106 CHORUS SMD by FEEDBACK [manual UPDATE]

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strat-1
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106 CHORUS SMD by FEEDBACK [manual UPDATE]

Post by strat-1 » Wed Mar 20, 2019 4:42 am

[UPDATE] : Files updated

I updated the SMD board to Rev1.2.
- one 4558 inverting buffer was added, so the output signal is not inverted anymore.
- replaced the offset trimmers with THT less expensive ones.
- I'm working on a complete manual+bom, available in a few days.

The new one is the one on the left :
ImageImage

THT version :
viewtopic.php?t=158257

www.feedbackmodules.com

ImageImage

The 106CHORUS is an accurate recreation in EURORACK format of one of the most sought after choruses, the one from a famous analog polysynth from the eighties.
This project is not exactly for beginners, but has the advantage that most of the parts needed are available at most parts distributors, the only rare/expensive parts are the BBD delay chips (MN3101 & MN3009) and the Toshiba 2SK30 FETs.
The SMD PCB is heavily tested, tens of boards were built. Please read the bom and manual before buying, to know all the details required for the project.

ImageImage

First demo is a simple sound from Ambika to 106 Chorus.
(no chorus/chorus1/chorus2/no chorus/chorus1/chorus2)

https://soundcloud.com/strat1/106-choru ... mbikato106

In second demo we used 2 System-X VCOs to 106 Chorus.
https://soundcloud.com/strat1/106-choru ... -xvcoto106

[video][/video]
Attachments
106SMD Build Files 1.2.zip
(11.99 MiB) Downloaded 42 times
106SMD Build Files 1.0.zip
(10.45 MiB) Downloaded 28 times
106SMD Build Photos 1.0.zip
(5.49 MiB) Downloaded 30 times
Last edited by strat-1 on Wed Jul 03, 2019 9:18 am, edited 5 times in total.

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Post by strat-1 » Wed Mar 20, 2019 4:45 am

[UPDATE] I divided the old 106horus thread in two threads, one for SMD version and one for THT version.
Now,any question about SMD version can be posted here without any confusion between the versions.

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Post by strat-1 » Fri Mar 22, 2019 6:55 am

3009 Pron! :)

Image

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Post by strat-1 » Tue Jun 25, 2019 7:23 am

[UPDATE] : I updated the SMD board to Rev1.2.
- one 4558 inverting buffer was added, so the output signal is not inverted anymore.
- replaced the offset trimmers with THT less expensive ones.
- I'm working on a complete manual+bom, available in a few days.

The new one is the one on the left :
ImageImage

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Post by JakoGreyshire » Thu Jun 27, 2019 11:25 pm

I know you are doing a new BOM and manual... I was just wondering from a design point of view.... Why the 50K trimmers are not needed in the new PCB revision... It looks like they got replaced with 30K and 47K resistors...

Just curious....

J.

EDIT: er... maybe the 50K trimmers on the old BOM were for the through hole version? Or an even older PCB version?
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Post by strat-1 » Fri Jun 28, 2019 4:41 am

JakoGreyshire wrote:I know you are doing a new BOM and manual... I was just wondering from a design point of view.... Why the 50K trimmers are not needed in the new PCB revision... It looks like they got replaced with 30K and 47K resistors...

Just curious....

J.

EDIT: er... maybe the 50K trimmers on the old BOM were for the through hole version? Or an even older PCB version?
Originally the chorus didn't had those trimmers, just 39k resistors to blend the fx signal with the dry signal.
I added the trimmers because the rare, dying MNs sometimes had a different volume at the output.
So, you could adjust them to the same volume, using the trimmers. But this was very rare.
Because now you can find only XVIVE versions of 3009, I returned to the original design, all the chips have the same specifications now.
Also changed the trimmers from smd ones to THT ones. SMD ones raised the cost allot and THT ones have a better quality.

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Post by jorg » Fri Jun 28, 2019 2:16 pm

Very pretty sound! Nice!

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Post by strat-1 » Wed Jul 03, 2019 9:20 am

[UPDATE]

I added the last files.
-Schematic for SMD version
-BOM Farnell and Mouser
-Complete building doc with layer transparency included

Please download the 1.2 version.

