solderdude
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Post by solderdude on Jul 9, 2013 5:03:45 GMT
The funny thing is the Ember (and it's cousins) all measure FLAT there is no rolling off in the audible extremes. Depends on the tube as well though. Some tubes are rolled off. Does this mean it cannot give the 'impression' of skewed sound ? No... it can and with good reason. In the Ember design (and alikes) the voltage gain stage is a tube without any feedback. So the FR but above all distortion depends on the properties of the tube and is NOT reduced by feedback as is done in 99% of all solid state designs and in a lot of tube amp designs with multiple tubes (and output transformers). A property of a tube is to generate more (higher level and higher frequencies) harmonics the bigger the input signal is. When playing softly the THD is very low and can reach levels of 0.001%. When you start to play louder distortion increases due to non-linear behaviour of the tube (the curved lines you see in the datasheets) Distortion is relative. Only a few harmonics being added is not heard as distortion as natural sounds also have harmonics with a type of time decay. tubes don't have a time decay and thus the harmonics are either masked by the original signal (which also contains harmonics) or they are added but sound 'natural' to us mortals. So it is the KIND of distortion that matters. I added some info on this HERE As the bass usually has the highest amplitudes the 'distortion' will be highest there and more harmonics will be present. Above 0.1% these will be audible. Since the bass is higher in amplitude it affects the bass the most and highs are small in amplitude and are 'unaffected' and thus sound nice. The added harmonics are sounding very natural and make the sound richer. At full power (1.8W) the distortion reaches 2%. Purists will laugh out loud and tell you there should be no distortion and perhaps ridicule ones odd listening habits. There shouldn't be distortion for them of any kind, but just like with vinyl .... if you LIKE that distortion and enhances your listening experience (like tone control or proper compression can do) I can't say someone is stupid for liking it. But YES the sound is different, altered, but in a nice way. This can be easily made audible with my beloved null-test by the way. The result (the actual harmonics) 'sound' strange when you listen to them separately but when COMBINED with the original signal do not. So in the end. Yes, the harmonics are added and is not very purist but if it sounds nice who cares what others say. For Solid state, as the spread of harmonics differs, high THD values are not wanted at all as THESE added harmonics are different (see article HERE.) You want the harmonics below 0.01% otherwise they become audible. When playing really loud you could want it below 0.001%. do NOTE that distortion of transducers (speakers/headphones) is HIGHER than those of amps but have a different 'spread' in frequencies and can have a time decay (ringing) which will mask harmonics generated by the ENTIRE chain (from microphone to speaker wire). |
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solderdude
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Post by solderdude on Jul 9, 2013 9:04:04 GMT
Both should sound more tubey than MF or SS.
The differences between Horizon and Ember should be small but there are differences in the kind of distortion that is added by the (2 component) output stage of SR/Horizon and the op-amp output stage of the Ember which has local feedback.
The op-amp (Ember) should perform better in the added harmonics department as far as the output stage concerns.
The total distortion is thus caused by the tube (by far the most and most pleasant) and in a lesser but not irrelevant amount, by the output stage.
In the measurements I have done the Ember output stage adds nothing so only the tube 'creates' the harmonics.
In case of the Horizon distortion of the output stage is slightly higher than that of the Ember output stage.
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Rabbit
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Post by Rabbit on Jul 9, 2013 10:38:00 GMT
Both should sound more tubey than MF or SS. In the measurements I have done the Ember output stage adds nothing so only the tube 'creates' the harmonics. In case of the Horizon distortion of the output stage is slightly higher than that of the Ember output stage. Yes, I have compared with MF V2 and it does sound more 'rounded', Frans. Perhaps tube rolling has a slightly greater effect as well on the Ember? I must admit, I am chuffed with this 'orange' one I stuck in. Also not needing adjustments gives you much more confidence to experiment with tubes. The 'orange' has introduced a tubey 'beef' sound I think!! It's a very luxurious sound. Perhaps the slightly lower distortion of the output stage in the Ember is what I'm detecting? (Although at the moment, I'm taking something called diazepam which is making me feel slightly weird at certain times of the day!!!) I really do like the sound of the Ember though. It is similar to the Horizon, as you say but since I'm disconnecting the power supply in order to use the other, my memory might be playing tricks. I just feel that it's a fraction less 'tubey' for some reason, although changing the tube has had a larger effect on its sound than I expected as well. The HD650 really blooms with it as well. I often find the raised bass and a 'thickness' somewhere in the lower treble a bit annoying, but it sounds really pleasant from the Ember. So that's two hits for me - the T40 and HD650. However, don't forget I'm on diazepam so it could be my head!!  |
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Crispy
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Madrigal music is playing - Voices can faintly be heard, "Please leave this patient undisturbed."
