That is good to know, I do kind of follow (from a distance) your endeavours in the DAC department though
.As soon as that goes multi channel....
Due to room constraints I don't see myself go without the added ambience. That would only work if there is plenty of room to set it up passively.
I've read pretty much everything Geddes ever wrote on this forum, as it was a good part of my learning process. But I'd have to disagree. He wasn't the only one to state this either, so for the longest time I did believe in that.
In fact the visit from koldby/BYRTT was the event that changed that. Koldby had stated as much and I was just as sceptical as you are now. He did prove his point!
In a way, as soon as the world gets rid of this virus that holds us all, I'd say we would need to organise more visits like what I've been fortunate enough to experience.
You need to hear it for yourself to believe it. Don't take my words for granted. But I still stand by my original view is that whatever you have now, you can improve on it by working on it and continue to improve upon those results. Don't give up on what you have, don't just swap out components etc. Make what you have behave better with simple means.
That has brought me a lot of joy as well as progress. Even though I've had to back peddle more than once. I'm still learning...
Improving what you have right now without the upgrade bug has helped me reach what I think is a pretty good level.
It is good enough to give me a lot of pleasure. Right now I'm sort of in a in-between phase, waiting for components I need to add to get back to a level I was at before.
But I could change everything, like getting that new DAC, but what would I learn from that? I still need to maximise what I've got right now before thinking of upgrading again.
Only then will i be ready for the next step.
That's why I did the cheap experiment with the JDS Atom amp. Once I have that step covered I'd expect to be working on my system for quite a while to get the best I can out of it.
Even the DSP I use isn't a concept I can lock up and call done. But I did learn a lot to be able to play with the stage I experience, being able to mold it to my liking. It just takes a long long time to do so. Babysteps and mistakes are eminent. But more often than not, the equipment isn't to blame if it isn't working. Nor is it the music I play back.
If it doesn't sound great, I've done something wrong. The potential is there.
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The Alpha Nirvana is designed by Hugh (AKSA), he is also one of the designers of the Fetzilla
Yes, I'm aware of the works of Hugh.
But I'd say the Goldmund is in a different league when compared to the Fetzilla. Even Hugh will have a few different designs he would put above the Fetzilla.
The Goldmund, probably helped out by it's sheer output potential, is a more complete solution from top to bottom.
The Fetzilla has a sweetness in the midrange which made me assume it would be perfect for ambience duties.
There's a Goldmund inspired amp project on it's way right now, but personally I don't like all the choices they are making as to me it deviates too much from Goldmund goals or visions for my taste. If I'm right it's sort of a continuation or a quest to improve upon an earlier Goldmund project. That project was based on an older Goldmund Mimesis amplifier. The Telos line-up could be considered a step up the ladder from that.
But I'd say the Goldmund is in a different league when compared to the Fetzilla. Even Hugh will have a few different designs he would put above the Fetzilla.
The Goldmund, probably helped out by it's sheer output potential, is a more complete solution from top to bottom.
The Fetzilla has a sweetness in the midrange which made me assume it would be perfect for ambience duties.
There's a Goldmund inspired amp project on it's way right now, but personally I don't like all the choices they are making as to me it deviates too much from Goldmund goals or visions for my taste. If I'm right it's sort of a continuation or a quest to improve upon an earlier Goldmund project. That project was based on an older Goldmund Mimesis amplifier. The Telos line-up could be considered a step up the ladder from that.
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The Nirvana is one of them
I have now the predecessor Alpha20 as my main amplifier,
soon to be upgraded to the Nirvana.
The best amplifier I heard until now on my speakers is the FirstWatt Sony VFET,
but too bad that the transistors used are unobtainable.
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I can't promise you'll get what you need but I can point you in the right direction. I'll PM you.
Yes but it is quite different from the Fetzilla. It was not Hugh that came up with the design ideas that is the basis of the Fetzilla, but he helped. One of the big differences between Fetzilla(and Goldmund) vs Pass constructions are that Pass uses D-type Mosfets where as Fetzilla (and Goldmund ) uses S-types. Even though Fetzilla and Goldmund are designed very differently, they are sounding much like each other, and far from the sound of the Pass constructions.
