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Hello,

it's possible to buy somewhere PCB's?

He's on ebay selling the PCB's :

https://www.ebay.co.uk/itm/CE1-CLONE-PCB-KING-OF-CHORUS-USES-THE-TDA1022-512-BBD/254107550399?hash=item3b29fd82bf:g:8pQAAOSwm-FcKVxP:rk:11:pf:0

I built one of these last year. It's a great sounding circuit.

I found the MN3204's to be very scarce at the time. I ended up taking a gamble here:

https://www.utsource.net/sch/mn3204

Needing 2, I ordered 4 hoping to get a decent pair.
2 of the 4 I received looked like they'd been de-soldered from something.
The other 2 had no solder traces but I didn't need to bend the pins to push them into sockets.
Obviously all 4 were used, so just keep it in mind if you consider buying any there.
I used the 2 that hadn't been soldered & they worked fine, so that's the main thing.
Luck may vary, although they did provide a tracking number, so there's no problem with that aspect of buying from there, but it should be clear why I bought extra at the time. If I built another one, I'd probably buy more than 4 because the de-soldered ones make me nervous.

Fair go, Lars, we don't all have the knowledge of scruffie with BBD's. He was very diligent to spot an oversight from drog_trog with the slight variance in BBD voltage. Most of us are just hobbyists or guitarists that assume things like that are already sorted before buying the PCB's.

Personally I've heard the term "headroom" applied to many pedals, run the Wrecktifier at 18v instead of 9v for better headroom, run the Zirconia compressor at 15v instead of 9v for better headroom, do Monty Allums Boss GE-7 EQ mod for better headroom & so on, but never heard it in relation to tuning in a BBD, nor did I expect it in relation to a circuit that has it preset without a trimmer.

With the capacitors in the old original CE1's, it's not such a crazy idea to replace them. That Dod Flanger 640 from the same era that I restored last year had one ceramic disintegrate in my fingers from age. When replacing the polyester caps, several measured way beyond their original tolerance which could've caused any number of problems. Most were still OK, but I concluded it was best to replace the lot. In Madbeans Collosalus, the capacitor that determines the clock frequency has to be accurate, so you wouldn't want some 40 or 50 year old part no longer functioning at the intended value in similar circuits. 

My misinterpretation, Scruffie, I was indeed thinking noise & clarity. To use dirt boxes as a comparison, to get it away from the compressed muddy sound of an Ibanez Sonic Dist & closer to the clarity & better dynamics of a Boss Blues Driver.

The only trimmer in the CE1 is across pins 13 & 14 of the MN3002, they're the 2 output pins, so useless in this case. Therefore, it's just a matter of determining which resistor(s) to replace with a trimmer to fine tune the bias.
1 volt may not seem like much, in fact it could be as much as 1.7 volts out of focus, but it's enough to cause the problem for him. Once established (I'd be surprised if it isn't already), that info would become a mod everyone that builds these (or owns the originals) would probably use.

@luchin542

Well done repairing your original CE1 with a TDA1022P.
As for the headroom, assuming all your capacitors are new & not still the old ones from the 70's, maybe you could try replacing the 2 opamps with something modern (not the LM1458 chip because that is the clock).

I was just looking at the schematics (original & clone) & noticed there are some changes between the original CE1 & drog_trogs PCB.
He was clear his CE1 was a part for part replica of the Retrosonic Chorus (CE1 clone). I always assumed the Retrosonic was an exact Boss CE1 replica, but I assumed wrong.
Most, if not all, of the transistors are different.
The original CE1 used 2 x ta7135p opamps (I think they're the old Toshiba single row parts). The clones are using the more common TL072 opamps instead. So you could try Burr Browns or whatever else to see if the headroom improves. Obviously it would get fiddly & time consuming, but it's up to you. Maybe socket some ribbon cable to a riser-board.
Unless you get lucky & find another MN3002, I can't see much else you can try.
Maybe try replacing the 50k level pot with 500k for better impedance if you're using guitars.

@luchin542

It was drog_trog that got the 2 different (but almost identical) CE1 PCB layouts done for MN3002 & TDA1022P chips.
He hasn't been registered on the forum for a while now, so I'm not sure he or anyone else will answer your question.
He also said interest in it wasn't as much as he expected, so I'm not sure doing another CE1 layout now would be a good investment of time, if that's what you're doing. Maybe the power supply section could be improved, but apart from that it's a CE1 circuit part for part.

