I PMed you a link. It looks like parts shortages etc. might be affecting power supplies as well and stock is low everywhere with lead times in the 50+ week range. Ugh.
Edit: If anyone else is interested in trying a better power supply I looked through a lot of data sheets and the other option that looked the best (along with the one sanbruno mentioned that is out of stock everywhere) was the Delta MDS-090AAS24 BA and there are about 50 of them in stock at digikey: https://www.digikey.com/en/products/detail/delta-electronics/MDS-090AAS24-BA/3909356
Thanks a lot! I just received my Big Six. The good news: The PSU is not humming at all. Either Iām lucky or it might also depend on the frequency of the power grid (Iām in Berlin.)
On the low frequency (DC) noise: Is there a way that we can measure it in a comparable way in order to compare the amounts and decide whether swapping the PSU might make a difference?
Hi rklem, I did some measurements and they are two separate issues. The noisy power supply I had did have some extra low frequency noise, mostly below 100Hz, but this is unrelated to the DC offset issue. With the new PSU, the DC offset is still there (but not the low f noise), but it could even be considered good design: best to remove the DC at mastering, so that you add low-frequency phases just once?
For anyone who may want to get a new PSU, in Europe, you can get them at: rs-components, distrelec, farnell, reichelt. And Mouser and Digikey ship them worldwide.
With respect to floating shell or grounded shell, I donāt know whether floating shell would be same, worse or better. Maybe someone from SSL could discuss?
The new Mod Dwarf pedals also had some PSU-related noise issues. There, it turned out that the answer was moving from grounded power supplies to double-isolated ones, but I donāt know if youāll find the same here.
Thanks for the explanation. Iād still love to hear if thereās a way to compare measurements. If you could describe what/how you measured ā and the results with both PSUs ā we could perhaps try to replicate that, to find out if all SSL PSUs are worth swapping or not?
I got my Big Six yesterday. The power supply that came with mine is fine, but I do have the DC offset. It is on every channel. It varies channel to channel from about -60dB to -70dB. It persists when I playback through the B6 (FROM USB ch. x). If I sum 12 channels with the DC offset (1 through 12) to stereo bus 15/16 it does not seem to stack up, it remains in the same range of -60dB to -70dB. Iām not sure if this will have any real impact on the sound quality. I do wish it was not there since I see it on the meters and it makes me want to investigate it.
Iām curious if others have found it to actually degrade the sound quality. I plan to do some recording with the B6 today.
Hi rklem,
First of all, the original PSU was a FiDUS EDA9024-C14, 24V 3.75A. (In the manual, it says that the PSU is 15V, but I think they just copy-pasted wrong from the SiX manual ā¦).
I noticed an audible noise in the mix (pulsating noise + white noise), when connecting a Korg Prologue that has non-balanced outs, and a ground connection (C14 plug). Noise was audible only on the channel with the Prologue. But, it was not a prologue problem, as the signal out of the it was clean (listening to one channel on the B6 and checking the other).
I started looking for ground loops, went where my PSUs are (I have 15 devices, with similar PSUs) and they were all quiet, except for the B6ās which emits a (low level) audible noise with my ear next to it, which matched what I heard in the mix, so it was an easy debug. I then set the input gain to maximum, and slider max, and main to max, but with no compression. Then, I recorded both the channel and main directly from the B6. I swapped PSU and did the same. Then I did the sonogram posted above in āAmadeus Proā. To me, what was most annoying was the pulsating noise, the low-frequency noise is readily measurable, but not really audible for me. Also, I checked other channels, and indeed, the noises were measurable, but not audible with the original PSU, and went away with the new one. I hope this helps! Also, here are links to my measurement files.
Interestingly, basic statistics donāt really show a change in noise level, even though it is immediately audible. This is maybe why it passed SSL tests ā¦ But, once you know what you are looking for, you can then use the right measurement (sonogram) which shows the atrocious difference.
Mine behaves the same, all my power supplies are quiet except the one for the big six that is making a humming and buzzing and clicking noise if you listen close to it (the same noise that it injects into the signal of the synths). But the noise comes through a lot louder on my mixer than in your examples, even with the channel gain at 12oclock and the channel and main faders at unity (so my synth is playing around 0db) it is very obvious. I hope there is not something wrong with my mixer itself and not just the power supplyā¦
And the noise problem is also the worst with pieces of gear with unbalanced outputs. I soldered up a pseudo-balanced cable (TS-TRS with shield only connected to the S of the TRS connector) to see if it would help in this case and the noise is not as bad with the pseudo-balanced cable as long as the synth is powered on, but it is actually worse when the synth is powered off. But I donāt want to have to solder special cables for all of my gear and rather just get a quieter power supply (or a mixer like all my previous ones that didnāt have this issue at all).
