| DJNUBZ |
| I know that class D is a newer amp topology and that it is getting better every day but I am curious how the new low distortion versions are comparing to Current class A designs. The amps I have in mind are along the lines of the Aleph, leach, and JLH. These amps have been around and all are well known as quality amps. So how do the new kids on the block stack up? |
|
|
| mastertech |
class-d as is digital is a translated form of audio when you compare this with true Analogue and its classes a,b,ab where
the original signal is processed as is you can see why hifi revolves
around them
digital and class-d are nice but not hifi
cheers |
|
|
| BWRX |
| why don't you both buy an AMP3 or other low power class D kit and give em a listen? they sound pretty damn good, are cheap and fun to assemble, and don't cause noticeable changes to your electricity bill while turned on :) |
|
|
| IndyAudi |
| quote: | | Originally posted by mastertech digital and class-d are nice but not hifi |
mastertech,
can you please clarify your experience - findings - results with these amplifiers.
since i'm in the process of buying a couple more your valued opinion would be very much appreciated.
thank you |
|
|
| DJNUBZ |
I currently can't afford to buy and try and find that it's not at the level of what I currently am using. I wish I could though.
Mastertech are you saying that Class D doen't even compare to SS and Tube amps? |
|
|
| sx881663 |
| quote: | Originally posted by mastertech
class-d as is digital is a translated form of audio when you compare this with true Analogue and its classes a,b,ab where
the original signal is processed as is you can see why hifi revolves
around them
digital and class-d are nice but not hifi
cheers |
Class A can be very nice at low volume/power but still is hopelessly old fashioned sounding like a 50's radio. It has extreme coloration and distortion above a couple of watts. It is totally at the mercy of all the parts that make it up and each one contributes to this coloration. I am not saying this can't be very pleasant, at least for a while but who wants syrup on every thing? The job the output transformers have to do makes them very expensive, large and limited in bandwidth. The class A claim to fame is the old “first watt” thing. This relates to letting through the low level information so is very noise dependant. Typical class A has high noise and low power meaning very restricted dynamics. The typical solution is to by a set of very efficient speakers that introduce even more coloration. WOW, now we are back to the 40’s!
If you want the state of the art regardless of cost, the best of the class D amps are your only choice.
The reasons are many as they are;
The very best at reproducing low level information without compression or distortion,
Very low in dynamic compression at all playback levels,
Very low in distortion at all levels and frequencies,
Very low in noise in the audio band,
Have no crossover or hysteresis distortion masking low level information,
(Any hysteresis distortion due to the output filter occurs at the peaks of the switching waveform and doesn’t interfere with the signal.)
Extremely low in coloration from parts that are within the feedback loop,
Extremely high in efficiency,
Have very little or no sonic penalty for higher power,
Have excellent rejection of power supply noise.
Have a real rightness about reproducing the leading and trailing edges of all sounds,
Have exemplary sound staging when coupled to an adequate power supply,
Their life expectancy is many years including obsolescence with no or very little maintenance required,
And last but far from least one of the modules will not cost as much as a single quality output tube. A really nice whole amp can be built for the price of a couple of quality class A output transformers.
Convinced yet? There is much more that I haven’t gone into!
You came to the wrong place to say that class D is not hi fi. But I guess it isn't if your reference is a 50's radio sound.
Roger |
|
|
| classd4sure |
| quote: | | class-d as is digital is a translated form of audio when you compare this with true Analogue and its classes a,b,ab where |
etc
Hi,
If class D is digital than so must be class B and AB? Really to me your post seems like a fishing expedition, why don't you do some research on the subject yourself and you'll sound better informed.
There's veery little, actually nothing I can agree with on what you've posted.
I have my doubts you've even heard a class D amplifier, and are amongst those still thinking it's for bass only.
I also agree with Roger and class A coloration, theoretically both class a and d are 100% linear, in reality a good class d probably outperforms a good class A, certainly it leaves it in the dust as it maintains performance over 10X the power band even possible with class A.