It's still a good question because there will be more genuine CE1's needing repair in the future & the MN3002's are too difficult to source now. The ability to replace a dead MN3002 with an IC socket & a small riser-board with a TDA1022P would be knowledge worth having.

I'll just add, having soldered up both versions for MN3002 & TDA1022P myself, the BOM & part count was identical for both versions.  One had a 14pin BBD the other had a 16pin BBD & the only other difference was a few parts reorganized (slightly moved out of the way on the PCB) to accommodate the longer 16pin IC.

Does anyone have the schematic for this project? The link in the first post does not work anymore. I am mainly curious about the powersupply part

Here's the schematic.
I had trouble posting it but Brian said the file was too big, so he resized the file & emailed it back.
I'm now just re-posting the smaller file size version for anyone else that needs it.
I was surprised by that because I downloaded the original from this thread months ago & tried posting the original at first to no avail. Not to worry. Computers, you know what they're like...

After 6 weeks off all things electronics, I got back to finishing the CE1 this week.
The MN3002 version was OK in the end. First thing I saw when getting back to it was it just had 2 wires that had worked loose from the mode 3pdt after all the dithering about replacing the caps/diodes mentioned previously. Instantly fixed.
But, as I wanted to future proof this & as drog trog had also sent me a TDA1022 version PCB, not to mention having several of those TDA chips on hand, I soldered up that TDA version.

It worked first go, but it had the same annoying hum present as my MN3002 version. I first thought it may have been because I wired the 2 x 3pdt's instead of soldering them directly to the PCB's. It wasn't caused by that though, I tested it with a 9v battery & it worked perfectly without the hum, so the power adapter was the cause of the hum. Oddly enough it works fine with a 9v battery in vibrato mode but seems to lack the current from a battery to kick in the chorus mode, but that's OK, I'll get a better power adapter later. I read somewhere that these things don't like switch-mode power supplies, so that's probably all it is.

I still have to wire up the mode LED's & think about whatever other mods later, but as a bare bones thing it is working exactly as it should. The enclosure already has spare holes for a toggle & a couple more pots, so I'll get all that sorted later.

The only change I made from the first board I did was the 3 power caps next to the recon power module. Instead of neat & small 35v caps, I used larger 50v Nichicon low ESR's (with better heat tolerance, longer life), which meant I had to lay them down on wacky angles, but they fit OK in the enclosure.

I'm not sure how to set the CE1 trimmer, but I've left it somewhere in the middle of its range & it seems to be fine as is. I think it would need an oscilloscope & the Boss service notes to sort that out properly though...

I put some more attention into the Dod 640 over the last couple of days.
I replaced the remaining old IC sockets, then sprayed on some PCB cleaner, as I'd left so much flux residue everywhere. There was enough still there from the early days to warrant a good clean. Most wasn't budging, so I left it overnight to soak a bit & then gave it a 2nd spray today. A sacrificial toothbrush & pin (for scraping between closer pads) later, it was clean enough to eliminate the possibility of any old residue having turned partially conductive. I let it dry a few hours, then I put all the IC's back in & it's now running as good as new. There's no noise artifacts or pops, just a great unique vintage flange. It all seems stable for now.

The range on the clock trimmer is back as well. I just set it at the end for best flange, then backed it off a little to stop it going mental, so I assume turning it towards the chorus end would be increasing the delay time, hence being better for chorus.
I'm not sure what the other trimmer was called (maybe "color") but that one only had a very small range to tune in the effect, so as usual, just a matter of hitting on the spot in the middle of that narrow zone with the least distortion. It took a few goes that one, but once in the right spot it sounds great.

Replacing the 3x D100k pots with B100k's works perfectly. I'm just not happy with the curve of the A500k as a replacement for the D500k (speed knob), so I think I'll have to swap that one for a B500k. It's feeling too bunched up at the fastest speeds.
Anyway, it's all done & working, no noise or any issues whatsoever, the 70's carbon resistors quietly live on, just have to swap a speed pot later to get the curve feeling better.

