Different Oscillator Volumes

[Motion Drive]

Hello everyone

I scored a brandnew Prophet 6 Keyboard for a very good price. Super happy with the purchase...had a P6 Module 2 years back and always regretet selling it.

Now...my Prophet behaves strange in the Mixer section. When both OSC at max. the OSC2 is around 2DBs louder than OSC1. Its clearly audible and I measured this in my DAW as well. I have to reduce the volume on OSC2 to around 2-3 oclock to get both Oscillators beeing at same volume. Of course I ran all the calibrations...nothing helped.

I contacted DSI Support. I did this via Email and with the Support Ticket on the homepage. Due to that...I got  respones from two guys at DSI. One told me, that 2DB difference is within the normal tolerances of a analogue synth and nothing can be done about it.
The other guy tells me, that this is ment to be and the gain difference between the oscillators is due to their respective core oscillator designs. They decided to leave the oscillator 2 output as is so that it hits the filter a bit harder.

So...thats kinda strange to me. If its really a concious desgin choice (and a very strange one), why one guy tells me that it has to do with tolerances. On top of that, the Oscillators are exactly the same...why should one be louder due its core design?

My question...can you ppl check on your Prophet, if you have the same issue or behaviour? Just initalize  patch and compare the volumes of your Oscillators.

I really have a hard time to swallow this...but maybe I'm all wrong.

[Manbird]

I've just been on contact with Sequential about the same thing. Support says that, yes, the difference in oscillator levels is within tolerance. I didn't get the word about it being an intentional part of the design, but if so, I can dig it.

I only noticed the difference in levels once I started playing around with the "James Meek GS" trick, i.e. not pumping the oscs full volume all the time. I wonder if this has to do with me never quite getting the detuned oscs to blur the way they do so naturally on the P5. Anyway, it's not a life/death issue for me, and I now know to bump osc 1 a bit louder than osc 2 when I need them balanced.

[Motion Drive]

I've just been on contact with Sequential about the same thing. Support says that, yes, the difference in oscillator levels is within tolerance. I didn't get the word about it being an intentional part of the design, but if so, I can dig it.

I only noticed the difference in levels once I started playing around with the "James Meek GS" trick, i.e. not pumping the oscs full volume all the time. I wonder if this has to do with me never quite getting the detuned oscs to blur the way they do so naturally on the P5. Anyway, it's not a life/death issue for me, and I now know to bump osc 1 a bit louder than osc 2 when I need them balanced.

Its not a dealbreaker for me either and if others can confirm, that this is really the way the synth is designed I'm ok with it. Eventhough I dont really understand why two identical Oscillators have a different volume. I never had this issue on any other analogue Synth...vintage or modern.

My impression is, this a classic quality issue where some are just unlucky and get model with bigger differences.

[osflaa]

2,2 dB difference here, too

[osflaa]

2,2 dB difference here, too

I should perhaps add that osc2 is louder than osc1 here and I bought the synth new two weeks ago, so this seems to be normal.

[Manbird]

Here's the word I just got from Sequential support:

"The oscillators are within tolerance meaning they meet the requirements for analog components and it is part of our design. Each oscillator can and will be different to some degree and we have also programmed it so it will interact and balance with the filter in a specific way. You'll hear differences from voice to voice as well. This is normal for our analog designs."

Works for me...

[Quatschmacher]

Are there internal internal trimpots to balance the levels? My Subsequent 37’s sub oscillator was noticeably quieter than the main oscillators when set to the same footage, level and wave shape. I queried it with Moog and they said they should be the same. I sent it off and they balanced it which was great (the bummer being it sustained damage in transit back to me (twice!)).

[MPM]

Same here, and also on my Rev2.

When I questioned support about the Rev2 they confirmed that a 50:50 OSC balance was meant to be around 2 o’clock on the Mix pot.

It’s not an issue as far as I’m concerned.
In fact it benefits me when using OSC 2 as a sub OSC (If I want a different wave form or interval to the TriSubOSC). The extra gain helps to even out OSC’s.

[Motion Drive]

Good to know, that it seems to be a design choice really. Even though I would have prefered a mixer with same volumes. At least I can sleep calm now, knowing everything is as it should be. Anyhow...really enjoying my P6

[Manbird]

Good to know, that it seems to be a design choice really. Even though I would have prefered a mixer with same volumes. At least I can sleep calm now, knowing everything is as it should be. Anyhow...really enjoying my P6

I think some of the tips have been posted on the Sequential site, but James Meeker on GS has a nice Prophet 6 tips thread going. Worth a look. Lots of advice to do with oscillator/output levels etc...

[Antti]

A quick test revealed that the volume difference is only for the sawtooth, not for triangle or pulse. This is probably intentional to slightly reduce the audible phasing when playing classic detuned sawtooth sounds.