Oscillator Issues

dsetto

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Re: Oscillator Issues
« Reply #60 on: September 09, 2017, 10:51:06 PM »
It's my assessment that it all gets sorted out.

Sleep of Reason

Re: Oscillator Issues
« Reply #61 on: September 11, 2017, 12:56:41 PM »
Well I can say that DSI were extremely responsive and got me new boards in no time, which fixed the issue.

Re: Oscillator Issues
« Reply #62 on: September 11, 2017, 02:45:02 PM »
jazzygb1 is right, Curtis chips rarely fail so that's more or less a non-issue.

I can't see how we're failing to acknowledge an issue publicly when it's being discussed on a public forum and we're directly commenting in the thread? As mentioned, since we are in the process of categorizing what's happening we don't have an official response as of yet. But that's completely different from not acknowledging that users are experiencing something, which we've done now, more than once.

It's understandable if you're new to DSI that you may not be familiar with our support, but we take care of our customers, and long after the warranty period has expired so if you have one of our instruments we support it as long as we can.
SEQUENTIAL | OBERHEIM

Propheteer

Re: Oscillator Issues
« Reply #63 on: September 12, 2017, 02:27:27 AM »
I wrote to support last Thursday, had a ticket number/email come through, provided more details (serial/retailer) heard nothing since? I just wanna know if it's gonna be easier to swap in a board that' sbeen pre-checked at/by DSI to be fully working, than sending this whole unit back to the retailer and taking another gamble on a unit that could be the same!

Would rather just get a new board if it's gonna def fix the issue.


Also I'm not letting this issue put me off the REV2, it remains an absolutely stunning synth in every respect and is going to have a lot of use on my stuff, it can do so much and in such a great package. I see NOTHING out there that competes with it for this price on sound, features, build, looks and versatility/usefulness, and with a (praise the lord) 5 octave keybed!

It's also super inspiring (thanks to easy programming, tons of easy to handle power and the poly seq which is great for rattling off ideas for later;though I admit it would be even cooler if was a 'live' sequencer to record into not just a step seq) and very expressive (not only the great aftertouch and nice feeling wheels but the sound itself which has an emotional or atmospheric quality about it when programmed right).
« Last Edit: September 12, 2017, 02:48:46 AM by Propheteer »

Propheteer

Re: Oscillator Issues
« Reply #64 on: September 12, 2017, 02:28:49 AM »
Well I can say that DSI were extremely responsive and got me new boards in no time, which fixed the issue.

I'm guessing you are in the US yeah?

Re: Oscillator Issues
« Reply #65 on: September 12, 2017, 10:35:50 AM »
I wrote to support last Thursday, had a ticket number/email come through, provided more details (serial/retailer) heard nothing since?

You must have used a different email address than the one you registered on the forum, I don't see any support inquiries from that one. If you wrote on Thursday, it's highly unusual to not have received a reply the same business day or the next business day. Please check your spam/junk mail, and I apologize if you haven't received a reply.

Feel free to PM me the email address you used to contact our tech support and I will look into it.

Being in the US or any other country has no bearing on the level of support we hold for our customers. We strive to help everyone quickly and equally.
SEQUENTIAL | OBERHEIM

Propheteer

Re: Oscillator Issues
« Reply #66 on: September 12, 2017, 12:59:35 PM »
I wrote to support last Thursday, had a ticket number/email come through, provided more details (serial/retailer) heard nothing since?

You must have used a different email address than the one you registered on the forum, I don't see any support inquiries from that one. If you wrote on Thursday, it's highly unusual to not have received a reply the same business day or the next business day. Please check your spam/junk mail, and I apologize if you haven't received a reply.

Feel free to PM me the email address you used to contact our tech support and I will look into it.

Being in the US or any other country has no bearing on the level of support we hold for our customers. We strive to help everyone quickly and equally.


Yeah I always use different ones for forums (for spam reasons!). I replied to the ticket with retailer/serial etc. Will PM you, Thanks!

I don't for one second think you'd treat other countries differently!?? I merely meant the speed with which he received a new main board is obviously going to be faster in the US than in the UK (where I am!), unless you have a service/parts centre here like Moog do (with source distribution).

« Last Edit: September 12, 2017, 01:05:06 PM by Propheteer »

Re: Oscillator Issues
« Reply #67 on: September 13, 2017, 08:10:38 AM »
My replacement REV2 arrived today (yay).
Hopefully it's a case of 2nd time lucky! :)
Will update you if it has any issues.

