
JP8 Filter
- emuarc
- Wiggling with Experience
- Posts: 251
- Joined: Sat Oct 02, 2010 4:23 pm
- Location: Horsham, West Sussex
- Contact:
The latest 2018 Mouser BOM for the AM8109 is on our website in the manuals section. www.amsynths.co.uk
Rob Keeble
Owner & Designer
AMSynths
Owner & Designer
AMSynths
- DmitryDistant
- Learning to Wiggle
- Posts: 3
- Joined: Tue Jun 18, 2013 2:43 am
- Location: Riga
Hi,emuarc wrote:The latest 2018 Mouser BOM for the AM8109 is on our website in the manuals section. www.amsynths.co.uk
I would like to built this super-filter but panels seems out of stock :(
Do you plan to restock them?
Thanks
- DmitryDistant
- Learning to Wiggle
- Posts: 3
- Joined: Tue Jun 18, 2013 2:43 am
- Location: Riga
- oscarthesquirrel
- Veteran Wiggler
- Posts: 585
- Joined: Thu Nov 27, 2014 2:31 am
- Location: Kuala Lumpur
I built one of these fantastic filters 18 months ago but have had an issue with output dying after a short time of operation.
Turn on my system, patch and send sequence to the filter..all hunky dory...but after 10-15 min (I'm suspecting as the system warms up), the output distorts and eventually fades to nothing,
I replaced the IR3109 chip and all 3 TL071 op-amps.....everything seems great for a few hours and then...same thing started... input volume pots only sent signal when almost fully clockwise (past 7 on the scale, whereas at the start input was heard at 2-3). Audio distortion then came back (although at the moment it seems to be only on the 24db circuit and not the 12db)
Any ideas what component could be the culprit....a bad transistor - 2N3906 or 2N3904 ? I'm really frustrated because this filter is the best sounding thing in my case !
If Rob is reading this...any help or guidance as to what to check ?
Turn on my system, patch and send sequence to the filter..all hunky dory...but after 10-15 min (I'm suspecting as the system warms up), the output distorts and eventually fades to nothing,
I replaced the IR3109 chip and all 3 TL071 op-amps.....everything seems great for a few hours and then...same thing started... input volume pots only sent signal when almost fully clockwise (past 7 on the scale, whereas at the start input was heard at 2-3). Audio distortion then came back (although at the moment it seems to be only on the 24db circuit and not the 12db)
Any ideas what component could be the culprit....a bad transistor - 2N3906 or 2N3904 ? I'm really frustrated because this filter is the best sounding thing in my case !
If Rob is reading this...any help or guidance as to what to check ?
"You can never have too many LFO's..."
- emuarc
- Wiggling with Experience
- Posts: 251
- Joined: Sat Oct 02, 2010 4:23 pm
- Location: Horsham, West Sussex
- Contact:
Hi
Possible cause is the M5210 switching op amp that takes the 12 and 24db outputs from the IR3109. Its a SIP chip. I can send you a repalcement for free just drop an email to sales@amsynths.co.uk
Possible cause is the M5210 switching op amp that takes the 12 and 24db outputs from the IR3109. Its a SIP chip. I can send you a repalcement for free just drop an email to sales@amsynths.co.uk
Rob Keeble
Owner & Designer
AMSynths
Owner & Designer
AMSynths
-
- Common Wiggler
- Posts: 65
- Joined: Sat Feb 03, 2018 3:53 pm
Just to add to what others have said - this is an awesome filter, super smooth sounding, and with extremely musical resonance. I use it on everything.
As you'd expect, it sounds especially good on polysynth chords. I don't much like the filter on my Korg Minilogue, so I open that up and then send it through the JP8 and bring the cutoff down that way.The res can be used to pick out harmonics. The sound makes me think of 808 State - which is odd because I don't think they had a Jupiter 8 until quite late on, so maybe it's just the fact that they used so much Roland gear, and this filter has that Roland sound. Roland really got something right with the IR3109 chip.
Having two attenuated CV ins and a three input mixer is also extremely handy. A classic use with the CVs is to have an envelope into CV1 and an LFO, random source or other sequence into CV2, and then play with both of those.
If you think that real Jupiter 8s go for about £10K these days, I doubt I'll ever get to play one, never mind own one. So this is a little piece of classic synth history in my Eurorack. Thanks to Rob for making such an awesome module.
As you'd expect, it sounds especially good on polysynth chords. I don't much like the filter on my Korg Minilogue, so I open that up and then send it through the JP8 and bring the cutoff down that way.The res can be used to pick out harmonics. The sound makes me think of 808 State - which is odd because I don't think they had a Jupiter 8 until quite late on, so maybe it's just the fact that they used so much Roland gear, and this filter has that Roland sound. Roland really got something right with the IR3109 chip.
Having two attenuated CV ins and a three input mixer is also extremely handy. A classic use with the CVs is to have an envelope into CV1 and an LFO, random source or other sequence into CV2, and then play with both of those.
If you think that real Jupiter 8s go for about £10K these days, I doubt I'll ever get to play one, never mind own one. So this is a little piece of classic synth history in my Eurorack. Thanks to Rob for making such an awesome module.
- oscarthesquirrel
- Veteran Wiggler
- Posts: 585
- Joined: Thu Nov 27, 2014 2:31 am
- Location: Kuala Lumpur
Hi Rob,
any update on when the AM8109 modules will be in stock ? Can I place a back order with you for 2 ? Website won't let me add to the cart because its currently out of stock.
Cheers!
any update on when the AM8109 modules will be in stock ? Can I place a back order with you for 2 ? Website won't let me add to the cart because its currently out of stock.
Cheers!
emuarc wrote:Hi
Panels will be back in stock in late January, along with a batch of skiff friendly AM8109 modules. Its a great filter!
"You can never have too many LFO's..."
- emuarc
- Wiggling with Experience
- Posts: 251
- Joined: Sat Oct 02, 2010 4:23 pm
- Location: Horsham, West Sussex
- Contact:
10x 8109 JP8 filters will be shipping in 10 days, drop me an email at sales@amsynths.co.uk to preorder. The 8328 filter module is in stock now, for anyone wanting a CEM3328 low pass filter.
Rob Keeble
Owner & Designer
AMSynths
Owner & Designer
AMSynths
- oscarthesquirrel
- Veteran Wiggler
- Posts: 585
- Joined: Thu Nov 27, 2014 2:31 am
- Location: Kuala Lumpur
Thanks Rob - email sent.emuarc wrote:10x 8109 JP8 filters will be shipping in 10 days, drop me an email at sales@amsynths.co.uk to preorder. The 8328 filter module is in stock now, for anyone wanting a CEM3328 low pass filter.
Also, any new 8320 panels coming in...if not can you upload the CAD file to the manuals section and I'll try and get one made.
Cheers
"You can never have too many LFO's..."
- oscarthesquirrel
- Veteran Wiggler
- Posts: 585
- Joined: Thu Nov 27, 2014 2:31 am
- Location: Kuala Lumpur
2 available
Jump fast; Two AM8109SE JP-8 FILTERS available on the website. There was three but, I grabbed one.
https://www.amsynthstore.co.uk/product/ ... -8-filters

https://www.amsynthstore.co.uk/product/ ... -8-filters