Building the Ultimate DIY TubeScreamer Clone

[dan-o-guitar]

Thought it would be fun to post a thread that walks through my latest project, along with pictures and notes as it moves along.

Project goals: To build a TS-808/TS-9 TubeScreamer clone that has most of the useful mods available, and switchable from the front panel.

Mods:
1. Stacked switchable opamps. Switch between JRC4558D, RC4558P and LM833 opamps or run all together at the same time.

2. Clipping mods: allows stock clipping, or various levels of asymmetrical clipping. Switching of standard 1N914, 1N4001 Silicon Power diode, 1N34A Germainum diode, and a Yellow LED on each side of the clipping chain.

3. TS808/TS9 mode switch: switch between both circuits or a hybrid of the two.

4. Tone-stack mod: switch between the stock TS "nasal" mid-hump tone stack and a full-range tone stack (lets more bass through)

5. Distortion boost: in place of the stock 4.7k resistor there is a 5k pot to increase distortion. This pot is hooked to a status LED and its own stomp switch so you can go between stock and boost with a tap of the foot.

6. Cleanup mod: In place of the stock 51k resistor there is a 50k pot to allow control over how it cleans up.

7. Voltage mods: the circuit can run at up to 12 volts. There is a voltage pot, along with a voltage meter so you can see where you are.

All my mods are based on the BYOC Screamer Clone board, with a lot of off-board switching.

Pics to follow.

[dan-o-guitar]

Semi-completed board and some of the switches started.
http://www.beavisaudio.com/Projects/screamerlab/boardandswitches.jpg

Stacking the opamps:
http://www.beavisaudio.com/Projects/screamerlab/stackedopamps.jpg

Stack with tails:
http://www.beavisaudio.com/Projects/screamerlab/stackedopamps2.jpg

Hmmm, maybe I'll need a cooling fan:
http://www.beavisaudio.com/Projects/screamerlab/stackedopamps3.jpg

Box all drilled:
http://www.beavisaudio.com/Projects/screamerlab/drilledbox.jpg

Front panel populated:
http://www.beavisaudio.com/Projects/screamerlab/frontpanelbare.jpg

A peek inside:
http://www.beavisaudio.com/Projects/screamerlab/insidebare.jpg

More to follow...

[PolyFmorf]

That looks highly impressive. But, WTF are all those switches for :confused:

Are you a EE?

[dan-o-guitar]

Originally posted by PolyFmorf
That looks highly impressive. But, WTF are all those switches for :confused:

Are you a EE?

The switches allow me to switch between all the mods. For example, set a certain way, the switches make a TS-808 clone. Set another way, it could be a TS9/TS-808 hybrid, with asymmetric clipping pumped up to 12 volts with three op-amps running in parallel.

EE? Heh, that's a good one. I barely made it out of high school.

[Bruce Bennett]

Originally posted by dan-o-guitar


Front panel populated:
http://www.beavisaudio.com/Projects/screamerlab/frontpanelbare.jpg

:eek:

and I thought some of my ideas were demented :eek:

but your a gen-u-wine :freak:....

how much for one?....:D

[bzja]

Originally posted by dan-o-guitar
Thought it would be fun to post a thread that walks through my latest project, along with pictures and notes as it moves along.

Project goals: To build a TS-808/TS-9 TubeScreamer clone that has most of the useful mods available, and switchable from the front panel.

Mods:
1. Stacked switchable opamps. Switch between JRC4558D, RC4558P and LM833 opamps or run all together at the same time.

2. Clipping mods: allows stock clipping, or various levels of asymmetrical clipping. Switching of standard 1N914, 1N4001 Silicon Power diode, 1N34A Germainum diode, and a Yellow LED on each side of the clipping chain.

3. TS808/TS9 mode switch: switch between both circuits or a hybrid of the two.

4. Tone-stack mod: switch between the stock TS "nasal" mid-hump tone stack and a full-range tone stack (lets more bass through)

5. Distortion boost: in place of the stock 4.7k resistor there is a 5k pot to increase distortion. This pot is hooked to a status LED and its own stomp switch so you can go between stock and boost with a tap of the foot.

6. Cleanup mod: In place of the stock 51k resistor there is a 50k pot to allow control over how it cleans up.

7. Voltage mods: the circuit can run at up to 12 volts. There is a voltage pot, along with a voltage meter so you can see where you are.

All my mods are based on the BYOC Screamer Clone board, with a lot of off-board switching.

Pics to follow.



and how, may I ask, do you know how all that shit works?
:D

[derek_32999]

Heh Heh Cool Beavis!!

Demented as always!! :thu:

[Ray18]

You make obsession fun :D



I'd totally buy one of these :love:

[Ray18]

how would running three opamps at once sound? :confused:


loud?


btw...someone got a bit crazier than you on one aspect...aparently this guy built a 4558 with discreet components which in themselves are switchable :eek: there's germanium devices in there!