Most of my pedals from those early 80's days were Boss & no Boss I've owned has ever needed a repair. They're all still working as good as new, even the oldies. I had an Ibanez analog delay fail on me during those days (the pink one with the small square chrome switch), but not the Boss DSD (digital sampler delay).
Quick story, I once used the DSD for a prank on some friends that I knew were on the way over. The house had a momentary button outside for the doorbell inside, so I used some jumper leads inside from the actual bell end to a regular guitar lead & used that as the sample trigger mechanism plugged into the socket on the DSD. Then I set up a seriously huge stack of speakers & amps behind the front door....and they were expecting "ding dong" haha. Good old Boss pedals, what can't they do....

With the CE1, I haven't given up on it, I'll just have to go over the area around the LM1458 where I replaced a couple of diodes & caps as there's a chance I missed something, dry joint or whatever, so there's hope for the MN3002 yet.
Due to the rarity of those chips & having no spares now, I still intend doing the CE1 TDA version (fortunately drog trog still had a TDA PCB to sell me) as I already have a few of those chips on hand, along with everything else needed. It's just to future proof my own CE1 so I can keep it going if the main chip does/or has failed on the MN3002 version. It'd also be quicker & more cost effective to populate another PCB than try searching for spare MN3002's.

With the Dod 640, I obviously missed the elephant in the room = the old IC sockets, corrosion on the top side etc, so getting rid of the remaining old ones is bound to clean up the signal a heck of a lot. Re-flowing their pins just wasn't good enough, lesson learnt. Another point is even the cheap IC sockets around these days do a better job maintaining their grip on IC pins than what was available circa 1980. The "turned pin sockets" even better. The resistors should still be OK & I reckon the worst thing that could've happened to a few over time is they may have started getting a little bit noisier. I'll see how it goes after getting the remaining old IC sockets out of there first, as I already re-flowed all the resistors recently. If new IC sockets get it stable & quiet, I'm not keen on replacing all resistors just for the sake of it.

The 640 was a fairly good flanger design (apart from the AC transformer causing some hum & risking power surges), but I really liked the chorus it could do as well. Most chorus circuits tend to use a single MN3007, being a single 1024 stage BBD, but there was something about the Dod using the 2 x 512 stages in parallel & out of phase that made it special. I'm sure there'd a be a few chorus designs around that do something similar, I just haven't searched for any, just going by what I have & only the 4 button Boss dimension springs to mind as a possibility of doing things that way (having built the blueshift last year with its 2 BBD's), albeit with buttons & not pots.
Same with Flangers, most don't use 2 x BBD's in parallel & out of phase, but a lot in the past used the 2 x 512 stage halves of the sad1024's in series which is being replicated exactly by a single MN3007 in remakes by the more experienced guys offering their PCB's these days. The BYOC Flanger is the only DIY one I'm aware of that did it with 2 x BBD's in parallel & out of phase. The Ibanez FL99 used 2 BBD's as well, but I haven't looked into if it's in series, parallel etc, sure sounds great that one though.

Scruffie, I didn't have any luck with frequency measurement. Maybe I was doing it wrong. No frequencies were fluctuating.
I've done it before with one or two other flangers, the reading goes increasingly up, then slowly down, just a matter of noting the top & lowest frequencies & adjusting the trimmers accordingly (or in this case seeing if there's any movement at all).
I looked over the pins of the 4013 on the trace side of the PCB. There were no breaks in traces so it was puzzling.

I remembered what happens to TV fly-leads when they've been in use for a while (the cable from TV to the wall). Even if they haven't been touched or moved for a few years they can suddenly stop working or give a bad reception. You can check them with a continuity tester, they'll check out OK, but still wont do their job. HDMI cables can suddenly go flaky too. And those LED torches, don't you just hate how they start flickering & you have to keep tapping them to keep the light on, you can't clean the battery contacts enough to keep them stable...
So I thought while I had the 640 guts out, I'll replace the whole socket the 4013 was in, as it was over a quarter of a century old.
I took out the BBD to keep it safe & then also the 4013. I used some trusty solder wick & the old 4013 socket popped right out with no damage to any traces. I soldered a new socket in place, put the chips back in & powered it up. The first BBD I put in got a result, so yes it's now sort of working almost but not quite as it should, but at least it's chorusing & flanging a bit now.