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Post by B0bcat » Thu Aug 01, 2019 1:43 pm

apologies for the kin-of-double post with the THT thread, but I believe it is relevant - please correct me if otherwise. Here goes:

I believe it should be more clearly stated on the Feedback webshop that all current kits and built modules come with the XVive MN3009.

I just had somebody over on Reverb yell at me because the chorus they had purchased from me had XVive chips (although they were pictured on the photos of the listing). They told me they only purchased the module for the vintage chips, and accused me of malicious intent (the alternative assumption of course being that I was stupid enough selling Matsushitas for the equivalent of $10 in 2019).
I would have thought it was obvious to any half-reasonable person that in 2019, Feedback would not be selling Matsushitas for $10 either (based on the price difference between the panel&PCB kit, and the one containing the chips), but apparently it is not.

The funny part of course being that there are still people out there willing to pay $80+ for a Matsushita - so if you happen to have some flying around in your chip drawer get in touch, I can hook you up :-D

/rant over
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Post by JakoGreyshire » Thu Aug 01, 2019 2:13 pm

Thanks for the wisdom B0bcat.... It is rather interesting that the person assumed there would be vintage chips in a relatively newly developed product. The 106 chorus from FeedBack has been available for what, a couple of years now? One, two years now? I don't recall... Anyway, it's not old enough to have vintage chips in it... I was talking about Reverb.com with someone who was saying that the benefit of Reverb.com was that most people do lots of research about an item before they buy it.. Most people do anyway...

By the way, I'm sure it's already out there and I haven't seen it yet but, is there a difference in the vintage ICs compared to the new Xvive chips? I thought they were supposed to be a rather spot on remake.. I mean, the FB 106 chorus has that vintage sound, right? That's why I bought one. Is there a comparison of the vintage 106 and the FB 106 chorus somewhere? Can you tell the difference and if so, does it really matter?
:despair:

I'd like to see your listing on reverb or at least the pictures you uploaded showing the ICs.. Bummer that you got accused of being in bad form but, your customer seems like the bad form is all theirs... Bless their tiny heart!
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Post by B0bcat » Thu Aug 01, 2019 2:20 pm

JakoGreyshire wrote:Thanks for the wisdom B0bcat.... It is rather interesting that the person assumed there would be vintage chips in a relatively newly developed product. The 106 chorus from FeedBack has been available for what, a couple of years now? One, two years now? I don't recall... Anyway, it's not old enough to have vintage chips in it... I was talking about Reverb.com with someone who was saying that the benefit of Reverb.com was that most people do lots of research about an item before they buy it.. Most people do anyway...

By the way, I'm sure it's already out there and I haven't seen it yet but, is there a difference in the vintage ICs compared to the new Xvive chips? I thought they were supposed to be a rather spot on remake.. I mean, the FB 106 chorus has that vintage sound, right? That's why I bought one. Is there a comparison of the vintage 106 and the FB 106 chorus somewhere? Can you tell the difference and if so, does it really matter?
:despair:

I'd like to see your listing on reverb or at least the pictures you uploaded showing the ICs.. Bummer that you got accused of being in bad form but, your customer seems like the bad form is all theirs... Bless their tiny heart!
That's what I thought too and why I prefer it over eBay, and it was my first negative experience in almost 100 transactions on the platform. I re-listed the item so feel free to have a look

There were some comments over on the THT thread that people A/B test with vintage chips (I did so myself) and I believe the consensus is that XVives are equivalent or better in terms of noise etc. I should say that the would-be customer was apparently going to replace his fried vintage 3009s in the Feedback chorus .. with another expensive pair of vintage 3009s :despair: :doh:

And from experience, yes, it does seem to matter to some people if something is vintage or not, and they would take the "mojo" of an unobtainable old part over the reliability and availability of a modern equivalent :despair:
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Re: 106 CHORUS SMD by FEEDBACK [manual UPDATE]

Post by strat-1 » Mon Jul 26, 2021 2:03 pm


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