[RoboPimp]

holy hell, another insane invention!

[dan-o-guitar]

Originally posted by Bruce Bennett
how much for one?....:D

I think it works out to about 250-300 in parts. And yes, I'm sidestepping your question :) Don't think I have the time actually turn these ideas into production units.

But others are welcome to take an entrepreneurial stab. Actually, I'd be honored if a commercial builder ripped off this idea :)

[dan-o-guitar]

Originally posted by bzja


and how, may I ask, do you know how all that shit works?
:D

Google told me. I started here:
http://www.geofex.com/Article_Folders/TStech/tsxtech.htm

and spent a lot of time asking questions here:

http://board.buildyourownclone.com/

and here:
http://www.diystompboxes.com/smfforum/index.php?board=2.0

and on HCEF.

And I searched and ready for days. I've got a looseleaf binder full of notes and drawings just about the TubeScreamer.

I ended up with the following wiring diagram:
http://beavisaudio.com/Projects/screamerlab/ScreamerWiring.gif

Note that the diagram is preliminary. I won't be sure about its accuracy until the project is built and tested.

[dan-o-guitar]

Originally posted by Ray18
how would running three opamps at once sound? :confused:
loud?
According to Jack Orman (http://www.muzique.com/):

"…what you get is increased current drive. Typically, a small value resistor, 10-50 ohms is inserted in the output of each opamp before they are combined to the signal output. This ensures that the opamps share the drive more equally. Using a pair of opamps in parallel will actually decrease the noise by about 3db due to random cancellations. Four opamps in parallel would reduce it even further, but that’s about the practical limit.”

btw...someone got a bit crazier than you on one aspect...aparently this guy built a 4558 with discreet components which in themselves are switchable :eek: there's germanium devices in there!

Ah yes, that would be Joe Davisson's Diode-Compression Op Amp (http://www.diystompboxes.com/smfforum/index.php?board=16.0). Ingenious pedal hackery!

I'm saving that for my Rat clone/lab.

[dan-o-guitar]

Originally posted by RoboPimp
holy hell, another insane invention!

Thanks dude. I was spurred on during the design by your opamp comments regarding shades of black when buying a car :) I think you'll end up being right about the audible differences between opamps, but I think the stacking part may be cool.

[Richard Guy]

Don't let Dan-O fool you, he is actually an instructor at MENSA and is an 'on-call' instrument consultant at NASA. In addition, his dart game and bird call skills are legendary. All-in-all, a great guy with vision. I am honored to have met him. :thu:

'If all you have is a hammer, then everything looks like a nail'

[Stratotone]

On all of those clipping section DPDTs, couldn't you make it even MORE flexible if you used the second pair of terminals for another diode instead of having it bypass? (that is, if you used an on/off/on switch, of course.)

Pete

[PolyFmorf]

Originally posted by dan-o-guitar


I'm saving that for my Rat clone/lab. Do keep us posted on a Rat clone. The two pedals i LOVE the most are the Rat and Tubescreamer. I'm currently only using the podXT versions, but I would like to build some.

I'm itching for a project since I finished all my guitars. Last big project was a Heathkit TV :D

[dan-o-guitar]

Originally posted by Stratotone
On all of those clipping section DPDTs, couldn't you make it even MORE flexible if you used the second pair of terminals for another diode instead of having it bypass? (that is, if you used an on/off/on switch, of course.)

Pete

Sure, but I don't know how many more diode types would actually benefit the circuit. Conventional wisdom seems to hold that the stock diodes, germanium, leds and signal diodes offer enough variations.

If I was really ambitious, I would have put five different caps in the tone stack mod with a rotary switch.

I guess I need to leave a few things left undone for the Mark II version :)

[dan-o-guitar]

Originally posted by PolyFmorf
Do keep us posted on a Rat clone. The two pedals i LOVE the most are the Rat and Tubescreamer. I'm currently only using the podXT versions, but I would like to build some.

I'm itching for a project since I finished all my guitars. Last big project was a Heathkit TV :D

I've got the stock Rat board from General Guitar Gadgets moving along. Have some good ideas--but I don't think there will as many switchable mods as in the TubeScreamer. I'll keep you posted.

[dot-dot-dot]

That is phenomenal - I'm staggered!

[dan-o-guitar]

Finally got the build article (as it stands so far) up on the beavis site:

http://beavisaudio.com/Projects/ScreamerLab/index.htm

dotdotdot: Thanks for the kudos! You've tempted me to build the BYOC delay with an expression pedal, but I've got to finish this frankenscreamer first!

[Pwn3d]

man, I love your stuff

You do what I want to do, the only difference between me and you is that Im flat broke.

Makes me sad because my tubescreamer clone/mod never got off the ground due to funds.

Anyways...


I wonder what it would look like if you made me an amp :eek:

[dan-o-guitar]

Originally posted by Pwn3d
man, I love your stuff

You do what I want to do, the only difference between me and you is that Im flat broke.

