Dynaudio C1 and Pass amp

Anyone has experience with this combo? Particular Pass XA30.5.
IMO not enough uuumph for those speakers
Since you have the Signatures that amp should be OK. My Sigs worked just fine with an Octave V40SE (40 watts).
Thank you for the comments. I shall find out next week.

Xti, how big is your room?
I had a Dynaudio Confidence 3 many years, for which the C1 was Dynaudio's next generation model, coupled with a pair of Pass Aleph 3s, which again were replaced by the XA30.5s. So the same system you describe is identical to mine except the next, newer generation.

I ran Nordost gen 1 Valhala speaker wire and Nordost quattro pro interconnects from a Theta front end. Sound was nuanced, with tube-like warmth in the mid-range coupled with tremendous transparency. Great dynamics and transient speed. Incredibly fun to listen to across a very broad range of music.

The only drawback was very little bass below 100hz - in my room, which was mid-sized, it fell off a cliff below there, and by 80hz you could barely hear the test tone. I bought a Velodyne 12inch which wasn't great but it made a all the difference in enjoyment.

I think your proposed gear supplemented by one of the terrific current subs (Rel perhaps) would make you very happy.
Looking back some of old XA30.5 and c1mk1 threads, it seems member vinw and audiofeil had had success using XA30.5 to drive Dyn difficult loads, c1mk1 for vinw and Sapphires in audiofeil case. Not sure about audiofeil's room but vinw's 21x17 room is only slightly smaller than my 18x25 room (my listening position is pretty much in the middle of the room with speakers a good 2 feet from the short wall). I think my room is above average in terms of acoustics as well, based on freq sweeping with 2 different sets of speakers using Anthem ARC.

On top of that, xti, who I think has tried both c1mk1 and c1mk2/sig, thinks c1mk2/sig is easier load. Perhaps I'm just making myself feel better before the arrival of c1sig. :) I shall find out soon enough and will make sure to report back. My budget definitely won't allow me to go up to XA60.5 esp. after buying c1sig and I'm too in love with Pass XA.5 to part with my XA30.5. C1sig also sounds like reference monitors that I've been waiting for (just read a European mini review in which they pair both c1sig and diablo utopia to devialet and favor c1sig slightly but declared no clear cut winner....except diablo stomped c1sig in terms of aesthetics lol, no argument there)

Meantime, crossing my fingers :)
I'm running a 100 watt tube amp with my C-1's and I would not want less power. I personally like the sound of dynaudio speakers with tube gear over solid state.
I just purchased the new PASS INT 30A which is almost identical to the XA30.5 ( a XA30.5 with passive attenuator). This is a 30 WPC class A amp and has all the amp one needs for hard to drive speakers like Dynaudio's. I called Pass labs and they say when really pushed, these amps switch into class AB and can sustain 100 wpc for musical bursts with no clipping. In fact, the INT 150 (150 WPC AB)is essential the same amp with a slightly bigger Transformer to raise the rail voltage about 5 V above the INT30A +/- 42V.

Most music rarely uses sustain demands above about 10 WPC even for difficult speakers. Thats why Pass designed all his amps to play in class A for the first 10 Watts.

I asked them if this is enough power to drive Avalon acoustic speakers (I think they are wonderful and require enormous current/power) and he said that the 30.5 is one of their finest and will drive easily anything with ease in a normal room.

Finally, I think if you double the power you only get about 3-4 dB more sound pressure.

I have sonus FABER Cremora Auditor M's and the INT30A is overkill, but wonderful. I'm going the REL route for sub myself.

Wish I could afford to take the XA30.5 off your hands...Its one of Nelson Pass's favorites.
Hi Rr999,
I do have a Paradigm Studio Sub12. But I'm thinking not to run with it at first and see where it takes me. During my brief demo at a dealer, C1Sigs did sound like powerful mini floorstanders and have more than enough bass to satisfy me. We shall see.