Mastertech, sell tube amps, do you? :)
Regards,
Chris |
|
|
| ssanmor |
The opinion from someone who says that Class-D means "digital" seems of little weight and validity to me. One cannot post such categoric affirmations without knowing what he is talking about.
For an easy and very light introduction to Class-D, please have a look at this article. I think it is quite educational and I hope it helps changing everyone's mind about this new and excitant technology, without hiding its difficulties.
http://sound.westhost.com/articles/pwm.htm |
|
|
| sx881663 |
| quote: | Originally posted by ssanmor
The opinion from someone who says that Class-D means "digital" seems of little weight and validity to me. One cannot post such categoric affirmations without knowing what he is talking about.
For an easy and very light introduction to Class-D, please have a look at this article. I think it is quite educational and I hope it helps changing everyone's mind about this new and excitant technology, without hiding its difficulties.
http://sound.westhost.com/articles/pwm.htm |
The most difficult thing about class D is deciding whether to buy Lar's design or Bruno's. From there it is straight forward implementation. Really, doing a class D design from scratch is nonproductive from a time and money standpoint unless you are doing something really different, unfortunately, then your chance of success drops even further. I consider myself a competent analog designer and have done some interesting and complex things but I know enough to realize how long it would take to get up to speed on this technology. And, I have to ask myself what would be the point in trying to do something that worked better than the 2 products mentioned. I am not saying there is no room for improvement as there is but by the time I got to that point they would be 2 years ahead of me. I am sure there will be more competent class D designers in the future as most of the fundamentals are now done and can be taught. Of course this will be a class in analog design, not digital and I am not sure how many students will be attracted.
Roger |
|
|
| ghemink |
| quote: | Originally posted by mastertech
class-d as is digital is a translated form of audio when you compare this with true Analogue and its classes a,b,ab where
the original signal is processed as is you can see why hifi revolves
around them
digital and class-d are nice but not hifi
cheers |
No, they are for sure not hifi, they are High-End.
And most of them are true analog as well and can easily beat many so-called high-end conventional amps. If you have heard a good class D amp, I`m pretty sure you don`t want to go back to conventional anymore.
Try it and find out.
Gertjan |
|
|
| t. |
You do have to keep an open mind with this new technology.
I've had a diy tube amp for a few years now, the stone each in weight output transformers alone cost more than a pair of the UCD400 modules, the sound is far from syrupy and measures extremely flat.
I've built and listened to various solid state amps and wasn't really blown away by any, yes a lot of tube amps do sound bad too;)
I also read bad things about class-D but decided to buy one of 41hZ Audio Amp3 kits to try out seeing as though it cost peanuts and should give me an idea how this new technology sounds.
To be honest I was amazed at the sound that came out of this tiny amp, it would put a lot of expensive solid state amps I've heard to shame.
My speakers could do with a bit more juice than what the Amp3 can give so I'm getting the parts together to build a pair of UCD400 amps:) at least these things run nice and cool unlike tubes:D |
|
|
| dmason |
"Digital and Class D are nice, but not hi fi."
This sounds like a statement made by someone who has never heard this implementation. A very well implemented single ended Tripath TA2024 based amp, same as the one in the legendary Sonic Impact, a $20 plastic amp, can provide a sound where many listeners prefer that signature to VERY high dollar single ended tube sound. I know, because I did exactly this experiment in my home, with my equipment.
Class D, such as it is called has become a very narrow-seeming term. It is the way of the future.
"Ignorance hath the loudest opinion." --Robert Burns |
|
|
| Jocko Homo |
Well, for once, I decided not to say what I had on my mind. Someone here should consider themsleves lucky.
Today.
The Class D stuff from years ago was rather nasty sounding, but with the newer generation, that is no longer the case. Still, it does sound different, and different enough to put off some people.
None of the people who design the technology on question call it "digital". They all hate that term. The amps are linear devices that essentially control a SMPS. All amps are nothing more than modualted power supplies. These just happen to have switching suppies.