Makes me sad because my tubescreamer clone/mod never got off the ground due to funds.

Anyways...


I wonder what it would look like if you made me an amp :eek:

Lack of funds sucks. Lack of time sucks. I used to have all the time in the world but no funds. Now I have funds, but not nearly enough time.

Of course, it beats being dead. Hang in there.

[Stratotone]

Originally posted by dan-o-guitar


Sure, but I don't know how many more diode types would actually benefit the circuit. Conventional wisdom seems to hold that the stock diodes, germanium, leds and signal diodes offer enough variations.

If I was really ambitious, I would have put five different caps in the tone stack mod with a rotary switch.

I guess I need to leave a few things left undone for the Mark II version :)

Aren't there enough variances in how much compliance/bounding each diode type does? In other words, what if you had a diode that measured higher than another one within the same general type? :D

Pete

[PolyFmorf]

dan-o-guitar,

The boxes are INSANE. After visiting your website, which is VERY well done, I thought I would stick my toe in the water, so to speak, and I ordered a BYOC screamer pedal.

If that goes well I will build another model, and another, ad infinitum...........

They are actually for #2 son who is a few orders of magnitude better on guitar than I am.

But I can solder and he can't :D

Regards,

Harry

[mumford]

Your stuff always impresses me. Very cleanly done, and super versatile.

[dan-o-guitar]

Originally posted by Stratotone


Aren't there enough variances in how much compliance/bounding each diode type does? In other words, what if you had a diode that measured higher than another one within the same general type? :D
Pete

Interesting questions, and I'm not completely sure of the answers. Why don't diodes come in tolerances like resistors and caps? I always assumed a certain closeness in tolerance for diodes. I guess that's the beauty of analog components--you never know until you try it.

The interesting part of this is that the stock TS used two identical diodes in the clipping stage yielding symmetrical clipping. I'm looking forward to trying out different types on each side to see how asymmetrical I can get it.

Of course, if was truly committed to this whole clipping thing, I'd also have a single 12AX7 acting as clipping pair...

[dan-o-guitar]

Originally posted by PolyFmorf
dan-o-guitar,

The boxes are INSANE. After visiting your website, which is VERY well done, I thought I would stick my toe in the water, so to speak, and I ordered a BYOC screamer pedal.

If that goes well I will build another model, and another, ad infinitum...........

They are actually for #2 son who is a few orders of magnitude better on guitar than I am.

But I can solder and he can't :D

Regards,

Harry

Awesome! Another pedal hacker joins the fray. Good luck with the BYOC Screamer--Keith's kits are awesome and you should have it up and running in no time. Be sure to keep #2 son inolved--seeing the insides of pedals and learning the basics of how they work is a cool thing.

[dan-o-guitar]

Clipping diodes on switches are done.

I put sockets on the switches with the LEDs to try different values.

Interesting fact of the day: some way-overpriced TS clones differ from the original only in that they use 20 cent yellow LEDs instead of stock diodes.

http://www.beavisaudio.com/Projects/ScreamerLab/DiodeSwitches.jpg

[Stratotone]

Originally posted by dan-o-guitar
Clipping diodes on switches are done.

I put sockets on the switches with the LEDs to try different values.

Interesting fact of the day: some way-overpriced TS clones differ from the original only in that they use 20 cent yellow LEDs instead of stock diodes.

http://www.beavisaudio.com/Projects/ScreamerLab/DiodeSwitches.jpg

Great idea of socketing the switches. I've been building some mojo-voodoo tube screamer clones (based off the terrific BYOC board, I just change some parts values and make some things switchable, like diode clipping) and the idea of the sockets on the switches is AWESOME. One thing I noticed in my experiments so far is that when you're pushing an already overdriven amp, the clipping diodes don't seem to make a whole lot of difference: It's more apparent when you're using the TS as a distortion generator more than a clean boost. Just my opinion.

Pete

[dan-o-guitar]

Originally posted by Stratotone


Great idea of socketing the switches. I've been building some mojo-voodoo tube screamer clones (based off the terrific BYOC board, I just change some parts values and make some things switchable, like diode clipping) and the idea of the sockets on the switches is AWESOME. One thing I noticed in my experiments so far is that when you're pushing an already overdriven amp, the clipping diodes don't seem to make a whole lot of difference: It's more apparent when you're using the TS as a distortion generator more than a clean boost. Just my opinion.

Pete

That makes sense about pushing a clean amp, which is pretty much what I do. I'd love to hear mo about your screamer clones--the BYOC kits are awesome testbeds for crazy idea.

Oh, and that kid in your avatar, that was me. Well at least I did that once when we lived overseas. 220 v knocked me across the room.

