Since trying this, I have changed my mobo. Right now I am using a cheap off-the-shelf 'regular' 5m USB cable between the PC and NOS1. I have no 'crackling' sound whatsover.

I haven't tried expensive Ridge Street Enopias cable with the new ASRock mobo for a couple of reasons. Firstly, I would need to use a USB connector to connect the Enopias to the 5m cable, and I don't want any additional USB connections between PC and NOS1 - working at the MHz range, reflections at these USB junctions may cause changes to the sound (this is pure speculation on my part, but it's been proven by Pat at AR-T in spdif cables). Secondly, I'm perfectly happy with the sound I'm getting from the PC/NOS1 combo now. The old mobo really was fatiguing to listen to (something both Nick and Brian found also) and I suspect the 'improvement' in sound I described above was down to the Enopias taming this somehow.

Mani.

Hi Leo, thanks for sharing.

It looks like I'm just not going to be able to find the time to visit Peter/Bert and take a listen to the Orelinos in person myself in the near future. But the decision has been made - I'm placing an order for them anyway. As you might imagine, doing this 'blind' (or should that be 'deaf'?) is a little uncomfortable, but reports such as yours really help.

Mani.

An update...

I did go ahead and swap the Asus mobo out for the ASRock mobo last week. Everything went smoothly up until I tried booting up and got nothing happening. My first thought was that I had buggered up the CPU or something. But then I realised that I wasn't even getting the BIOS screen appearing. Looking at the mobo, I saw an error code being displayed on the LEDs. Consulting the manual it seemed that I had a memory error. Looking deeper I realised that the ASRock mobo doesn't accept the 4x DDR3-2133 memory cards I had transferred directly from the Asus mobo. Fortunately, the music PC in my office had 4x DDR3-2400 memory cards and was happy with the DDR3-2133 cards, so I just swapped them around. After this, everything worked fine. Phew!

I didn't do any tweaking other than disabling all the USB2 ports  and one of the two USB3 ports (first in Win8 and then in the BIOS). I'm not using a USB3 PCIe card, and there remains just one SATAIII HDD connected to the mobo. The keyboard and mouse are both connected via PS/2. The NOS1 is connected via a single run of regular 5m USB2 cable (no separate data and power lines or anything fancy, though my 'USB grounding scheme' remains). And the sound...?

Well, I agree with everything that Nick and Brian say 100%. This is no placebo. This mobo really is better than the Asus, it's as simple as that.

Furthermore, in my 'USB cables... again' thread, I mentioned that I could 'hear' my mouse and HDD, etc through my horns if I used a regular USB cable (with both data and power lines) between the PC and NOS1. Well this has totally gone - proof that this mobo really is quieter/better than the Asus?

Thanks for all the encouragement to get off my backside and do this guys.

Mani.
 

A quick update on the Tube Distinctions Soul 15 amp. Anthony Matthews got back to me. He checked the amp out and according to him, everything is working as normal. He suggested, and I agreed, that the Soul probably isn't the best match for my 115dB speakers. It just isn't quiet enough. He has given me a full refund.

It's a shame because it had a really nice quality to its sound. But if this was down to noise, then I'd rather not have it. In any event, the BD-Design gainclones are dead quiet (well, one channel at least) and are sounding seriously nice with the Swings. I'm going to have a crack at replacing the one noisy trannie this weekend. I'll report back on whether this affects the (slight) noise coming from the horn.

Mani.

Thanks Peter. I was actually thinking of getting a calibrated mic (Earthworks, or something) and using the RME software to capture some 20-20 sweeps. But I'll look into your approach too. Thanks again.

Mani.

Sure, any 'preamp' is going to matter. But I always thought that the control the power-amp has over the driver is a larger factor.

Mani.

I'm not really the gambling sort. But I have to say that since yesterday evening, I'm more inclined towards a pair of Orelinos than I ever have been and I think it's a pretty fair chance that I'll go ahead and order a pair after listening to them. What makes me say this? Well, yesterday I tweaked around a bit with the BD amps in place and I have to say that I was getting a seriously nice sound out of the Swings. I mean, seriously nice. Satty and I sat through the whole of Beethoven's 7th after the kids had gone to sleep. Never happened before - not the whole symphony. And as fate would have it, just when I get a really nice sound, I'm off travelling for work

My feeling now is that if the Swings sound this good, how bloody good do the Orelinos sound? I've decided that I'm not going to jump ahead of myself and will let you and Bert develop the 'complete Orelino' concept a bit further. Meanwhile, I'm going to try to stay away from tweaking for a while and just enjoy what I've got. Gonna try at least.