Usually fed from a good ol' transformer/filter cap combo.
I don't agree that Class A has to sound syrupy. Power hungery, yes. Which is why mine are all turned off now.
Jocko |
|
|
| t. |
Hi Jocko,
Its not like you to hold back:D
Your a man who knows his stuff, what amp design would you class as good sounding? |
|
|
| classd4sure |
Hi Jocko,
I wouldn't say class A has to sound syropy either, but I think the only point it was worth bringing up for was to simply to say that while on paper they're both ideal, in reality...
Therefore I don't find it a valide argument to hold over class D. They both have their problem areas, I think it's much more feasible to overcome most limitations with class D however.
I do agree with mastertech, all class-d's that I've heard do share similar characteristics, lots of air, lots of dynamics, lots of detail... I'd never call that digital, I really like it, and sure a sonic impact would be a good way to find out, but if you had to pick 1 class A amp to stand for all the rest..... would you be content with it being a 20$ chip amp?
Regards,
Chris |
|
|
| sx881663 |
What is it about class d that gives this sonic effect, if it is an effect at all? I think it relates back to the physical properties of all conductors that are crystalline in nature. When an electrical signal crosses the gap from one crystal to another it takes a certain amount of energy to do so. This energy is then lost from the original signal. Think about how much more information comes across a really good set of monocrystalline cables. It also explains why there is such a thing as break-in. This could be the process of these crystals welding them self’s together. All this relates to low level information transmission. We would be more sensitive to the high frequency aspect of it because the treble contains less energy and the loss percentage would be greater.
Could it be the high frequency residual and in fact the main power switching solidly bridges these energy gaps allowing the low level stuff to get through where before it was lost? In careful listening to both d and a/b amps it does seem to me to be this kind of difference we are perceiving. If all this is true this would separate the d amps from all the rest and I think that is just what is happening!
Now if you really get to thinking about this it answers a lot of questions about different sounding stuff and what makes them different, of course disregarding all the readily measurable stuff. Maybe all we need to do is turn down our THD test signals to really low levels to get a more accurate correlation with what we hear. This could be important!
Roger |
|
|
| DJNUBZ |
Thanks for the responses but it seems mastertech kinda bumped this post in a different direction then I ment it to go. I am more intrested on how the amps like the zappulse line (ie. 700xe) and the UcD line against other quality DIY amps such as the ones I posted before. I really don't think it makes much sense arguing about classes.
I don't want to get off track but classd4sure when you say "class A coloration" are you refering to tube amps. If so I understand that statement due to the fact that there are a a lot of poorly designed tube amps around. If you are talking about SS class A amps could you explain more of what you are talking about? |
|
|
| classd4sure |
| quote: | Originally posted by DJNUBZ
Thanks for the responses but it seems mastertech kinda bumped this post in a different direction then I ment it to go. I am more intrested on how the amps like the zappulse line (ie. 700xe) and the UcD line against other quality DIY amps such as the ones I posted before. I really don't think it makes much sense arguing about classes.
I don't want to get off track but classd4sure when you say "class A coloration" are you refering to tube amps. If so I understand that statement due to the fact that there are a a lot of poorly designed tube amps around. If you are talking about SS class A amps could you explain more of what you are talking about? |
Hi,
I think you're question is best answered by just looking at the specs of the different amps, keeping in mind what you expect from an amp. Yes THD is implied when I say that but that hardly scratches the surface of what you should be looking at.
I think in the end the result will clearly show high end class d amps have a definitive edge over the rest as it simply gives you alot more of what most people want and enjoy in an amplifier, and alot less of what you don't want, namely cost per watt and power loss, assuming equal quality, which I don't believe it is, I prefer class d for it's sonics without question.
Roger, while I personally would not be so ready to start discussing the mono crystal theory, I will certainly agree that class d has an edge in that it modulates instead of amplifies, thereby largely doing away with most of the individual components influences. You have to have a good modulator and treat that like an analog system, since it is one.
