Not sure what you mean by "direct delay time modulation," but the 41 and 42 both set basic delay time by manipulating the memory counter and swept delay times by modulating the sample clock, if memory serves. I'll see if I can go back and look at the docs.

Yep, that's sample rate (clock) modulation rather than modulating delay time itself.
Thanks

Just realized that I duplicated a post I'd put in this same thread a while back. sorry about that!

By the way, I'm looking at 41 and 42 schematics side-by-side right now and there were a few more differences in the analog circuitry than I remembered. For one, a few 353 op-amps were changed to 5532s, in the 42. Also, there were two limiting stages: diodes on the input, and an opto-isolator a little further on down the signal path. Not seeing too much difference beyond those.

The envelope follower was my favorite as well. It did something magic to a vocal when I set a delay time then added some of the envelope follower to shift the delay. It was a sound that couldn't be copied by just using the LFO.

Was the delay set to short time, like doubling/chorus range, or to longer values for echo... when you applied ENV modulation to it?

Appreciate the technical information that you and TheLastByte have posted about the PCM42, and am curious if anyone has successfully made (or attempted) a swap of the unit's NE5532 opamp to a Texas Instrument (Burr-Brown) OPA134PA-ND? I'm also looking to find a replacement for the CLM-50 043 chips... Has a cache of CLM 50 chips been found anywhere, suddenly, like, this last week?? (Fingers crossed!) Thanks folks..

They're not hard to find, put it that way!
Cheers
TLB

any thoughts on the best one to use in front of an EMT 140 ? as a dedicated pre delay unit ? would the limiter on the 42 make it a better way to hit the plate?

Well, if it’s a Mono EMT 140 not /S then certainly I’d not want to go near limiting on such a beautiful plate design, I’d actually (having used all units mentioned and still using all save a 140) in my room, profffer that a PCM-41 would be more then adequate for the Job, yet a 1300/M or S (possibly if used in mono with, the 1300/S used as a Regeneration device, by using the max delay and routing one output into another input), you’ll increase repeatability yet you’ll lack Envelope and waveform Control. There’s none!

I’d also hesitate here to mention that whilst PCM 41/42 units have a certain sound by the use of one A/D converter the 1300 operation is very different thus it’s details in Regeneration will be 16 bit clarity. (Near a PCM 80 Sound). Here a PCM 80 DDL of a first generation could (18 bit unit) might offer more in total overall control though beware, its a tiered operating system you’ll have to learn even in Go mode, as in the 80’s Go verses Pro modes are vastly different in options. One is for quick noodling the other deep programming.

I’d certainly now steer clear of possibly more esoteric DDL’s from other OEM’s including EMT as those proprietary parts aren’t easily obtained. The Korg 1000-3000 and Roland SDE and earlier might too give safer ground in repair and spare parts. Again I’d suggest these units have differences in waveforms. Korg favoured a Triangle waveform, whilst square to sine are options the classic Env following in known 41/42 to Prime Time 93/95/97 designs are different.

Whilst I’m writing this post I might as well include a fact for those aspiring 41/42 to Prime Time owners. Previously it has been asked and discussed if these units were let’s say using a different way in modulation for the signal. This is a very valid point for many minus use or immediate access to these units looking to buy them.

Put simply, the modulation of the Delay in the 41/42 comes from the waveform and the clocking, naturally extended delay times equate to a lower frequency bandwidth this comes about from TTL Operation and design to XTAL (Crystal) or Waveform modulation. To be as succinct as possible when use of both options is deployed its the reason why the 41/42 to 93/95/97 have and give “That Sound” and whilst I personally have found no gain in extending the 41/42 delay times (per the 42’s previous MEO 4.2 second board and newly designed 24 second MEO board - I’m wary here to warn, do be aware the New MEO board design takes Clocking away as a viable option meaning it can’t be triggered via CV to Gate). Then moving on:

The Prime Time MEO boards 93/95 did extend Delay and modulation Frequency its again here time rates increase pitch shifting on the original 93 becomes near a flipping contest and on the 95 you’ll land at 9.7 seconds more then enough time to capture a phrase loop it and toss it back into a mix, the 93 requires much more care. The 97 or Super Prime Time, I do warn many against buying simply due to the fact that whilst cleverly implemented for its time, those registers and micro controllers can lock a unit into deep diagnostic trouble. Much worse many are sold to new owners as perfectly fine, faulting when their not, you’d just not know, the unit wasn’t performing “To Specification” in buying one, the exact situation with the M200.

Please do be aware: the Orginal 224/X to XL as a Reverberation unit was so prohibitively expensive that the M200 PCM 60’s and Prime Time units were really a way of Lexicon saying to owners in marketing strategy “Sure we understand you’d love two 224/X units as in...say one for Effects and another one for Reverb yet can’t afford them, so we’ve built an M200 or PCM-60 and Prime Time 93/95/97 for your A or B room to give you those extended sound design tools”.

