EURO x0x-heart - Complete "Kit"

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morbank
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Re: EURO x0x-heart - Complete "Kit"

Post by morbank » Sat Dec 05, 2020 5:11 pm

We are taking about U4 and U5 on the x0x Heart, not the Pacemaker, correct?

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Re: EURO x0x-heart - Complete "Kit"

Post by guest » Sat Dec 05, 2020 5:36 pm

no, on the pacemaker. the HC14 and the nand gate.
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Re: EURO x0x-heart - Complete "Kit"

Post by morbank » Sat Dec 05, 2020 8:25 pm

Mod completed, works great!

I ended up adding an on/off toggle switch to the front panel. Looks more or less like it was meant to be there. Thanks for the help with this!

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Re: EURO x0x-heart - Complete "Kit"

Post by guest » Sat Dec 05, 2020 8:39 pm

great to hear!
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Re: EURO x0x-heart - Complete "Kit"

Post by morbank » Sun Dec 06, 2020 2:00 am

Another question...

Would there be anyway to get the slide to work when using the External input? Is there a way to output the slide cv to be used with the external oscillator’s V/Oct input?

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Re: EURO x0x-heart - Complete "Kit"

Post by guest » Sun Dec 06, 2020 2:50 am

morbank wrote:
Sun Dec 06, 2020 2:00 am
Would there be anyway to get the slide to work when using the External input?
im not certain what you mean here.

but, for the VCO CV, you can take that from J5 pin2 on the x0xheart. this is the CV after the slide circuit. maybe a 100ohm or 1k resistor from here might not be a bad idea to protect it. generally its not a good idea to have VCO CVs with high output impedances, but in this case is probably better than hurting the x0xheart due to an accidental mispatch in the future.
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Re: EURO x0x-heart - Complete "Kit"

Post by morbank » Sun Dec 06, 2020 1:50 pm

Sorry, let me see if I can explain this better...

When I use the External input in the x0x Heart the external oscillator doesn’t track the slides since that ‘slid’ voltage isn’t being sent to the external oscillator in any way. So I am looking for a way to be able to get the slid voltage out of the x0x Heart and into the v/oct input on my external oscillator.

That said, I think your solution is what I am after!

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Re: EURO x0x-heart - Complete "Kit"

Post by morbank » Sun Dec 06, 2020 6:13 pm

Added an extra Jack for the ‘slid’ CV output and it works as expected!

For the previous Accent mod... When I switch to the “decoupled” mode the Decay knob no longer changes the decay time. Is there a way to control the decay when in the decoupled mode? You had mentioned needing to add an extra jack (see quote below) but that was from earlier in our conversation so I’m not sure it’s still relevant?
guest wrote:
Tue Dec 01, 2020 2:53 pm
awesome. another way to do it, would be to mod the pacemaker so the 2 aspects of accents are independently controllable. the accent does 2 things - add a bit more punch to the VCA and VCF, and reduces the decay time. these can be decoupled in the pacemaker (although youd need to add a jack to control the extra parameter).

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Re: EURO x0x-heart - Complete "Kit"

Post by guest » Sun Dec 06, 2020 8:23 pm

ok, just to make sure i understand:

1. decoupled mode is the new switch you put in, that makes it so accent gates do not set decay to minimum.
2. when you set to decoupled mode, and you apply an accent gate, the decay pot no longer controls decay time?
3. when in decoupled mode, when accent gate is low, then the pot does control decay time?

that is a bit odd, and shouldnt be happening. how long is the decay time in decoupled mode? is it max length, min length, or somewhere in the middle? if its min time, then check the voltages on either side of the resistor you put in, they should both be 5V.
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Re: EURO x0x-heart - Complete "Kit"

Post by morbank » Sun Dec 06, 2020 11:28 pm

Doh! Re-reading past posts to answer your last set of questions I discovered that I didn’t add the 10k resistor you specified for (see below)...
guest wrote:
Sat Dec 05, 2020 1:43 am
shoot, youre right, i forgot about that. accent wont engage until there is an accent gate. youll have to cut the trace between U4 pin9 and U5 pin1. then tack a 10k resistor between U5 pin1 and U5 pin14 (+5V). if you want, you can put a switch in where the cut trace used to be, so you can toggle the mod on/off.
Should the 10k resistor connecting U5 pin 1 and U5 pin 14 also be switched?

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Re: EURO x0x-heart - Complete "Kit"

Post by guest » Sun Dec 06, 2020 11:32 pm

no, you can leave that resistor fixed in place.
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Re: EURO x0x-heart - Complete "Kit"

Post by morbank » Mon Dec 07, 2020 12:26 am

Ok, 10k resistor installed. Please ignore the previous issues I was having with the decoupled mode and decay time. It’s working as expected now!

One more question tho... In Decoupled Mode, if I have the accent knob turned all the way up (CW), and I feed +5v CV to the Accent CV input and I am sending gates to the Accent Step input on every step when I engage Slide the volume instantly drops to a no-accent level which makes the slides sound very low in comparison. Would there be anyway to keep the accent level high when slides are engaged?

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Re: EURO x0x-heart - Complete "Kit"

Post by morbank » Mon Dec 07, 2020 12:35 am

... I still have the XOR modes on both of Plog’s logic channels (one for Accent and the other for Slide) set up so that I am either sliding or accenting but never both at the same time. Perhaps this explains why I am getting the drop in volume when I engage Slide? I’ll do some investigating...

