Bucket brigade chips

[Steve Blackdog]

Evening folks,

As the Christmas hols arrive, I am starting to plan my next pedal. I have in mind the Andy Summers “Walking on the Moon” flanger. As far as I find, he used an EHX Electric Mistress.

Is it still possible to buy SAD1024 BBD chips? Is there an affordable alternative?

Any information much appreciated.

Merry Christmas

Steve

[nosaj]

unfortunately not, there are no pin for pin SAD1024A equivelants.
nosaj

[Mick Bailey]

Pin compatibility wouldn't be an issue, but the characteristics of the IC are unique. The only ones I've seen for sale are old stock or 'pulls' at great expense.

There's a possibility of replacing the IC with another more complicated circuit as done here; https://www.thegearpage.net/board/in...ngers.2273082/

Edit: Do a search on MN3007 Electric Mistress - some interesting background and builds. This one sounds pretty good; https://www.youtube.com/watch?v=YvpQi2ZSTbQ

[Mark Hammer]

If the need is for something that aims for modest delay times, such as for a chorus or delay, a Panasonic (MN type) chip can conceivably sub if one does the pin rerouting. If the desire is for much shorter delays, like a flanger, a Panasonic chip COULD sub if one added buffer circuitry. The clock input pins on MN type bucket brigade chips have an input capacitance several times higher than on a comparable sized Reticon chip. This corrupts the clock pulses at higher frequencies, the way a very long unbuffered cable between guitar and amp robs your guitar of highs. This is why the traditional MN3007/3101 combo is only spec'd to clock as high as 100khz. With proper buffering, however, I've seen a 3007 clocked as high as 1.5mhz.

[Mick Bailey]

I'm really impressed with the MN3007 A/DA flanger clone in this link. The vero layout is verified. This may be one to build for myself.

https://www.youtube.com/watch?v=oOByPAHY9nI

[Steve Blackdog]

Maybe the A/DA is a good idea. Harald Sabro has this version on his site:

https://www.sabrotone.com/ada-flanger-vero-layout/

it is certainly a pretty versatile pedal.

If the YouTube comparisons are anything to go by, PastFX Elastic Mattress is a decent clone. I believe that uses MN3007. It would help to find a schematic for it.

[Steve Blackdog]

If the need is for something that aims for modest delay times, such as for a chorus or delay, a Panasonic (MN type) chip can conceivably sub if one does the pin rerouting. If the desire is for much shorter delays, like a flanger, a Panasonic chip COULD sub if one added buffer circuitry. The clock input pins on MN type bucket brigade chips have an input capacitance several times higher than on a comparable sized Reticon chip. This corrupts the clock pulses at higher frequencies, the way a very long unbuffered cable between guitar and amp robs your guitar of highs. This is why the traditional MN3007/3101 combo is only spec'd to clock as high as 100khz. With proper buffering, however, I've seen a 3007 clocked as high as 1.5mhz.

Is there a good book or resource that explains how effects circuits actually work? I realise I am still painting by numbers. It would be great to be able to work out some of this stuff myself. I realise that you can’t learn without experience, but I feel I am making pedals based entirely on other people’s brains!

[nosaj]

Is there a good book or resource that explains how effects circuits actually work? I realise I am still painting by numbers. It would be great to be able to work out some of this stuff myself. I realise that you can’t learn without experience, but I feel I am making pedals based entirely on other people’s brains!

https://www.electrosmash.com/
is as good as any they do circuit analysis on several popular pedals. Their site certificate expired 77 days ago but you can still visit site.
nosaj

[Mark Hammer]

Like many who have been in this game for decades, you can't go wrong with Craig Anderton's various books, some of which can probably be found as bootleg downloads. You should also look for bootleg downloads of Nicholas Boscorelli's "Stompbox Cookbook". The gang were reticent to post scans because they didn't want to step on the toes of someone who had clearly put so much thought and work into it. But years of collective searching failed to find any evidence that Mr. Boscorelli was still alive, or that any relatives/descendants were hoping to garner some royalties from sale of the book. So, it got posted around.

Though it doesn't get into the circuitry much, I have a fondness for Craig Anderton's "Guitar Gadgets" book. It's 4 decades old, now, but explains what all the knobs do on a very wide range of effects, and nudged me into systems thinking about guitar signal processing, for which I am thankful. I met and chatted with Craig at NAMM a few years ago, and he remains an excellent teacher.

