Tellurian Drive (Sarno Earth Drive)

[MichaelW]

Build Rating

5.00 star(s)

I have admit this was a total impulse buy during the last sale. I had just placed an order using the coupon code, then right after that order got processed that I placed another order.......I bet I drive @Robert nuts with that....not the first time I've done it hahaha......

@Robert has been cranking out the new projects like crazy lately and I was catching up on the new releases thread when I saw this.
I'd never heard of it before but it sounded cool in the couple of demo's I watched so I ordered it.

Robert then also sent me a Schnobel Daily Driver (Chauffer) board because he thought I might like since I'm into lower gain overdrives.
That was so cool! I built that first....which I posted about in the build report linked above.

Well since the two projects were contextually linked, I decided to build the Tellurian next, it was also an experiment for me in a "patched up" boogered enclosure.
I'll document what I did in a separate thread. It didn't come out quite as well as I had wanted but I think I know what I did wrong.

As you can see in the pic below the "patch" is still visible at certain angles.

Anyway about the drive, when I fired it up I was like WOW I LOVE THIS THING! It may be my next "new favorite low-medium gain" dirt pedal.
I've built most of the classics and variants and to some degree I like them all, they all have their own thing going on. It's ironic that my favorite ones are also the simplest circuits. The Je T'aime (JTM Lovepedal) and the Mach 1 (Greer LightSpeed).

Right now I have the Tellurian side by side with Chauffeur comparing them. They have some similarities but also some differences. The Tellurian has more gain and I would categorize it was a medium gain drive that you can back down and do the low gain thing very well with. In that sense it's somewhat like the EQD Talons that I had recently built. Both pedals can cover a lot of ground in terms of gain.

The Tellurian has a thicker, warmer, perhaps a touch more colored gain than the Timmy or LightSpeed. It's really a lovely organic sound. I started out on my Strat and was getting some really gorgeous edge of breakup neck pickup sounds, then moved to my P90 guitars where the higher output pickups pushed the pedal into a creamier breakup. Really really nice.

The irony here is that the Chauffeur Daily Driver is twice the size board and quite literally 5x the number of components (5x dual opamps! ) where the Tellurian uses a single 4558, a small handful of resistors and caps, a pair of 1N914 clippers and a pair of Ge clippers and kinda gets to the same place. The "creaminess" of the breakup is attributed to the Ge diodes. I used a pair of 1N270's that measured in the mid 300's on my Mega328 based tester. I socketed the Ge diodes because I just took advantage of the SmallBear sale and ordered a "tasting flight" of Ge diodes that I have never tried before, including some "mojo" Mullards. I want to be able to try them in this pedal. I also did not have a 680nf cap so I rummaged up a couple of metal film caps to make up a parallel pair.

This is also a new rattle can color that I picked up. I didn't really notice the little bit of "spitting" until I looked at the picture I took of it. The pedal looks better in person than the picture which accentuates the little imperfections. I really like this paint. It's a satin finish brick red, dries very quickly and doesn't show fingerprints like some other colors. I put one coat of primer down and two color coats. After my "patch job" the inside of the enclosure looked messy so I gave it a light coat of shielding paint. Highly recommend this pedal if you like the lower to medium gain stuff.

 

[GratefulEight]

I have admit this was a total impulse buy during the last sale. I had just placed an order using the coupon code, then right after that order got processed that I placed another order.......I bet I drive @Robert nuts with that....not the first time I've done it hahaha......

@Robert has been cranking out the new projects like crazy lately and I was catching up on the new releases thread when I saw this.
I'd never heard of it before but it sounded cool in the couple of demo's I watched so I ordered it.

Robert then also sent me a Schnobel Daily Driver (Chauffer) board because he thought I might like since I'm into lower gain overdrives.
That was so cool! I built that first....which I posted about in the build report linked above.

Well since the two projects were contextually linked, I decided to build the Tellurian next, it was also an experiment for me in a "patched up" boogered enclosure.
I'll document what I did in a separate thread. It didn't come out quite as well as I had wanted but I think I know what I did wrong.

As you can see in the pic below the "patch" is still visible at certain angles.