UPDATE: No problems with the oscillators on the replacement REV2 - wohoo! :)
It shipped with OS v1.0.6.5 so will update to the latest version, but assuming that introduces no problems then I'm a happy bunny! :)
« Last Edit: September 13, 2017, 09:16:57 AM by jazzygb1 »

Sleep of Reason

Re: Oscillator Issues
« Reply #68 on: September 13, 2017, 03:05:39 PM »
I must say, the pulse on the new boards has a pretty massive volume discrepancy on some of the shapes. On the lower percentages, the expansion voices are much loader and on the higher percentages the C notes become almost inaudible. Support over at DSI said this was normal due to the extreme nature of pulse and is the same for all REV2s.
« Last Edit: September 13, 2017, 03:27:57 PM by Sleep of Reason »

Re: Oscillator Issues
« Reply #69 on: September 13, 2017, 05:03:54 PM »

UPDATE: No problems with the oscillators on the replacement REV2 - wohoo! :)
It shipped with OS v1.0.6.5 so will update to the latest version, but assuming that introduces no problems then I'm a happy bunny! :)

Okay, well strictly speaking there is still an issue with a voice not sounding right on my replacement REV2. :(
This time it's on voice 16 rather than voice 1 and it only occurs at the extreme end of a shape modded Pulse wave (between values of 0 & 3, or 97 - 99%) or on a triangle and only on the highest 5 or 6 notes of the synth.
It's much more subtle than it was on my previous REV2 (there's no silent notes) and in all honesty I'm unlikely to encounter it as an issue in 'real world' playing so will live with it for now.
It's not a big enough deal (at the moment at least) to make me return the synth again, but I'll keep an eye (or ear) out for any further issues.
Hopefully there will be none.

Sleep of Reason

Re: Oscillator Issues
« Reply #70 on: September 13, 2017, 06:03:30 PM »
Just checked and the C notes on the triangle higher percentage shapes are almost inaudible too.

Re: Oscillator Issues
« Reply #71 on: September 13, 2017, 06:41:19 PM »
This is true for any of our synths with the Curtis DCOs. Sometimes you may want a thin pulse width, and you may notice after dialing in a pulse width of 0-1 or 98-99 or similar, some keys appear dead or the sound is barely there.

At extreme pulse widths, there will be a voice -to–voice and a frequency dependent variation. When really thin, the analog electronics are just not going to be perfect. This is especially true on the upper end of the range around 95-99, where there may be some fluctuation of the pulse width signal. Calibrating the filter can get them as close as they're going to get.

If a thin pulse is desired, use the low range of the keyboard, where voice-to-voice consistency is much better. If it were perfect (i.e. digital), a pulse width of 99 is the same as 1, just inverted, so it sounds the same and either value can be substituted.
SEQUENTIAL | OBERHEIM

Propheteer

Re: Oscillator Issues
« Reply #72 on: September 15, 2017, 01:11:19 AM »
I can understand the shape mod/pulse width thing a bit. And being analog, though I've never had any other analog synth (inc old VCO like polysix that were way out of calibration) that exhibited this issue! Voice to voice could vary... slightly. But the pulse issue is like just one voice is completely off, way off, to the point it falls silent while the others don't. If I dial back the shape mod to hear that voice, it still continually sounds thinner/weaker than the other 7 voices, which is really obvious until you get it back to 50%. I guess if you were modulating it it wouldn't matter at all, you want that movement and variety, and analog-ness, but if you are doing a static pulse tone where you want each key/note/voice to at least trigger and you have the shape mod above 50 then it presents a problem with a sound that has this glaring flaw.

Similar with the triangle, in many cases it's never an issue and you could use the other osc instead for when it's most obvious (a single osc soft triangle sound when that one, in my case, voice pokes through more like a saw which ruins the sound), the issue is that some other people don't have this issue! If we were all on the same page here it wouldn't be such a big deal I guess, but as some don't have it and some do, and some don't have the pulse issue (as much or on the same amount of voices) etc it makes me worried that in future it will become known as an infamous issue with the rev2 and put second hand buyers off buying my unit to seek out one that doesn't have that issue. And while I do not plan on selling it, never say never, have bought and sold many many synths over the past 10 years and am always honest about issues on ebay.

