Which stripboard layout next?

[seraph]

[Uncle Krunkus]

Exactly.

[Scott Stites]

Hey Uncle K,

Yes, a BBD clock can really ruin your day if you make the leads too long going to the BBD - they like to spray that RF out, and there's the potential of mutally inducting that into other parts of the circuit. If you look at most devices that use BBD's, the clock will be butted up as close to the BBD as possible.

Noise is the middle name of BBD's, so when I'm doing a final build with them, I take about every precaution I can to keep the noise from going where I don't want it to. In the case of the Dim C, having two BBD clocks, the real danger is hetereodyning clocks regularly crossing clock frequencies with the product of the clocks being in the audio band. The original Dim C circuitry actually has a lot of built in precautions - a sub regulator for the voltage powering to the BBD's and clocks, with filtering on each 'draw' off of it for example. Obviously companding makes a *huge* difference as well. Heterodyning is not something to worry about in the STD-1, unless you put another BBD in there for wild multi-tapped TZF or something crazy like that that I would never do no never not me, no sirreee .

Not so obvious from the Dim C schematics is that you want to make sure that the BBD clocks have their own 'noisy' ground that is connected to the other grounds at one point only, preferably where ground enters the board (IE a 'digital ground'). On my Dim C, I took the extra precaution of jumping any audio from board to board and to the front panel through grounded coaxial cable. Audio only went from board to board in the compressed state - it was expanded on the main board before going to the front panel. The unit is ultra quiet - hard to believe there are two BBD's in there just asking for trouble.....

For those who voted for the Dim C and those maybe sitting on a rail, what really tripped my trigger and made me build one were the Boss DC-2 (Dimension C) samples at Modezero:

http://www.modezero.com/

Go to the page, check out the samples, and take a look at that busy, busy PCB. That engineer earned his pay (You want me to put a Dimension D into a Stompbox - what are you, crazy?).

Speaking of Dimension D, the Dimension C is the little brother of the D. Same concept, only rack mount, using MN3007's. One of the legendary effects units of all time.....

Juergen Haible built a clone of the Dimension D using four TDA1022's instead of 2 MN3007's (TDA1022 is easier to get hold of in the EU, apparently).

Cheers,
Scott

[Uncle Krunkus]

What kind of a nutcase would even think of putting two MN3011s in a stereo STD-1 clone with assignable taps and cross regeneration and all that kind of stuff? Someone like that would have to be criminally insane!!

[Scott Stites]

Only a lunatic with deep pockets would use two MN3011's. Us cheapskate lunatics would use an MN3007 to provide a single delay and rake the taps across that (or vice versa).

Here's a post I made to the Stompbox list a while back on the subject:

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Here's a graph I did of the delay times of the taps of the STD-1, a 'superfluous' seventh tap which is processed through a 1024 stage device from the last tap of the MN3011, and the delay range of the delayed 'dry signal' (labeled as Delay 2). All of these delay times assume the 30 kHz to 150 kHz clock range of the STD-1. The SST (Superfluous Seventh Tap) is there for other reasons which are beside the point of TZF, though it would also serve to give the TZF STD effect even more variation.


The Delay 2 section is bordered by two red lines delineating the through zero range. Notice that it overlaps all of the delay taps at some point. You'll also notice that modulating just the MN3011 while leaving Delay 2 fixed at a specific delay would not allow all of the taps to go through zero with a single sweep of the LFO, because the delay times of all of the taps will not pass through T=0 with a single fixed setting of Delay 2. Two ways to lick this would be to modulate both lines in anti-phase, which would guarantee all of the taps going through zero, or to extend the max clock freq of delay 2 up a few notches beyond the minimum delay of Tap 1, which could be easily done (after all, it is pictured here at a max clock of 150 kHz, and an MN3007 can easily superscede that, no matter what the spec sheet says). Being me, I'll use both methods.

It obviously would be a different effect than modulating two MN3011's through zero, but at the same time I'm thinking it would be a very spiffy effect in itself.
=====

The entire thread can be seen here:

http://www.elixant.com/~stompbox/smfforum/forums.html?topic=34557

The Superfluous Seventh Tap was an MN3007 fed with the longest tap of the MN3011 as done in the Scholz Rockman to get a 'cake and eat it, too' reverb feature. I later dropped that idea in favor of a theta processor for other things. The theta processor was inspired by JH's clone of the Eventide Flanger, which he dubbed the "Storm Tide" flanger.

That, in turn, led to even more noodling and led to a full blown phase shifter that could be inserted into the signal path at various points. I actually toyed with that (with the circuit I had controlling the MN3007) and the effect was marvelous. This is before EH produce the Flanger Hoax, which uses phase shifting as well. In the same manner, I'm not sure.

