Decent vintage pedal score. Now to fix / refurbish. Suggestions?

[Delicieuxz]

I got this Morley Pro Flanger with a non-working expression pedal for what I think is a pretty good price (slightly under the listing's price), going by more recent sales that I've seen. I've got some questions about fixing it up.

https://reverb.com/item/42921165-vintage-1979-morley-pro-flanger-pfl-semi-working-in-need-of-repair-easy-fix

According to the listing details, the internal lightbulb and a resistor in the expression pedal's circuit need replacing, but the flanging part of the pedal works fine.

I think the bulb is a 318-767 model. Edit: Actually, the bulb might be a 387: https://www.tubesandmore.com/products/bulb-morley-effects-pedals-replacement



Does anyone have the Morley Pro Flanger schematic? I looked online but didn't find it - but did find schematics for other old Morley pedals, so I wonder if it's out there. I've also sent Morley a message asking if they have the schematic.


If the schem isn't available, my next goal would be to identify the resistor from internal photos of other Pro Flangers. The only photos I've found of it so far are these:

https://images.reverb.com/image/upload/s--Pul8JM_G--/a_exif,c_limit,e_unsharp_mask:80,f_auto,fl_progressive,g_south,h_1600,q_80,w_1600/v1414884006/ieuclkfhhpu3zlblvmn4.jpg
https://images.reverb.com/image/upload/s--4hHvi6DV--/a_exif,c_limit,e_unsharp_mask:80,f_auto,fl_progressive,g_south,h_1600,q_80,w_1600/v1414883983/qjyjloyz9s0rzf8ul3bw.jpg

From this listing: https://reverb.com/au/item/333792-morley-tel-ray-pfl-pro-flanger-vintage-reticon-sad-1024

It looks like, for that Pro Flanger, there are two resistors in parallel in that space (mine had just one), or otherwise one really fat resistor. Unfortunately, they're partly covered by that white-and-orange wire. Here's a cropped version of the image, re-orientated, colour-improved, and the resistors circled:



I'm not certain of what the colours on the resistor are. It's like 3 different shades of brown and a yellow-brown, lol.

Here's the burnt resistor removed from the Pro Flanger I've bought.





Does the fried resistor indicate any other possible problems that I should look into? If so, I would probably just take the pedal to a tech, as I'm not informed enough to trouble-shoot on my own.


Beyond replacing the resistor and internal lightbulb, is there anything else you'd do with this pedal? I'm thinking of giving it a good polishing with Simichrome polish to make it look nice and to remove the spots of rust on the chassis.

[idy]

The two resistors in parallel (or one really fat one) suggest that the circuit could have been delivering too much current sometimes to the bulb, and either a higher wattage (fatter) resistor or two in parallel would have double power capacity (wattage.) Yours did not have that "fix"....

I would confirm if that resistor connects directly to the bulb. If they do, I would measure what voltage is present at that point when the circuit is working. And it should be easy to choose an appropriate resistor and bulb combo.

[Delicieuxz]

I've found this other internal photo of a Pro Flanger. But, oddly (to me), it's missing the entire part of the circuitry that I'm wanting to have a look at:

https://fr.audiofanzine.com/flanger-guitare/morley/pro-flanger-PFL/medias/photos/#id:71515


I've also found this internal photo, which appears to show the resistor as being a 1/2 watt Yellow-Violet-Brown-Gold.

https://cdn-ak.f.st-hatena.com/images/fotolife/B/Billl/20111126/20111126144414.jpg
Source page: https://electricpartslibrary.hatenadiary.jp/entry/20111214/p1

The two resistors in parallel (or one really fat one) suggest that the circuit could have been delivering too much current sometimes to the bulb, and either a higher wattage (fatter) resistor or two in parallel would have double power capacity (wattage.) Yours did not have that "fix"....

I would confirm if that resistor connects directly to the bulb. If they do, I would measure what voltage is present at that point when the circuit is working. And it should be easy to choose an appropriate resistor and bulb combo.

It does look like there's an orange wire going from the resistor directly to the bulb. I'll verify that once I've received the pedal.