Anyway about the drive, when I fired it up I was like WOW I LOVE THIS THING! It may be my next "new favorite low-medium gain" dirt pedal.
I've built most of the classics and variants and to some degree I like them all, they all have their own thing going on. It's ironic that my favorite ones are also the simplest circuits. The Je T'aime (JTM Lovepedal) and the Mach 1 (Greer LightSpeed).

Right now I have the Tellurian side by side with Chauffeur comparing them. They have some similarities but also some differences. The Tellurian has more gain and I would categorize it was a medium gain drive that you can back down and do the low gain thing very well with. In that sense it's somewhat like the EQD Talons that I had recently built. Both pedals can cover a lot of ground in terms of gain.

The Tellurian has a thicker, warmer, perhaps a touch more colored gain than the Timmy or LightSpeed. It's really a lovely organic sound. I started out on my Strat and was getting some really gorgeous edge of breakup neck pickup sounds, then moved to my P90 guitars where the higher output pickups pushed the pedal into a creamier breakup. Really really nice.

The irony here is that the Chauffeur Daily Driver is twice the size board and quite literally 5x the number of components (5x dual opamps! ) where the Tellurian uses a single 4558, a small handful of resistors and caps, a pair of 1N914 clippers and a pair of Ge clippers and kinda gets to the same place. The "creaminess" of the breakup is attributed to the Ge diodes. I used a pair of 1N270's that measured in the mid 300's on my Mega328 based tester. I socketed the Ge diodes because I just took advantage of the SmallBear sale and ordered a "tasting flight" of Ge diodes that I have never tried before, including some "mojo" Mullards. I want to be able to try them in this pedal. I also did not have a 680nf cap so I rummaged up a couple of metal film caps to make up a parallel pair.

This is also a new rattle can color that I picked up. I didn't really notice the little bit of "spitting" until I looked at the picture I took of it. The pedal looks better in person than the picture which accentuates the little imperfections. I really like this paint. It's a satin finish brick red, dries very quickly and doesn't show fingerprints like some other colors. I put one coat of primer down and two color coats. After my "patch job" the inside of the enclosure looked messy so I gave it a light coat of shielding paint. Highly recommend this pedal if you like the lower to medium gain stuff.

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View attachment 34824

Michael, you nailed the description--the sound is...well, how you said, lol This (Earth Drive/Tellurian) is one of my favorite drive circuits of the many ones I've tried (along with Fairfield's Barbershop), which is why I traced the original Earth Drive I've got in the first place--I wanted to build one myself to get into the nuts and bolts of it. The fact that Robert picked up on the tracing post and ran with it (he got it from trace to saleable board in, like, 3 weeks or something; unbelievable!) is a SUPER huge bonus, as now I don't have to lay out all the traces myself on perf or something. I'm going to build the circuit and test it out with various socketed diodes as well, and then it's going in a micro-board-in-a-box combo build I'm doing in a 1590D. And I'd love to get your take on what different diodes sound like in the Tellurian, so consider this a formal request for a thread on that topic if you get to doing that part before I do.

Also, great job with patching up the enclosure--sure, you can still see the patch a little, but it almost looks like it's supposed to be there--like there could be a punch-out for another optional indicator light or something. Either way, I'm loving getting to watch your builds happen--they've contained little tricks I've picked up to make mine easier and better (top-mounted jack 1590s for instance)--thanks for sharing!

 

[Harry Klippton]

I've heard great things about this pedal elsewhere, so now I'm really intrigued

 

[music6000]

I think it's a good chance it would sound even better with an BB OPA2134!???

 

[MichaelW]

I think it's a good chance it would sound even better with an BB OPA2134!???

I can pop one in and try it. Lemme finish my other build report hahaha.......

 

[GratefulEight]

I've got one of those sitting in the TSV808 I'm working up--I can also pop it in this and try if I get around to it before Michael does.

 

[MichaelW]

Update:
Ok did a little taste testing.

Please note all the comments below are HIGHLY subjective and really splitting the finest of hairs.
I'm doing this all for the sake science and the good of mankind............and because I can......