Hence their (Lexicon’s prolific number in sales) unit wise and certainly much easier to handle at that particular time then say AMS 1580/S to RMX in design and operations let alone cross Atlantic pricing in the USA and other areas save The U.K and Europe.

Here it should also be remembered that the original AMS RMX unit did both things, sampling 1580-S style to shifting and Reverb, it was all dependent on the cards dropped in. The Dram cards at 1.5 seconds and all to drop in a snare replacement something only an Eventide 2016 AD or Publison to more esoteric sampling and FX units provided better options as the 42 to 93/95 had much less in control of Rocking Back & Forth specifically designed Loop points.

The sheer fact that in 24 months sample emancipation would come from Akai made a huge difference as a AKAI to E-MU sample unit (Drum specifically to Keyboards) meant Dram/RAM easily cost less then a full boat optioned AMS 1580/S to SP2016 by Eventide. Whilst Lexicon continued in offering sampling on the 480L understanding that the SME card was optional or not required and in total delay the 480L offered 3.2 seconds of delay made the SME card/board not of priority for many users (Another story leading into the M300 units). simply as sampling became a defacto scenario in its own right.

I think it is very sage advice for many new to these units who truly haven’t used them beforehand in any real capacity (Yes YouTube can give you an idea, yet even at 8Khz not fully give bandwidth unless High Resolution) to the true and actual sound, grit and what simple single A/D units performed like, you’ll certainly get an idea, though you will not have “Lived such experiences” so to speak. That in 1979 no one had really seen anything like the PCM 41 or Prime Time 93 units before that the closest thing or nearest units were Eventide and their 910 to 949’s and even then, the companding DBX modules designed to keep the noise floor down had gone from version 1.x to 7.X in refining such new technologies. That AMS units were literally sold at midnight from the boot of a car their boards made on Plywood. Not unusual hence the PCB nickname “Breadboards”.

So in closing I’ll simply say to anyone thinking of buying an FX device with such deep early Microcontrollers you might possibly want to think again on the M200 and Super Prime Time units. Unless you’ve got access to a great tech, all schematic material, can solder and replace yourselves and diagnose faulting units.
These units full of brand new Z80 and other processors were starting to bring a 2nd Gen. of actual stability in processing control and serviceability.

These units are the H3000 to 4000 and PCM 80/81 to 90/91 and late 1980’s to early 1990’s units where LSI processors and AD/DA conversion alongside total stability in operating systems meant these 2nd Gen units did as said. They might sound a touch different being sharper and cleaner though it’s nothing Eq and compression can’t dumb down. Has the pricing on some units gone way too far? That again is for each person to decide as simply there exists no full boat software H3000 plug in or PCM-80/81 plug in.

Do the PSP Plug In’s of the PCM 41/42 to others actually sound like the real thing? No...certainly not to someone like myself with access to both nor in isolation! Whilst Sound Toys to UAD do make alongside other companies amazing software they are simply software Plug In’s and I think to anyone listening at Apple iTunes sampling rates who knows no better or to some one thinking of blowing a stack on one FX unit amazing choices exist in both hardware and software. Possibly we do offer a huge analysis of once amazing technology at a period in time were options were simply very few indeed. Rose tinted Glasses off here?

Personally I live on the side of either good software does great things to good hardware does great things the main difference one accepts Voltage and this hums and buzzes coursing its way thru units creating half busted caps to diodes to dodgy parts imparting those “Unique Inherent Flaws” while software does simply amazing things that in 1979 to 1984 were unthinkable unless you had so much money nothing was out of reach in being custom built. Lastly is a PCM 41 or 42 worth the money...? Prime Time to any FX unit?

Simply if you can test it, it shows no errors and you’ve done your best in thorough research to diligently affording evaluation and use in deciding to purchase, then cool.. go for it! Though PSP once made a 42 emulation and to many it sounded good, possibly there’s two reasons? 1. Possibly that very romantic rosy glassed view of remembering the original. 2. The heartbreak of a busted unit unfixed to its actual dirtier plug in usability in context of Tape, Analog signal chains and less defined speaker systems all tied up in a CV triggered to TTL chain.

Certainly with the 41/42 as units and a 949 to 969. This was a different time in FX design period. Let’s not get too romantically involved here as Larry has discussed saying the two units save for a few features are near identical. So unless you can remove yourself by degrees and rational thought, their inanimate objects minus power and cables, it is new technology and user study and operational techniques nothing you do with a unit hasn’t been tried before. Unless your trying to do things back then, simply couldn’t be done...certainly that’s possible so, great, maybe then you might be on to something!

No the Andy Wallace limiting trick is a load of bull sh*t as the 6dB roll off limiting filter to point in (understood this was rooted for use in design to stop units requiring repair (41) as it honestly was simply soft signal protection as per any insurance what it’s not is - It is certainly not Compression to Limiting as defined in any way save purely for technological being unable to fault a unit as in not exploding the guts of a unit. Nulled with no delay, it will sound crunchy and certainly, different and not in any way quick enough to over or undershoot a waveform in compression to true Limiting. Wallace has as others have openly denied this myth and net lore! It’s more simply home brewed truths justified by owners bought at ridiculous pricing.

