Verbos complex oscillator tuning issues (always)

[anderson303]

Been trying to figure out if this module is broken since I got it a year ago.

depending on the case/power supply it's in (by itself in a 32 hp doepfer case = less instability vs in a monorocket case = most instability) trying to tune this to any key is either bad, or really bad.

tracking it on a tuner shows how unstable it is... Am I the only one with this issue? should I send it in for repair or is this the nature of the beast?

Thanks!

[The Junglechrist]

Mine isn't instable at all, it might take some time to track correctly but no problematic tuning behaviour

[huffnPuff]

Been trying to figure out if this module is broken since I got it a year ago.

depending on the case/power supply it's in (by itself in a 32 hp doepfer case = less instability vs in a monorocket case = most instability) trying to tune this to any key is either bad, or really bad.

tracking it on a tuner shows how unstable it is... Am I the only one with this issue? should I send it in for repair or is this the nature of the beast?

Thanks!

Mine has allways been behaving this way, and it’s too bad this hasn’t been acknowledged and addressed properly.

I contacted Verbos support a couple of weeks ago, and got a strangely worded answer from a guy named Paul. Still waiting for him to respond to the mail I sent him.

[droningspaghettimonster]

well, I received mine brand new a month ago and it was tracking 2 octaves... i had to calibrate it to my pitch source the same day as I installed it...

the verbos complex can easily track 4 octaves, alongside your other vcos. here is how I did it, and to make that clear right away, this calibration procedure is for verbos complex only, not your other vcos. it worked like a charm on my unit and 4 octaves is heaven compared to 2.


there are two holes on the vco, next to the cv ins for exponential cv. those are for calibrating it to your preferred pitch source. it will track reasonably well ( 2-4 cents +/- after warming up for an hour, depends on your CV source I guess) within four octaves, which i find more than enough for "musical purposes." that vco doesn't have accurate exponential converter like dixies etc and it is not sold as "precision" unit.

all you need is a very small screwdriver with a flat head (be careful, its easy to mess the module up by not being careful when messing around with the screwdriver), very accurate vst guitar tuner (i use gtune freeware, its great, fetch it here: http://www.gvst.co.uk/gtune.htm) and your midi 2 cv interface or cv sequencer.

turn on your system, remove all your cables and wait for it to warm up for at least an hour to be safe. than send 0v into the pitch of both vcos, try to have it as stable as possible at C (it will always fluctate -/+ 1, even 2 cents, that thing is alive and breathing) and than send 4v into the pitch in. adjust the trimmer with the screwdriver until the 4v C is as precise as possible, but remember, it will never be dead stable on C without drifting 1-2 cents. now play your four C-s. the verbos should track musically across 4 octaves, as long as your pitch source is precise. it's not going to be 0-1 cents perfect like a dixie, but I find it a much better sounding VCO.

[anderson303]

Would this help with tuning?

well, I received mine brand new a month ago and it was tracking 2 octaves... i had to calibrate it to my pitch source the same day as I installed it...

the verbos complex can easily track 4 octaves, alongside your other vcos. here is how I did it, and to make that clear right away, this calibration procedure is for verbos complex only, not your other vcos. it worked like a charm on my unit and 4 octaves is heaven compared to 2.


there are two holes on the vco, next to the cv ins for exponential cv. those are for calibrating it to your preferred pitch source. it will track reasonably well ( 2-4 cents +/- after warming up for an hour, depends on your CV source I guess) within four octaves, which i find more than enough for "musical purposes." that vco doesn't have accurate exponential converter like dixies etc and it is not sold as "precision" unit.

all you need is a very small screwdriver with a flat head (be careful, its easy to mess the module up by not being careful when messing around with the screwdriver), very accurate vst guitar tuner (i use gtune freeware, its great, fetch it here: http://www.gvst.co.uk/gtune.htm) and your midi 2 cv interface or cv sequencer.

turn on your system, remove all your cables and wait for it to warm up for at least an hour to be safe. than send 0v into the pitch of both vcos, try to have it as stable as possible at C (it will always fluctate -/+ 1, even 2 cents, that thing is alive and breathing) and than send 4v into the pitch in. adjust the trimmer with the screwdriver until the 4v C is as precise as possible, but remember, it will never be dead stable on C without drifting 1-2 cents. now play your four C-s. the verbos should track musically across 4 octaves, as long as your pitch source is precise. it's not going to be 0-1 cents perfect like a dixie, but I find it a much better sounding VCO.