I designed the schematics of the Bow Technologies ZZ-1 with the same S-type mosfet and it also has the same character as the Fetzilla and the Goldmund.
These are of course all subjective observations, but it is the ears that will tell you what suits you best, not measuring instruments. Unfortunately there is a quite wide gab between what we hear and what we measure in amplifiers and we are having a hard time making correlations between the measurements (however sophisticated) and what our ear/brain are telling us. It would be very nice if there was a 1 to 1 correlation, but that is far cry from the situation.
Do I come across as a skeptic? I'm more an agnostic. I sometimes attempt to express irony in my posts which may not come across the internet. I am open to being convinced. I haven't had the knock me off my horse experience that you have had but I have experiences that hint at it.
Part of that non-skepticism comes from knowing how unperceptive I am of harmonic distortion. I took a test once and was up into single digit percentage distortion before I could pick it out.
Perhaps I am also a monist. That was where I was until I was introduced to Heisenberg. Its the same position you take in your signature. But I also believe in engineering - the reduction to practice has to be as good as the theory is correct.
I know that good measurements are necessary but not sufficient. But when I experience a good measurement that doesn't sound quite right I wonder what did I fail to measure or overlook in design and analysis. Are my assumptions valid?
It was interesting to compare certain aspects of new Purifi amp module, Ncore, and Goldmund, which per thread you linked appears to be old school class AB.
The first thing I noticed was Purifi amp had voltage gain of only 12.8 db vs typical 26 db for pro amps. That means one would need a pro audio style DAC to drive it directly, allowing one to take full advantage of the DACs dynamic range but OTOH easily compensated with an attenuator in front of higher gain amp. I wouldn't be surprised to find that less gain in the forward path of the amp is one of the things that allows a higher degree of feedback.
The other big thing is the Goldmund retained its low THD performance all the way up to its power limit whereas the Purifi is rated at 1% THD. You need to be well below its rating to enjoy its vanishingly low distortion - but that is where we usually are with our relatively high efficiency speakers. Cross a threshold and distortion rises dramatically.
The Goldmund no doubt has a really robust power supply whereas the class D designs typically allow load regulation (voltage drops under load to occur) to increase the peak power capability without a corresponding increase in cost.
I can imagine that load regulation appearing on the outputs reduced by the power supply rejection ratio.
If I were to look for the difference in perceived sound quality between these two style amps, these two things are where I would look.
But what the Purifi does offer is very high loop bandwidth. Higher bandwidth means lower phase shift and lower phase shift allows a higher degree of feedback. Each extra db of feedback is another db that the distortion is pushed down. Purifi touts this on their data sheet. But Bruno in his previous position wrote a whitepaper warning against using feedback to mask nonlinearities in the forward signal path. I don't think he is doing that here but I question those who perceive the lack of feedback as an advantage. Its good not to need it but better to not need it and use some anyway.
Part of that non-skepticism comes from knowing how unperceptive I am of harmonic distortion. I took a test once and was up into single digit percentage distortion before I could pick it out.
Perhaps I am also a monist. That was where I was until I was introduced to Heisenberg. Its the same position you take in your signature. But I also believe in engineering - the reduction to practice has to be as good as the theory is correct.
I know that good measurements are necessary but not sufficient. But when I experience a good measurement that doesn't sound quite right I wonder what did I fail to measure or overlook in design and analysis. Are my assumptions valid?
It was interesting to compare certain aspects of new Purifi amp module, Ncore, and Goldmund, which per thread you linked appears to be old school class AB.
The first thing I noticed was Purifi amp had voltage gain of only 12.8 db vs typical 26 db for pro amps. That means one would need a pro audio style DAC to drive it directly, allowing one to take full advantage of the DACs dynamic range but OTOH easily compensated with an attenuator in front of higher gain amp. I wouldn't be surprised to find that less gain in the forward path of the amp is one of the things that allows a higher degree of feedback.
The other big thing is the Goldmund retained its low THD performance all the way up to its power limit whereas the Purifi is rated at 1% THD. You need to be well below its rating to enjoy its vanishingly low distortion - but that is where we usually are with our relatively high efficiency speakers. Cross a threshold and distortion rises dramatically.
