Any source for CCD (bucket brigade) IC's?

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David Kulka

Well-known member
Joined
Dec 10, 2006
Messages
241
Location
Burbank, California
Does anyone here know, is there any source for CCD (bucket brigade) type IC's, as used in the old flangers and analog effects boxes? I wonder if anything like that is currently being manufactured or if there are any reliable sources of NOS parts. Thanks in advance.
 
Thanks for the replies. The Small Bear and Coolaudio sites look promising. I need these IC's to repair some Marshall Time Modulators. They had custom analog delay modules that were built around CCD IC's.

The old Bucket Brigade IC's were very vulnerable to static damage and there were high reject rates.

Are these modern chips also easy to blow up, and how's the quality control? The distortion specs don't look so great. Has anyone here used these ?

Many thanks.
 
David,
The Marshall Time Modulator delay chips were encapsulated in epoxy.
Do you have a circuit ?
As far as I know the delay chips were Reticon SAD1024.
Very hard to get hold of now (i.e. expensive).

I managed to repair my Time Modulator. Very fortunately it wasn't the Delay Lines (or Analog RAM as Steve St.Croix called them). It was one of the DBX boards that had blown.
I tried many times to get Mr. St. Croix (or Marshall) to give out technical information but he refused point blank. I think we've already discussed at length in this forum about what a bullshitter he was. A very clever man - but an ego the size of a house. Anyway R.I.P.

As I say, If you have any technical info then could you share it ?
 
Well, David's been careful not to pimp his situation, and I most definately repect that, but... (and I hope I'm not misrepresenting the situation here):

The St Croix estate has authorised David's company to be the sole agent for Marshall electronics service. While Stephen was a man of strong (and frequently-voiced) opinion, he was also rater secretive. Much of his research sounds like it was undocumented, and David s now responsible for picking up the pieces, and 'forensically' determining ways to keep these beasties alive when bits of them fail.

The dbx boards are apparently another favourite failure in the MTMs, but fortunately they're serviceable... There appear to have been two (or perhaps more, but possibly only two) versions of the dbx board, and if anyone has any info on the less common variant, I'm sure David would appreciate it.

So I'm not sure that David can share certain proprietary details (which most likely remain the intellectual property of the St Croix estate; I doubt that the design IP would have been transferred with the servicing agency) but it none the less has become his responsibility to somehow pull replacement parts out of thin air... or an electric mistress if necessary... (while I do very much enjoy the electric mistress, given the choice between letting an MTM live, or letting an electrc mistress live... It's goodbye Electro-Harmonix every time, for me!!!)

Hopefully I'm not misrepresenting the situation here... By the way, the Time Modulator is one of my ALL time favourite pieces of gear: the affection and esteem in which I hold it is immeasurable.

Keith
 
I don't know which part was in the MTM, but there were only two general sources for BBD ASRs (bucket brigade analog shift registers), Panasonic aka Matsushita who licensed the technology from Phillips, and Reticon. I recall using some parts direct from Phillips (N449?) in early '70s but AFAIK these were not production parts.

The SAD1024 (RET) and MN3001 (PAN) were BBD ASRs. There was a later CCD R5101 from Reticon that was a different process than the BBD ASRs while I believe they may all technically be "charge coupled" devices. Reticon made the naming distinction between their own BBD and CCDs. The CCDs had pretty low noise and were capable of long delays but had an additional HF roll off beyond the anti-alias/anti-imaging filters. I know that Reticon stopped making the CCDs in the early '80s since I was using them in a consumer design being manufactured by Bozak.

I believe the old Panasonic/Phillips series, now from CoolAudio (?) may be the only current build silicon available. Even if the MTM used Reticon or some unknown (to me) other ASR, the cool audio parts can probably be made to work, but they won't just drop in.

JR

PS : Steve St Croix (Marshal, or whatever) was an interesting character and I enjoyed his writing in Mix magazine. (RIP)
 
John, thanks for the info. I've been looking into these devices for the last few days. Some of these newer versions have poor distortion specs but the Panasonics look interesting. I anticipate a lot of experimentation, matching, and more than a little frustration but I'm sure I'll come up with a solution in the end. It seems like Digikey carried the Panasonics up until recently so maybe they're not too hard to find.

I was a little distressed to read the negative comments here about a person whom I admired tremendously. The man achieved incredible accomplishments in his short lifetime. His most remarkable achievements may be the least publicized ones. I'm sure I've caused a few people to grumble over the years; I hope that despite our differences they won't bad mouth me when I'm gone.

Yes, as Keith said, we have signed an agreement with SSC's estate. We'll be servicing Marshall products and selling a small number of NOS units over the next year or two. I have an NDA with the estate, so no schematics and please don't ask for proprietary circuit details. I'll be glad to offer repair advice though and will do my best to support owners of the products.
 
Well, I am sorry to hear that you were distressed about comments regarding Mr. St Croix. Nothing I have said here is new and has already been said in this forum.
Obviously you admired the man and having met and spoken to him several times before his untimely demise, I agree that he was a very clever man.
But anyone who had a faulty Time Modulator and tried to get it fixed will have had a similar experience i.e. no help from him at all. I believe that people who bought the Paris system also had the same response.
If that's bad-mouthing someone, then I can live with that.
In order to fix the Time Mod units I had, a considerable amount of research and reverse engineering was required. A lot of searching to find info on the DBX boards, the clocking by the NE566 to the delay lines. How to line up the presets etc. I'm always willing to share info will fellow audio techs, but I don't believe in one-way traffic.
Good luck with your chip search.
 