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Post by Crispy on Jul 10, 2013 16:35:17 GMT
Thank you very much for noticing the attention to detail, my OCD is quite bad when building. The amp you received is 100% to the quality standard of all units that get shipped out. Enjoy and looking forward to reading about your opinions when you get more time to listen! Jeremy, I am the same I just have to check things over and over again until I am 100% sure I am satisfied and I still miss things. So browsing through the manual again trying to find out about the Input cap by-pass jumper and the input gain jumpers I noticed another slight error in the manual. Page 14 - Adjusting the input gain "The default setting is Low Gain" you have this quoted twice. I had a little listen as a pre-amp today and I am not going to say nothing as I am busy listening and taking notes, then later I will give you a review. One more observation today while looking at the amp on my HiFi table I thought it looked like a miniature Taj Mahal and built to the same standards.    |
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Post by jhelms on Jul 10, 2013 16:44:44 GMT
Opps! Guess I really wanted to get the point across that the default is low gain  Will correct asap in the next manual revision. |
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Deleted
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Post by Deleted on Jul 10, 2013 22:28:04 GMT
I think there were a few Pandas with the same thing. It could be mine was faulty but it was too big to shunt back and forth to Scotland. It did the journey twice. I moved on. S2 is a good 'UN but if you're happy with the Panda, then stick with it, Simon. It doesn't't cost much to try the Ember and then you could do a direct comparison. I'm certain the Ember would hold up against it. Just a question of whether you like a tube sound imo. i do indeed enjoy the tube sound. i had an mf xcanv1 and v2 with x-10d for a length of time. when i bought the panda, from Mike, it just seemed to give everything much more body and oomph compared to the x series gear. i think i read that the ember is similar in design to the mf xcan v2 but with more power? i have just got my new headphones, Javier is working on a correction filter for me. if i was to trial an alternative amp, all in a short period of time, it may just confuse my brain! but it would also be a shame to miss out on trialling the ember while it's here! i cant win really, or lose for that matter  |
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solderdude
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Post by solderdude on Jul 11, 2013 5:10:45 GMT
I have been told the Ember drives HE-6 pretty loud and quite well.
And yes it could be used as a buffer... but a buffer with a volume control.
So more like a pre-amp with no input selector (Jeremy is thinking of that now as well)
So in between a CDP and Panda for instance.
After Chris it is going to Mick, Simon could be next.
If there are no more takers after that it will be off to the Vikings as well.
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Rabbit
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Post by Rabbit on Jul 11, 2013 7:31:01 GMT
It wouldn't hurt to have a listen, Simon if you like the tube type of sound. The Ember is more tube like than the X-Can though.
If you've heard any of the Bravo types, it is more similar in timbre to those, I'd say but a whole lot better in all respects.
I liked the Indeed. (More than the others actually) However, it was the timbre I really enjoyed and had never realised the problems until Frans pointed one out dramatically - crosstalk was appalling at high volumes. Then the noise levels, then the oversensitive pot and finally, the final insult was the heat build up. It cooked itself to an early death.
The Ember has this luxurious tube sound with plenty of detail and real power. The configuration means that you can tinker around with a few things to make it more suited to what you want. There is NO heat build up. (That's a biggie for me since I blew up a Little Dot and fried about 4 Bravo types) It runs perfectly cool.
However, it just sounds rich and detailed. You don't get the same richness from the X-Cans. In fact, I did a lot of valve changes in order to 'up' the richness on all of them. The difficult one was the V8 which Mike did an enormous amount of work on in order to get what I was after. He knew what I was looking for and in the end, he did get it to sound more like what I thought a tube sound should be.
The Ember is a glorious, detailed tube sound. Fran's sign off on his posts shows that he means it .... 'use your EARS to enjoy music ..... not as an analyser'. (He uses American!!) The evidence is in what I hear from the Ember. It is a really good little amp and it's a lot smaller than the enclosures used for the Panda.
My guess is that you will instantly like it if you like tubes.
BTW - my gold knob wheeze is basically to give the volume control more sensitivity since it's bigger than the one on the version that you have coming if you have a listen. (It's also a lot more flashy looking and I'm quite chuffed with the Ember)
It's worth a go.