The Goldmund no doubt has a really robust power supply whereas the class D designs typically allow load regulation (voltage drops under load to occur) to increase the peak power capability without a corresponding increase in cost.
I can imagine that load regulation appearing on the outputs reduced by the power supply rejection ratio.
If I were to look for the difference in perceived sound quality between these two style amps, these two things are where I would look.
But what the Purifi does offer is very high loop bandwidth. Higher bandwidth means lower phase shift and lower phase shift allows a higher degree of feedback. Each extra db of feedback is another db that the distortion is pushed down. Purifi touts this on their data sheet. But Bruno in his previous position wrote a whitepaper warning against using feedback to mask nonlinearities in the forward signal path. I don't think he is doing that here but I question those who perceive the lack of feedback as an advantage. Its good not to need it but better to not need it and use some anyway.
I dont think this is the case. I made an UCD 700 with a really massive PS (and also made one (on demand) with battery powered (!) and this was best) but it always kept its sonic signature even though you could make other things better (focus , 3-d soundscape , dynamics)
Goldmund certainly is old school class AB. They've been playing with this schematic for 30 years. Slowly trying to improve upon it over the years. At least that is what they sell to us.
All I know is that whatever they did, sounds very good to me, see koldby's post.
It just matches very well with my speaker/room setup, at least to my ears and taste.
The list on the Purify firm's employees/owners is impressive. It will be hard to know how it sounds though, without being able to try it in the comforts of your own home.
Upon request Tom even designed a slightly different variant of the Universal Buffer to use with that amp: Purifi 1ET400A / Hypex NC500 Input Buffer – Neurochrome
I'm signing off now as I have limited time to listen to some tunes...
All I know is that whatever they did, sounds very good to me, see koldby's post.
It just matches very well with my speaker/room setup, at least to my ears and taste.
The list on the Purify firm's employees/owners is impressive. It will be hard to know how it sounds though, without being able to try it in the comforts of your own home.
Upon request Tom even designed a slightly different variant of the Universal Buffer to use with that amp: Purifi 1ET400A / Hypex NC500 Input Buffer – Neurochrome
I'm signing off now as I have limited time to listen to some tunes...
I tend to agree with you here. But not always.. Have you ever tried to put feedback into a well behaving non-feedback construction? Of course you have to make sure it is stable. More often than not you loose more than you gain by doing that. The problem is of course, that you have to have an amplifier with very high gain in order to get the advantages of feedback and such an amplifier would be a pain in your royal a** to use without feedback so you cannot do the same sonic check.
I don't know what the load regulation of a battery but I know it doesn't have any self switching noise on its output, nor any that increases under load like an SMPS. Power supply noise also feeds through to the output reduced by PSRR.
Load regulation from a low frequency tone would be a source of IMD. Whether these account for subjective preference I can't say.
PSRR is by definition the transfer function from power supply output to audio output. UCD has 65 db PSRR; Purifi has 90 db!
That is something I never did nor was asked to do professionally because that isn't the world I worked in. I only dabble from time to time and look over people's shoulders out of interest.
I question doing anything to something already well behaved. Better to do design from the start.
I think its quite difficult to master nonlinear control, especially with a high level of feedback. That difficulty is where pain comes from, why we ask "are we having fun yet", but the rewards are proportional to the difficulty, even if only intellectual satisfaction. My hypothesis was that the high bandwidth enabled the high level of feedback with stability, likely reducing the pain but hopefully not the rewards.
... I needed that! 2.5 Hours of listening fun! I haven't had that in weeks...I've listened to a strange variety of music and really enjoyed it.
Playing some Jethro Tull, the album Thick as a Brick really got me into it.
Manasas - Witching Hour also sets a strong mood.
Donna Summer - I Feel Love is just crazy...
