Rocktek - FLR-01 Flanger

rocklander · Post by **rocklander** » 15 Dec 2008, 11:25

in case they;'re of any interest to anyone.. cheap pedal, will rehouse, repot and true bypass it at some stage. more pics can be taken if there are specific requests for bits.

osa · Post by **osa** » 18 Dec 2008, 00:43

MN3204. Nice.

Dave

rocklander · Post by **rocklander** » 18 Jul 2010, 07:52

finally broke into this thing to rehouse... and I notice it has a 500KD pot... so I have some A, B, C pots, but what's a D?

lolbou · Post by **lolbou** » 18 Jul 2010, 15:48

rocklander wrote:finally broke into this thing to rehouse... and I notice it has a 500KD pot... so I have some A, B, C pots, but what's a D?

Maybe you should trace the rotation vs. resistance graph to check the type of curve it has?

rocklander · Post by **rocklander** » 18 Jul 2010, 19:59

yeah, I guess... that sounds a lil boring

johnnyg · Post by **johnnyg** » 06 Dec 2010, 17:07

I have one of these - it's getting on a bit now... like me I guess!

I got it not long after my first electric guitar way back when - I'm guessing around 1994. I don't use it much - hardly ever in fact - but how often does a flanger see much action?

I like it a lot though - maybe sentimental reasons, but it's lo-fi and dirty and for that reason... great! I will never need another flanger

I just pulled it apart and it's exactly the same as yours Rocklander - same codes on pcb - so nothing to add to your photos.

Googling brought up the diystompbox site for the D taper: https://www.diystompboxes.com/smfforum/ ... _next=next

How are you going to bypass this? I'm guessing there's some fancy electronic switching here (that's beyond my knowledge at present)... hopefully Dirk H won't read this - I think he has a problem with bypassing through a switch, heh!

I am thinking of rehousing mineas well - I'm not that sentimental about it that it has to stay in its shitty plastic case. I think it woudl thank me if I put it in a fancy powerdercoated or electroplated aluminium box after all these years together

rocklander · Post by **rocklander** » 06 Dec 2010, 19:30

well consider carefully the process and ramifications. to fit into a 1590BB, I had to hacksaw off a bunch of the PCB.. it's still not housed as yet BTW.. on my 'partly done' pile.

I couldn't figure out the circuit, so I just tried it disengaged and put an audio probe in a bunch of places till I could hear it flanging and the pots made the differences they are supposed to.... prolly totally the wrong thing to do, but my electronics kung fu is weak

johnnyg · Post by **johnnyg** » 06 Dec 2010, 23:49

Excellent - that's my kind of approach!

I like it...

I've googled about a bit in the vain hope there is a schematic or some info about this pedal - but absolutely zilch... not even a homepage for Rocktek (perhaps they don't exist any longer). I was hoping maybe this was an old design from Boss or Ibanez or similar and there was a schematic for the original pedal it copies - but I can't find any info about who might have owned Rocktek.

This pedal is a sadly neglected mystery

What a shame as it's pretty cool and can make some strange sounds.

I could find a schematic for the Rocktek chorus - maybe using that it won't be too hard to isolate the buffer/buffers and turn the pedal into a mechanical bypass one (which is what I'd like to do - there's some tone suck with this thing). But I haven't a clue about tinkering with buffered effects at present - I've yet to progress from simple enough fuzzes and overdrives if I'm honest

I'm just a solder jockey as they're called in these here parts

jorgezorro · Post by **jorgezorro** » 17 Feb 2011, 23:45

Interesting project. I took a stab at tracing the circuit and drew up a schematic for this worthy pedal. I was comparing with the schematic for the Arion Stereo Chorus when I drew it.

There are probably at least a few errors in the schematic. Corrections are welcome.

Link to PDF: http://www.jorgezorro.com/Images/SCHEMA ... Rschem.pdf

A PNG format is available as well.

Tonetweaker · Post by **Tonetweaker** » 22 Feb 2011, 02:27

johnnyg wrote:I've googled about a bit in the vain hope there is a schematic or some info about this pedal - but absolutely zilch... not even a homepage for Rocktek (perhaps they don't exist any longer). I was hoping maybe this was an old design from Boss or Ibanez or similar and there was a schematic for the original pedal it copies - but I can't find any info about who might have owned Rocktek.

I was just making fun of this pedal on another thread. Mine's a crazy, self-oscillating, noisy old beast... but a blast to play around with.

I think Rocktek was a Chinese company that went belly-up in the 90's. It was owned at one time by Charlie Stringer (RIP), who was also involved with Snarling Dogs (perhaps Rocktek became Snarling Dogs?).

I also have their Vibrator pedal (gotta love the name!) and I just bought the distortion NOS in the box for a whopping $15 on the Bay.

:BB Steve

johnnyg · Post by **johnnyg** » 23 Feb 2011, 22:25

Tonetweaker wrote: I was just making fun of this pedal on another thread. Mine's a crazy, self-oscillating, noisy old beast... but a blast to play around with.

I think Rocktek was a Chinese company that went belly-up in the 90's. It was owned at one time by Charlie Stringer (RIP), who was also involved with Snarling Dogs (perhaps Rocktek became Snarling Dogs?).

I also have their Vibrator pedal (gotta love the name!) and I just bought the distortion NOS in the box for a whopping $15 on the Bay.

:BB Steve

Interesting history

It really is a junky thing... I hope I didn't oversell it earlier too much

. But junky things have their place - and it can be fun just like you say

I saw a Rocktek Flanger for sale for less than £5 on ebay at some point

They're pretty much worthless - but at that kind of price maybe fun to mod or develop at all if that's possible.

Dirk_Hendrik · Post by **Dirk_Hendrik** » 24 Feb 2011, 06:56

johnnyg wrote:How are you going to bypass this? I'm guessing there's some fancy electronic switching here (that's beyond my knowledge at present)... hopefully Dirk H won't read this - I think he has a problem with bypassing through a switch, heh!

No at all

I have a problem with using a switch where one can use a relay just as well.
And I have a problem with TB-ing pedals that don't have a bypass problem.

As for the fancy switching, refer to any Arion schem for the topology og using a 4027 plus FET's for bypassing.

Tonetweaker · Post by **Tonetweaker** » 28 Feb 2011, 04:29

johnnyg wrote:It really is a junky thing... I hope I didn't oversell it earlier too much . But junky things have their place - and it can be fun just like you say

I didn't think you oversold it at all, Johnny. Pedals like this can be a blast to fiddle with. I'm the guys who sweeps the low budget pedals off eBay at least once a week.

In the other thread, I mentioned that I love old noisemakers like for noodling around every now and then. I pull this one out every now and then to get that noisy lo-fi sound for stuff like Nirvana. This thing is perfect for songs like "Come As You Are."

Cheers...
Steve

vax71 · Post by **vax71** » 16 Oct 2017, 08:21

Hello
I've just get one of this cheap pedal. Nothing great to add to this thread… on mine :
opamps are JRC 2904 and JRC 4558 (instead of 6358 and 6458)

I found some errors and missing parts in schematics:
R39 = 2.7k
R18,R19,R21 = 10k
R21 is between Q3 E and ground
R27 is between wet output and ground
C11 = 22000p = 2.2nF
C12 = 220p = 0.22nF
C22 = 6.8nF
Q1,Q2,Q3,Q4,Q7 = 2SC536
Q5 = 2SC3576
Q6 = 2SK772
C21, R29… near IC1/output…

Before I mod it I have to get rid of a very annoying noisy buzz. Poor design or does my pedal need some fixing?

Rocktek - FLR-01 Flanger [schematic]