Tag Archives: tubescreamer

TS Overdrive – new enclosure & sound samples

Old enclosure ready for tear-down

Old enclosure ready for tear-down, next to the new one.

Why?

When I built my first Tubescreamer clone (built with a great circuit board from DIY Effects) I was very pleased but left with a few issues that at the time I could not be bothered to fix.

Firstly, the paint finish I used on the enclosure did not turn out very well. I used Rustoleum, and sprayed it on way too thick (because I was impatient…lesson learned). It looked cool, but it didn’t wear well.

Secondly, the DC power connector I originally bought for it turned out to be the wrong size. I only discovered this when I got hold of a power supply, and it didn’t fit. In fact, it was at this point that I tried to use what I thought was an adapter for a smaller power connector. Little did I know that although the adapter fit, it was actually a polarity inverter too; so I blew up 3 JC4558 chips in the process.

So I decided to try an enclosure from Mammoth Electronics, who can provide a painted an drilled enclosure for around $10. Ridiculously cheap.

Wires for the LED "off-board"

Wires for the LED "off-board"

Getting on with it

The rehousing process was very easy; mostly a case of taking the old one apart and carefully assembling it all back into the new enclosure. I did have to redo the LED as the DIY Effects PCB allows you to solder it directly to the board, and let it just stick through the enclosure. I couldn’t do that with the new enclosure and still have it line up with the hole, so I attached wires to the LED and then soldered those to the board. Nice and easy.

The shiny copper on the MOSFET clippers

The shiny copper on the MOSFET clippers

Clipping with MOSFETs

Months ago, after I built my OD2 which uses plain diodes for clipping, I decided to change this OD to use MOSFET clipping. SLW had mentioned it in the excellent PDF file that lays out instructions for building the pedal, and he rated it highly. I was able to purchase the parts easily, and after doing the necessary physical modification (i.e. cutting off most of the mounting lug) the mod was trivial. But what a result in terms of sound! You’ll hopefully hear in the MP3 file below that it has a wonderfully soft clip. It’s as if it has rounded edges. Like an overdriven Marshall, but without the harshness. It does definitely get harsh if you turn the tone all the way up, and responds very well to tone adjustments on the guitar itself. In the clip you’ll hear a variety of pickups and guitar tone control settings (and sadly a lot of repetitive playing).

The setup was:

  • My own build of an AX84 P1 Extreme, with a 6V6 for the output section.
  • Tokai Les Paul with a 1961 Gibson PAF in the neck, and a modern Seymour Duncan JB in the bridge.
  • 2×12 cab with Celestion G12T-75
  • SM57 microphone
  • Recorded in Logic on a Mac. And a touch of reverb in the master output channel.

Click here for the MP3

Almost done

Almost done

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OD2 – final assembly

The Clay Jones circuit, plus layout

The Clay Jones circuit, plus layout. Click to see the big version.

In my previous post I was discussing a new project. Another distortion pedal based on a clone of a Landgraff Dynamic Overdrive. The circuit was drawn out (possibly from looking at the Landgraff device) a few years ago by someone called Clay Jones. See the picture on the right here. This circuit was made available to me, as a beautiful pre-built PCB, by the guys over at DIY Effects. They have a great OD circuit (currently at revision 2, I believe) that I had used previously, but this one is using their “revision one” board.

The clipping switch

The clipping switch. 3 diodes on the left, 2 LEDs on the right.

Clipping

The major difference between the revisions has to do with the clipping section of the circuit. Rev 2 has ample space for all kinds of options whereas Rev 1 is limited in terms of on board space. In this context that didn’t matter. I knew I wanted to mess around with clipping options and that meant it was easier to do that with a switch off the main board. I chose to try 3 diodes in one position and 2 LEDs in the other. The middle ‘off’ position is just the raw clipping of the circuit alone.

OD1 and OD2

OD1 refuses to make eye contact with the conspicuously naked OD2

Initial tests

I was able to wire up the board with power, pots and jacks very quickly, due to the great instructions, and had it plugged into my amp in no time at all. The goal here was to compare the clipping options and just make sure I wasn’t going down the wrong path. And I was not disappointed at all. The 3 diodes position has tons of gain, but in the lower positions sounds much like a cranked Marshall, but with a slightly softer attack. It doesn’t have the harsh bite of the typical Angus Young tone, which isn’t a bad thing. Then I switched it to the middle ‘off’ position, and it immediately got much louder, presumably because there aren’t any diodes clipping anything. Also for the same ‘drive’ position, the middle position had way less drive. Position 3, the 2 LED’s wasn’t a huge change from the middle position, but it softened the attack a little. Either way, I completely love this pedal!. So now to get it into a usable enclosure.