The effects used in Roger Waters - Amused to Death are still shockingly good
Loved the mood/space in Fleetwood Mack - Gold Dust Woman
And John Barry's Goldfinger really is a masterpiece. At least in my mind. (Love Dame Shirley Bassey's voice)
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John Barry was a genius! The other on the list are not that bad too
Giorgio Moroder know how to do it! German were good with electro and synth. Made my older son first listening to Kraftwerk's 'radioactivity' yesterday: 'is this robot's music daddy?' Yes my son those are robots ( still looking the same after 50years... they must be robots!). ;D
Giorgio Moroder know how to do it! German were good with electro and synth. Made my older son first listening to Kraftwerk's 'radioactivity' yesterday: 'is this robot's music daddy?' Yes my son those are robots ( still looking the same after 50years... they must be robots!). ;D
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I couldn't agree more with this post. I have a four channel UcD400 amp with a massive trafo and filtering. It is superb and is probably the second best amp in my collection. But when it comes to the best, the honor goes to the M2. With the UcD, the individual location of an instrument, in a symphony, for example, is less stable than the M2. With the M2, it is all very stable and the resonances of individual instruments, i.e., the sounds that make the instrument unique, all ring out with clarity. These are very minor differences but I can hear them. It is a bit disappointing from a scientific perspective that we are not able to objectively quantify these differences through measurements. They are both good amps but the M2 provides greater enjoyment.
Hi Gassit,
Yes, it did work out as planned. The mayor difference is I can now play Home Theatre without worries, it really is a lot of fun for that.
But I also have an advantage in Stereo replay. I don't use a crossover on the arrays, instead I use a low shelf set at 160 Hz to shave off a lot of boost EQ that was used below that point. The subs do have a low pass crossover set at the same 160 Hz number (linear phase) and another steeper slope at 700 Hz (also linear phase). The arrays only contribute a small piece to the low frequencies, but together with the sub I could get a better balance between the left and right channel all the way down.
Whereas before I had the left array channel support the right array at ~30 Hz while the right array helped out the left at a nul at ~70 Hz to create a good stereo sum.
Bass remains tight and impressive. Now I can play a song like 'A Perfect Circle - Lullaby' full force without worries. I expected to hear a boost in dynamics and clarity due to the arrays being relieved from playing the low frequencies as loud as before. The difference wasn't as big as I had hoped for. That led to an experiment using a pré-amp on the array channels. That change did bring back the dynamic sound and clarity I had experienced before.
Where one can up the volume without it being obvious it is much louder. Until you try to talk to each other...
Plans are to get a 6 channel pré-amp. To be able to reduce the overall digital level a bit, creating more headroom there. Planning to use 3x the Universal Buffers from tomchr with a fixed gain as a pré-amp. Reducing the digital gain with the same amount. Lots of other solutions were discussed in between, using a Pro-DAC etc. but I want to keep what I have right now, one change at a time.
It never ends.
Yes, it did work out as planned. The mayor difference is I can now play Home Theatre without worries, it really is a lot of fun for that.
But I also have an advantage in Stereo replay. I don't use a crossover on the arrays, instead I use a low shelf set at 160 Hz to shave off a lot of boost EQ that was used below that point. The subs do have a low pass crossover set at the same 160 Hz number (linear phase) and another steeper slope at 700 Hz (also linear phase). The arrays only contribute a small piece to the low frequencies, but together with the sub I could get a better balance between the left and right channel all the way down.
Whereas before I had the left array channel support the right array at ~30 Hz while the right array helped out the left at a nul at ~70 Hz to create a good stereo sum.
Bass remains tight and impressive. Now I can play a song like 'A Perfect Circle - Lullaby' full force without worries. I expected to hear a boost in dynamics and clarity due to the arrays being relieved from playing the low frequencies as loud as before. The difference wasn't as big as I had hoped for. That led to an experiment using a pré-amp on the array channels. That change did bring back the dynamic sound and clarity I had experienced before.
Where one can up the volume without it being obvious it is much louder. Until you try to talk to each other...
Plans are to get a 6 channel pré-amp. To be able to reduce the overall digital level a bit, creating more headroom there. Planning to use 3x the Universal Buffers from tomchr with a fixed gain as a pré-amp. Reducing the digital gain with the same amount. Lots of other solutions were discussed in between, using a Pro-DAC etc. but I want to keep what I have right now, one change at a time.
It never ends
.
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