Think about the slew rate between a switching amp and any other for instance... perfect example.
Now when I said class A coloration I was paraphrasing what I believe was the context of a previous post. In that I meant any class A and coloration by be it your mono crystral theory or the usual delays, bandwidths, parasitics, etc.
We still have all those to deal with in a class d amp design but they can and do get dealt with in such a way that they're no longer the controlling factors in the audio that results, exactly because they operate in switch mode.
That's not to say each component doesn't have it's influence on the sound either, certainly the passives.
No easy answers.
Regards,
Chris |
|
|
| KLe |
Hi DJNUBZ: IMHO, I think that you will find the Zappulse 700XE to be a very fine amp. I am currently using the Zappulse 2.3SE, which after tuning, is a very good amp and I believe that the 700XE will be better (at least Lars and listening testers say that it is?). ;)
I have found that the sound of the Zappulse 2.3SE is dependant on the quality of the PS. Eg. 1KVA tranny is better then a 500VA tranny, short wire connections to the PS Caps is important, 0.22uF caps controlling zener diode noise is critical, etc? :bigeyes:
I cannot comment on the UCD amps, but wrsto UCD amps, I am sure that someone will be able to provide you with a summary :att'n: |
|
|
| pmkap |
| quote: | Originally posted by dmason
"Digital and Class D are nice, but not hi fi."
This sounds like a statement made by someone who has never heard this implementation. A very well implemented single ended Tripath TA2024 based amp, same as the one in the legendary .....
"Ignorance hath the loudest opinion." --Robert Burns |
This sounds like a statement made by someone who has never read a spec sheet, understood a schematic, or has a clue as to topology, yet nevertheless spouts technobabble, feeling that such throwaway descriptiors as 'single ended' to describe the TA2024 gives their opinions credence.
In which alternate universe would the bridge tied load TA2024 be considered single ended? I've no problem with your sharing your opinion that you find your Red Wine amp preferable to your previout SET amp, but please spare us the nonsense.
"Ignorance hath the loudest opinion." --Robert Burns |
|
|
| IVX |
pmkap,
this is an enthusiasm, which can be well explained - class D amp have no such bad sound as predicted, if they show shame specs even (e.g. zappuls have several percent THD in highs, and people likes it yet). Maybe not so much loop gain, or/and higher pole frequency vs typical class AB, maybe something else do the sound of class D amp better then their specs. About the specs.. no problem, by the huge loop gain or/and faster switching, which, of course, preferable - day by day faster&cheaper MOSFET's appears. Some time ago i've made UcD400 THD measurement, at the factory adjusted dead time the module gave .0175%@-3db(80W@8Ohm) with good efficiency. Decreasing dead time gave .005%@-3db, but pretty bad efficiency, i'm sure that newest MOSFET's, in this case, will help to avoid the losses, and keep performance same or better (loop gain around 30db, 35khz pole=flat THD/Freq plot in the audio band). BTW, that's excellent initial linearity, so amp without feedback would be have THD=.15%@80W!
Other excellent example is JohnW amp, i don't know how much feedback he has used, but the specs is the same or better vs best of the audio DAC chips. |
|
|
| KLe |
Hi DJNUBZ: I forgot to mention a couple of other things about the Zappulse 700XE.
The THD, according to Lars and unlike the 2.3SE, is <0.02% across the audio range. This might mean that you do not have to be so fussy with the PS, although being fussy will not hurt.
The 2.3SE does have some EMI issues, but I do not know if the 700XE will have the same EMI issues? You will need to ask Lars about any EMI issues. Just be aware that he is somewhat slack at replying to emails?
If there is anything else I can think of, I will post it.
Hope this helps |
|
|
| pmkap |
IVX,
The intent of my post was not to criticize switching amplifiers in comparison to other linear amps. I've heard well implemented amps based upon that same TA2024, and within its power constraints, have been very impressed. I've also heard UCD amps and have similarly been impressed. The choice at this point is not one of technical measurements, but rather one of subjective preferences based up details of implementation rather than constraints inherent in topologies.