After my heart re-booted, I *knew* I had to do stuff with electronics. What a rush. Now I'm older, but I still change light switches and outlets around the house with the power on. I'm like fuckin' Macgyer defusing bombs and shit :)

[Mr country boy]

hey y'all,
you can find a rat clone here..

http://www.tonepad.com


have fun

mr cb

[dan-o-guitar]

Originally posted by Mr country boy
hey y'all,
you can find a rat clone here..

http://www.tonepad.com


have fun

mr cb

Tonepad does great stuff. Another one is at:

General Guitar Gadgets (http://www.generalguitargadgets.com/index.php?option=content&task=view&id=63&Itemid=95)

OLC is also offering a kit based on the TonePad layout:

OLC (http://www.olcircuits.com/olckits.html)

[Mr country boy]

Hi yall ,
Dan,

THANK YOU!!! awsome links!!!!

[bdecorsey]

Originally posted by PolyFmorf
Do keep us posted on a Rat clone. The two pedals i LOVE the most are the Rat and Tubescreamer. I'm currently only using the podXT versions, but I would like to build some.

I'm itching for a project since I finished all my guitars. Last big project was a Heathkit TV :D

Sorry for the basic question, but I'm pretty new to this:

What exactly is the difference between the Rat and the Tubescreamer?

[bibleboy3]

hey Guys whats up...


Does anybody make their own PCB??? if so what method do you use???




Bill

[dot-dot-dot]

I've used various methods; back at school I used UV exposure, developer and etch. Long winded but good results. Then more recently I used Press N Peel and etch, which I hated - the PnP never stuck to the copper properly. Now I have a CNC router that does boards for me.

[henk]

Originally posted by PolyFmorf
dan-o-guitar,

The boxes are INSANE. After visiting your website, which is VERY well done...

After reading this I got curious too. I must agree with PolyFmorf. Very nice site and insane but beautiful projects can be found there. If you haven't seen it already then you must check out dan-o's site.
I love it. Great stuff!

[dan-o-guitar]

Originally posted by bdecorsey


Sorry for the basic question, but I'm pretty new to this:

What exactly is the difference between the Rat and the Tubescreamer?

At the simplest level, the Ibanez Tube Screamer is an overdrive whereas the Proco Rat is considered distortion. The circuits are very different and so are the sounds.

Plus, one is green and one is black :)

[bdecorsey]

Originally posted by dan-o-guitar


At the simplest level, the Ibanez Tube Screamer is an overdrive whereas the Proco Rat is considered distortion. The circuits are very different and so are the sounds.

Plus, one is green and one is black :)


:D

I think I get it. Thanks.

[bucky]

Originally posted by dot-dot-dot
Now I have a CNC router that does boards for me.

Lucky bastard.:) How much did that cost?

[dan-o-guitar]

Clipping section (mostly) done.

http://www.beavisaudio.com/Projects/ScreamerLab/clippingsection.jpg

[Ray18]

any updates?

[IndyGuitarist]

That's freakin' wild!! :eek:
However, that is definately a knob tweakers wet dream. :D

Looks great, I can't imagine EVER putting it into production without it costing over $500 EASY.

:freak:

Great job though. :)

[dan-o-guitar]

You guys had to go and remind me about the Frankenscreamer...

It will get done, this year, I'm pretty sure.

[dot-dot-dot]

Mr Dano - dunno if you've already tested it, but I used a 47k sag pot in my Screamer, and that was way too much - I'd suggest a 4.7k or thereabouts...

[lp_man]

I'd just like to say, you are an inspiration to beginner modders/builders just like myself :thu:

[dan-o-guitar]

Originally posted by dot-dot-dot
Mr Dano - dunno if you've already tested it, but I used a 47k sag pot in my Screamer, and that was way too much - I'd suggest a 4.7k or thereabouts...

What does a 4.7 drop the voltage too?

[dan-o-guitar]

Originally posted by lp_man
I'd just like to say, you are an inspiration to beginner modders/builders just like myself :thu:

Wow, that's just too cool. Thanks man. It is an addictive, yet rewarding pursuit. Welcome to the pedal hacker club.

[dot-dot-dot]

Originally posted by dan-o-guitar


What does a 4.7 drop the voltage too?

Dunno - I had mine in-line, so it's a current limit rather than a voltage sag. 47k is deinitely too much though - you get about 1/10th the travel of the pot usable, the rest is silence.

[gmr1]

DPDT's are ON-ON, yes?

what about the "Joe Walsh Mode" mod that makes 4.7k resistor on the opamp input switchable to a smaller value like 1k or 2.2k while keeping the same capacitor for more treble bite (like Joe's tone in James Gang)?

[Jarick]

Finished it yet?

Personally, I'm planning a TS build, but the only thing I'd do is have a switch for "flat mids". Maybe a couple component swaps, but really, I got a Bad Monkey which is a cleaner and flatter TS. I LOVED the TS RI I played at GC...so that's that obsession.