First thing I noticed was it was very difficult to find the sweet spot for the 2 trimmers, so at this stage I'm close to zeroing in on the right spots, but I'm not getting the seriously over the top flanging I know this thing is capable of, it's more mild & chorusy. From memory, it was never that difficult adjusting the trimmers, they had a much wider working range. In fact one of the trimmers I could adjust to use the 640 as more of a flanger or adjust it the other way for one of the best chorus sounds ever. Now it's like I'm trying to find the 2 sweet spots of both trimmers just to get it working at all.

Also it's making some random popping noises & after messing about a bit since freshly wiring it up, moving or tapping the PCB seems to set it off somewhat as well, also has the effect of the effect cutting in & out or going clean straight through, so I'm thinking loose wire(s) or flaky something somewhere.
It's great to make some major progress though, at least now it's working again, but for the moment it still sounds like any old pedal that needs a service & tune up, so I'll have to put a bit more time into it to get it stable, clean its carbies etc.

Thanks again for the encouragement to stick with it. I thought I had it narrowed down to being the 4013 as the problem & when I replaced it with the exact brand & model AE chip & it still didn't work, I was really disappointed because I had already re-flowed the pins of that 4013 socket & checked the traces etc. Yet, by replacing the socket itself today, the thing decides to start working. Unbelievable.
Now I'm wondering if I should replace the other 3 sockets as well, they might all have corrosion or whatever else impeding contact from the other IC pins. Some of the pins could be working as resistors now. I shudder to think...

Besides the BBD, the only other chips on it are an LM324N & RC4136N, both op-amps, which test OK in my IC tester (the part number pops straight up on the screen). That just leaves the 4013, which is a flip flop chip (also tests OK), so that must be the clock of the thing.  I'll check out the 4013 pinout & get my head around what is what & get the multimeter out. It does have a frequency counter, had to use it to calibrate a few others along the way. I just wish the IC tester could check BBD's...

If everything checks out clock related, then resistors are all that's left that I haven't replaced on the 640. Generally if they aren't burnt out or contaminated with anything that's causing them to disintegrate, they usually stand the test of time. However, if it turns out it's a resistor gone bad all this time I will kick myself. It'll be a first for me, a bad resistor that is, not kicking myself, never said I was perfect...

I could understand if replacing a few caps on the CE1 may have loosened a wire somewhere causing an issue, but the dreaded signal not passing through the BBD issue wasn't one I wanted to see. It's looking like it didn't survive the tinkering. I was mindful of not touching the pins etc, so it's disappointing it happened.

With the SAD's failing with Flanger feedback up high, that's just something I read recently googling around, so it's grain of salt stuff, if it's wrong it's wrong & appreciate the correction. It's not related to what's happened with these 2 circuits, just meant to emphasize they can fail much easier than other chips.

I'm certainly nowhere near an expert with these things, that's for sure. I haven't done this professionally, so it's all learn as I go over the years. More often than not, they work first go & if not I can eventually get them working.
After building my own oscilloscope a while ago, I wasn't happy with it because apart from being a single probe thing, I found the 2 mini calibration trimmers both failed after just a few turns. I never bothered trying to fix it, although it could be done to get it tuned in a little better, I just ended up buying a dual probe scope recently instead. It's not a small USB thing, it's a standalone Gratten. It's actually larger than I anticipated, but it is what it is. It came in handy setting up the Ibanez FL99 from Dino & Phil recently, getting the 2 waveforms on screen & adjusting the trimmers to match the waves. A couple of other times I've tried using it things didn't make sense to me, hence my inexperience with it.

If you think it's worth persevering with the Dod 640, I'll keep going, but no output signal from the BBD's gave me the impression they have problems, ie failed. I agree, it doesn't mean they have all failed, it just really inconveniently looks that way despite hoping at least one if not more are still OK. I haven't tested the clock, nor am I a modulation engineer, I've only used a voltmeter to check if voltages were fluctuating on some of the various IC's pins & it looked that way, but it's not a clock test by any means. I can only go by every replacement part testing OK before going on the PCB. So it should work, it just isn't getting past the BBD's & apart from your suggestion of checking the clock, I'm not sure how to progress for now, so I'll try to figure out how to test the clock if nothing else.

Thanks for the advice too. By the way, I've put together quite a few of the Lectricfx builds & all worked well first go. The Zirconia was the only one that sounded weird & unusable but Keefe emailed me back within an hour saying increase the voltage from 9v, which I did & it worked perfectly after that.