My intent (using the exact words that Dmason started his post with, and ending with the same patronizing quote from Robert Burns) was to point out to him that he was guilty exactly the same transgression he accused mastertech of - not knowing what the heck he was talking about. |
|
|
| classd4sure |
| quote: | | The choice at this point is not one of technical measurements, but rather one of subjective preferences based up details of implementation rather than constraints inherent in topologies. |
Well said.
Personally I can't imagine anyone not liking it.
In the end specs don't mean a damn, but the smile it puts on your face will be the deciding factor.
Regards,
Chris |
|
|
| Kenshin |
what's the major difference between the newer generation and the old generation?
MOSFET gate drivers? or feedback?
| quote: | Originally posted by Jocko Homo
The Class D stuff from years ago was rather nasty sounding, but with the newer generation, that is no longer the case. Still, it does sound different, and different enough to put off some people. |
|
|
|
| classd4sure |
Mosfets were the real barrier that put a cap on switching frequency that limited them to being for sub use only.
Also it seems not many knew how to make a good amp of it, but I'm sure had the right mosfet existed back then placed in the right hands... some amp would have rose above the rest. |
|
|
| classd4sure |
Just testing out some FX on my new soundcard. Under Vocal/Wide Enhancer I found preset #27 by the name of "Transistorized".
It has a veeery edgy, bright, gutted sound with ear bleed fake highs and zero bass, the "full feedback applied" sound.
Reminds me very much of a very cheap class A/B only with an unusual clarity. Scary. |
|
|
| IVX |
Chris,
preset #27 by the name of "Transistorized", this is just a four band EQ.:) |
|
|
| classd4sure |
Hi,
Yeah I can turn it off and it's back to a decent sound :)
Same sound card Ivan?
Regards,
Chris |
|
|
| IVX |
| aha, EMU 1212M for measurement purpose, nice loopback THD - .0001%. BTW, i've plans to change output opamps. |
|
|
| soongsc |
| Today I used a USB class D dongle driven by a notebook to drive a pair of 3" speakers, the sound field was amazing for such small wattage (2W) and speaker efeciency of around 86db/W. |
|
|
| sx881663 |
Yes, nice but wait till you add in a small powered sub woofer to get the lower octave! I am using a pair of Altec 4” subs and they do an amazing job without taking up much room. Of course this is all near field listening, they won’t fill up a room with sound.
Roger |
|
|
| sx881663 |
| quote: | Originally posted by IVX
aha, EMU 1212M for measurement purpose, nice loopback THD - .0001%. BTW, i've plans to change output opamps. |
Ivan,
This is the sound card I am planning to use as well. I too will be tweaking it, replacing caps and op-amps, etc. I am also planning to use it for a listening reference and as a THD instrument. What software are you planning to use for this? I have no money to buy an expensive package so am looking for something to do the job that I can download. Do you know of anything available that actually works? Have you used a sound card this way before? If you have I would like to know what problems I can expect.
Thank you,
Roger |
|
|
| Rivendell61 |
Just a hint....
If you want to read that Stereophile Review dstockwell linked above:
Click the "print this" link at the bottom of page 1--then the entire review is loaded onto one page.
Mark |
|
|
| IVX |
Roger,
You can try RMAA free soft, or something else 30 day trial, but much convenient. I see one problem with 1212..it's 10 times more expensive vs my previous audigy, which have .002% THD loopback, that is worse, but still well enough.:drink: |
|
|
| soongsc |
| quote: | Originally posted by sx881663
Yes, nice but wait till you add in a small powered sub woofer to get the lower octave! I am using a pair of Altec 4?subs and they do an amazing job without taking up much room. Of course this is all near field listening, they won’t fill up a room with sound.