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solderdude
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Post by solderdude on Jul 11, 2013 7:47:17 GMT
 This is a plot from Nixiekits and it shows the distortion in the cheap indeed/bravo designs that occurs above a certain output voltage. The sudden 'knee' where the distortion increases, this is caused by the LM317 being 'switched off' in the Indeed thingies because the heater is in the audio path as well. This is what the TSR mod prevents. It doesn't show the crosstalk as that only occurs with stereo signals in the 'not measured' channel. When an Indeed is modded with the TSR it will also perform like the Nixie amp. Needless to say all the Garage 1217 amps all do NOT have these problems and the 'distortion' is many times lower as well. Just enough to give it that 'full' natural twist in it's sound. |
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Rabbit
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Post by Rabbit on Jul 11, 2013 16:21:06 GMT
A bit more playing with valves today on the Ember. (Well, I have plenty of time on my hands at the moment - I'm quite enjoying being ill now!!)
The beauty of no setup procedures for the Ember and the tube makes it possible to just go in there and swap the tube, so I did.
I heard an immediate difference as a result. I just paused the track on a point where textures etc stayed the same and quickly rolled away to another tube.
This time the Mullard E88CC, vintage 1964.
Again .... super sounding. The orange Amperex (1965) is immediately impressive. It has a big bass but something I noticed when swapping for the Mullard was that the mids became more obvious with the Mullard.
It's funny because when I was younger, I kind of took Mullard tubes for granted. (I used to repair peoples' TV's (black and white) in the days of valves and I kept a whole batch of Mullards for that purpose) I thought they were cheap and worked well with no troubles. In fact, I had an old radio that went forever with a Mullard in it. So my impression of Mullards has always been biased I guess by the fact that I have taken them for granted.
In an audio application, they seem a little more 'balanced' than the Amperex that has a 'loudness' button effect on what you hear by comparison.
The problem is - I like both a lot. I'd say the Amperex is a real rocker and the Mullard is more transparent.
What I have found really surprising is that on the Ember, the effect of the valve is instantly heard and plain as daylight, You can really get a timbre that you like via the valve route. There is a strong correlation between valve and the perceived sound in the headphone.
This is SUCH a fun amp. It'll have you buying valves just out of curiosity. I'm lucky in that I have about 20 here but still wonder about others.
Frans, is there any mileage in running 12v tubes or no real sonic benefits?
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Deleted
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Post by Deleted on Jul 11, 2013 20:07:59 GMT
I have been told the Ember drives HE-6 pretty loud and quite well. And yes it could be used as a buffer... but a buffer with a volume control. So more like a pre-amp with no input selector (Jeremy is thinking of that now as well) So in between a CDP and Panda for instance. After Chris it is going to Mick, Simon could be next. If there are no more takers after that it will be off to the Vikings as well. Frans i would love to give the ember a listen, especially as it can be used as a tube buffer. what confused me, was that i was informed that the MF X-cans (1&2)' "line-outs" could NOT be used as a tube buffer. i just assumed the same for the ember. BTW, my D7000 are already for the chop. as soon as i can work out an asking price, i will sell them. i just cant get the LCD-2 off my head, and thats before i try your filter and the ember. cant justify keeping a 2nd expensive headphone unused. good news ,for my wallet, is that the denon's should easily bring in enough funds to purchase the ember. then i may experiment with a different dac , as in the JK cuinas. i will of course, spread all this out over the coming months. if the cuinas suits me, i can then sell the stagedac & hiface2 to offset the cost again. so the overall outlay will not be toooooooo bad , in the end. so many options  |
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BMF
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Post by BMF on Jul 11, 2013 23:01:39 GMT