For those with noise issues using unbalanced instruments, this was an issue with the original Six as well. It wasnāt an issue with all unbalanced instruments, but some are just more finicky than others. Itās because all of the connections on the Six and Big Six are balanced. Using a DI box should clear this up, because many have a transformer which helps remove noise and DC interference, and also a ground lift switch. And if some are having issues with their power supply, then maybe this issue is being amplified even more.
Are the inputs on the Six and Big Six balanced in a different way than other cheaper mixers? I have never had a problem like this with any of my other mixers (for example a tascam model 16 I used) and they all had balanced inputs as well of course.
I really donāt know, other than they are different products. I just know Iāve seen this issue crop up a couple of times in regards to the Six in certain synths. I could take a guess though, and maybe itās the type of components used in a Super Analogue channel? Or maybe itās the power supply and power handling of that specific synth that is causing issues? Or maybe itās a combination of things? To get so much headroom, things are probably juiced up quite a bit on the Big Six. Just some guesses, maybe someone who knows more about this can chime in.
I tried with the small SiX, and there is no noise on the same synth (prologue). I only had noise when connecting a guitar ampās cab emulator (mesa) to it, but it had a ground lift switch that solved it, and, I believe, the issue was the amp, not the six.
From my perspective, with the B6 it is a power supply issue, the original power supply sounded like it was failing, and I would have changed it for safety reasons anyway, even if using only balanced gear. The unbalanced connections are slightly more noisy than the balanced ones, but I guess thatās normal.
Apart from these issues, how are you finding your B6. I am finding it really well thought out and convenient, exactly what I wanted.
This page gives some detail. If I interpret it correctly, to connect an unbalanced instrument to an ssl balanced input, one should make a ts to trs cable with floating s and s ā r
I have been using standard ts cables with no issues though.
Yesterday I set it back up and tried out the Ableton DC correction that you had mentioned above. It works well, and all of my readings are in the -90ās or better.
Apart from the issues, I think the package is perfect for what I need. Itās pretty much what I had asked for after using the Six. They nailed where the ins and outs are on the USB channels, and the tactile experience is great. My favorite new feature is the āST CUE 1 TO G COMP & SUM TO MAIN BUSā switch. It makes it so that ST CUE 1 goes through the Bus Comp and then it is summed back in with the Main Mix. This could be great for parallel processing drums. Itās not something I will always use, but it is just one of those clever routings they came up with.
Another aspect of the Big Six I am enjoying is when I am listening music, I route the computer output to one of the stereo channels. Well hey, now I have 3 band EQ at my fingertips. Listening to a banger and want more bass, done. This scooped track need little more mids, done. Well, you see where I am going with this. Just part of the great and easy routing options.
Just a funny thought; When I had the Six on my desk, it seemed so small. But with the Big Six on my desk, it seems so large.
Okay, now Iām hearing the noise you mentioned too ā loud and clear. Itās a humming plus a rhythmical clicking noise. I only hear it on my Prophet 10 channel, not on the Buchla 200 channel (both unbalanced outputs).
Did any of you try to isolate the unbalanced input with a transformer? Or does swapping the PSU get rid of the entire noise?
Anyway: This is a very obvious problem that should be solved by SSL. Iāll write a support ticket too.
Have you tried a balanced cable? I know itās not a balanced output on the prophet 10, but I read some comment from Sequential about this being possible and helpful in some situations. Itās been a while and from memory it helped me with noise on the P10 and an interface.
This is what SSL recommend, but I guess they assume that the noise does not come from the mixer (power supply) itselfā¦
Just in case, I found that https://www.designacable.com/ sell pseudo-balanced cables in the UK.
Thanks so much brucegill! Using a TRS cable to connect the Prophet solved the problem entirely and got rid of the noise on that channel.
This is so weird and counterintuitive. Usually you should never use a TRS cable for a unbalanced to balanced connection because yourāe loosing 6 to 10 dB of the input signal. I accidentally used TRS cables to connect an externel effects processor to the Big Six and it completely destroyed the signal. But in the case of the Prophet it works.
Something about the balanced IOs of the Big Six seems to be ā¦ very different.
