EHX - Echoflanger  [schematic]

Discussion regarding early stompbox technology: 1960-1975 Please keep discussion focused and contribute what info you have...
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Scruffie
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Post by Scruffie »

Govmnt_Lacky wrote:
GodSaveMetal wrote:Please someone a single sided PCB??? PLEASE man!!

Ummmm...... Have you READ this thread? :slap:
Ummmm...... Have you not MET GodSaveMetal? :lol:

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Govmnt_Lacky
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Post by Govmnt_Lacky »

Scruffie wrote: Ummmm...... Have you not MET GodSaveMetal? :lol:
Yes.... but I always have hope! :thumbsup

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Post by sodapep2 »

Scruffie wrote:
GodSaveMetal wrote:
Stasss wrote:....Sorry for bad english! My Echoflanger works perfectly with MN3007 BBD. Very thank Paul Nelson and Govmnt Lacky!
PCB, LAY, BOM, and PHOTOS please man!! THANKS!
Along with someone else i'll be releasing a fabbed project for a 3007/3207 echo flanger project soon.

You could adapt the SAD1024 etchable layout without too much work though.
:!: :!: :!:

I can hardly wait.

I took mine into testing and failed miserably. :oops:

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Scruffie
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Post by Scruffie »

sodapep2 wrote:
Scruffie wrote:
GodSaveMetal wrote:
Stasss wrote:....Sorry for bad english! My Echoflanger works perfectly with MN3007 BBD. Very thank Paul Nelson and Govmnt Lacky!
PCB, LAY, BOM, and PHOTOS please man!! THANKS!
Along with someone else i'll be releasing a fabbed project for a 3007/3207 echo flanger project soon.

You could adapt the SAD1024 etchable layout without too much work though.
:!: :!: :!:

I can hardly wait.

I took mine into testing and failed miserably. :oops:
We're just getting done with our 1590BB A/DA flanger release and then it'll start moving, the schematic is done, just need to get the PCB drawn up and prototyped, probably be a few months with the shipping times.

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mth5044
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Post by mth5044 »

Hello!

I've been looking at Nelson's adaptation of the circuit for MN3007's using the simplified switching and wanted to point out there was a missing voltage reference (either V3 or 7.5V, depending on what schematic you go with) between R36 and R35.

I have two questions that I'm hoping someone knows the answer too - the first is what clock goes to what MN3007? I'm assuming that CLKA/B = CLKA/B and that CLKA1/B1 = CLKA2/B2 when comparing the oscillator page to the audio page. This is because 47pF is engaged when the single MN3007 is used, which seems like it would flange, and is connected to CLKA/B which is the faster of the two.

The second is why is there far less filtering and now 'bbd level control' trim when the single, faster clocked MN3007 is being used compared to the Sallen Key Filter that's employed when the MN3007's are in series? Is it because the clock rate is so far out of the range that it's not needed? The combination of R35/36 threw me for a long time until I realized there needs to be voltage there, which made the switching make more sense, but the lack of filtering still eludes me.

Thanks!

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mth5044
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Post by mth5044 »

No way to edit?

Anyway, it LOOKS like in the SAD version, there are some differences in the mode selection. In the MN3007 with modified switching, S2 allows for either the LFO or 7.5V to be injected to the VCO. How it appears in the SAD versions is:

Slapback: neither LFO or 7.5V
Chorus: Only LFO
Flanger: LFO and 7.5V
Filter Matrix: Only 7.5V.

The way the MN3007 version approaches it does not allow for the Flanger or Slapback settings to opperate correctly, unless I'm reading the very strange switchign schematic wrong, but it appears to work like an elevator selection various poles to be grounded (then opening or closing the two switches for LFO and 7.5V (and the timing cap, but that's simple enough)).

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Post by soggybag »

This looks awesome, did anyone successfully build one of these yet?