I will also recommend a visit to RG Keen's GEOFEX site ( www.geofex.com ) and reading his various "Technology of..." articles, and a visit to Jack Orman's AMZ site, where his Lab Notebook documents explain much ( http://www.muzique.com/lab/main.htm )

Finally, while not directly guitar-related, the scanned back issues of Electronics & Music Maker ( http://www.muzines.co.uk/mags/emm ) and Polyphony ( http://www.muzines.co.uk/mags/pl ) magazines are always a great resource for understanding how things work. Indeed, you may find much to browse through productively at this site, courtesy of the good folk who had the patience to scan their personal magazine collections: http://www.muzines.co.uk/mags

[Mark Hammer]

I'm really impressed with the MN3007 A/DA flanger clone in this link. The vero layout is verified. This may be one to build for myself.

https://www.youtube.com/watch?v=oOByPAHY9nI

The A/DA makes use of a buffered clock pulse, as I described in an earlier post. Earliest issues used a Reticon chip, then switched to an MN3010, which was a cascadable pair of 512-stage sections, like the SAD1024. But that used a buffered clock to be able to push the maximum clock frequency well above 100khz. The MN3007 version also employs this strategy.

[Mick Bailey]

I saw that when I took a look at the schematic. I didn't know the earliest ones used the Reticon chip - I have a very early Bell Electrolabs true stereo studio flanger that's been hanging around for years that uses Reticon chips and a problem with them is the IC seems to deteriorate over time rather than fail outright. This is the second unit I've had for repair, though they're something really special when working properly.

Getting hold of genuine MN3007 IC's at a reasonable price is a challenge over here in a market awash with fakes.

[Steve Blackdog]

I saw that when I took a look at the schematic. I didn't know the earliest ones used the Reticon chip - I have a very early Bell Electrolabs true stereo studio flanger that's been hanging around for years that uses Reticon chips and a problem with them is the IC seems to deteriorate over time rather than fail outright. This is the second unit I've had for repair, though they're something really special when working properly.

Getting hold of genuine MN3007 IC's at a reasonable price is a challenge over here in a market awash with fakes.

I have an electrolabs phaser, which was pretty good. I have just take it off of storage. Unfortunately the batteries were left if and the cells outgrew the battery cases! I have posted a couple of pictures.

[Steve Blackdog]

Like many who have been in this game for decades, you can't go wrong with Craig Anderton's various books, some of which can probably be found as bootleg downloads. You should also look for bootleg downloads of Nicholas Boscorelli's "Stompbox Cookbook". The gang were reticent to post scans because they didn't want to step on the toes of someone who had clearly put so much thought and work into it. But years of collective searching failed to find any evidence that Mr. Boscorelli was still alive, or that any relatives/descendants were hoping to garner some royalties from sale of the book. So, it got posted around.

Though it doesn't get into the circuitry much, I have a fondness for Craig Anderton's "Guitar Gadgets" book. It's 4 decades old, now, but explains what all the knobs do on a very wide range of effects, and nudged me into systems thinking about guitar signal processing, for which I am thankful. I met and chatted with Craig at NAMM a few years ago, and he remains an excellent teacher.

I will also recommend a visit to RG Keen's GEOFEX site ( www.geofex.com ) and reading his various "Technology of..." articles, and a visit to Jack Orman's AMZ site, where his Lab Notebook documents explain much ( http://www.muzique.com/lab/main.htm )

Finally, while not directly guitar-related, the scanned back issues of Electronics & Music Maker ( http://www.muzines.co.uk/mags/emm ) and Polyphony ( http://www.muzines.co.uk/mags/pl ) magazines are always a great resource for understanding how things work. Indeed, you may find much to browse through productively at this site, courtesy of the good folk who had the patience to scan their personal magazine collections: http://www.muzines.co.uk/mags

Thanks, Mark,

If I can just dig a little deeper, that will be great!

[Mick Bailey]

I really like the Bell stuff. I had a Bell ADT pedal that was really something special, though all the ICs had their markings sanded off so repair was quite difficult. It was part of a modular system where each pedal plugged into the next - no cables needed.

Stompbox Cookbook is about the best work I've ever come across for any music related subject and It's a real shame it was never re-published. I suppose the market is very small for such a niche interest.

[Mark Hammer]

I really like the Bell stuff. I had a Bell ADT pedal that was really something special, though all the ICs had their markings sanded off so repair was quite difficult. It was part of a modular system where each pedal plugged into the next - no cables needed.

Stompbox Cookbook is about the best work I've ever come across for any music related subject and It's a real shame it was never re-published. I suppose the market is very small for such a niche interest.

Perhaps it would have had better and broader distribution if Mr. Boscorelli or family-members were available to promote it. But it seems to have tragically been his swansong. There was the short-lived "Stompboxology" newsletter, which one can find a few instances of, for downloading, on the Moosapotamus website. http://moosapotamus.net/stompboxology.html

While many of the projects in that collection and the book are interesting, I find them unnecessarily complex sometime. And as grateful as I am for the PCB layouts, few are mindful of the space requirements of common enclosures. That's a shame, because it means fewer people will build them.