I hope this post helps those deciding if “That Purchase” is actually 100% worthwhile as try the software side by side, try the 41/42 next to each other and also remember these units used alone in isolation as 1 single unit was a rarity mostly they were chained together building larger FX options and this sent via Aux Send and Return to destinations ahoy! Lastly if someone won’t accept returns walk away, you’ll need 14 days to get down here, not 14 hours!

Kind Regards (Apologies for the iPad spelling here)
TLB.

I did want to touch on this aspect and thought I’d use this previously posted material to save everyone the details unless required. Simply No! You do really need the original NE5532’s and whilst CLM’s can be replaced by another pcb board rejigged those CLM-50’s are becoming rare. Yet are they honestly required, not if your driving levels properly as again let’s remember these were built in safety precautions to stop blown repairs repeatedly. Whilst replacing options do exist I’m certain in time so will a drop in replacement pcb board 1/3rd inch square to just squeeze in.

I’ll simply say again not all op amps were created equally and variant 5532 chips often cause more problems I found this out to my own detriment in repair of Eventide and Lexicon gear from this 1979-1983 period. Generally Lexicon were pretty good in using “Off shelf and catalog parts” that today still exist I.E you can could and many have bought 224/XL boards, populated them with ZIF sockets and replaced old, acidity ridden 224/X/XL boards. Once again, unless you’ve got seriously deep pockets don’t go there! An guy I know recently went on a quest to get the 224/X sound and from a PCM 60 to 480L to 224 he went so deeply down the rabbit hole his head is still elusive to lost in the clouds. He can’t sell it, or afford to repair it?

If you must have those 2 main or 3 Algorithms the 224/XL gave go with a PCM-60 or 70 as you’ll get Plate, Chamber to Rich Hall. No they will not sound exactly as 12-14 bit as a 224 or 14-16 bit as a 224/X/XL though they’ll sound closer with delay (41/42 to Prime Time) then a 224 in pieces is worth! Sometimes half of something is actually better then half of nothing! A lesson many must learn themselves!

Regards
TheLastByte!

Wow thats a ton of info..i'll need to read that a few times... thanks for your answer.. all that said ..i wonder if the otari 5050 would take away all the complication... right now i'm using my studer b67 which sounds gorgeous ..but i will be mixing to it..so can't use it.. BTW its mono in /stereo out

Here in 2007/8 I am just simply going to say, I’ve admired Thrill and since perusing this board, on GS his advice has been quick, well thought and most sage, always fact and truth, in fact years ago when I read this post regarding the 41/42 and 1300S I too thought, amazing I must grab one! I did...and oh yeah, Thrill was right!

Just be warned the 1300M/S is exactly as presented by Thrill, a delay with - no Regeneration, no Waveforms, and no Modulation Controls, it’s simply a Delay, and most are around 300-600 milliseconds like myself many got the wrong idea as I did? No opto Limiting not that it was required!

There’s a huge difference between a broadcast DDL type delay that repeats once and once only to making it repeat. Nothing amazing except here considering its 1983 this 1300 was a landmark design it showed just how the “Technology Race” was on, more so in Audio and music, broadcast, video, post, film and radio indeed all genres.


Thank you Thrill!

Yeah, I do apologise I simply wanted to get it right and written yet again as done previously and so no mistakes are made especially now there’s deep money involved for many. If you’ve read my previously written FX errata you’ll know I like to simply spit it out, leave it...say here, that should sort out most things! Ok I see you’ve got the Stereo out option. Tools and outbound depending I’d not use Tape you’ll get tired too soon. Grabs a lo-fi Korg 2000 Delay it will work perfectly and do a great job, if Delay Regeneration is required rerouted a 1300/S to non routing waveform changing PCM 80 version 1. Of you really want duller try an older Roland 12-14 bit BBD or stereo delay in summary they’ll all sound, minus waveform as repeatable I guess a vintage tape delay if you can pony up for one? Sony to Ibanez to I guess anything you feel adds.

Best of luck
Regards
TLB.

TLB
rocks and rules!
cheers J.....

At my old 'shop' I had both a PCM 42 & 41 in the racks, but I almost never touched the 41.... though I think you really couldn't go wrong with either one..

The PCM 42 I found at random - dirt cheap literally in a pile of broken junk in a music shop eons ago & it's one of the outboard pieces I would never ever willingly part with as long as I live... (even though I tend to generally prefer electro-mechanical delays (tape) and reverbs) ... so many great uses for the PCM 42, from magnificent vocal delays in a mix to wild 'loops' with the hold function... I never liked the sound of 'smashing' the input - to my ears it just makes the signal sound compressed & weirdly 'thwappy'....

Fwiw a good pal of mine swears by the PCM 41, which will never be prised from his grip, having made 'epic' mixes and sounds with it for decades....