The enclosure

Measuring and drilling the enclosure holes

Measuring and drilling the enclosure holes

Based on a recommendation from DIY Effects I bought a box from Pedal Enclosures, specifically the YY type, in red hammer finish. All that remained was to drill some holes and start the assembly. This meant I had to think about how I wanted to lay things out inside the box as well as outside. But the basic dimensions of the box decided a lot of this for me. Here’s the basics:

  • The circuit requires Drive, Tone and Level pots.
  • I wanted to eventually add a switchable boost, so I need 2 foot switches. This will be like the “more” switch on Joe Satriani’s Vox distortion pedal.
  • I need a hole for my clipping switch.
  • LEDs for both the switches so I know where I am.
  • The usual 1/4′ jacks and power.
Making sure the parts fit as I go

Making sure the parts fit as I go

I covered the box with masking tape and found my old vernier calipers and a pen. With the box of components at hand, for dimensions, I was able to mark out the locations for the holes and punch them quite quickly. Then it was time for the drill press. After starting with an 1/8th ” bit for pilot holes, I layed into it with my El Cheapo “unibit” that I got from Harbor Freight Tools.

Assembly

Belly up, with new parts

Belly up, with new parts

Now for the fun part! As I had done most of the assembly work with parts I had laying around, I did have to replace the pots with smaller ones (16mm rather than 24mm), and also I had to wire up the full bypass switch (and the LED). But all of that was just busy work. This time, I purchased extra components from Small Bear Electronics.

I was lucky enough to have wired it correctly first time (as with the original OD pedal) so within the hour I had it plugged into my amp and was jamming away.

I am very, very satisfied with this pedal. I can get a wide variety of usable tones from it very quickly. I do need to replace the drive pot with something else as the range of “no drive” to “loads of drive” all happens in the first few degrees. Not sure if this is simply the difference between linear and logarithmic taper. Anyway, here’s another photo.

(Almost) finished in it's shiny red box

(Almost) finished in it's shiny red box. The toggle switch is for the clipping options. Forward is the 3 diodes, backwards is the 2 LEDs.

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New distortion pedal project, based on Landgraff Dynamic Overdrive

A few months ago I built a clone of a TS-808 Tubescreamer (based on a PCB and build instructions from DIY Effects) and that proved to be successful.

I recorded a sample of what it sounds like: Steinberger into P1 Extreme, with OD pedal

Now that pedal was built with the standard clipping circuit i.e. two diodes. Some would say this is dull, and indeed the DIY Effects build instructions contain other recommendations. These range from using three diodes instead of two, for a kind of asymmetric clipping, to using MOSFET devices.

So to try these out I bought a pre-populated board from DIY Effects.; one that had been wired up in the style of a Landgraff Dynamic Overdrive. I had no idea what this pedal actually sounded like but a quick trip on YouTube told me what I needed to know.

The clipping arrangement has been deliberately left up to me to configure. I plan to use a switch to allow for the different clipping methods. I think I’l do the following:

  • Two diodes: for the traditional TS-808 style.
  • Three LEDs: asymmetric clipping.
  • Two MOSFETs: I have no idea what it sounds like, but its worth a try.

SLW from DIY Effects sent me great instructions on how to do this, and recently posted about it. He uses a DPDT, but I might need 3 positions to do this. I’ll see if Radio Shack has some in stock. A nice cheap project if I can retrofit this into my existing grey enclosure.

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Building a TS Overdrive – from DIY Effects

Adhoc workstation

Here's the board with the instructions on the left. All the components were in neatly labelled baggies.

After my initial trepidation about which transistor to use (and with some patient guidance from Shawn at DIY Effects) I was ready to build the TS Overdrive guitar effects pedal. I’d read the build document many times as I learned from building my AX84 P1 eXtreme that you can never go over this stuff too much.

Components

So step one was to start installing components and get soldering.  I had my less powerful 15W iron this time as it has a smaller tip and will be less likely to cook any components. I also brought out my very handy clip stand device, which helped me hold components as I assembled them. It also has a magnifying glass attached…very handy. I began with resistors, then moved onto capacitors (electrolytic first). Then it was the IC socket and transistors.

Standard TS 808 clipping diodes

Standard TS 808 clipping diodes. There are many options available here.