But I hear you...I'm in the planning/ordering stages of a RAT/Guv'nor/OCD pedal right now :D

:thu:

[elguitardude]

Hey man, thats some crazy shit you got going there. im thinking about building a tubescreamer for a first pedal but just the basic thing with out the mods. I already have a boss metal zone and i think a tubescreamer could be cool for a different distortion. Do you think id be a good pedal to make, and how much do you think making a stock tubescreamer would cost?

[dan-o-guitar]

Originally posted by Jarick
Finished it yet?

Personally, I'm planning a TS build, but the only thing I'd do is have a switch for "flat mids". Maybe a couple component swaps, but really, I got a Bad Monkey which is a cleaner and flatter TS. I LOVED the TS RI I played at GC...so that's that obsession.

But I hear you...I'm in the planning/ordering stages of a RAT/Guv'nor/OCD pedal right now :D

:thu:

Haven't touched it in over a month, so many other projects. Yeah, I know I need to finish it!

Good luck on your builds. The TS is fun, but the Rat is "funner".

[dan-o-guitar]

Originally posted by elguitardude
Hey man, thats some crazy shit you got going there. im thinking about building a tubescreamer for a first pedal but just the basic thing with out the mods. I already have a boss metal zone and i think a tubescreamer could be cool for a different distortion. Do you think id be a good pedal to make, and how much do you think making a stock tubescreamer would cost?

If this is your first build, I'd definately recommend BYOC's screamer kit. Everything you need to get going and even a few mod parts thrown in. Very good docs also. I think the TS clone kit costs around $75.

[Web Surf]

Originally posted by dan-o-guitar


I think it works out to about 250-300 in parts. And yes, I'm sidestepping your question :) Don't think I have the time actually turn these ideas into production units.

But others are welcome to take an entrepreneurial stab. Actually, I'd be honored if a commercial builder ripped off this idea :)


I love your idea

I am sure it will work as a concept ( But not sure on what is the best way to switch in/out multiple op amps. I have never tried stacking them up. I suppose you only switch the power on/off to the chip that you want but I am not sure how the signal going in parallel to the other chips changes the sound versus purely having the desired chip in circuit.

There ready is Indy Guitarists Multi-screamer which has a somewhat similar concept as yours.


PS : I am interested to try networks of diodes with resistors in series/parallel with them rather than just pure diodes.

The idea is to have smoother clipping rather than chopping. Suppose a Diode goes from 100K to 20 Ohms, but with a resistor in series, we can make it go from 100K to 20K ie hopefully more pleasing soft clipping. ANyone try this ?

[Web Surf]

Originally posted by dan-o-guitar
[B]
According to Jack Orman (http://www.muzique.com/):

"…what you get is increased current drive. Typically, a small value resistor, 10-50 ohms is inserted in the output of each opamp before they are combined to the signal output. This ensures that the opamps share the drive more equally. Using a pair of opamps in parallel will actually decrease the noise by about 3db due to random cancellations. Four opamps in parallel would reduce it even further, but that’s about the practical limit.”



I suppose that Increased Current drive is only try when we use the outputs of all ICs at the same time

I suppose that your circuit uses the outputs one IC at a time ?


In any case, increased Current drive is not what we are after. We are after voltage.


Using a resistor Like 100-200 ohms at the output pins of parallel voltage sources before they are paralleled is because these ICs have close to zero output impedance.

Suppose there are two ICs in parallel with the same input signals. Some small difference in other component or inside the ICs leads to miniscule 1mv difference between the output pins.

1mv into zero impedance = infinite current from one IC into the output of the other, blowing the IC's output stages.



Not sure about less noise with stacked ICs. What about random additions ?

[dan-o-guitar]

Originally posted by Web Surf



I love your idea

I am sure it will work as a concept ( But not sure on what is the best way to switch in/out multiple op amps. I have never tried stacking them up. I suppose you only switch the power on/off to the chip that you want but I am not sure how the signal going in parallel to the other chips changes the sound versus purely having the desired chip in circuit.

There ready is Indy Guitarists Multi-screamer which has a somewhat similar concept as yours.


PS : I am interested to try networks of diodes with resistors in series/parallel with them rather than just pure diodes.

The idea is to have smoother clipping rather than chopping. Suppose a Diode goes from 100K to 20 Ohms, but with a resistor in series, we can make it go from 100K to 20K ie hopefully more pleasing soft clipping. ANyone try this ?

I was having trouble with the op-amp switching via the stacking method. Got a lot of noise. Jack Orman suggested in a post somewhere to use resistors in the stack to even things out.

The Multiscreamer you mentioned is actually from Mohomods:

http://www.mohomods.com/store.htm

A very nice piece of work and the guy who runs Moho Mods is very cool.

If you search DIYStompboxes.com for "clipping diodes" you'll find hundreds of posts on this subject. Resistors in addition to diodes has been done so you should able to find some info there.

[Richard Guy]

Originally posted by Web Surf



I love your idea

I am sure it will work as a concept ( But not sure on what is the best way to switch in/out multiple op amps. I have never tried stacking them up. I suppose you only switch the power on/off to the chip that you want but I am not sure how the signal going in parallel to the other chips changes the sound versus purely having the desired chip in circuit.