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Re: EURO x0x-heart - Complete "Kit"

Post by morbank » Mon Dec 07, 2020 12:44 am

... So yeah, if I change Plog’s logic channels to OR instead of XOR I get Accented Slides :)

Definitely going to have to write this patch down or I will have to start all over again!

Thanks again for all the help guest!

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Re: EURO x0x-heart - Complete "Kit"

Post by guest » Mon Dec 07, 2020 2:26 am

slides shouldnt drop the accent level. does this not happen when not using decoupled mode? what does happen when you hit a slide (at least with your external circuitry) is that gates are not retriggered, and the extra volume comes from the envelope, so if there is no envelope, then you wont get the extra volume, the notes will just decay out.
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Re: EURO x0x-heart - Complete "Kit"

Post by morbank » Mon Dec 07, 2020 7:13 pm

guest wrote:
Mon Dec 07, 2020 2:26 am
slides shouldnt drop the accent level. does this not happen when not using decoupled mode? what does happen when you hit a slide (at least with your external circuitry) is that gates are not retriggered, and the extra volume comes from the envelope, so if there is no envelope, then you wont get the extra volume, the notes will just decay out.
Yes, sorry. That is indeed what’s happening, or what was happening, with the logic set to OR instead of XOR I am able to have slides without the level drop. Actually sounds really cool to be able to apply accent after a slide has started. Gives it some extra punch.

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Re: EURO x0x-heart - Complete "Kit"

Post by guest » Mon Dec 07, 2020 7:31 pm

yes, accent after slide is a great effect!
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Re: EURO x0x-heart - Complete "Kit"

Post by morbank » Fri Dec 18, 2020 2:34 am

For the ‘Slid CV Output’ mod that I did (if you recall this mod required taking the VCO CV from J5 pin2 on the x0xheart), I am noticing something odd... With the added ‘Slid CV Output’ patched to the V/Oct jack on an external oscillator (Dixie II+) the slides are working fine, but when I engage the Accent the pitch of the external oscillator moves up in pitch slightly. In other words, when I send +5v to the x0x Heart’s Accent CV input the pitch at the ‘Slid CV Output’ rises slightly on each accented step. This is not the case for the internal oscillator btw.

Any idea why this is happening and how I might fix this issue?

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Re: EURO x0x-heart - Complete "Kit"

Post by guest » Fri Dec 18, 2020 6:10 am

just to understand correctly, the external oscillator changes pitch, but the x0xheart does not? how much does the external oscilator shift by? and is it up or down? can you measure the CV out with your multimeter to see what the voltage difference is (will most likely be in the millivots - so if you use a CV under 2V, your meter might be more accurate)?
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Re: EURO x0x-heart - Complete "Kit"

Post by morbank » Fri Dec 18, 2020 2:01 pm

Both are changing/tracking pitch, but while the x0xheart's internal oscillator has the correct pitch (with or without added accents), the external oscillators pitch rises when accents are active.

The external oscillator shifts up by a very small amount. With the internal pitch CV and external pitch CV measured against each other on my scope at a setting of 50 microseconds the two traces are just slightly offset. But I can definitely hear the difference.

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Re: EURO x0x-heart - Complete "Kit"

Post by guest » Fri Dec 18, 2020 3:42 pm

is the pitch error related to any other parameters, like position of the accent knob, or notes played? whats odd, is that the VCO is not effected at all by accents, and the output CV is the exact same CV that drives the internal VCO. were you able to measure the pitch CV out for both accented and not accented notes, to see how much the voltage increases by?
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Re: EURO x0x-heart - Complete "Kit"

Post by morbank » Fri Dec 18, 2020 4:36 pm

guest wrote:
Fri Dec 18, 2020 3:42 pm
is the pitch error related to any other parameters, like position of the accent knob, or notes played?
The higher the accent knob position the higher the pitch rises. Notes played doesn't seem to have any effect.
guest wrote:
Fri Dec 18, 2020 3:42 pm
whats odd, is that the VCO is not effected at all by accents, and the output CV is the exact same CV that drives the internal VCO. were you able to measure the pitch CV out for both accented and not accented notes, to see how much the voltage increases by?
For a non-accented note I get a pitch CV reading of 2.0v, and for an accented note I get a pitch CV reading of 2.22v.

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Re: EURO x0x-heart - Complete "Kit"

Post by guest » Fri Dec 18, 2020 5:44 pm

oh wow, thats a huge jump (almost 3 half steps!), and your input CV is the same for both of these? can you measure the input CV just to be sure?
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Re: EURO x0x-heart - Complete "Kit"

Post by morbank » Fri Dec 18, 2020 6:48 pm

guest wrote:
Fri Dec 18, 2020 5:44 pm
oh wow, thats a huge jump (almost 3 half steps!), and your input CV is the same for both of these?
I have the pitch CV coming out of my x0xb0x and going into the x0x Heart's 1v/oct input, and then the modded 'Slid CV output' is patched to the 1v/oct input on the Dixie II+.
guest wrote:
Fri Dec 18, 2020 5:44 pm
can you measure the input CV just to be sure?
My previous measurement of 2.0v for the non-accented CV was a measurement of the "input CV". The CV input and the 'Slid CV' output have the same voltage when an accent isn't present.

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Re: EURO x0x-heart - Complete "Kit"

Post by guest » Fri Dec 18, 2020 7:08 pm

ok, can you measure the 12V and 5.333V rails on the x0xheart for slid and non-slid? if the CV is changing for the x0xheart, but the pitch is not changing, then the rails must be moving around.
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