I felt the Reticon parts were slightly better performance but the Panasonics were solid parts. I sold a bunch through my kit company back in the '70s and as I recall had near zero rejects, which was not typical of all ICs back in '70s.

I consider the CoolAudio parts an unknown, it looks like these may be new parts perhaps based on the old BBD technology but run across different process (fab) with different masks, so they will need to be characterized from scratch. Look like they’re dialed in for battery operation and may be higher clock capacitance than even MN series which was higher than SAD.

If you are substituting MN for SAD parts you will need to change the output source follower loads to pull ups from pull downs. A more subtle point is that the chip ground is on the positive side so their app notes always show it powered from a negative rail. I had good results running them from a positive supply but those output follower loads need to be connected to a well regulated (clean) power source as any ripple voltage there will couple into the signal. The new CoolAudio parts look like negative is ground again.

Bias and peak signal swing may vary slightly, but that's easy to see with a scope. All such devices have some operating point shift due to clock frequency so if the design is doing any first order correction for that, it may need tweaking.


JR

PS: I self edited my personal comments since Steve could be a difficult character dealing with competitors, (or anybody who dared question him). At this point It's old history and I prefer to dwell on his contribution.
 
Well... -the only word which raised my eyebrows a bit was "bullshitter", which to me usually means someone who knows or understands rather much less than they discuss... but not exclusively, I'll readily admit.

SSC was less of that sort of person, though I did disagree with much stuff that he published, he also made some towering contributions, and he WAS a character...! -Pretty soon there may come a time when there is a dearth of character; -who knows?

Anyhow, for now I prefer to dwell on the decent stuff that he did: Elsewhere I posted a story about an encounter I had with Adrian Gurvitz when I was pitching for engineering an album mix in the mid-1980's, and those of you in the UK who were around in that period will only associate the name with a single hit that he had...

...That hit was MADE by a marshall time modulator.

No need to repeat the whole thing here, but there are other wonderful things that have been done by time modulators, and if anyone ever bumps into me over a glass of something frosty, I can be firmly relied upon to warm to the task of recounting a few tales... A couple of folks here know how it is when I get into fireside story mode! :wink:

Anyhow, while David has apparently signed an NDA with the SSC estate, I can at least attest to his willingness to help out and share other information: in fact only last week I got into a bit of a bind with an SSL matter, and David was one person whom I did turn to, though I generally try to get things worked out by myself first, if only for pride's sake! (It hurts to ask for help sometimes! :wink:)

Keith
 
Well Keith. One final comment and then I'll leave it.
I had a non-working Time Modulator that someone had tried to fix and had also tweaked the presets inside. Now there is nothing available that gives any clue of how to line these units up.
I had managed to get the unit back into some kind of working order but it was obviously out of alignment so I spoke to Mr. St. Croix.
He told me that it was impossible to line up a Marshall Time Modulator without a computer and that was how they were set up when manufactured. I said 'that's bullshit Steve because this unit was made in the 70's'. After much rhetoric and probably realising that I wasn't just a tape op, he finally conceded that it was possible. But he was extremely unhelpful and the whole conversation was like pulling teeth.
Now that's my personal experience. By all means remember the best about people when they're gone.
If I'm wrong to relate the past - then I can take the flak.
There are many great records with Time Modulator - 'Secret Life of Plants' is another one that comes to mind.
Oh and speaking of Adrian Gurvitz, you are aware of his nickname aren't you?
It's a classic (pun intended).
 
I'm sorry that you had a bad experience getting (or not getting) your MTM serviced. I know that Steve wasn't too thrilled when others attempted to fix or tweak his gear though granted, your options must have been very limited.

I can tell you that among the documentation and parts I received there was a thick folder containing a couple hundred service requests from North American and overseas Marshall owners, each with notes about the completed repairs. (Actually, those letters, on the letterheads of famous but now defunct studios, famous names of that era, and many people we never heard of, were almost all complimentary and quite fun to read.) I believe that the vast majority of owners had good repair experiences.

Keith thanks for the kind words, even though I was no help at all with your SSL problem. (Maybe next time.) I meant what I said about doing my best to support the products. I won't distribute schematics or other non-public data, but I'll do what I can to help Marshall owners with basic repairs, tech questions, manuals, patch sheets, etc.
 
Barclaycon, It sounds like that's the way it may well have gone down, so I don't really blame you for having slightly soured memories; but I do think that with David taking over service, the user experience should be more pleasant and professional by an appreciable degree! :wink:

I don't know of Adrian's nickname, but I'd be fascinated to hear it... -Since my own experience with the man (which was probably as much fun as your one with Stephen! :twisted: ) I've spoken with others who are or have been friendly with Adrian... all of them tend to land on the same theme, and it's not very complimentary: David, one of them is from 'Salome Bangladesh' a great Indian Restaurant at Lankershim and Magnolia, in N. Hollywood... Last time was there, I looked to try and find it, but did't see it, so perhaps it's gone the way of all things; who knows...?



Keith
 

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