheering you on as you get your Trem Face going. For being such a simple circuit with so few parts, this has been one of the most troublesome circuits out there to build!!

Toddy
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Re: Dallas Arbiter - Tremface

Postby Xplorer » 30 Sep 2011, 13:25

hello ! yes it's very surprising. like you said at diy, i too built a coupls of effects before trying this one. and now i learned that i'm not good at wiring the ground of a schematic, and i always prefer the layout, cause it's easy for someone inexperimented to connect all the grounds in a bad way.
thanks ! i'll show it, and if i can help building this "trem face working nicely" recipe, i'll be glad to.
you know, i like to collect some datas on my computer, opening a folder , looking at the layout/ schematic / indications, and knowing that this works with absolutely no problem, wih no need to remember years after what tiny thing had to be done to make the circuit balanced and working. we'll work on that.
thanks.
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Re: Dallas Arbiter - Tremface

Postby theehman » 30 Sep 2011, 14:06

I have a Trem Face pedal here if it's any help.
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Re: Dallas Arbiter - Tremface

Postby Xplorer » 30 Sep 2011, 14:57

oh, sure it could help to compare the layouts ! thanks ! do you perhaps have some pictures ? of the traces, parts ... is it an original trem face ?
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Re: Dallas Arbiter - Tremface

Postby theehman » 30 Sep 2011, 16:23

Xplorer wrote:oh, sure it could help to compare the layouts ! thanks ! do you perhaps have some pictures ? of the traces, parts ... is it an original trem face ?


It's an original Trem Face I picked up years ago as non-working. Still not working as I haven't got around to working on it but now I'll have no excuse.
I'll dig it out this weekend and get some pics.
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Re: Dallas Arbiter - Tremface

Postby Xplorer » 03 Oct 2011, 02:34

Could an effect work at first ??? :lol: damn, you do your best, you look for everything and it just doesn't wanna do what's expected lol.

well, guys , so i build a clone of the tremface on a breadboard. the good new is that it has some signal when its on, and it's pulsating, slow or fast, deep or light, but bad new is that the signal doesn't pulse, instead you hear pt' pt' pt' pt' pt' pt' pt' pt' pt' ......... and you can hear the signal at the same time, but constant, normal, like a dry signal.
i have no clue for this.
tomorrow i'll post some pictures and every infos i have, and the breadboard layout, on a debugging page i'll link here if you're interested.
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Re: Dallas Arbiter - Tremface

Postby Xplorer » 03 Oct 2011, 21:06

Hi R.G ! hi guys ! i've posted my build here , of course , almost working lol.

http://www.freestompboxes.org/viewtopic ... 10&t=14473
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Re: Dallas Arbiter - Tremface

Postby Xplorer » 06 Oct 2011, 13:24

Hi R.G,

do you think that if the signal isn't brought into the pulse, it would be because of the transistors type or something ?
it's wierd ... there's definitely something going on, working like it should, and i can hear it, but it doesn't touch the signal at all. it's separated somewhere.
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Re: Dallas Arbiter - Tremface

Postby R.G. » 06 Oct 2011, 16:01

Xplorer wrote:Could an effect work at first ??? :lol: damn, you do your best, you look for everything and it just doesn't wanna do what's expected lol.

Happens to me all the time. I personify the whole assemblage of natural laws, physics, electronics, etc. as Mother Nature, a stern mother figure always reminding me that I've forgotten something or there is something I have not yet learned. Mother Nature is a disciplinarian, insisting that everything be done exactly, perfectly, 100% right before She will let my projects work. And she does not just tell me the necessary info - she makes me figure it out from unexpected results. Over the years, I've come to realize that things working in unexpected ways is Mother Nature whispering in my ear that there is something I have overlooked or forgotten to do correctly.

...it has some signal when its on, and it's pulsating, slow or fast, deep or light, but ... the signal doesn't pulse, instead you hear pt' pt' pt' pt' pt' pt' pt' pt' pt' ......... and you can hear the signal at the same time, but constant, normal, like a dry signal.

I'm guessing that the pt' pt'... is in time with the speed control. If so, Mother Nature is telling you that the oscillator is getting stuffed into the signal path, and that the JFET is not loading down and reducing the level of the dry signal. She expects you to figure out that this probably means that the pinout on the JFET you used is not correct, and that the gate is being forward biased and letting the LFO signal into the audio signal path through the depth control.
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Re: Dallas Arbiter - Tremface

Postby Xplorer » 06 Oct 2011, 17:11

that's a very good lesson, thanks. in fact i'm too far from understanding how a transistor works, for now. but i'm progressing, little by little. indeed i felt such thing going on with the tranistors, as if there's a signal when it's on, this would probably mean that the rest is ok, with no cold joint. when i built it, i checked the datasheet of this 2n5485 and i used it the way they said but sdg and ebc might change from a builder to another, and i'll plug it differenty.
i'm wondering : for ebc of a normal transistor, i can use my multimeter which has some pnp and npn ebc plugs, and so i can verify it. but for a jfet, is there another way to test it, without simply try every configuration, and know which is which ? it would have been useful when i restored my echoplex ep3, because the jfet was soldered the wrong way ! stock ! and turning it changed a lot of things. but still, i'd like to be able to verify with a simple method which is which with sdg, when for example i have a transistor with no name and brand.
thanks RG ! i'll read your reply on the debug thread.
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Re: Dallas Arbiter - Tremface

Postby R.G. » 06 Oct 2011, 20:32

Xplorer wrote: i checked the datasheet of this 2n5485 and i used it the way they said but sdg and ebc might change from a builder to another, and i'll plug it differenty.

I think it's SDG. The trick is identifying which end the gate is on.

for a jfet, is there another way to test it, without simply try every configuration, and know which is which ?

JFETs are a low resistance between source and drain, and a diode on the gate to either source or drain. For an N-channel (2N5485 is one) any pin which will not conduct to both the other two when you hook up the positive lead to it must be the gate. Note that I said positive lead, not red lead. Most meters with ohmmeter settings make the red lead positive, but I ran into a couple that had that reversed. Confused me until I tried it on a diode that I already KNEW the orientation on. You might want to verify which way your meter does it, just to make sure.

For an N-channel JFET which is supposed to be SDG, the gate should be one of the end pins, not the center one. So you only need two tests to identify it at most. Negative lead to outside pin, positive lead to center pin. If it conducts something like 50-5K ohms, that's not the gate. On the other end, if it's open, you're reading the gate reverse biased, so you've found the gate. The source and drain are interchangeable on almost all low frequency small signal devices like the 5485.
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