Roger |
They actually had a 2.1 USB device on a 10cm * 10cm card, I just didn't have a sub for that. But I though if they could get a 5.1 out of it, that would be great! |
|
|
| thoriated |
| quote: | | If you have heard a good class D amp, I`m pretty sure you don`t want to go back to conventional anymore. |
I own both a Crown K1 and K2 and neither one comes at all close to the sonic accuracy or sound quality of my home brew DC coupled all triode OTL amplifier (which has a damping factor of over 100 out to 20khz, btw), and consistently sounds more incisive and musical with much more detailed imaging and far, far more consistent sound stage in every way than the class D amplifiers.
Not to say that Class D amps aren't best at what they do, which is high efficiency, but any decent tube amp matches Class D wrt low level linearity. |
|
|
| IVX |
| I'm afraid of repetition, but.. No matter is the amplifier topology class, but, maybe there are designer class matter. :) |
|
|
| thoriated |
| The K1 and K2 are better sounding than many other SS amps and particularly good in the bass (the K2 is just the thing for my proposed HT subwoofer system using 16 long throw 12" drivers wired to 3 ohms/side to get all the class D bass goodness possible out of a 15A circuit)and I'm sure there's a number of better Class D implementations than them sonically nowadays that I haven't heard but it doesn't seem to me to be a case of having once heard Class D, never back to linear amplification. |
|
|
| KLe |
| Hi thoriated: what class D amps have you listened too, sofar? |
|
|
| Ricky |
[Hi.
Sorry, but I beg to differ. I have just designed a valve pre driving 2 250 watt Class D power amps and took thiem to a high end HiFi consultant. He used a Copland CD player and Pro-ac Response speakers. It's not valve or Class D in presentation. It's something a bit special according to him. Class D IS HiFi if you surround it with the appropriate kit.
Ricky. |
|
|
| marconist |
| quote: | Originally posted by thoriated
I haven't heard but it doesn't seem to me to be a case of having once heard Class D, never back to linear amplification. |
What is your idea of linear amplifiers ??
:xeye: |
|
|
| Ricky |
[Hi.
What's my idea of a linear amplifier? My idea of a linear amplifier is either a conventional Bi-polar or Mosfet design that uses a + an - power rail. Class D seems to behave in a very similar way to Class A. That is to say that it draws current all the time. On the ones I use, they are fed from a well regulated single rail supply of 48volts. If you place a meter on either of the output terminals and the other to 0volts, you read half the supply voltage i.e. 24 volts. In a linear circuit, voltage or current only flows when a signal is applied to the input (with the exception of Class A).
I have to say that the sound, with a valve pre-amplifier driving it, is something I have never heard before. Fast, tight and the bottom end is extremely well controlled unlike some "linear" designs I have heard where the supply rails drop as you ask for low frequencies. The result is un-controlled low frequencies or "One Note Waffle" as one critic wrote a few years ago.
Ricky. |
|
|
| marconist |
ANY amplifier is linear, as it is nothing more than a linear system multiplying the signal with a constant.
It does not matter how the linear system is constructed, so in case of a class a,b,c or d amplifier it is al the same.
The problem of non-linearity lies in the fact that due to the linearity curves of (mainly) tubes and transistors there are serious problems to overcome which are most prone with class b and class c amplifiers (class c is not used in audio circuits).
Class d is special in the sense that it is in fact a very fast thrown switch. There is a relation between the switching frequency and the signal frequency you want to amplify. As long as the switching frequency is relatively high, the class d amplifier acts as a linear system.
The fact that most amplifiers drawn current whether or not they are actually "amplifying" has nothing to due with fidelity in itself. It follows from the way you design it. In so far there is a relation with linearity that you use some bias currect to get out of the nonlinear curve-part of tubes and transistors. Or you have some losses due to the fact that switching takes time, like in the class d circuit.
Due to the way you design, all systems (amplifiers) have their pros and cons and so a right to exist.
Class d is not actually "new", but could not be realized before due to the fact that there were no fast (enough) power switches.
So listen to a good class d amp, you may like it! :) |
|
|
| LukasLouw |
| quote: | Originally posted by Ricky
[Hi.