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Post by Govmnt_Lacky »

soggybag wrote:This looks awesome, did anyone successfully build one of these yet?
If you mean the SAD1024 version... YES!

I dont think there has been a completed and successful MN3007 conversion done yet. At least... not one that has been shared.

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Scruffie
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Post by Scruffie »

I'll just leave this here...

Image

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Fender3D
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Post by Fender3D »

Nice work Scruffie :applause:

What's the rotary?

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Scruffie
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Post by Scruffie »

:D well I can't take all the credit, Keefe my partner in crime is responsible for the layout, I just did the circuit bit.

The rotary is one of these https://www.ebay.com/itm/20pc-Rotary-Ba ... 460deca292

Great little switches, pretty much spot on size to a board mounted 16mm pot.

I should mention I used the voltage divider trick from the A/DA LFO to ditch the C2M rate pot as well. Currently it's only 3007 as we hit the Diptrace 500 pads limit but we'll be getting 3207 switching in there as soon as we can. Even has an onboard charge pump and fits in a 1790NS or 1590XX.

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Post by jalmonsalmon »

[quote="Scruffie"]I'll just leave this here...

Wow, that is great, be looking forward to build this one when it is released.
Good times ahead! :applause:

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Post by Dirk_Hendrik »

Nice!~
Sorry. Plain out of planes.

http://www.dirk-hendrik.com

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Govmnt_Lacky
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Post by Govmnt_Lacky »

@Scruffie

Ohhhhhhhhh......... :shock:

Did you duplicate the CD4053 switching scheme with this or did you use another one?

Can't wait to hear this one in action!!!

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Scruffie
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Post by Scruffie »

Same 4053 switching as the original, tried to keep it as stock as possible down to the pot and switch layout matching the original (that's what that cut out up top is for, can put the blend switch up there rather than the board mounted position if desired) apart from a few minor mods that can be omitted if desired.

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Scruffie
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Post by Scruffie »

Does anyone have an original echoflanger/polychorus/polyflange and can take some clock readings for us just to make sure everything is as it should be? We'll happily offer up a free board of the finished product for the trouble.

Once that's sorted this should be good to go :thumbsup

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Post by LaceSensor »

Scruffie wrote:Does anyone have an original echoflanger/polychorus/polyflange and can take some clock readings for us just to make sure everything is as it should be? We'll happily offer up a free board of the finished product for the trouble.

Once that's sorted this should be good to go :thumbsup
Ive got the stereo big box reissue from the 90s but thats a different animal, but just shout if you want me to check anything on it.

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Scruffie
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Post by Scruffie »

Thanks for the offer Lace but don't think i'll be able to glean too much from the reissue, i've got the calibration procedure for the vintage unit but just want to check against the original frequencies to be sure the lfo/vco/clock doesn't need any extra alteration.

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Post by Govmnt_Lacky »

Scruffie wrote:Thanks for the offer Lace but don't think i'll be able to glean too much from the reissue, i've got the calibration procedure for the vintage unit but just want to check against the original frequencies to be sure the lfo/vco/clock doesn't need any extra alteration.
When I built my Echoflanger from Nelson's layout I used Ron's calibration procedure. It was spot on! Sounded great and just like the demo videos online.

I don't know if you used Nelson's material as a reference however, some of the part values and info were wrong. I sent him the corrections but he never put them on his site. If you need that info, let me know.

Also, let us all know when the boards are ready.... definitely interested! :applause:

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Scruffie
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Post by Scruffie »

I worked from the original factory schematics and some gut shot pictures, i'm pretty good at reading the old EHX schematics (don't know if you've seen my previous redraws, some of them were from a LOT worse originals) so fairly certain everything is correct, it all works/sounds right and I tripled checked it all.

It's more of a double check that the conversion hasn't affected anything else, just to make sure it's all spot on before it's released.

There'll be a few tweaks we have to make, I don't know if it'll require another prototype or not but i'm sure you'll see once they're released :wink:

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