BTW what speakers do you have now? Sounded like you don't have the C3s anymore.

Hi Yeast,
Not so fast. :) I am not selling XA30.5 for foreseeable future yet. I just love this amp.

From talking with Desmond from Pass when I bought the amp (I believe he holds a very high position at Pass), XA30.5 output is actually closer to 60 class A watts into 8 ohm (spec says 30 watts class A). That probably also means 100-120 class A watts into 4 ohm. I didn't directly ask this but I just assumed. One can always hope.

Like you mentioned, my understanding also is Pass XA.5 series amps don't just stop at their rated class A spec. They go higher in class A/B to a certain level if needed (for dynamic swing peaks). Based on Stereophile measurement of XA30.5, the clipping (THD 0.1%) happens at ~200 class A/B watts into 4 ohm.

In terms of current, XA30.5 has double the bias current than that of Pass X150.5 (150wpc class A/B rated), which, in its own right, is not a slouch.

But I think it's more than 3-4 db benefit by going up to XA60.5 mono blocks. One being, obvious separate power supply. Secondly if I remember correctly, from Nelson Pass's "leaving class A" article on Pass website, XA60.5 has more bias current than XA30.5, almost 3 times the bias current of X150.5.
I had the X250.5 amp on the C1s and they LOVED the power. I would not even attempt a XA30.5.

Wonderful speakers that need high current.
Hi Kzhtoo,

Congratulation for your new speakers! I have seen that you have also posted a
message on "my" Focal Micro Be vs. Dyn C1 review thread. Sorry,
for the late reply, I too have bought new speakers (Avantgarde UNO) and was
busy setting them up :).

IMO there is no reason you should doubt your current amp. Watt ratings can
be very deceiving, e.g. both me and Xti have reported cases where "small"
quality amps (like yours) have put to shame power horses like Bryston when
driving the C1s.

Keep us posted!
Hi Keithr,
I already have the XA30.5 and C1 Sigs are on the way as well. I shall find out soon enough. If X250.5 is indeed more "suitable", there's always Reno Hifi to move "up". :) But looking at the numbers from Nelson's Leaving Class A article, XA30.5 seems to have higher bias current and higher class A peak - 1.3 vs. 0.8 and 57 vs. 20. I'll make sure to report back how XA30.5 drives the C1 Sigs in my big room.

Hi Paul,
Good to hear from you again. To be honest, it is your review of C1s that made me start looking at them. It has been awhile when I first stumbled upon that review, but Xti just reminded me the other day to read it back again, which I did and gave me a whole new perspective.
I used to have Bryston 4BSST2 but XA30.5 is just at another level entirely in terms of refinement and seduction. I didn't get to test them out driving difficult loads however, as my old Electra 1008 Be2s were quite efficient. Both amps drove them with ease.

Since the Dyno's are a 4 ohm load it is important to find a mating amplifier with plenty of current capability. It is not really about the so called amplifier 'power' because that does not tell you much about the amps ability to drive current into low impedances.
Interesting thread as I decided to go with a similar combination.I recently heard the Pass XA 30.5 with the Dynaudio Anniversary 25, which have similar specs to C1s and C2s. They sounded wonderful together. The Pass easily handled the Dynaudios even at loud listening levels. I was so taken by the combination that I ordered the XA 30.5 on the spot to run my Dynaudio Confidence C2 IIs. The dealer assured me the XA 30.5 would be sufficient. I had come into the store inquiring about the X350.5, which is more expensive, but the dealer suggested I give the XA 30.5 a listen first. He obviously could have sold me either. Pass is shipping the amp next week, so I will be able to assess in my own room with the C2s soon, but based on what I heard, I am optimistic that the XA30.5 will be able to handle the Dynaudios.
I have XA30.5 and Dyn Special25 (88db/4ohms)
Wonderful combo!
No problems with lack of power. The needle on the pass never bounces.
Let me get this straight. You guys are saying a 30 watt amp is driving C-1's to a loud volume? I find that hard to believe. I'm driving C-1's with a 90lb 100 watt tube amp and I feel I don't have enough power.
Hi Pnmeyer,
Keep it posted how it goes. C2 II and XA30.5? I thought I was optimistic. But I guess it depends heavily on the size of the room. With C2 II though I don't suppose your room is remotely close to small at all.