1) With @music6000's wondering if this pedal would sound better with an OPA2134, well wonder no more. It doesn't. Not to me anyway. And this is consistent with every time I've tried an OPA2134 in a circuit that was designed for a different opamp. The OPA2134 is a bit too high fidelity and for lack of a better term "thins" the sound out a bit. The 4558D I had originally sounded better, so it went back in.

2) I had to do a little taste test with the Ge Diodes I got in from Smallbear today. Again, it was @music6000 that turned me onto these ITT Ge Diodes. So before I go any further, at .59 a piece at SmallBear these are an absolute steal. Go and buy some before I go grab them all.
Here's the link. I tested about 10 pieces of the ones I got and they are all in the 300-400 range on my tester @10ma. Which translates into about 20% lower on a Peak DCA from my experience. These sound fantastic, and sound better than ANY of the NOS Russian D-series for about 1/2 the price.

Anyway I originally had a pair of 1N270's in the pedal that measured in the mid-300's on my tester. They sounded really good already but I wanted to try some of the new ones. Some of the ones I tried:

- the aforementioned ITT Red Band Cathode Ge diodes (no designated part number). They sounded really good. Maybe a hair better than the 1N270's but it's a close call.

- Amperex OF129. These NOS radial diodes made in Holland that measured in the high 200's. They sounded really cool too but didn't knock my socks off.

- Mullard CV7364 - Another radial NOS diode. These had a distinct sound to them. Hard to put into words but there was a hollowness or flutey overtone with these. Very interesting to me.

- Phillips OA9 - yet another radial NOS diode also made in Holland. These were the best of the bunch I tried. They had a bit of that Mullard sound but also some of the more meaty, creaminess of the ITT Red Bands. I wound up selecting two of these that measured right around 300 on my tester, and made a commitment and soldered them in. The legs were too skinny to really hold well in the sockets. I am very happy with my choice and it makes an already great sounding pedal even better.

I'll state my disclaimer again here, ALL of the above sounded great in this pedal. The difference is extremely minimal and the difference is just that, different. Not better or worse. I'd be happy with any of the choices I had on hand but I liked the Phillips the best. YMMV. The real takeaway here is the ITT Ge Diodes are a great price to sock a few away for any future builds that require a Ge Diode or call for a 1N34A.

 

[slowpogo]

I've got my Tellurian up and running and I love it, it's kind of what I was hoping the MXR Duke of Tone would be. It's not totally transparent, more like translucent. Pretty neutral but with a hint of character that I really like. Also, the tone knob does exactly what I want it to.

Not sure I have enough to say for a separate build report so here's my $0.02 on diode selection. I tried three types, two are mentioned above, ITT Red Band and Philips OA9. I also tried 1N60P because some people think that's what is in the Sarno version.

Interestingly, if I were listening to someone else test these, I'd probably prefer the ITT and OA9 because they are definitely more sparkly and harmonically rich. They sound great.

But ultimately I went with the 1N60P. The 1N60P is a little more "boring" in direct comparison but sounds really good too in its own way. Where it really catches my attention though is under the fingers. In my experience it just felt better to play. Even though it's not quite as rich, it has a texture that I can feel in a tactile way. The 1N60P was the one where I found myself getting carried away playing, forgetting that I was only testing things. I think that's a good sign that you've found the right parts (for you). Of course, this is all dependent on my particular guitar and board and amp so YMMV but I think the 1N60P is worth trying.

FWIW all these diodes measured around 260-280 on my multimeter.

 

[Crawdawg]

I finished building the Tellurian yesterday (my first pedal build) and am happy with it. I went with the Phillips OA9 as suggested by slowpogo. It seems to me that versus the original, my pedal is brighter and perhaps a bit thinner, like the tone knob at zero is about the equivalent of the ED at noon. Is there a possible explanation for this, ie I built it wrong, or used cheap/ different components, etc, or have others had the same experience with this clone?

 

[MichaelW]

I finished building the Tellurian yesterday (my first pedal build) and am happy with it. I went with the Phillips OA9 as suggested by slowpogo. It seems to me that versus the original, my pedal is brighter and perhaps a bit thinner, like the tone knob at zero is about the equivalent of the ED at noon. Is there a possible explanation for this, ie I built it wrong, or used cheap/ different components, etc, or have others had the same experience with this clone?