[idy]

Y V Br =470ohms.
I wonder what the supply voltage of the pedal is?
The bulb that site is suggesting is rated .04 amp at 28v...about a watt. It probably will do the job with much less juice than that.

The calculator says that resistor should keep that bulb below its maximum rated current up to 18 volts. Usually you want to stay *safely* below that. I would maybe try a 1k pot in series with a safe resistor and try to dial in the lowest brightness that does the job. You want the bulb to last longer this time...

I think on these things the treadle controlled the speed of the LFO?

[idy]

Should be pointed out: Exercise extreme care with anything that has "mains" voltage in it. This thing plugs into the wall and if you don't know basic rules about poking about with a meter in a "hot" box, take the time to straighten that out. Or have a tech do it. We don't want to let the magic smoke out of you!

[Delicieuxz]

I received a reply from Morley to my request for the Pro Flanger schematic. They said:

"Thank you for the inquiry.

We only share Morley schematics with authorized repair centers.

The Pro Flanger has two bulbs, the heel end bulb is 387, specs are here:
https://www.morleyproducts.com/faq/#24

The Pro Flanger PCB lamp is 2187 Bulb (28V 40mA)"


That sounds like the schematic exists, they just won't give it to me.

Y V Br =470ohms.
I wonder what the supply voltage of the pedal is?
The bulb that site is suggesting is rated .04 amp at 28v...about a watt. It probably will do the job with much less juice than that.

The calculator says that resistor should keep that bulb below its maximum rated current up to 18 volts. Usually you want to stay *safely* below that. I would maybe try a 1k pot in series with a safe resistor and try to dial in the lowest brightness that does the job. You want the bulb to last longer this time...

I think on these things the treadle controlled the speed of the LFO?

Yes, the treadle controls the LFO speed. I could ask them what the supply voltage is.

[stallik]

Quick web search turned up this...
https://elektrotanya.com/morley_flb_flanger.pdf/download.html
Or this
https://www.diystompboxes.com/pedals/prophaser.gif

[Delicieuxz]

Quick web search turned up this...
https://elektrotanya.com/morley_flb_flanger.pdf/download.html
Or this
https://www.diystompboxes.com/pedals/prophaser.gif

Thanks, but the Pro Flanger is abbreviated PFL. The FLB is a different, but also great, Morley Flanger. The second schematic there is for the Pro Phaser.

[stallik]

Sorry, my mistake

[Delicieuxz]

Sorry, my mistake

No prob.


I've wondered how similar the FLB / Deluxe Flanger is to the Pro Flanger. They both use the SAD1024 chip, but YouTube videos suggest they sound pretty different.

I have the Deluxe / FLB Flanger, so I'll get to compare them when the Pro arrives. I think the YT videos for the Deluxe / FLB Flanger don't do it justice. And my impression is that neither do the videos for the Pro Flanger, other than Andy's.

[Delicieuxz]

I got another response from Morley:


"The Pro Flanger is one of the few Tel-Ray pedals that we do not have a schematic on file.

Our head engineer had a look at the pictures but cannot be 100% sure what the missing component was.

Since we have no schematic, we are unable to assist."


Maybe a schematic for the Pro Flanger doesn't exist after all.

[Delicieuxz]

I found someone who is selling their Pro Flanger and was kind enough to send me a photo of their Pro Flanger internals. But it turns out their Pro Flanger is like this one I posted a link to previously, which is without the components I'm wanting to have a look at.

"Hi, well my pedal only has a current transformer, it's not the same as yours (I attach a photo ), but do'nt worry, you only need a 220 Ohms +/-5% 1Watt resistor (Red, Red, Brown, Gold).
I hope the information will serve you .. Greetings"

I wonder why they believe it should be a 220 Ohm resistor.

[GGBB]

The reverb images you posted earlier to my eyes look like 150-ohm brown-green-brown - not sure if the last band is 1% brown or 10% gold. I think every other vertical resistor in the images have the tolerance band at the bottom - so 150-ohm make sense.

[Delicieuxz]

I have the pedal now. I haven't opened it up yet, I'm cleaning up its exterior first.