[stephentrask]

Once I bought the Arturia Keystep calibrating the Verbos CO became a breeze. I don't need a meter because I know the Arturia is dead on with it's 1v/oct. This the makes it a breeze to calibrate the Verbos touch plate.

[huffnPuff]

The problem with mine isn’t tracking as much as it’s pitch stability. Can’t really tune it when it’s all over the place.

The thing is I’m not even sure it’s a problem with my copy. I think I can here something similar during his videotaped presentation of the Random Sampling module, while the oscillator is droning in the background.

I was told something about PCB revisions, so maybe later modules do not behave this way.

[anderson303]

The problem with mine isn’t tracking as much as it’s pitch stability. Can’t really tune it when it’s all over the place.

Yes, this is my problem. And if this is normal behavior for it, at least my older (it is older) revision than It's working as expected. no point sending it in for repair.

It's a great noise module, I could see just using it for wave folding/distortion which I've been doing.

[huffnPuff]

The problem with mine isn’t tracking as much as it’s pitch stability. Can’t really tune it when it’s all over the place.

Yes, this is my problem. And if this is normal behavior for it, at least my older (it is older) revision than It's working as expected. no point sending it in for repair.

It's a great noise module, I could see just using it for wave folding/distortion which I've been doing.

I’d like to know if newer revisions address this, and if so whether mine can be modded. Would be nice to get more use from the oscillator, it does sound good.

[droningspaghettimonster]

this is not pleasing to read, as even though the module really shines in FM scenarios where pitch is not something that matters a much as with "east coast" vcos, having both options is very important to me. my verbos does not behave in this way, neither the carrier nor the modulator. as I said, mine drifts 1-2 cents when it it at C, high or low, but that is far away from being all over the place. mine is the newest revision, if that has anything to say. maybe other user with more knowledge should chime in, as I though this was only calibration issue.

i've also noticed, when checking the module out at schneidersladen, there seem to be vactrols at the back of the module. maybe its the very first version? does your module have vactrols? https://www.schneidersladen.de/media/ca ... 7_back.jpg

i hope you both get this sorted, as I use the verbos complex all the time for east coast bass duties due to its huge wavefolder sound.

[anderson303]

That’s the one I have:

i've also noticed, when checking the module out at schneidersladen, there seem to be vactrols at the back of the module. maybe its the very first version? does your module have vactrols? https://www.schneidersladen.de/media/ca ... 7_back.jpg

i hope you both get this sorted, as I use the verbos complex all the time for east coast bass duties due to its huge wavefolder sound.

[droningspaghettimonster]

beautiful...

so thats clearly an older revision than mine. hopefully anybody here can either confirm that those older revisions are supposed to drift in pitch or not... i wish i could be of more help.

[anderson303]

There's drift and then there's chaotic swings across the tuner range. I'm fine with a little analog drift.

The other peculiar thing is that each case I put it in gives off a slightly different note (range)

I made a recording of 3 cases and was careful not to change any settings and it plays back like a melody.

[slow_riot]

one thing that seems possible is that with heavily automated production (like an SMT pick 'n place machine) as a manufacturer you are quite exposed. Analogue parts like opamps and transistors do have a percentage that are DOA (or within that timeframe). Each module does need a burn in time and inspection that is quite labour intensive, and in fulfilling higher numbers of orders I can see why this might get rushed.

I've had similar failures on my bench. Over multiple customers it may have been a bad reel of components.

[anderson303]

This would be good news, then it could be serviced? I'm basically trying to figure out if I should go to the hassle of shipping it out. Maybe I should get in touch, there is a guy affiliated with Control in Brooklyn that can service Verbos in the US since their move to Berlin.

one thing that seems possible is that with heavily automated production (like an SMT pick 'n place machine) as a manufacturer you are quite exposed. Analogue parts like opamps and transistors do have a percentage that are DOA (or within that timeframe). Each module does need a burn in time and inspection that is quite labour intensive, and in fulfilling higher numbers of orders I can see why this might get rushed.

I've had similar failures on my bench. Over multiple customers it may have been a bad reel of components.