First of all congrats on your first build! That's great that it worked out, hope it's the first of many

I would wager that if you sampled a half dozen of the retail pedal you'd probably find some variances from pedal to pedal. It could simply be tolerances in components, most of which have a pretty wide margin, specifically tolerances in the potentiometer, that can be off either way by 20%.

 

[Crawdawg]

Thank you. Is it possible to measure these tolerance variances with a multi meter while the components are in the PCB or do they need to be out on their own?

 

[MichaelW]

It depends but in most cases you would need to remove at least one leg of the component.

 

[HamishR]

Phew - thanks Slowpogo! I wanted to build this but have no Ge diodes left - but I do have a heap of 1N60Ps. Are they Ge?

And it seems that Michael and I have a love of low-gain ODs in common. I agree - I tend to like the simpler ODs too. I built a Schnobel Daily Driver and I like it but it's kinda lacking in character, something I value in an OD. The Daily Driver has everything you could want except fun. And it uses a ridiculous number of parts.

I also recently built a simplified Blues Power and it is very much a Timmy with a few altered values, but it's simple and sounds great. I am collecting quite a posse of modded Timmys! I have a modded TSV-808 which is a modded Timmy which has become an absolute favourite.

So I'm looking forward to building the Tellurian now.

 

[HamishR]

Just finished my Tellurian and I agree - it's a good 'un! It's not a super complex sound but all of the bits are there. Now I simply have to work out how to make one with a bass pot - I don't think it should be that difficult, but who knows?

 

[MichaelW]

Just finished my Tellurian and I agree - it's a good 'un! It's not a super complex sound but all of the bits are there. Now I simply have to work out how to make one with a bass pot - I don't think it should be that difficult, but who knows?

That would be cool, do share once you figure it out. Having said that, I kinda like the way it "cuts" in a mix. I've been playing around with boosting it with the Mercurial if I want a bit more bass.

 

[MountaintopPedals]

Does anyone know what GE diodes are actually used in the original Sarno Earth Drive?

 

[jjjimi84]

Well after a write up like that I gotta get one now! @MichaelW with another great build report!

Anyone remember the Sarno Black Box? I used to have one and really loved it, it was hard to keep a pricey box like that around during some lean times though.

 

[slowpogo]

I finished building the Tellurian yesterday (my first pedal build) and am happy with it. I went with the Phillips OA9 as suggested by slowpogo. It seems to me that versus the original, my pedal is brighter and perhaps a bit thinner, like the tone knob at zero is about the equivalent of the ED at noon. Is there a possible explanation for this, ie I built it wrong, or used cheap/ different components, etc, or have others had the same experience with this clone?

Mine was also a bit bright and lacking in bass. I subbed in a JRC4580 op amp and that evened the tone a bit and just sounds a little better overall.

JRC4580 is a bit hard to find now, I think I got mine at Small Bear years ago but they don't have any now. I don't know how close the TI version sounds (RC4580) but it's only 50 cents at Mouser, worth trying in my opinion.

EDIT: I realized I have some JRC4580s in my stash. If you want one @Crawdawg let me know and I'll send you one

 

[MichaelW]

Mine was also a bit bright and lacking in bass. I subbed in a JRC4580 op amp and that evened the tone a bit and just sounds a little better overall.

JRC4580 is a bit hard to find now, I think I got mine at Small Bear years ago but they don't have any now. I don't know how close the TI version sounds (RC4580) but it's only 50 cents at Mouser, worth trying in my opinion.

Interesting, I do have some JRC4580's I got from PedalHacker last year. But then I'm pretty happy with mine the way it is.
It cuts through a mix well.

 

[Crawdawg]

Thanks to the kindness of @slowpogo I decided to build out a second Tellurian and I am very glad that I did. The JRC sounds great. I also built a sand spur earlier this week, and this is my cleanest build yet. Both will be going on my board as soon as I christen them with Velcro.

I was super sad when I went to try it out before boxing it up and I got absolutely nothing, but I soon realized that I had put a socket for the chip in and never installed the chip.