I could post a block diagram of that work. If anything, it would demonstrate what a nutcase I really am.

That experimentation begat my 12 stage phase shifter, which is still on breadboard, waiting for an additional 12 stages to become a 24 stage phase shifter (that's a whole other story).

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[gavgomad]

Hey all! New member, but long time lurker (hey Scott! Followed the development of the TZ Dimension on Synth DIY! Great work!)

I'm a little latecoming to the poll.... Was a consensus reached on your next layout?

Gotta admit that for me, the Dimension C (and it's big brother) are very unique, and although there are some tricks to mimic the overall effect with multi-fx, nothing has done it for me.

Accordingly, that's where my vote went (FWIW as late as it was!)

I suck at layouts, so I've just been watching the boards to see if anything popped up to put into maybe a half rack unit.

For me, the idea was to integrate some of the improvements that Scott implemented (in particular the pre-stage and the mono/stereo inputs; the TZF function and the VC controls were a sweet bonus!), and on the front end throw a nice low noise mixer (seeing as though I want to use the Dimension as a standard processing unit on my few remaining outboard units, mostly mono).

Back to my little "repair" hole! Great work all!

Gavin

[seraph]

Hi Gavin
welcome to electro-music.com

[Scott Stites]

Yes, Welcome Indeed!

The Dim C is one of those projects that I'm really, really glad I did. I fell in love with it the first time I heard the ModeZero samples of it. It's hard not to use it for everything. I love that line some guy wrote in a review of the Dimension C - something along the lines of "I use it so much, it's more of an effect when I'm not using it." One nice thing about it that sets it apart from other effects is that it can be set to be almost subliminal - you don't notice it until you actually bypass it. Of course, it can be obviously much more than subtle, and *really* not subtle when it's being trashed by external CV. It's also great for creating a groovy stereo image out of a mono signal (I think that's what Roland meant by calling the D and the C 'Dimension' effects)

As for the STD-1, it's got to sound really good. I had an A/DA flanger for years, and it was the best flanger I've ever had or worked with since, no contest. I imagine anyone that creates such a ripping little box knows their way around a multi-tapped BBD.

Take care,
Scott

[StephenGiles]

Hi folks, just been trawling through this section of the forum and very interesting it is too. This is my ADA Flanger sitting in an Electro Harmonix 5 knob case.

[Scott Stites]

Welcome Stephen!!!!!! Great to see you here and also great to see that cool A/DA flanger. I used to own an A/DA flanger. I loved that box with all my heart - traded a blonde Gibson L6-S for it brand new and never regretted it.

Don't know if it was the SAD1024 or MN3010 version I had though (got it new in '79).

Cheers,
Scott

[Uncle Krunkus]

Great work Stephen!
Sorry this layout still hasn't been realised, I should never promise anything until it's finished, as I get sidetracked so easily.
With Hanna about to born and me back at TAFE in a week or so, I can only say that I'm making an effort to finish some projects when I get the chance, and not starting any new ones, so the chances of me sitting down to this layout are going up. I just wouldn't promise it as a christmas present for your girlfriend or anything like that!

[kokoon]

so did you decide for the STD-1? cause that's what i'd really like to see... i have a couple of 3011s arriving soon and i'm currently searching for good diy reverb designs utilizing the said bbd. so far i've only found the ETI one... so - any progress on this?

[Uncle Krunkus]

Not yet,
I'm working on finishing my ASM2 at the moment.
This is one project I'm still keen on though. I haven't got any 3011s yet, so when I get my act together to get one, this will go ahead. Where did you get yours? Small Bear?

[kokoon]

yeah small bear... i ordered 4x 3011 and 4x 3101 ... quite expensive. and i already have 2x 3208 and 2x 3205... any ideas where to look for good chorus designs with those? or maybe combine them in series to get multiple taps? i got 2 clocks for them so each clock could drive one of each BBDs... hmm that's 4 taps from the straight chain, then you can feed forward to 3 points which makes 7 taps. but the 05s and 08s are a bit long for a reverb chain huh?

[Uncle Krunkus]

I'm not sure if you can combine two independantly clocked BBDs in the one circuit. I think there may be interference between them. According to Scott BBDs can be quite twitchy about their operating environments. He's the best person around here to talk to regarding anything BBD related. (as far as I know)

[kokoon]

so how often does scott show up here?

[Uncle Krunkus]

Often,
he wrote half of this thread!
His pet project at the moment is the Super Klee Sequencer he's working on. Send him a PM and tell him this threads active again, he'll soon chime in. Can't help himself, he's a BBD junkie!

[kokoon]

or maybe if i make a separate thread for BBD discussions...