Carlsbro - Flanger  [schematic]

All about modern commercial stompbox circuits from Electro Harmonix over MXR, Boss and Ibanez into the nineties.
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lasermonkey
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Post by lasermonkey »

Hi, here's a few pics of the aforementioned flanger. Please excuse the pic quality, but I didn't have the camera handy and had to use my mobile phone.

Like the Phase 2, it's a big beast!

Image

Uppersurface of PCB:
Image

Image
note the 'roll your own' opto coupler.

Image

Image

PCB underside:
Image

Component values not apparent from the photos:
Capacitors:
C1 220nF
C2 1nF
C3 220nF
C4 10uF/10v
C5 220nF
C6 220pF (?)
C7 220nF
C8 220nF
C9 100nF
C10 220nF
C11 3.3nF
C12 470pF (?)
C13 220nF
C14 100uF/6.3v
C15 68uF/10v
C16 10uF/10v
C17 220uF/10v
C18 2.2nF
C19 470nF
C20 100uF/6.3v
C21 22pF (?)

Semiconductors:
TR1 BC212
TR2 BC214C
D1 1N4002
D2 1N4002
ZD1 6.2v

Pots
Speed 22k lin
Depth 4k7 lin
Colour 100k lin

Trimpot values are not visible, and the trimpot near IC1 has a 150k resistor tacked between the wiper and PCB.

I bought this off eBay and like the Phase 2 I bought recently, isn't working properly. The 'in a drainpipe' sound is there, so I think the BBD is ok, but there's no sweep. Exposing the LDR in the optocoupler to an external light source results in flanging being heard, so I'm thinking the problem lies somewhere in the LFO. I haven't managed to track down any schematics or anything useful so far and haven't seen any schematics for other flangers that look even vaguely similar!
It looks like someone has had a go at repairing it in the past: the TDA1022, 4007 and 4049 had all been removed and socketed and there are obvious signs of desoldering/resoldering. I can't even be sure that the wiring is correct. Ther two PP3 battery snaps are wired in parallel, which I've never come across before. However, seeing as none of the polarised caps are rated higher than 10v, I assume that this is correct. What is strange is that the jack socket grounds are wired to the +9v rail!
Really? :shock:

I'd really like to get this one working, as the soundclips I've heard were very nice indeed. If anyone out there has one of these and could confirm the wiring, or has a schematic they wouldn't mind sharing, I'd be very much obliged.
Cheers.
Last edited by modman on 25 May 2015, 20:14, edited 2 times in total.
Reason: Edited title.

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Dirk_Hendrik
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Post by Dirk_Hendrik »

Thanks!
Interesting to see this one. The ADT and the chorus both use SAD1024's (2 in the ADT). Therefore I would have expected this one to use a SAD too. Interestinf to see a TDA1022 in there. You don't see them too often.

The 9 volts is odd indeed. Just the same that it is battery only. Most of these giants have a 230VAC power supply. The positive ground might very well be possible. Look up the TDA1022 datasheet. All app notes are for positive ground.
Sorry. Plain out of planes.

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Post by lasermonkey »

Having traced the supply rails around, I came to the conclusion that it must have been a +ve ground.
I started swapping components and eventually, the LED in the opto-coupler started flashing. I think it was one of the three 741s in the centre of the PCB that was faulty, but I can't say for sure. I'm just glad to have got it going, tbh. :D
I really like this flanger, quite a different flavour from what I already have.
I think I'll have to keep an eye out for the ADT, chorus and delay pedals now.

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pz
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Post by pz »

note the 'roll your own' opto coupler.
I may by wrong, but... isn't the LED/LDR combo soldered backwards? I mean, the left side looks like there's an LED (shape, square terminals), right side LDR, while the text underneath suggests something different.

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lolbou
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Post by lolbou »

lasermonkey wrote:t looks like someone has had a go at repairing it in the past
And these Siemens MKT caps are looking newer than the rest of the unit (unless i'm wrong).

edit : I'm wrong, see below... :slap: I would have expected these caps to be "younger" ones...
- Are you a mod or a rocker?
- Uh, no, I'm a mocker.

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lasermonkey
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Post by lasermonkey »

lolbou wrote:
lasermonkey wrote:t looks like someone has had a go at repairing it in the past
And these Siemens MKT caps are looking newer than the rest of the unit (unless i'm wrong).
The Phase 2 (mine was dated April '79) had those Siemens caps too. I switched them out on both pedals, as we had lots of problems with them at the last company I worked for: the pins would shear off the end of the cap without much provocation.
The LED/LDR combo is the right way round, although it's hard to tell with the heatshrink on there.

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Post by robinbowes »

lasermonkey wrote:I think I'll have to keep an eye out for the ADT, chorus and delay pedals now.
I have a delay pedal. PM me if you're interested.

R.

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bobster
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Post by bobster »

hi laser monkey
thanks for the great pics and contribution.
iv just got one of these flangers off e bay and im having some problems with it.
there is a volume drop i can live with when i switch on pedal even with two brand new batteries
but i wanted to ask you , when you switch to the invert setting , do you find it is a lot quieter than even the normal flange setting? this second volume drop is too much it really spoils the enjoyment of the effect
so that is what is hapening with mine and i wanted to know if this is a normal symptom or if i should be looking to some faulty or out of spec part somewhere. my soldering skills arent great and i am reluctant to change out all the caps right away.
i wonder whetner to change out the tantalum caps might be a place to start?
hope to hear from you soon
cheers
bob

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lasermonkey
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Post by lasermonkey »

Just found a schematic on an eBay listing. Apologogies for the poor quality, I had to do a screen grab to get hold of it.
Image

Still, it's the first time I have come across the schematic, and thought it would be worth having!

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Post by Dirk_Hendrik »

Excellent!
Thanks a mega-lot! :hug:
Sorry. Plain out of planes.

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