DSI have been very helpful and are working with on this, they tested a new board for me and said the pulse issue is still there as it's 'meant to be' that way (but whether it's just on one voice, 7 voices or w/e I don't know) and apparently the triangle issue isn't present on the new board (so I assume that means each voice sounds similar without one being a lot brighter)

as said I've had many analogs DCO and VCO and the only time I recall anything like this was in an MKS-50 that had a filter chip out of calibration and had to go in and tweak some pots, it wasn't 'normal' and it wasn't really accepted as normal or "as per analog". Analog has subtle variances, these issues just sound out of calibration to me and we have no way of user calibrating them (not talking about the menu soft-calibration). On that mks-50 1 out of 6 voices would sound a lot brighter (filter opening too far for that voice), the synth was sold dirt cheap (to me) due to that issue, easy fix for me but it does show that buyers and synth nuts are aware when something isn't quite right on a voice to voice basis.

If all the voices varied a little on repeated keys (triangle issue going brighter or shape modded pulse falling silent) then it would be more tolerable, even welcome, but when it's just ONE it stands out like a sore (saw? ;) ) thumb and definitely doesn't feel anything like what I'd think of as an analog "bonus".

I'm not sure how to proceed at the moment as having the board sent out to me, and me having to return the old one from the UK to the US + fitting it etc is quite a bit of hassle considering the synth is just over 2 weeks old, which I wouldn't mind if the new board was 100% a some others have claimed theirs are. So is it worth it just to fix the triangle issue but not the pulse one?? or should I return it to the retailer and try another unit from them (free). I'll let you guys know what I decide. Am gutted though because I really love this synth and thought I'd found my 'keeper' (workhorse) after years of many synths.
« Last Edit: September 15, 2017, 02:21:05 AM by Propheteer »

Propheteer

Re: Oscillator Issues
« Reply #73 on: September 15, 2017, 01:27:25 AM »
This is true for any of our synths with the Curtis DCOs. Sometimes you may want a thin pulse width, and you may notice after dialing in a pulse width of 0-1 or 98-99 or similar, some keys appear dead or the sound is barely there.

At extreme pulse widths, there will be a voice -to–voice and a frequency dependent variation. When really thin, the analog electronics are just not going to be perfect. This is especially true on the upper end of the range around 95-99, where there may be some fluctuation of the pulse width signal. Calibrating the filter can get them as close as they're going to get.

If a thin pulse is desired, use the low range of the keyboard, where voice-to-voice consistency is much better. If it were perfect (i.e. digital), a pulse width of 99 is the same as 1, just inverted, so it sounds the same and either value can be substituted.

Sounds good, but am sure on my Polysix (VCOs that are 30+ years old and definitely not 'in calibration' at the moment) that when I set the pulse width to just below max (so it's super thin - and the polysix can collapse the wave all the way if you go max so its not some weak/tame thing like some synths) that all the voices and all the notes still make a sound, none are silent, unless ALL are silent (by going to max). It must surely be harder for old discreet oscs with loads of old caps to stay in tolerance and yet it still sounds fine, while the curtis synth on a chip stuff is very modern and with very few components to get in the way, it seems implausible that they should be out by that much, esp on modern easy to reproduce fully-on-chip voice/filter/vca combos such as these curtis PA chips? It definitely doesn't seem to me like just some analog life or charm, it 100% feels like one voice is out of calibration. In old synths I can go in and dial some pots to get them all singing from the same hymn sheet, this is impossible on a modern SMT/all in one synth like the rev2, it has to be done at the factory. The chips themselves should be extremely close/similar from voice to voice, otherwise there would be a bit of an issue in manufacturing, the fact 7 out of 8 voices are close to 'perfect' shows this!

I wonder if it's the extra components around the curtis chips causing it, like smt resistors or capacitors for that one 'off' voice, could be a bad cap or something.

Also given that there seems to be some randomness happening based on frequency/notes played and with the triangle too (which is definitely not 'normal') it does show that there are areas that are open to mis-calibration or faults on these boards (or possibly chips but I find that hard to believe as the whole point of ICs is to be as close to perfect/replicable as possible no matter if it forms part of an analog synth or not - many chips SSM, Curtis, Roland and others from synths 30+ years old could be swapped into a voice circuit and sound 99.9% the same, within tolerance). This sounds like bad chips or components or mis-calibration. And saying that shapemod/pulsewidth can vary between voices doesn't really cover the issue some of us are seeing, again only SOME of us, which makes it more like a fault than as designed.

Does the prophet 08 do this on triangle btw? (I know it doesn't have shape mod to test the pulse thing).

