How to Make.. The PM-69    601 to 901  auto Pipe MOD (mar 2012. updated:may 2012)

For Auto-Lovers

o you have a malfunctioning 601 pipe ready to throw away ? Chances are, the sensor is flooded with old juice and just needs a cleaning. Problem is, ithe 601 is not designed to be taken apart.

With brute force you can dismantle it, but difficult to re-assemble. Nevermind, the atty is not that good anyway. Why not just replace the whole atomiser and mouth piece?

This mod is a simple replacement of the 601 atomiser with a 901 using the original 601 sensor switch and regulator circuit.

Here is a video of it's usage.

Let's be honest, the DSE-601 is a cheap and cheerful china e-pipe with the following low-points;

  • Sensor starts to  mis-behave within a week.
  • Low throat hit (atty is too big for the battery)
I won't bother to go over the good points, since you own one, you would know (you can read my review here).

If you're about to throw it away, first try this mod. It will replace the atty to a 901 assuming the 601 sensor switch still works after cleaning it. And that the circuit regulator (built into the battery holder) is still working.

First Take it Apart

You can actually pull out the main barrel with a pair of pliers. The trick is to twist it to break the glue. You will however get a dent on the barrel mouth because the pliers are flat but hey, so what ?

Be careful not to break the wires.
Inside the main barrel is a sleeved vacuum sensor. Usually this is a decent sensor switch..

..unless of course it's drenched in e-lliquid !!

You'll find the sensor starts working again after a cleaning and drying (also blow it out).

It even got rid of it's famous constant green flashing syndrome.

Clear The Barrel and throw away the old atty

Connect a 901 Atty
Get a 901 connector. (You can pull off an old one from a faulty 901 battery,)
You will have to extend the wires with your own to make it comfortable.
Make sure you pass the wires through the barrel.

Insulate any middle joints.

Seal the Barrel
Position the 901 connector and your seal up the barrel with DIY putty or glue.

This must be air-tight but you must not obstruct the air-flow to the switcher sensor.
You can push in a paper clip to make sure the hole and air-path doesn't get blocked by the sealing material.

The barrel is actually difficult to push all the way back in, which is a good thing because it's a good air seal.

You don't need to push the barrel all the way back in, infact it may look better if it doesn't. And you'll want something to grip if you have to pull it out again for cleaning.

The PM-69 mod is now my regular vape.

It's just surpassed my box mod for consistency (probably due to it's built in regulator).
Here's a youtube Video.

<- Pic showing pipe mod with RN4081 adapter.
(The RN4091 is  cloud monster when combined with the 601 switche.
Note the thread air-inlets have to be closed with tape.
Also, to make the RN4081 drippable, the inner cart is discarded and  a hole is drilled on the mouth of the cap).

You will want to tape over the hole of any 901 atty or the draw will be too light.

Similarly, adapters for 501 and others need  tape around the holes of the threads. (The 601 switcher is designed to rely on air flow through the centre of the atty only.)

Alternatively you could used the updated solution below :-

Tighter Sensor Solutions

1. The Aux.Hole
If you don't want to have to tape up the air-holes around the atomiser, I have also found a way to increase the vacuum around the sensor. Simply block the auxilliary hole located on the rim of the sensor with part of a toothpick.

This will ensure the sensor will fire-up  on every draw but you must not tape over any of the atty air-inlet holes, otherwise the draw will be too tight.

A permanent solution would be to use some glue to close the aux.hole. But I would advise you to first try it out before doing this.

Personally I don't block the hole,  I usually use a 901 atty which is no hassle to tape over the body hole.  It's also easier to blow-clean the pipe since more air-flow is allowed through it.

2. Barrel Proofing

It is important that the circular gap between the metal-barrel surrounding the sensor when inside, is air-tight. If the sensor feels 'loose' when you push it in, then you are going to have problems with the sensor not firing.
If this is the case, the solution is to fill the gap with a thin piece of sticky/scotch tape around the sensor or maybe some cling film.
Open aux.hole advantages Closed aux.hole advantages
Same consistent air-flow through centre hole for ALL atomisers.

No whistling noises.

Easier to 'reverse-blow-clean'.

No need to tape over atty or adapter air-inlet holes.

Reliable firing for ALL atomisers.


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Update : (2 weeks)

ell it's been a few weeks now, and the mod has been holding up.
My current setup is an Ultrafire 18350 XSL 1200mah and EM LR 901 atomiser with drip tip and tape over the hole.

This gives a lot of vapour and taste with an easy draw and just the right tightness.