Mani.

This may well be the case in most systems, but not with mine. I have two passive vol. controls - one RCA the other XLR. I can put them between the NOS1 and the various amps and the noise through the horns doesn't change at all with the control set to 0 vs. max. Remember, the noise out of the NOS1 is in the single-digit µV range.

Mani.

Huh?

So, are both the LF and MF/HF amps built into the Orelinos? Hell, why not go the whole hog and build one channel of the NOS1 into each Orelino and connect via dual AES or something?

Really looking forward to hearing the Orelinos myself... and maybe placing an order thereafter.

Mani

Slightly off topic...

I'm interested in understanding the mechanism that causes the bass to change its quality with different amplifiers. Generally, the more powerful amps have a tighter and more controlled bass. This is exactly as one would expect. HOWEVER... the amps are not driving the 15" bass driver directly. They are driving the in-built gainclone amp, which increases the LF gain by I guess 15dB or so to match the MF/HF horn sensitivity. Presumably, this in-built amp has a very high damping factor.

So how is it that the bass quality can change so much when none of the amps are even 'seeing' the bass driver? Any thoughts anyone?

Mani.

Nick, I'll try this over the weekend.

Mani.

Edit: Not sure of the gain of the Sauermann or BD amps.

Haha. I didn't try any lower with the Sauermanns, but with the quiet channel of the BD amp, I can hear the tone with XX's vol set to -144dB!!!

Weirdly, as the attenuation gets very high, the tone starts coming and going. At > -132dB attenuation, it seems to be riding on a 1-2Hz modulation.

Now, I have no idea if XX's vol control is at fault here. Or maybe there's some sort of 'Nick effect' going on - the house is 130 years old, so ghosts can't be ruled out.

Mani.

Thanks Coen. I will remind Anthony of this if he comes back and says his amp is as quiet as it can be.

Cheers, Mani.

Arghhh!

I'm an idiot, and I admit it.

When I've been comparing amps in the past, one of the things I haven't been doing is adjusting the gain of the bass amp in the speakers. What I did today was to try all the amps (minus the Soul) but adjust the gain of the speakers' bass amp to get a nice balance. Without doing this, the SS amps can sound too anemic, and it's no wonder that I've preferred the low-powered SE valve amps, with their larger bass 'bloom'.


But what's perhaps more striking is the fact that the amps have different levels of noise in this order (from most to least):

1. Soul (15wpc DC-coupled valve SE)
2. Berning (5wpc DC-coupled valve SE)
3. Sauermann monos (40wpc class A PP)
4. Sanders (~500wpc class AB)
5. BD-Design monos (~100wpc gainclones - currently with input caps)

Stupidly, I've never tried the BD amps with the Swing speakers for any prolonged period of time until today. Why? Well firstly because of the aforementioned anemic sound (not their fault as I wasn't adjusting the bass gain). But also because one of the PSU transformers has always hummed from the day I received the amps. Bert immediately sent me a couple of replacement trannies to try, but to this day I've not gone ahead and taken the soldering iron out to do this.  I've now got the BD amps in the system and one of the trannies still hums a little, but nowhere near at the level of hum from the single Soul trannie.

I really am an idiot. With the bass gain much higher than 'normal', I really like what I'm hearing from the BD amps. I've said before that the BD amps are simply the cleanest sounding amps I've ever heard. But with the bass gain increased to a nice balance, they're very sweet and musical too.

As mentioned, they're also easily the quietest amps I've tried with the Swings. What's interesting is that the channel with the quiet PSU has virtually no noise coming out of the horn (or the powered bass driver for that matter). I really mean virtually nothing. With my ear in the horn, I can hear just a little hiss. That's all.

However, the channel with the humming trannie has humming noise coming out of the horn and bass. At a pretty low level, but it's still audible from a couple of meters away.

So I'm now wondering whether I even have a 'global' noise issue. Maybe I don't! Perhaps the issue is simply noisy PSUs? This would also explain why the BD amps are quieter than the Sauermann amp. The former are class AB and draw virtually nothing at idle, whilst the latter are class A, so the trannies are working overtime even at idle. (Edit: I think the Sauermann monos have a higher gain also.)

Of course, the next step will be to eliminate the noisy trannie from the single BD amp. I should have some time this weekend to try this and will report back.

As for the Soul, well I will only take it back now if it is as quiet as the BD amps. They are now my new reference.

Mani.

Hi Flecko, thanks for your thoughts. But see next post...

Mani