NPD! (BBD Content)

[Scruffie]

Not quite, i'm saying I have the factory schematic for this so it does not need to be reverse engineered.

Also it uses the MN3008 and a MN3009 not MN3101 (which is a clock chip).

The 3008 is available but supply is dwindling and the 3009 is very hard to find, it would be possible to convert it to a 3208 and use a 4049 clock buffer to clock a 3207 to the 3009 delay times but IMO it would be better to just purchase the pedal.

However, what would be very possible and not too tricky would be to convert the vintage version to 2 x 3207s.

[GrindCustoms]

Ok! I do get it now. thanks

If not too complicated to convert the SAD layout to 2x MN3007/MN3207, what have kept it from being made?

Sounds like a cool and simple alternative to me.

[Govmnt_Lacky]

If not too complicated to convert the SAD layout to 2x MN3007/MN3207, what have kept it from being made?

Simple.... most builders look and see that it is BBD-based and say... "Nah!" 

[Scruffie]

Only thing putting me off is the size for prototyping and what to do about the switching.

I'm working with someone to get new projects released though, so I may dig in.

I think it may possibly be better with 3207s over 3007 as the 3207 is spec'd for twice the clock frequency of the 3007 to the same range as the 3004. Plus the circuit is already companded so that should help with the lower headroom of the 3207 anyway... that and the circuit is already set up for N-Channel J-FETs so less changes to make.

Even easier would be would be to break it up in to two circuits, a flanger/filter matrix, the LFO/VCO/Clock is pretty much the electric mistress one except this would be companded and a chorus/slapback... although I suppose if you can build 2 similar circuits you can build one larger overall one.

[LaceSensor]

Or just build a DEM and a Small Clone in one box with a rotary to select the modes.
Maybe.

[Scruffie]

Or just build a DEM and a Small Clone in one box with a rotary to select the modes.
Maybe.

Honestly that wouldn't be that far off 

The one major benefit of the circuit is the companding and if you count it as a benefit, being a multi-efect.
Although for flanging the companding could be considered a negative... probably puts it in the more 'musical' territory rather than the dirty jetting flanging a lot of us like.

Well I suppose that and the chorus uses a proper VCO rather than a variable resistance element so it's probably quite deep and watery.

[GrindCustoms]

I've been playing a lot with the unit i have right now for the past 2 days and i find the double track and filter matrix to be a bit redundant.

If i was to make a Polychorus workalike... i'd just have the Chorus and Flange mode in the layout. Parts and PCB real estate wise, i don't know how much it would free up space, but it would definitly make the switching easier, like having the 2 different modes available from a footswitch.

Not having the schem in hand does limit my ability to work the idea further.

Scruffie, for the cost of prototyping PCB i might have an alternative for you, a new fab house have openened and their pricing on prototyping for wich they have special deals is more than interesting and the quality of PCB fabbing is equal to iTead, Seeed or the other China fabbers... my guess is that they all get them made at the same place.

Anyway check out for Elecrow, i have made 2 orders with them for proto's that enters the 20x20cm sizing and i'm really satisfied so far.

[Scruffie]

While I agree both of those modes aren't the most useful features for everyone, for the small amount of extra effort they may as well be included.

I'll look in to this, I think it'd have to be a 1790NS circuit though, it's quite the large circuit cause of all the ICs (3 x 16-Pin DIP, 2 x 14-Pin DIP & 5 x 8-Pin DIP) and the rotary.

Thanks for the tip  i'll check 'em out.

So is this something people would like to see? It wouldn't be your average fuzz box build that's for sure.

[GrindCustoms]

1790NS is also what i was thinking to keep it reasonable.

If you can fit the layout in a 15x10cm pcb fabbing package, you're golden, it will run you for about 40$ shipped for 10 proto board, turn around time being in the 3-4 weeks.

Looking at the requests that i get via email or when i post BBD stuff on facebook page and people always asking me when i'll be releasing that sort of project but that i stay away because i don't have sufficient knowledge to correctly support them... i doubt that it would be hard to reach minimum numbers to get this type of project going.

Even if not directly implicated in it, make it happen and i'll promote it like if it was my baby

[Govmnt_Lacky]

So is this something people would like to see? It wouldn't be your average fuzz box build that's for sure.

I'd be interested for sure! Especially if it could be reconfigured for 2xMN3207 operation!

Also, there is a LOT of unused real estate on some of those EHX designs. Keeping seperation of the clocks and LFO signals not withstanding, I am sure you can save a LOT of space. 

I would give it a try but, I suck at PCB design and have zero experience with Eagle 

[Scruffie]

There's only one clock and LFO so... that bit's easy! Some extra power decoupling and basic BBD circuit layout practice should be all that's needed.

The EHX designs were also single sided  that's why there's all that space, they're actually incredibly well done layouts.

I shall consult with my partner in crime on this...

1790NS is also what i was thinking to keep it reasonable.

If you can fit the layout in a 15x10cm pcb fabbing package, you're golden, it will run you for about 40$ shipped for 10 proto board, turn around time being in the 3-4 weeks.

Looking at the requests that i get via email or when i post BBD stuff on facebook page and people always asking me when i'll be releasing that sort of project but that i stay away because i don't have sufficient knowledge to correctly support them... i doubt that it would be hard to reach minimum numbers to get this type of project going.

Even if not directly implicated in it, make it happen and i'll promote it like if it was my baby

That's a great price!

I've got the knowledge just not the funds but some BBD projects which I have put my hand in with a colleague will be coming soon which I think people will appreciate. This is a possibility so i'll order the parts i'm missing to breadboard it.

I'll probably make it 3007/3207 switchable, but I think this is one of the cases where the 3207 will be perfect.