nice review!
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thank you
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nice review indeed…
do you really believe AD/DAs are on the same level as your older Apollo interface (which was quite good)?
Both compressors (channel and bus ) sounds quite good. Channel comp should be very useful on vocal, bass, some guitars and live instruments, but do you think they will be useful on more “techno”, “electronic” / drum / faster attack material?
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I have had the Audient ID44 and I was not impressed by the converters they were just fine, my metric halo 2882 sounded much better and the sound is much more open
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Well I would hope so. Metric Halo are in a whole different price bracket. If there was no difference I would be worried.
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I bought a new power supply (XP Power, “medical grade”), with the same specs, and it seems to have solved the problem. It also reduced low-frequency noise somewhat. Here is a sonogram from the same channel and settings powered with the new PSU (left) and the original one (right).
SSL made a great decision to put an external, and fairly easy to find, PSU ! But they were probably a bit unlucky with the supplier. With the current covid restrictions, doing quality control in China must be close to impossible. I would have paid maybe 1k more for it to be made in the UK. Quality control is better when the engineers can visit the production line. Nothing wrong with Chinese brands making products in China though!
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Great, I might try this as well. I got a replacement power supply from SSL yesterday (same brand and everything) and switched it and am still having the same problem. Do you have a link to the power supply you used?
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Sorry to hear that, you would have thought that they would test it before sending it, knowing that the batch may have an issue… I bought the ALM120PS24 from XP power. There are versions with and without chassis ground connection. Not sure which is best in which context, maybe someone can help here. I just got a “medical” one (70$), because I figured they may undergo a bit more testing, but there are less expensive ones (50$) that are probably just as good.
Still, I am a bit surprised by these power supply failures, I engineered some power supplies in the past, and I remember you had to make official tests, costing ~50k, and if they fail, you have pay again. You can skip the test by signing that you take responsibility, but, as the damage can be massive (e.g. fire), I don’t know anyone who would risk it.
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Thanks! It looks like the one with the shell grounded is the type they used since it is an IEC 320-C14 connection for the input.
Edit: after looking at the specs for a few different choices for equivalent power supplies it looks like you chose a pretty good one, I might go the exact same route and report back.
Could you please post a link? My Big Six is finally on it’s way – and as sad as this is – buying a better PSU might be a better solution than asking SSL to swap theirs and receiving a similar one.
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
I also ordered one of these and will report back.
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Thanks a lot! I just received my Big Six. The good news: The PSU is not humming at all. Either I’m lucky or it might also depend on the frequency of the power grid (I’m 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?
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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 don’t know whether floating shell would be same, worse or better. Maybe someone from SSL could discuss?
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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 don’t know if you’ll find the same here.
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Thanks for the explanation. I’d still love to hear if there’s a way to compare measurements. If you could describe what/how you measured – and the results with both PSUs – 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. I’m 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.
I’m curious if others have found it to actually degrade the sound quality. I plan to do some recording with the B6 today.
T
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 …).
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 B6’s 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 “Amadeus Pro”. 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 don’t really show a change in noise level, even though it is immediately audible. This is maybe why it passed SSL tests … But, once you know what you are looking for, you can then use the right measurement (sonogram) which shows the atrocious difference.
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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 supply…
Power supply noise: Dropbox - IMG_0298.MOV - Simplify your life
Coming out of monitors: Dropbox - IMG_0296.MOV - Simplify your life
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 don’t 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 didn’t have this issue at all).
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For those with noise issues using unbalanced instruments, this was an issue with the original Six as well. It wasn’t an issue with all unbalanced instruments, but some are just more finicky than others. It’s 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.
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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.
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