Hello Guys, I have the privilege of owning Project Ember, Serial No. 0000. I've been listening to a wide variety of headphones paired with Ember and I am impressed. Frans and Jeremy knocked it outta the park with this amp! I love the build quality and the automatic tube settings for voltage and bias. Then, there are all the tweaks available that sweeten the pot. I've tried a variety of tubes and settled on my favorite which is NOS/NIB Telefunken E88CC (Ulm factory codes). I've listened to the following headphones paired with this audio chain: MacBook Pro with Lossless Files --> glass Toslink or USB --> Dacmini DAC section --> RCA interconnects --> 'phones Fostex (Current Production Modified by me): T20RP mk2 T40RP mk2 T50RP KODA Re-built, Repaired, new Transplanted drivers, and Re-modified by me; posted in head-fi Orthodynamic Roundup thread at this link: www.head-fi.org/t/111193/orthodynamic-roundup/21810Mad Dogs v3.2 with Alpha Pads Vintage (Modified by me): Fostex T10 Fostex T20v2 TDS-7 TDS-5M NAD RP-18 (Mylar version) Yamaha YH-100 Yamaha HP-1 TDS-15 Transplanted into a Takstar HI-2050 "Foster Fone" and modified by me; posted in head-fi Orthodynamic Roundup thread at this link: www.head-fi.org/t/111193/orthodynamic-roundup/21765Vintage (All Stock): Wharfdale ID1 NAD RP-18 (Kapton version) Sansui SS-100 Fostex T50v1 Yamaha HP-1 Yamaha YH-100 Yamaha YH-2 Yamaha YH-1000 Vintage (Modified by others): Wharfdale ID1 Transplanted Yamaha YH-100 transplanted Current Production (All Stock): LCD2 v1 HiFi Man HE-6 Sennheiser HD-800 I'm not big into subjective audiophile descriptive terms because they have no a priori operational definitions. What I can say with certainty is that Ember sounds wonderful with all these headphones. Ember drives them all without breaking a sweat. Even the insensitive HE-6 sounds fantastic with Ember. With the jumpers set to Low Resistance and Low Input Gain, Ember easily drives HE-6 with the volume pot set to 12 o'clock delivering ~95 dB with a lot of headroom to spare. Setting the jumpers to Medium Resistance and the volume pot at 2 o'clock or High Resistance with the volume pot set to Full, Ember delivers equivalent SPL without clipping. For comparison, my LCD2 produces the same SPL with the volume pot set to 9 o'clock. In my opinion, HE-6 Rules and trumps my LCD2 with a bit more treble detail whereas my LCD2 edges out HE-6 in the sub-bass range. HE-6 sounds better than the HD-800 in terms of bass extension and its silky smooth ortho midrange whereas the HD-800 sounds more precise (?). All three of the current production headphones beat the rare, highly sought after vintage phones, even YH-1000, particularly in the treble range. Of course, this is All in my opinion using my "ears and gears." HE-6 sounds, quite simply, Amazing driven by Ember. The bass is fast, Deep, and musical without Boomy Bass Bloat - the bass does not color or veil the midrange, nor does it stifle the treble frequencies. The midrange is super smooth, lush, and crystal clear. I love female vocals and acoustic jazz with this combo. The treble range is incredibly detailed with air to spare...and shimmer free of fatigue, shrill, and sibilance. There is no grain. The background is Black. The soundstage is wide but not quite as wide as HD-800. Imaging/instrument and vocal placement is wonderful. The HE-6 (with Black Dragon 3-pin to 1/4" TRS adapter and A Pure Sound 3-pin XLR cables) even beats Sennheiser HD-800 (with Stefan AudioArts VOICE hardwired cable that costs as much as the HD-800), in my opinion. For the unbelievably low price of Ember with it's clean sound, extra power, automatic settings and feature set, buying one is a no brainer. |
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Rabbit
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Post by Rabbit on Jul 12, 2013 15:12:56 GMT
There are a few 0000 going around!! I have one and so does Chris at the moment. Mine's a prototype, but I am now using it all the time. The tube rolling is so easy as well so you can easily compare tubes within seconds really.
At the moment, I'm using a Mullard E88CC 1964. It has perhaps stronger mids than the Ameperex ornage globe I was using before it; although I liked that as well!! Can't decide really.
I wonder whether there are any advantages using 12v or 6v tubes or whether it doesn't really matter.
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BMF
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Post by BMF on Jul 12, 2013 15:39:49 GMT
There are a few 0000 going around!! I have one and so does Chris at the moment. Mine's a prototype, but I am now using it all the time. The tube rolling is so easy as well so you can easily compare tubes within seconds really. At the moment, I'm using a Mullard E88CC 1964. It has perhaps stronger mids than the Ameperex ornage globe I was using before it; although I liked that as well!! Can't decide really. I wonder whether there are any advantages using 12v or 6v tubes or whether it doesn't really matter. LOL! Serial Numbers 0000, 0000-1, 0000-2, etc. Mine came from Jeremy so I suppose I have J-0000 and you guys across the pond have F-0000  I've got more tubes than I know what to do with. I like them all with their different flavors but like Telefunken E88CC the most. I've read on the Sunrise II and Horizon head-fi thread that some people think the 12 volt tubes generally sound better except for a few 6 volt exceptions. |
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Rabbit
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Post by Rabbit on Jul 12, 2013 15:48:46 GMT
I think Chris has J-0000 and I have an F-0000. Chris got his 'touring' one in a posh suitcase as well!!
Mine has a silver board and it's staying here!
Perhaps I'll have a look around for some 12v tubes. It's so easy to change them in any case.
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Will correct asap in the next manual revision.