I've given it a thorough wipe-down with a damp cloth, and I'll soon polish it with Simichrome to hopefully remove any rust specks and prevent any new rusting.

The plug had some corrosion on it, so I sandpapered it and have had it sitting in vinegar for some hours. It looked clear of corrosion after 20 seconds of swirling in the vinegar, but there are some spots on the plug that look to me like they might be rust, so I'm keeping it in the vinegar for a bit.

[Delicieuxz]

I have a question If there's found to be corrosion in the jacks, like there is on the external switches and like there was on the plug, is it a good idea to not use the pedal until the jacks have been replaced?

I haven't checked the jacks on the pedal yet for corrosion, but I'm thinking if I stick a patch cable into corroded jacks, then the corrosion could spread to the patch cable connector, and that if I put the patch cable into another pedal afterwards that some specs of corrosion could come off in the other pedal's jacks and spread corrosion there.

[Delicieuxz]

Having cleaned the connectors and found no corrosion in them, I plugged in the Pro Flanger and tried it out. It seems to work properly except when the switch to engage the expression pedal is engaged - just as the listing suggested.

When the expression pedal, which controls the modulation rate, is turned off, all the dials work and the sound modulates, but does so at a very slow pace - perhaps the slowest speed setting the pedal handles. It's almost, but not quite, stationary.

When the expression pedal is turned on, the pedal emits a high-pitched squeal.

[danfrank]

I received one of these Pro Flangers about a month ago. The info you received is correct... The burned resistor should be a 1 watt 220 ohm resistor, that is the value in my pedal. The bulb should be a 387 bulb, rated for 28 volts @ 40ma. That resistor is used for dropping the voltage going to the bulb. Mine measures 25.8-26 volts going to the 387 bulb.
Mine also had a bad LM324 IC, the IC closest to the two LDRs. This is the LFO IC.
Here's a link to the schematic, it will cost you $5:

http://ronsound.com/index.php?main_page=advanced_search_result&search_in_description=1&keyword=Morley+pfl

[Delicieuxz]

I received one of these Pro Flangers about a month ago. The info you received is correct... The burned resistor should be a 1 watt 220 ohm resistor, that is the value in my pedal. The bulb should be a 387 bulb, rated for 28 volts @ 40ma. That resistor is used for dropping the voltage going to the bulb. Mine measures 25.8-26 volts going to the 387 bulb.
Mine also had a bad LM324 IC, the IC closest to the two LDRs. This is the LFO IC.
Here's a link to the schematic, it will cost you $5:

http://ronsound.com/index.php?main_page=advanced_search_result&search_in_description=1&keyword=Morley+pfl

Thanks for that information! That's great.

Does your Pro Flanger also have two transformers, like mine?

[danfrank]

Yes, one transformer for the board electronics and the other transformer to power the light bulb.
Mine was originally an export model made for the UK so it had transformers with 240 volt primaries. I had to change them out for 120v ones. The secondaries of both transformers put out 28 volts, but one has a center tap on its secondary.

[Delicieuxz]

I had dropped my Pro Flanger off at a music shop, which delivered it to a tech repair shop they outsource stuff to, to be fixed, as I wasn't comfortable to do it, myself, not knowing what else might be involved aside from replacing the resistor. I heard from the shop today that they sent back my Pro Flanger because Morley isn't a brand that they work on. Apparently, they're only willing to work on specific brands. So, I guess I'll try replacing the resistor and hope that fixes it.

Is is likely that the resistor burned from a separate issue in the pedal that would also need to be diagnosed, or more likely that the resistor burned from maybe the lightbulb going out?

Yes, one transformer for the board electronics and the other transformer to power the light bulb.
Mine was originally an export model made for the UK so it had transformers with 240 volt primaries. I had to change them out for 120v ones. The secondaries of both transformers put out 28 volts, but one has a center tap on its secondary.

Cool.

I got the schematic from the webpage you gave. It shows the resistor as being 220 ohm 1/2 watt, rather than 1 watt. Would it possibly be better as a 1 watt resistor, though, to prevent future burning-out? The first reply in this thread suggested a higher watt resistor could've "fixed" an issue with the circuit delivering too much current to the bulb.