Prescription Electronics - RX Overdriver

Fuzzer · Post by **Fuzzer** » 19 Apr 2009, 19:02

Those are not diodes, they're capacitors;

And Man, what a piece of crap.

noirengineer · Post by **noirengineer** » 19 Apr 2009, 19:54

weird.. i thought that initially, but then second guessed it,
i've never seen a clear see through cap as such.. I agree.. poorly
made, but i really dig the pedal itself.. it's such a bummer he just
slopped it all together like that.. it's def cool circuit nonetheless

Fuzzer · Post by **Fuzzer** » 19 Apr 2009, 20:11

sure, it isn't a reason to sound bad...

The cap type I believe is polystyrene film.

Naz Nomad · Post by **Naz Nomad** » 19 Apr 2009, 21:32

puppiesonacid wrote:you post out loud you know that right?

You talkin' to me there?

sonicvi · Post by **sonicvi** » 20 Apr 2009, 00:06

I hate this mindset that if a pedal isn't built with the wires at right angles or all twisted together that it's a piece of crap. I like neat looking wiring as much as the next guy, and yeah that wiring looks messy, but does that really mean it's poorly made? That pedal was made 14 years ago and is still working (I'm assuming). If my pedals last that long with no troubles I'll will be satisfied (and not that I expect them not to last that long).

puppiesonacid · Post by **puppiesonacid** » 20 Apr 2009, 00:38

Naz Nomad wrote:
puppiesonacid wrote:you post out loud you know that right?
You talkin' to me there?

yeahup. didn't get the post. would you care to elaborate?

Fuzzer · Post by **Fuzzer** » 20 Apr 2009, 00:42

sonicvi wrote:I hate this mindset that if a pedal isn't built with the wires at right angles or all twisted together that it's a piece of crap.

I never conditioned my opinion to those parameters

; I don't care about angles or twistings (as long as it doesn't cause oscillation), but that thing is just poorly built, besides, my statement is just an opinion.

sonicvi · Post by **sonicvi** » 20 Apr 2009, 01:42

Fuzzer wrote:
sonicvi wrote:I hate this mindset that if a pedal isn't built with the wires at right angles or all twisted together that it's a piece of crap.
I never conditioned my opinion to those parameters ; I don't care about angles or twistings (as long as it doesn't cause oscillation), but that thing is just poorly built, besides, my statement is just an opinion.

on what are you basing your opinion that it is a piece of crap out of curiosity?

Fuzzer · Post by **Fuzzer** » 20 Apr 2009, 02:41

Well, on the layout, for starters. The way the components (particularly the electrolytic axial caps) are put. On the wiring (apart from being a mess, there are cables going inside everywhere around the board).

controller700 · Post by **controller700** » 20 Apr 2009, 14:47

Hey guys,
at the moment I have a Rx Overdriver at home (borrowed from a friend) because I wanted to test it before buying my own.
To me it sounds awesome!! It´s damn quiet for a ´70s design, the EQ works optimal on Guitar signals and the Fuzz sounds that this pedal can deliver cover a very wide range (and can even replace a Fuzz Face and a Treble Booster on your board).

I really love it and want my own, but for a price of 170 Euro the craftmanship is way way below my tolerance...

Plastic jacks, cheap footswitch, BAD solder joints and a mess of solid core wires which isolation is burned by the soldering-iron at a few places!

So I decided to build my own boutiqe clone of it. Will cost 50% of the Prescription, will be 100% better and I will post it in about 3 weeks when it´s ready.

JimiB · Post by **JimiB** » 20 Apr 2009, 16:00

so the cap on the underside of the board dosent seem to be in the original. Can you confirm that it is going from the Base to the Collector of Q1?

ekajjake123 · Post by **ekajjake123** » 21 Apr 2009, 23:25

Sweet controller700, that's great news. Let us know!

noirengineer · Post by **noirengineer** » 22 Apr 2009, 20:15

JimiB wrote:so the cap on the underside of the board dosent seem to be in the original. Can you confirm that it is going from the Base to the Collector of Q1?

I haven't really gotten that far yet, as I've been busy as hell lately,
but i will try to get a verified template and PCB trace up soon as well.
This will likely be either A) exact values + layout of Prescription's pedal,
or perhaps a slightly modified version. but i'll just update the list so far

PS: i have organized strangely.. sorry for the weird way i took the order of these.

anyway.. I still can't make out the values of the 2 clear polystyrene caps.. I see 50v,
but don't know what they are rated in.. you guys have any clues? Farads? check out pics.