How big is your room?
Not yet for me. But I will pretty soon.
I had no problem with volume on my aleph 3 + Confidence 3 combo -- just a sharp drop off in bass response below 100hz. This was a problem in 3 different listening rooms of different dimensions from small to large in three different houses. The problem may have been the speakers, may have been some bass-dampening phenomenon common to each room -- or it may have been an under-powered amp.

The sound I did get was astonishingly beautiful, though.
Hi Rr999,
Does Aleph 3 go into A/B mode after it goes out of class A? My understanding is Pass only starts doing that with their XA.5 series. This should help in dynamic swings and maybe able to explain your 100Hz roll-off? I could be wrong.

Hi. There is some debate about the pass xa30.5 driving speakers to a high levels. I have used this amp since its launch and prior to this a X350 power amp which claims some 350 watts output power. What i can say is that both provided lots of power at usable levels. Certainly more than enough volume. Im talking about volumes that are comfortable but loud, not ear damaging loudness thats no use in normal domestic settings. However I do recall the 350 having a touch more slam but not quite the extreme clarity of the newer but weaker model.
C1 Sigs have arrived. XA30.5 has absolutely no problem driving the Sigs in my 18x25 room. My normal listening level is 75-80db average SPL with peak of 85-90db at the sweet spot (I listen with lower level at night). Meter doesn't move from 11:30 position even for bass heavy materials. I tried to push a bit harder and it seems I have a good 8-9 db headroom above my normal listening level before the Pass needle starts to move to the right side (leaving class A). And that is at very loud level and I'd never listen at this level for extended period of time.

I set the speakers on the short wall with 8 feet between them. 2 feet from the back wall and sweet spot is 9 feet away from both speakers. The music has great slam and dynamic swings are handled pretty well.
I have that exact combo in my den. It's great at lower levels but when you turn it up you can some of the dynamic range go away imho. Then again I have tinnitus so what do I know, lol
Hi Acropora,
Interesting. Would you care to elaborate "some of dynamic range go away"? As far as I can tell, at my normal listening level, it is not missing much in big dynamic swings, if any.

I guess the easiest way to find out is getting another Pass amp like X250.5 (as suggested above by Keithr) and do an A/B. But I'm not sure if I need to do it. The amp needle doesn't move.

I received my Pass XA 30.5 a couple of days ago, which I am using to power Dynaudio Confidence 2 II speakers. No trouble driving my Dynaudios at reasonably loud listening levels (just before it becomes uncomfortable). No trouble with bass. The meter stays at 12 position (in a couple of instances, just over). I have an open floor plan. No problems with sound levels. I mostly listen to Jazz, pop and rock. Don't know how it would handle symphonic music. I replaced Class D amps that were rated 575 watts per channel, doubling output into 4 ohms. I don't feel I am missing anything power wise and the Pass sounds so much more lush and involving than my prior amps right out of the box.
Pnmeyer, thanks for sharing. Hope you're enjoying your C2s. I'm sure they sound as good as they look. My room should be great for C2s but I can't swing it right now, plus I prefer audio gears that can be moved by one person.
Kzhtoo - C2's aren't that heavy. When I had an in home demo I moved them around. About twice the weight of C1's and stands.
Xti, you know what I'd wish? A medium size between C1 and C2. Something like C1 + a bass driver from C4. :p
half of c4:) actually that is what dyn manufacturing for studios, like "air 20"
Me personally I think I would like to have a dyn speaker with the mids and highs of the C1's but the bass slam of the sapphires. Although that may not be a real balanced sound it could very well be interesting.