Sleep of Reason

Re: Oscillator Issues
« Reply #74 on: September 15, 2017, 03:16:41 AM »
Agreed, if this is not an issue that everyone is encountering, then we should receive replacement boards that are fully functional. I don't understand why my new boards weren't fully tested (actually played) to see that everything was fully functional as requested and not just tested with ground probes. Not only have I spent money that I shouldn't have had to for shipping, I've also spent an exorbitant amount of time trying to sort this out as well.

Re: Oscillator Issues
« Reply #75 on: September 17, 2017, 01:02:29 AM »
Hi,

So I've been lurking here and another board reading about Rev 2 user experiences. I like the sound of this synth from some of the video demos I've seen, but this whole voice board issue has me a little hesitant to take the plunge. Like so many I'm an old analog guy having started with the Moog D in the late 70's .. and selling off the last of my analog poly's in the late 80's (a Jupiter eight), and I'm kinda longing for the experience again now in my late middle age. The only issue I ever had with an analog poly is an OBXa that blew a power supply .. So is this Rev 2 voice board issue just a few units out of thousands that have gone bad? And has the jumpy encoder issues I've read about been ironed out? I can't lift over 10 pounds now because of health issues, so having to lift and ship a Rev 2 back for repair would be difficult to say the least.

Re: Oscillator Issues
« Reply #76 on: September 17, 2017, 03:02:28 AM »
This issue is unacceptable for such a pricy synth , I would think that DSI would stop shipping and fixeed the issue first.

I sent back the Rev2 to get my money back and got a Novation Peak instead, not only it can do a lot more it's cheaper. I will repeat what i said before even if admins get upset , it's not the quality us users are expecting from such pricey products !

Re: Oscillator Issues
« Reply #77 on: September 17, 2017, 07:22:39 AM »
This issue is unacceptable for such a pricy synth , I would think that DSI would stop shipping and fixeed the issue first.

I sent back the Rev2 to get my money back and got a Novation Peak instead, not only it can do a lot more it's cheaper. I will repeat what i said before even if admins get upset , it's not the quality us users are expecting from such pricey products !

Well the Peak my be a lot of things, but it certainly isn't cheaper...or analogue for that matter!

If you compare the Peak (which is desktop only), to the Rev2 desktop they are exactly the same price.

The Rev2 has 8 analogue voices (which the peak does not) and can be upgraded to 16 voices (which the Peak cannot), and is Bi-timbral (the Peak is not - mono timbral).

Also, for just £150 more, you get a 5 octave, 52 knob, keyboard with velocity and aftertouch, plus separate outputs for the bi-timbral voices - fantastic value.

I'm pleased you're enjoying the Peak, but it's a totally different product to the Rev2 and the 'lot more' you claim it can do is subjective at best and wrong at worst.

There only 2 LFO's on the Peak for example and there's no sequencer either.

It could be argued then that it does a 'lot less'! :)

As someone who has had a faulty Rev2 I can understand your frustration, but the fact remains that it is an excellent analogue synth that sounds great and for the money and there isn't really a comparable product out there.

Anyway, enjoy the Peak. :)

Propheteer

Re: Oscillator Issues
« Reply #78 on: September 17, 2017, 07:54:55 AM »
I agree with jazzy, had my fill of 'fake' synths (digital oscs through analog filters or all digital for that matter). REV2 is the only analog synth in its class to deliver this spec, build quality, thought of design and robust analog sound. I can spot the peak and other hybrids and VAs a mile off, they just don't fill the same need. Of course they are cheaper, so is software... for a reason!

Also I've read many people had issues with the Peak too, distortion issues among them.

This gremlin with the rev2 isn't the end of the world and most people seem to have good units.

Re: Oscillator Issues
« Reply #79 on: September 17, 2017, 07:55:03 AM »
This issue is unacceptable for such a pricy synth , I would think that DSI would stop shipping and fixeed the issue first.

I sent back the Rev2 to get my money back and got a Novation Peak instead, not only it can do a lot more it's cheaper. I will repeat what i said before even if admins get upset , it's not the quality us users are expecting from such pricey products !

At the least, it would be handy to have an official document that describes the perceived problem, a factory test mode that allows one to cycle through the voices (8- or 16-voice variants), and a procedure to set the default patch to pass / fail the test. This would allow distributors or retailers to, at the customer's discretion, identify a unit which suffers from the problem prior to dispatch / purchase.
Sequential / DSI stuff: Prophet-6 Keyboard with Yorick Tech LFE, Prophet 12 Keyboard, Mono Evolver Keyboard, Split-Eight, Six-Trak, Prophet 2000