R1 500K
R2 500K
R3 10K
R4 500
R5 150K
R6 100K
R7 1.8K
R8 500
R9
R10
R11
R12
R13 4.7K
R14 32.7K

Q1 2N3704 ECB
Q2 2N3704 ECB
Q3 2N3704 ECB

CLEAR POLYSTYRENE CAPS
C1 (TOP MT) UNKNOWN / 50V
C2 (UNDER) UNKNOWN / 50V

CAPS (RADIAL Blue Film?)
C1 0.1K μF / 250V
C2 0.01K μF / 250V
C3 0.01K μF / 250V
C4 0.22K μF / 250V
C5 0.1K μF / 250V
C6 0.22K μF / 250V

CAPS (ELECTROLYTIC ) +/-
E1 (+) 10 μF / 16V
E2 (-) 10 μF / 16V
E3 (-) 22 μF / 16V
E4 (+) 22 μF / 16V
E5 (?) 22 μF / 16V
E6 (?) 22 μF / 16V

POTENTIOMETERS
Bass Pot 100K LINEAR Alpha 6E3
Treble Pot 100K LINEAR Alpha 6E3
Drive Pot 2K LINEAR Alpha B2K
Volume Pot 200K LINEAR Alpha 5J3

sonicvi · Post by **sonicvi** » 22 Apr 2009, 20:55

noirengineer wrote:
JimiB wrote:
anyway.. I still can't make out the values of the 2 clear polystyrene caps.. I see 50v,
but don't know what they are rated in.. you guys have any clues? Farads? check out pics.

They look like 220p and 1000p to me.

I used to own this RxOD. They sound really good.

SPeter · Post by **SPeter** » 22 Apr 2009, 22:39

CLEAR POLYSTYRENE CAPS I think too are 220p and 1000p!

groselicain · Post by **groselicain** » 25 Apr 2009, 19:12

I am giddy, I really love the PE version of this pedal, so I can't wait for an update!

Naz Nomad · Post by **Naz Nomad** » 25 Apr 2009, 21:02

puppiesonacid wrote:
Naz Nomad wrote:
puppiesonacid wrote:you post out loud you know that right?
You talkin' to me there?
yeahup. didn't get the post. would you care to elaborate?

Never mind ... as soon as you have to explain a joke, it becomes unfunny.

Maybe next time.

ekajjake123 · Post by **ekajjake123** » 08 May 2009, 01:10

What voltages are the collectors biased to on the rx OD??

I've been dying to build this but have heard that the trannys in it are really finicky.. Any tips?

noirengineer · Post by **noirengineer** » 08 May 2009, 17:56

There are only 3 x 2n3704 trannies..
They are pretty low gain IIRC but haven't
Tested but i cant imagine its too finnicky
Just ur standard silicon trans. Not sure which
Companymanufactures the chips in my Rx
But it doesnt appear to be the fairchild semi-con
Brand which i see commonly on digikey.. Mousr

Sorry fo typos... Posting from iphonne

Barcode · Post by **Barcode** » 08 May 2009, 18:42

controller700 wrote:Hey guys,
at the moment I have a Rx Overdriver at home (borrowed from a friend) because I wanted to test it before buying my own.
To me it sounds awesome!! It´s damn quiet for a ´70s design, the EQ works optimal on Guitar signals and the Fuzz sounds that this pedal can deliver cover a very wide range (and can even replace a Fuzz Face and a Treble Booster on your board).

I really love it and want my own, but for a price of 170 Euro the craftmanship is way way below my tolerance...

Plastic jacks, cheap footswitch, BAD solder joints and a mess of solid core wires which isolation is burned by the soldering-iron at a few places!

So I decided to build my own boutiqe clone of it. Will cost 50% of the Prescription, will be 100% better and I will post it in about 3 weeks when it´s ready.

just to make sure no one is spreading misinformation...

plastic jacks actually have a lower fail rate than metal jacks (they have fewer points of assembly for one thing), metal jacks being "better" is true only in aesthetics, and even then only for certain people. I've tried both, and so far all of my plastic jack builds have, under heavy abuse, FAR surpassed my metal jack builds, and I've used all of them from neutrik to switchraft and every one in between. please, no mojo here.