[slow_riot]

This would be good news, then it could be serviced? I'm basically trying to figure out if I should go to the hassle of shipping it out. Maybe I should get in touch, there is a guy affiliated with Control in Brooklyn that can service Verbos in the US since their move to Berlin.

Yes it seems very unlikely that Verbos would put out a module that displayed such erratic behaviour, and I've seen this behaviour occur with a bad part. In any case I would contact the retailer or Verbos themselves and they can tell you how to proceed.

[anderson303]

Yes it seems very unlikely that Verbos would put out a module that displayed such erratic behaviour, and I've seen this behaviour occur with a bad part. In any case I would contact the retailer or Verbos themselves and they can tell you how to proceed.

Excellent, thank you!

[huffnPuff]

That’s the one I have:

i've also noticed, when checking the module out at schneidersladen, there seem to be vactrols at the back of the module. maybe its the very first version? does your module have vactrols? https://www.schneidersladen.de/media/ca ... 7_back.jpg

i hope you both get this sorted, as I use the verbos complex all the time for east coast bass duties due to its huge wavefolder sound.

Mine is also VER 2 and it behaves the same way. I don’t think it’s a bad opamp...

[huffnPuff]

This is the response I got.

A part in your module suffered. It can be easily repaired - in fact it is a simple modification to both oscillator cores so this issue won’t happen ever again.

[huffnPuff]

I sent info@verbos a link to this thread, I hope it helps.

[slow_riot]

Mine is also VER 2 and it behaves the same way. I don’t think it’s a bad opamp...

JFET input opamps like tl07x that some manufacturers use for every amplifier in a board have relatively high noise in the 0-10Hz region. The performance of a part is not guaranteed to be at the level given by the datasheet, but instead a spread of values around a middle position. I've personally had to deselect parts that gave behaviour like this in a VCO.

[cwejman music]

Best PSU are analog, linear regulators + shortest possible ribbon cables. Sensitive modules like oscillators should be closest to the internal PSU. Analog ones. You'll avoid a lot of problems with voltage instability and, very important, noise. For the safety reason; avoid PSUs with high current capacity (bigger than, say, 2 Amps) / two rows of modules.

[cwejman music]

one thing that seems possible is that with heavily automated production (like an SMT pick 'n place machine) as a manufacturer you are quite exposed. Analogue parts like opamps and transistors do have a percentage that are DOA (or within that timeframe). Each module does need a burn in time and inspection that is quite labour intensive, and in fulfilling higher numbers of orders I can see why this might get rushed.

I've had similar failures on my bench. Over multiple customers it may have been a bad reel of components.

The short answer to this claim is NO. SMT components are very stable, resistors 1% tolerance, even capacitors with tol. 1%. Matched transistors in tiny case (SOT363). All together make modern circuits much more stable and precise. Somebody mentioned op-amps. Forget it. I produced synths and modules during last 14 years and i'D NO ISSUES WITH BAD STABILITY. look instead at the monster cases with bult-in switched PSUs.

[slow_riot]

This is nothing to do with SMT but simply the automated assembly process. I've had to deselect opamps for very high 1/f noise that made them unusuable in DC control circuitry (note that the TL07x datasheet does not quote a figure for it). It's certainly one thing to consider.

Of course eurorack infrastructure with respect to power, distribution is another, it's easy to forget how bad it is sometimes, but PSRR with opamp circuits can be good enough to at least make things usable.

[mritenburg]

one thing that seems possible is that with heavily automated production (like an SMT pick 'n place machine) as a manufacturer you are quite exposed. Analogue parts like opamps and transistors do have a percentage that are DOA (or within that timeframe). Each module does need a burn in time and inspection that is quite labour intensive, and in fulfilling higher numbers of orders I can see why this might get rushed.

I've had similar failures on my bench. Over multiple customers it may have been a bad reel of components.

The short answer to this claim is NO. SMT components are very stable, resistors 1% tolerance, even capacitors with tol. 1%. Matched transistors in tiny case (SOT363). All together make modern circuits much more stable and precise. Somebody mentioned op-amps. Forget it. I produced synths and modules during last 14 years and i'D NO ISSUES WITH BAD STABILITY. look instead at the monster cases with bult-in switched PSUs.

This point has been discussed ad nauseum in all the Verbos threads, yet people continue to ignore that you need a good linear power supply. People use switched power supplies and wonder why they have problems.