Filter sounds and ordering with the main board

Hi, I’m new to this forum, apologies if this has been covered.
I’m a bit confused about the kit and whether it can be ordered with different filter boards. What I am looking for is a big sounding filter for simple monosynth sounds, throbs and the like, something like an SH09 filter would be great!
I’m thinking of building one to replace or complement my Bass Station, which is great for electro leads and squelchy basses. I’ve listened to a few demos and I think all I’ve learnt is that I don’t want the polyvox filter.

I’m no stranger to soldering and have no problem sourcing components. Can the kit be ordered with any filter board, it doesn’t appear so?
I’ve included a couple of links to youtube videos to illustrate some filter sound examples I would like to replicate, they are a bit boring I’m afraid. at 3:33 the pitch bent sound 1:48 bass throb

The kit comes with the SMR 4 filter board, period.
The only way to get a kit with a different filterboard as a kit is to wait and hope that Olivier makes a special edition kit available, which seems highly unlikely, so you’re better of getting the individual parts, or doing the SMR 4 kit :slight_smile:

Yes, only the SMR4 (mkII) filter board is available as a full kit, all parts included. Luckily for you this is the most “classic” filter, and it is indeed quite Rolandish.

Since you seem to be used to DIY, you could even consider getting a standard kit, and stack a polivoks filter in parallel with the original SMR4 filter (which would mean build a custom case - you would have to source the parts of the polivoks filter apart as well). Mix the two filters together and you should get a real big and nasty sound.
Although Your SMR4 filter might not work optimally in // with a pvk filter board, because of value range corrections relative to certain filter - not sure about this.

Wow fast response guys, that is very encouraging!
Ok, thanks. So the kit comes with the parts for the main board and the SMR4 (Mk2) filter. So if I wanted another type of filter I would need to buy the PCB and get my own parts, looking at this all the parts are easy to get but I dont know about the ATMega chip, I guess that runs some code and that it is different for each filter.
I’ve just seen a link on the BOM page to different filter sounds so I will have a listen and report back.

There’s no atmega chip programming required for just a filter board, unless you want the digital filter board. The ATMega chip provided with the kit is already programmed, and compatible with any available filter board (just an option to select in a menu to get it working right and enable the additional specific filter options).

Hi, I’ve just looked again and the ATMega chip appears to be on the same board as the filter I’m going to reread the website as I’m getting confused!

Thanks MicMicMan!
I’m going to have a listen to the standard filter examples and get back

So, to explain a bit :
In any shruthi you have 2 boards :

  • one is the digital control board, and is common (with absolutely no hardware nor software change) to all the shruthi versions
  • one is the filter, and is basically the power supply of the whole synth + all the analog processing of the sound. It doesn’t require any programming. There’s one exception though : the digital filter board.
    If you want to try every available flavour of shruthi, you can buy a kit, build every separate filter board, and try all of those filter boards with always the same (and only) digital control board.

But chances are great that you’ll get addicted, and want one digital control board and one case for each filter board… :smiley:

Oh dear I think I’m tired, I’ve been looking at a mix of the Ambika and the Shruthi web pages, no wonder it didn’t make much sense.

I’m a recovering addict as it happens! Oh well this seems like a safe addiction.
If I do want another filter I suppose I would need to ask for a kit without the standard filter board and to include another filter board instead. I’m thinking it would be sad to buy it and not use the standard filter board. Perhaps that is why the 2 filters at once option has been mentioned? Would you just split the control signals to both boards and then mix the outputs afterwards?

He will not do the kits with another board, besides that would require different parts for the filter board. Order the digital control/filter you want and even the programmed chips for the control and check the mutable wiki for BOMs to use.

Hi, sorry I should have been more clear, I wander if he would do the kit without the filter board?
I think it does not really matter as it might be best to start with the full kit to make sure it all works. Then get the parts and the pcb for another filter if I want one.

Could just keep the outputs separate, and then mix them in software later, if desired?

I’m fairly certain that he doesn’t split kits, it is however very easy to assemble a ‘kit’ yourself -
0)Do some research… For the love of god, read the descriptions, if possible look for common errors (74hcxxx comes to mind for the 4PM), so that you can avoid them;

  1. Find the filter board flavour you want, add the PCB to the cart;
    2)Add a digital board PCB to the Cart;
    3)Add a preprogrammed Atmega to the cart;
    4(optional))Add a case to the cart, or order one from fcd72;
    5)Check out & pay;
    6)Check the filter board carts found on the forum+on some filter board pages, find a seller that is near you/and or is convenient, add all the parts to your cart (don’t forget the parts for the digital board :D),
    7)Pay for those;
    8)Wait for the parts to arrive;
    9)Assemble new shruthi :slight_smile:

it would be sad to buy it and not use the standard filter board

But actually, given the samples you’ve posted and the type of sound you’d like to reproduce, the SMR4 mkII seems like the right choice. The polivoks filter has a lot of character and it doesn’t seem to correspond very well to what you’ve posted.

And treat yourself to an OLED display if you can score one from where you’re buying your components! Totally worth it™

V’Cent, thanks for the how to order guide, I must come across as being a bit thick!

MicMicMan, Hi, yes if you look back I said " I think all I’ve learnt is that I don’t want the polyvox filter."
Your advice is appreciated on the sound being like a roland

I think I will have a think, the kit sounds like it could be a good place to start but it is good to know I could source the parts and do it that way as well.

Thanks for all the help!

Oled display, I will have a look, sounds expensive, i like the look of the lcd white on blue ones on ebay for £5

Ohh, never mind then. An OLED will set you back about £17.50 from Mouser or Reichelt. Dunno ATM how much Rapid wants for those…

Edit: £13.95 for the normal Winstars, £16.95 for white/blue or red on black. Gotta think about if should Pimp my Polivoks™ Red on black!

Thanks for the suggestion though!