Clipping options and transistors

There are several options included with the board design that allow for different clipping methods. You can use the stock diodes, or MOSFETs or even LEDs. I went for the original method (which is regular diodes in position D1 and D3. D2 gets jumpered) because I wanted to hear what the original TS 808 circuit sounds like. These things are legend and I’d never had one in my arsenal before. As mentioned in the previous post, I had an issue getting hold of the prescribed MPSA18 transistors and in the end found an assortment of general purpose ones at Radio Shack. So this build used a pair of 2N3904 transistors.

Heat shrink on the pot terminals

Heat shrink on the pot terminals

The remainder of the build went very well. It really was a case of following the build notes, and carefully marking off each component (or indeed wire) as I assembled it. I knew that the board had to mount on top of the pots so I was careful to heat-shrink the wires coming off the pots themselves; I didn’t want any random wires to short out parts of the circuit.

Final assembly

This was tricky for a few reasons:

  • I used solid-core 20AWG wire. This mean that while the wires stayed where I put them, it also meant it was harder to orient the board. See next point.
  • Rats nest of wires

    Rats nest of wires, but it's physically sound and ready to go!

    The holes in the pre-drilled enclosure from Pedals Parts were such that I had to choose between having the tone pot right near the top of the pedal (which looked crap) or the tone pot near the stomp switch. I opted for the latter, but that meant the board had to be oriented the other way round, which then meant the wires I had already soldered in were about an inch too short. Coupled with them being sold core and the result was physically sound, but looked really messy.

Fire it up!

Almost done

Almost done. The view through the looking glass!

So all that remained was to solder in the LED, and put the knobs on. I’d failed to order a bezel for the LED, so right now it’s just kind of floating there. The knobs went on easily, and look good. After using a mix of Alpha and CTS pots on my amp build, I must say I like the action on these Alphas. The CTS pots I used on the amp were nylon shaft whereas these are solid aluminium which feels so much better.

Next step was to plug in a battery, screw on the back, and fire it up. And I must say it sounds excellent! I dialed my amp to be as clean as it gets…i.e. no pre-amp distortion/saturation, and dialed the TS OD to be a clean boost (no Distortion, Level just a bit louder). Harder to  dial in was the Tone. The documents are correct when they say that most of the range is at the end of the knob’s travel, so there’s a kind of sweet spot where you get some good “bite, but it’s not harsh. With the tone on maximum it can be a bit “fizzy”.

Result!

From here on I jammed for quite some time, punctuated by twiddling with the knobs on the pedal. It was hard to make it sound bad, to be honest. It’s definitely not a high gain machine, but I wasn’t expecting one (and that’s why I got the Boss DS-1). It’s a fantastic blues overdrive that works well with single-coils as well as humbuckers or P90s. If my SM57 wasn’t broken (might be the cable) I’d record some samples.

I plan to do a number of things from here:

  • Try different clipping options.
  • Try different transistors.
  • Re-finish the enclosure. This Hammerite stuff isn’t pretty. It’s been a week and it hasn’t dried properly, so I think I sprayed it on too thick. I’d probably go for green enamel as a nod to the original Ibanez TS 808 that started all this.
  • Record some samples.
  • Minor adjustments such as mount the pots lower so the knobs don’t stick up so much. Also, buy and install the bezel for the LED (which I might change to blue, just cuz).

UPDATE!

An older version of the DIY Effects board, but with a different/better design.

UPDATE AGAIN!

A new enclosure, different clipping method, and a sound sample.

Final assembly of the TS OD

Final assembly of the TS OD from DIY Effects

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Tubescreamer transistor substitution

As part of the Tubscreamer clone project, I ordered parts from Mouser based on the list provided by the DIY Effects build documents.  They listed the MPSA18 as the transistor of choice, but at the time of my order Mouser had none, and I substituted a PN2222ATF. But, I realised much later that I didn’t have even the slightest clue as to whether this was a good thing.

From the Geofex site, there are some recommendations on choosing components:

6. Transistors: When in doubt, use a 2N5088. Or a 2N3904 – or a 2N4401 – or a BC549 – or… find cheap, available NPN and PNP devices that you can get easily and use them.

From a Tonepad customer on a forum:

Tonepad site indicates using a 2N3904. This is certainly acceptable, but you may have a little more oomph on the output with a 2N5089 or an MPSA18. 2N3904 are fine units for a lot of purposes, but in this case not so much. You’ll likely be more satisfied with MPSA18 or 2N5088/5089. Stock TS9s come with 2SC1815 transistors which tend to be higher hfe than 3904s, though not quite as high as the A18s or 508Xs.