There ready is Indy Guitarists Multi-screamer which has a somewhat similar concept as yours.


PS : I am interested to try networks of diodes with resistors in series/parallel with them rather than just pure diodes.


The idea is to have smoother clipping rather than chopping. Suppose a Diode goes from 100K to 20 Ohms, but with a resistor in series, we can make it go from 100K to 20K ie hopefully more pleasing soft clipping. ANyone try this ?



Try dis-similar components and component count on either leg of the 'clipper' circuit. Your monster will dance :freak:

http://img206.imageshack.us/img206/4541/5312rd4.jpg

[falcon42]

Originally posted by dan-o-guitar


If this is your first build, I'd definately recommend BYOC's screamer kit. Everything you need to get going and even a few mod parts thrown in. Very good docs also. I think the TS clone kit costs around $75.

Big +1 for BYOC. Keith is great- his kits have all the parts and the instructions are VERY good. My first two builds where BYOC ones and they might cost a bit more than sourcing parts yourself but it's worth it as a beginner. I think arguably the best part of all is that you get a lot of confidence when your first build fires up from the start- it is a lot harder to get builds to work from the start now that I perf stuff.

[Web Surf]

Originally posted by dan-o-guitar


At the simplest level, the Ibanez Tube Screamer is an overdrive whereas the Proco Rat is considered distortion. The circuits are very different and so are the sounds.

Plus, one is green and one is black :)

And overdrive is considered as soft/mild distortion

and Distortion is considered as very hard overdrive !!!

[lp_man]

I think it would best be used for customrers to borrow and write down what options they liked best then those could be made into a production pedal! :)

[Guitar George]

Dude you are way over the top and I am lovin' it!:thu:


I wonder if you could explain to me how you are getting 12 volts out of your 9 volt supply?

How about another toggle to change the bias voltage? You could change the 10k off of V1 to an 8.2k and end up with roughly 4.945054945054945 as your bias voltage or you could change the 10k to ground to an 8.2k and end up with a bias voltage of roughly 4.054945054945055. This will change your tone as well.

Transistors and mosfets could also be used for clipping. What's a few more toggles? LOL

The cap in the tone stack could also be changed to alter the shelving eq of the circuit.

Want to know how to figure out the rolloff points of this circuit?
I will tell ya'll anyway..

4.7k (resistor) times .047 (cap) equals 220.9
Then divide 159 by 220.9 and this equals 719.7827 hz

159/(4700 x .047)= 719.7827
159/(4700 x .22) = 153.7717
159/(4700 x .1) = 338.2978

159/(3300 x .047) = 1025
159/(3300 x .22) = 219.088
159/(3300 x .1) = 481.8181

a popular mod uses 2k4 and a .1 for a rolloff of 662.5 hz. The bottom end is fattened up with this since it's 662.5 versus the 719.78 standard and the drive is increased as well since the resistor is lowered to 2k4 from the standard 4k7.

500k drive pot/4k7= gain of roughly 106x

gain is increased lowering the resistor to 2k4 since 500k/2k4=208x

These gain numbers can be doubled by using a 1 meg drive pot as well.

Had you gotten to run multiple op-amps at the same time yet?

Perhaps more toggles for chaning the input and output buffer transistors?
Like maybe low hfe, moderate and then ultra hi gain transistors?

Regards,
George B.

www.PedalworX.com

[bluesmann]

GG you are the man:thu:

[dan-o-guitar]

Hey Big George! Thanks for the info. I knew a few of those but the more info the better.

I'm actually working on different clipping diodes right now, but in a Rat clone. I've been playing around with si, ge and leds in both symmetrical and asymmetrical layouts. I tried to get some MOSFET clipping going, but only have BS170s on hand and haven't got those to work yet. My favorite Rat mod so far is RED leds for clipping and a pot on the opamp's bias. Crank the gain pot, turn up the bias resistance and it turns into the best overdrive I've heard yet. Sweet.

Regarding the 9volts from 12 volts question, its easy. I use a 12 volt adaptor :) There is no battery option on the ScreamerLab.

Keep on hacking...
Originally posted by Guitar George
Dude you are way over the top and I am lovin' it!:thu:


I wonder if you could explain to me how you are getting 12 volts out of your 9 volt supply?

How about another toggle to change the bias voltage? You could change the 10k off of V1 to an 8.2k and end up with roughly 4.945054945054945 as your bias voltage or you could change the 10k to ground to an 8.2k and end up with a bias voltage of roughly 4.054945054945055. This will change your tone as well.

Transistors and mosfets could also be used for clipping. What's a few more toggles? LOL

The cap in the tone stack could also be changed to alter the shelving eq of the circuit.

Want to know how to figure out the rolloff points of this circuit?
I will tell ya'll anyway..