What's my idea of a linear amplifier? My idea of a linear amplifier is either a conventional Bi-polar or Mosfet design that uses a + an - power rail. Class D seems to behave in a very similar way to Class A. That is to say that it draws current all the time. On the ones I use, they are fed from a well regulated single rail supply of 48volts. If you place a meter on either of the output terminals and the other to 0volts, you read half the supply voltage i.e. 24 volts. In a linear circuit, voltage or current only flows when a signal is applied to the input (with the exception of Class A).
Ricky. |
This has nothing to do with Class A. You are simply seeing, as with any bridged amplifier, that each output of a bridged channel will sit at an average DCV of 1/2 supply rail, to keep the net across the load at zero volt. You will measure exactly the same with any bridged amp running off a single rail, whether Class A, B, AB or D.
Lukas |
|
|
| marconist |
| quote: | Originally posted by LukasLouw
This has nothing to do with Class A. You are simply seeing, as with any bridged amplifier, that each output of a bridged channel will sit at an average DCV of 1/2 supply rail, to keep the net across the load at zero volt. You will measure exactly the same with any bridged amp running off a single rail, whether Class A, B, AB or D.
Lukas |
Quite right, Lukas! (If you replace bridged by balanced ..... ;) )
In my "theoretical view" I missed that point. Thanks. |
|
|
| Ricky |
| quote: | Originally posted by marconist
Quite right, Lukas! (If you replace bridged by balanced ..... ;) )
In my "theoretical view" I missed that point. Thanks. |
I have to say that I find all of your comments fascinating. I could spend hours on her but I don't have the time or want to pay the phone bill!!! I do agree with your comment though. Try a good Class D amp sometime.
While I was having my amp appraised at the dealer's place I mentioned, I listened to a Class T driving Wilson WATT/ Puppy 7's. Not sure about what my ears were receiving. Didn't make music for me.
Keep it coming. I'm learning one helluva lot.
Ricky. |
|
|
| sx881663 |
| quote: | Originally posted by Ricky
I have to say that I find all of your comments fascinating. I could spend hours on her but I don't have the time or want to pay the phone bill!!! I do agree with your comment though. Try a good Class D amp sometime.
While I was having my amp appraised at the dealer's place I mentioned, I listened to a Class T driving Wilson WATT/ Puppy 7's. Not sure about what my ears were receiving. Didn't make music for me.
Keep it coming. I'm learning one helluva lot.
Ricky. |
Ricky,
From the experience I have had with small class T amps I suspect all of them have problems driving complex loads like any speakers with crossovers. This is probably due to their output filters not being in the feedback loop. I personally have never actually sat down and listened to the Watt Puppies but they are respected. I also suspect they do have a complex crossover network with all that implies sonically and load wise.
My experience with this situation is the sound becomes strained and irritating with real problems around the crossover point. Was this the kind of thing you heard?
With good single driver/no crossover speakers the class T can be dazzlingly good! A truly worthy replacement for 2-15 watt class A triodes at the price of one good tube too boot!
Roger |
|
|
| Ricky |
| quote: | Originally posted by sx881663
Ricky,
From the experience I have had with small class T amps I suspect all of them have problems driving complex loads like any speakers with crossovers. This is probably due to their output filters not being in the feedback loop. I personally have never actually sat down and listened to the Watt Puppies but they are respected. I also suspect they do have a complex crossover network with all that implies sonically and load wise.
My experience with this situation is the sound becomes strained and irritating with real problems around the crossover point. Was this the kind of thing you heard?
With good single driver/no crossover speakers the class T can be dazzlingly good! A truly worthy replacement for 2-15 watt class A triodes at the price of one good tube too boot!
Roger |
Hi Roger.
I have to say that I didn't have this problem because these class D's produce a full 250watts into a 4 ohm load. The WATT's are quite efficient so the amps were never pushed that hard. It's an interesting point though. I'll see if I can duplicate what you've said with Inductive/resistive load on the bench and measure it with a scope.
Ricky |
|
|
|