Hi Scruffie,

I've only audio-probed the BBD's while they're socketed. The signal makes it to the input pins but not the output pins, so that is not a good sign.

With the CE1, it was chorusing as is, all that was changed between powering it up was a pot, some capacitors, diodes & a fresh LM1458 chip. So that BBD has gone from signal passing through the BBD to no longer reaching the output pins (signal only making it to the input pins).

With the Dod 640, literally everything has been replaced except the resistors. I've spent a lot of time making sure there are no shorts & that every trace goes where it should. I can never rule out 100% that there may be something somewhere causing this to happen, but my gut feeling is all the sad1024's are bad. They're very sensitive to age, static, handling & so forth. When used in Flangers they can fail a lot quicker just by using the feedback/accent knob at higher levels (perhaps in delay units that are tweaked for lots of repeats too), although that isn't the cause on this occasion.

I'm confident the ones I have aren't fakes, just more inclined to believe they have all failed for whatever reason. The last 2 reticons I bought were from a repair guy that had recently retired & closed his repair shop. He was just selling off a few odds & ends he had left over. They were from a large batch he sourced through official suppliers in the 80's & he'd used many from that batch over the years to repair vintage gear. They were stored professionally & mailed to me shielded & packed professionally, no bent pins, just NOS. It doesn't mean they were still working after so long & it doesn't mean I can rule out 100% that I may have missed something causing them to appear dead either, but they're sure looking dead. The other 2 I had were bought years ago, one new from an audio place in LA & one used & tested working before being mailed to me at the time by one of those synth guys, so my confidence in their survival isn't high after so long.

I've asked drog trog if he still has any of the TDA1022 version CE1 PCB's left, because at least I have all the parts here to whip up another PCB, including several TDA chips (which are at least still buyable to future proof it). If/when more MN3002's surface, I can get back to sorting that version out & also happy to have both versions or to give one away later.

It's just one of those things, it's not that I couldn't just buy an original CE1 or one of the clones floating around, it's more for the challenge & the whole DIY thing. A challenge that KO'd me on this occasion,hehe, but that's the way it goes sometimes. Also, I'm not one to post build reports, don't have the time or space for painting labels etc, there's so many people better at it than me, but I just liked the effort DT put into this one & wanted to support it as there wasn't much additional info or many people posting on it.

On a more crazier note, I've got another couple of sad1024's on the way, this time from the same place I got the working MN3002 from.
I know, I'll never learn, hehe...

In addressing the issues with my CE1...
Replaced the Level pot, as it was sounding scratchy & weird when turning it.
Chorus mode was working, not Vibrato, so using the schematic, following the route from the Ch/Vib 3pdt I replaced C35,C36,D13,D14 & put in a new LM1458.
There was a loud pulsing hum in both Ch or Vib modes, so considering I already replaced the Recom, I replaced whatever else was in the power supply section, which was C7,C11,C12,C16,C17, also the 3 diodes, D1,D2 & D6.
Powered it up & this is the story. Level pot is no longer sounding abnormal when turned. The loud pulsing hum in either mode is gone, but a lower volume constant hum is present in both modes.
And here's the bummer, after all that messing about, the MN3002 chip seems to have died, no longer getting Chorus & audio probe is now stopping at the MN3002 input pins. As I don't have another MN3002, I'm unable to continue working on this one indefinitely.

Someone on Ebay back in September advertised 100 x MN3002's, in lots of 10 for $100, but one buyer came along & bought them all for $1000. The only other MN3002's on Ebay (at the time of writing) are not Panasonic BBD's. Apparently (from reading around the web) there's a new chip called MN3002 that has an entirely different function. On top of that there's bound to be fake Panasonics & remarked chips around as well.

As for the Dod Flanger 640, some vintage RCA brand CD4013AE chips turned up. They tested OK in my IC tester, so I decided to replace the 4 old pots in the 640 while I was at it. They were 3x D100k & 1x D500k. I just used 3x B100k & 1x A500k. Got all that done & put the CD4013AE in. Powered it up & although I now get a slightly filtered clean signal through in effect mode (as apposed to nothing at all), the audio probe is still stopping at the input pins of all the SAD1024's I've tried in it. When the Accent knob is on max, no signal through in effect mode. Looks like all the SAD1024's I have (4 of them) must be bad. I've eliminated every other possibility I can see. So this is another one I have to put away again indefinitely.