4.7k (resistor) times .047 (cap) equals 220.9
Then divide 159 by 220.9 and this equals 719.7827 hz

159/(4700 x .047)= 719.7827
159/(4700 x .22) = 153.7717
159/(4700 x .1) = 338.2978

159/(3300 x .047) = 1025
159/(3300 x .22) = 219.088
159/(3300 x .1) = 481.8181

a popular mod uses 2k4 and a .1 for a rolloff of 662.5 hz. The bottom end is fattened up with this since it's 662.5 versus the 719.78 standard and the drive is increased as well since the resistor is lowered to 2k4 from the standard 4k7.

500k drive pot/4k7= gain of roughly 106x

gain is increased lowering the resistor to 2k4 since 500k/2k4=208x

These gain numbers can be doubled by using a 1 meg drive pot as well.

Had you gotten to run multiple op-amps at the same time yet?

Perhaps more toggles for chaning the input and output buffer transistors?
Like maybe low hfe, moderate and then ultra hi gain transistors?

Regards,
George B.

www.PedalworX.com

[Guitar George]

Hey Dano,

I was just looking at your layout and perhaps it's my old eyes but it appears like you are hooking up pin 6 as the second output. Your layout says 7 but pin wise and even your stacked wiring job appears to be pin 6 to me.

The IC layout is something like this I think

1 8
2 7
3 6
4 5

Let me know if I am missing something here.


Regards,
George

[dan-o-guitar]

Hi George,

I never got as far as using the op-amp stack. As I recall, I started playing around with testing the thing with a JRC in the socket and played with the clipping stack and that's about when I stopped.

It is very possible that I screwed up the pin-out :) Thanks for pointing this out, I'll take a look.

Originally posted by Guitar George
Hey Dano,

I was just looking at your layout and perhaps it's my old eyes but it appears like you are hooking up pin 6 as the second output. Your layout says 7 but pin wise and even your stacked wiring job appears to be pin 6 to me.

The IC layout is something like this I think

1 8
2 7
3 6
4 5

Let me know if I am missing something here.


Regards,
George

[lp_man]

I 'borrowed' a couple of your ideas from this project for my SD-1 :D I thought the use of single in line sockets was great so I've encorporated it into my SPDT switch so you can opt for a range of sounds and toggle between two :)

[dan-o-guitar]

Originally posted by lp_man
I 'borrowed' a couple of your ideas from this project for my SD-1 :D I thought the use of single in line sockets was great so I've encorporated it into my SPDT switch so you can opt for a range of sounds and toggle between two :)

Awesome! What are your favorite SD-1 switch mods so far?

[lp_man]

Originally posted by dan-o-guitar


Awesome! What are your favorite SD-1 switch mods so far?
I did the Keeley five star mod, but just didnt like the use of the germainium transistor I had, so I tried swapping it for all kinds of stuff, I had some spare diodes lying arround so at the moment I've got a sillicum 1N4148 in and a NOS Germanium one in it. I plan to do a bit more experimenting with LED's in the near future :D

[Web Surf]

Along with trying out different diodes,

I wish you would try out multiple Diode arrays.

The idea being that different parts of the circuit kick in at different voltages.

Which allows you to tailor/smoothen the transfer response curve and get more tonal variety

[dan-o-guitar]

Ok, I finished everything on this last night except the op-amp switching. Results so far:

Clipping section: does all the standard symmetrical/asymmetrical stuff. Being able to switch different parts in and out on each side yields some interesting tones. Switch them all out of the chain and the pedal becomes a clean boost.

Tone-Stack Mod- this changes the cap in the tone stack. I can go from the standard TS mid-hump tone to a full-through tone. Changes the pedal pretty dramatically.

TS-808/9 Mod - This is switching the two resistors that appear in the output buffer between the 808 and 9. No audible difference. Useless mod.

Cleanup Mod - Just sort of mucks with the gain in a diferent way. Haven't played with it enough to make a final decision yet....

More Distortion - This is the part of the circuit that I added an additional stompswitch to. It does a pretty good job of making some pretty gritty distortion sounds.

Voltage sag - not particularly useful unless you are running 12 volts into the box for more headroom. Sag allows you take it down to the standard ~9volts if you want the standard TS tone.

I've never been a TubeScreamer fan. And even with all the mods, it just isn't my bag. I have a few TS fan friends. I'll let them play through it and hopefully get a more un-biased opinion.

[falcon42]

I'm not a big TS fan either, but I just modded my TS to Landgraff specs (made it like a Landgraff Dynamic overdrive) and I do think that it definitely improved it a bit. You might wanna give that a try.

[dan-o-guitar]

Originally posted by falcon42
I'm not a big TS fan either, but I just modded my TS to Landgraff specs (made it like a Landgraff Dynamic overdrive) and I do think that it definitely improved it a bit. You might wanna give that a try.

Ahhh. The silky sounds of the Grandlaff Dynamic Overhype.