So it’s all quite ambiguous as these all come across as “opinions” rather than an objective assessment. Time to learn something about transistors, as right now all I know is:

  • They’re all black plastic things on 3 legs
  • See previous point.

Now of course I know that tubes aren’t readily substitutable without knowing more about the application. You can’t blindly replace a 12AX7 with a 12AT7, even though they’re both 9-pin glass bottles, without knowing that the AX has a gain of 100 but the AT is more like 20. Searching around for answers led me to a document that has been plagiarised all over the inter-tubes:

Understanding the transistor data will definitely helps you to find the right and correct part number for substitution.

So, comparing the various parameter’s ratings as written in the “official” Fairchild PDF documents linked above, I see that the PN2222A is actually a pretty good fit for the MPSA18 in terms of VCEO, VCBO, IC etc. But when I look at HFE, the DC current gain, I see:

  • MPSA18  (VCE = 5.0 V, IC = 1.0 mA ) = Min 500
  • PN2222A (VCE = 10V, IC = 1.0mA) = Min 50

This seems to be off by an order of magnitude (even if you adjust for the current difference), almost like the 12AX7/12AT7 tube swap I hinted at before. So it seems the PN2222 is NOT a good fit. I’m going to ask a very knowledgeable friend about this to confirm my guesstimate.

Until I find a good answer, RadioShack has 2N3904 and 2N4401 transistors on their website, so I’m going to wander over to their store at lunchtime and buy a few of each.

UPDATE: RadioShack has little packets of 15 “assorted transistors” for about $2.50. Guess what’s in there? 2N4401, 2N2222 and 2N3904. So I bought a pack each of NPN and PNP. On the back of the pack it describes the NPN types as:

  • Typical HFE: 200
  • VCE 30V
  • IC 800mA
  • Power dissipation: 1.8W
  • …designed for high-speed, medium-power switching and general-purpose applications.

UPDATE AGAIN: Here’s the post with all the details of the final build.

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The quest for tone

Further to the Tub-screamer pedal project (I’m waiting for a few final parts), I found a great article on the Geofex site all about the original Tubescreamer internals. Here’s a quote I found amusing:

The best thing to do, I believe, if you’re hunting the Tube Screamer Holy Grail is to stick in an 8 pin socket on the board, noting the orientation of the original chip carefully, and then just plug in various dual opamps until you find one that conjures up images of your own personal guitar deity.

In this world of tube amplifiers and guitars/effects there are snake-oil salesman around every corner trying to get us to spend hundreds (if not thousands) of dollars on all kinds of gadgets that’ll bring us closer to “that tone”. They recognise that at the heart of it we (guitarists in general) are star-struck wannabes that have a very simple desire to be “as good as that guy”. And “that guy” may be Clapton or Vaughan or whomever. In quiet moments when we’re listening to our favourite music we think “if only I could sound like that”. I don’t care who you are, you do it. I bet even Clapton does when he’s listening to Buddy Guy, or Freddie King.

For me it’s Eric’s tone on the studio version of “Spoonful”. It’s clearly some kind of Gibson, probably a Les Paul. It’s also certain to be a 100 watt Marshall cranked pretty high so it’s “alive” and on the brink of feedback. In my view that’s the sweet spot for any rig. In the mix there’s an ocean of reverb on the track which adds to the haunting sound she creates. You can hear him playing with a variety of pick strength…sometimes he’e gentle, other times he’s really digging in. Never does his guitar sound harsh; it’s always creamy smooth and very, very musical. Now for me to get that tone I simply use my 50w 2204 Marshall and either my mid-70’s Les Paul or my Tokai copy. That’s all I need to fulfill that particular dream; especially as I realise I’d never truly be able to recreate that sound as I’m not Eric.

However, if I were more susceptible to the snake-oil salesman I could do the following:

So the question is, how much closer to that tone will I get by spending > $200k? Maybe 1% closer. I can get 95% of it with my so-called cheap rig. The other 5% is all about Eric.

Back to Tubescreamers. The aura surrounding them is due to people like Stevie Ray Vaughan. He used a TS-808 in his rig, so naturally everyone wants one. Conversely, nobody wants the TS-9 or any kind of reissue as folklore would have it that they “aren’t the same”. The fact is, the pretty much are the same. The Geofex article linked above proves that beyond doubt. So why is it that people will pay $350 for a handwired TS-808 from Ibanez? Why is it that sellers on eBay think they can get $600 for an old one? It’s all snake-oil.

I’m going to build my $37 clone from the circuitboard I got at DIY Effects, and the parts in got from Small Bear Electronics/Pedal Parts Plus, and be 95% there. 🙂

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