The only gripe I have is that it does get a bit gurgly after a while because some liquid collects, not around the switch which is now a good distance away from the atty, but at the mouth of the atty-socket. A a blow in at the battery end while holding a tissue at the mouth of the atty socket will usually clean it out. For a complete clean, you'll need to open it up and a cotton bud into the barrel at the other end,

Pic of tube all the way back into the body.                  306 atty+adapter.

Update : (
1 month)
Re-Enforcement and ciruit board investigation

Hands up those who have broken a mod through messing and tweaking it too much. Yes, me guilty as hell, I broke the contacts to the circuit board through too much yanking in and out of the switcher.
You can pry off the lid-threading. 

And yank out the bowl providing the switcher is not attached. Turns out the wires are connected quite delicately to a circuit board located in the bowl that holds the battery.

If the bowl is very tight, then burn a hole in the side and pry it out with a screwdriver.  I had to re-solder and re-enforce the bottom with hot glue.

Well it's been over a month now,  and I am prefering the pipe over my box mod which uses two 14550 batts. The box mod has better throat hit but tends to overburn the liquid to a point when the flavour is lost and the atty gets too hot. The harshness also gets the tongue sore, so I have to admit, it's not as good as this 601 mod which doesn't have any of these problems. It's a nice cool vape with loads of vapour. The most striking thing is the consistency. And of course, it's auto. Manual mods are great but to truely re-capture that analog experience, it has to be an auto.  It's the only way I can vape and day-dream at the same time (without having to click a button).

Apart from the obvious, I was wondering what in the DSE601 was giving the 18350 batt such a good run that the simple box mod couldn't, namely;

Constant cool vape.
Constant high volume vapour.
Atty doesn't get too hot , therefore liquid doesn't get overburnt or boils wierdly and not perform (vapour-wise).
Consistent taste. (taste doesn't disappear through overburning).

And it can do this whether or not it's an LR or SR atomiser, hmm, there's something going on here.
On the same meter at full charge, BoxMod: 4.2v, 601:4V.  BoxMod:1.9A, 601:1.7A. Theres not a lot of difference.

For some curious reason, this 601 mod is able to eek out the deep flavour of my RY4 and generate consistent vapour even while chain vaping, a feat that other mods have a hard time doing. Is it some magical voltage or current regulation?

I can't confirm it, but I suspect it as something to do with the control-circuit. I actually took apart an older 601 and ripped out the circuit board.  


I think maybe there's a current regulator in there, I don't know (can't identify the parts). I also think there's an opAmp there too, cos it shows up in a voltage test, if you blow lightly on the sensor, it let's through a low voltage, but if you blow hard, it goes up to about 4V. It's a very clever design to mimick pipe puffing (I guess).

But don't think it's the opAmp that's giving a nice vape, so there's probably some sort of current or voltage regulator too. Correct me if I'm wrong, Any ideas?
(you can mail or message me on ECF/humpty).

Update : May 2012
Circuit board wiring and wire replacing

You can't see it clearly in the pic but covered up are the terminal markings and I figured out which wire goes where.

S1,S2 - goes to the switcher.

D1,D2 supplies power to the Atty.

I have also replaced the wires with the more flexible ribbon type.

Update : Jun 2012
Complete circuit board replacement.

The circuit board on one of my pipe mods failed on me (probably too much heat while soldering).
So I had a cheeky idea of replacing it with the tiny auto-chip from the cheapest e-health cigarette I've ever paid for ($8).

Original circuit board incased in silica gel.
Auto-chip from an $8 e-health type e-cig.

The e-health chip is less than half the size of the old chip and has a 5 sec cut-off function.

Re-enforcement is very important if you are always pushing and pulling the parts because the wires are fragile.

Make sure the wires are bunched enough to fit through the openings.

As you can see, there are two wires for two colors of led and a common anode for the e-health chip.
The output is the same, a pair for the vacuum sensor switch (blue) and a pair for the output-power (purple).

You can't quite see it, but there's a cut purple wire on the far upper right (pic 1) that is unused here but was attached to the original chip. It's function is unknown, but it is connected to that square block you see near the master switch. I think it's just used for testing.

And here is the video of it's performance. Differences (between the old and replacement chip),
i) red light dims slower after a puff (analog simulation)
ii) regulates to 3.75V instead of 4V.
iii) annoying 5 sec cut-off.

A regulated vape is miles better than one that's not (since it doesn't overburn the liquid, the flavour just eeks out).
My next project is to put one of those chips in my simple box mod and see how that goes.

Update : Oct 2012  Found Air Leaks

(See updated section : Tighter Sensor Solutions : Barrel Proofing)

That's all for now!