Sorry, I couldn't resist.

So LEDs for clipping. What other changes did you find useful?:)

[thomasmiranda]

Originally posted by Stratotone


Great idea of socketing the switches. I've been building some mojo-voodoo tube screamer clones (based off the terrific BYOC board, I just change some parts values and make some things switchable, like diode clipping) and the idea of the sockets on the switches is AWESOME. One thing I noticed in my experiments so far is that when you're pushing an already overdriven amp, the clipping diodes don't seem to make a whole lot of difference: It's more apparent when you're using the TS as a distortion generator more than a clean boost. Just my opinion.

Pete

can someone please tell me where I can get these sockets like he has on the switches?

Ive looked all over and I cant find them so if anyone knows where I can get them that would be great. A part # would be even better.

Thanks

[lp_man]

Single in line sockets (SIL sockets) you can get them from small bear. You can also take apart a chip socket if you feel like it.

[Web Surf]

Originally posted by dan-o-guitar
Ok, I finished everything on this last night except the op-amp switching. Results so far:

Clipping section: does all the standard symmetrical/asymmetrical stuff. Being able to switch different parts in and out on each side yields some interesting tones. Switch them all out of the chain and the pedal becomes a clean boost.]
Now that you have a laboratory of sorts built up, It would be so nice if you could try that multiple diode soft clipper config that I posted !!!


Tone-Stack Mod- this changes the cap in the tone stack. I can go from the standard TS mid-hump tone to a full-through tone. Changes the pedal pretty dramatically.

I would love a full pre- and post-equaliser with distortions !!

I can see on my digital guitar workstation that changing the pre and post makes a HUGE difference. Thats what Keen says in his dist primer as well.


TS-808/9 Mod - This is switching the two resistors that appear in the output buffer between the 808 and 9. No audible difference. Useless mod.
That's what I have been saying earlier !!!

Only way this mod makes a diff is is we drive that stage with a lot of input and the emitter is too close to any rail and we manage to drive it into saturation or cut-off.

What is the emitter voltage on the last stage ?



I've never been a TubeScreamer fan.

Now you tell me, after building the Mother of all TS !!!!

[dan-o-guitar]

R.G. Keen has long extolled the virtues of EQ before *and* after the distortion stages. That way you can control the frequencies to be clipped, and the frequencies that are clipped. Makes sense to me.

I'm sketching up some ideas for a "Distortion Lab" box. I'm thinking of building blocks, connected and routed via various switching schemes:

1. Input buffer - three variations: classic tube screamer, JFET simple buffer, and a JFET gain buffer.

2. Pre-EQ: flexible EQ stage just after the input buffer. At least three bands, most likely active.

3. Transistor clipping - switch it in or out. 2 or three trannies that have their own controllable gain section.

4. Op-amp stuff: have an opamp section that has switchable clipping in the feedback loop (i.e. TS) and on the ouptut (i.e. Rat and just about everything else.)

5. Clipping: all the variations. I have a bunch of 16 pin DIP sockets--they make very nice diode platforms. I can house up to 16 diodes on two of them, and still be able to pull and insert different types. Various switching schemes will be available for the diode clipping in both the op-amp feedback loop.

6. Output buffer-standard TS style, switchable in or out of the loop.

7. Post EQ. Same setup as the Pre-EQ. Needs to be active.

Imagine the possibilities....



Originally posted by Web Surf

Now that you have a laboratory of sorts built up, It would be so nice if you could try that multiple diode soft clipper config that I posted !!!



I would love a full pre- and post-equaliser with distortions !!

I can see on my digital guitar workstation that changing the pre and post makes a HUGE difference. Thats what Keen says in his dist primer as well.


That's what I have been saying earlier !!!

Only way this mod makes a diff is is we drive that stage with a lot of input and the emitter is too close to any rail and we manage to drive it into saturation or cut-off.

What is the emitter voltage on the last stage ?




Now you tell me, after building the Mother of all TS !!!!

[Richard Guy]

I also saw RG's paper regarding EQ. I like EQ after a dirt box. I've tried flanking on either side of a dirt pedal and the biggest variation happend having EQ after. Sure, having it on both sides is cool too but if space on your board is tight, I would choose to put EQ after. :freak: Just my uneducated .02 :bor:

[dan-o-guitar]

Originally posted by Richard Guy
I also saw RG's paper regarding EQ. I like EQ after a dirt box. I've tried flanking on either side of a dirt pedal and the biggest variation happend having EQ after. Sure, having it on both sides is cool too but if space on your board is tight, I would choose to put EQ after. :freak: Just my uneducated .02 :bor:

I think I'll go ahead and do the EQ on both sides just for the fun of it.

Hey, did you leave me a message. My wife said that somebody left a message for me but she deleted it.:freak:

Here's the block diagram of the Drive Lab in its early stages:

http://www.beavisaudio.com/Projects/DriveLab/DriveLab_BlockDiagram.gif