Full range class D amps?

determinus · 3rd December 2007, 09:35

Was browsing through eBay on old school amplifiers and one chrome finished mono caught my attention. It was Xtant x1001. Specs and reputation was truly amazing. I also found that Xtant has a Class D amplifier with full range called 1.1i. CarAudioMag has given some excellent ratings for the product. A little more googling revealed that Class D for full range is patented in 1999, and even Pioneer (Premier range) has one that is full range. Would request gurus to comment on this type of amps. And also on the Xtant series. Are they as good as they sound?

EDIT: (PS: I generally look for reputation by the number of bids on eBay, and the average rate of completed listings. Xtant is high on that scale)

navin · 3rd December 2007, 09:55

Quote:

Originally Posted by determinus

I also found that Xtant has a Class D amplifier with full range called 1.1i.

Class D is not new. Class D amps ar improving all the time and there are even a few HTiBs that sell with 5.1 channels of Class D amplification.

Using a Class D amp for fullrange is very possible however in well regulated rigourous listening tests they still fall short of traditional (Class A and Class AB amps) in audio quality. However the gap is fast closing and also i believe once some of the better designers get interested in Class D for fullrange they will use their talent and energies to produce Class D amps that can rival their Classs AB (if not Class A) equivalents.

That said I also beleive that while Class D closes in on Class AB there will alwyas be a market for Class A Solid State and Class A/AB Tube amplification atleast for my lifetime. Maybe the younger ones here will see Class D replace Class A, tubes, etc.. in all forms of amplifiation. I surely hope so. Class D is so much more efficient in managing power and will help reduce our energy foot print on planet Earth.

This is my opinion. I am very very often wrong. So wrong, in fact, that you may be sure that none of the above will happen and in all probablity Class D will replace all form of amplifcation is under 5 years. :-)

low_bass_makker · 3rd December 2007, 11:38

Navin Ji there is a T class also coming up.

navin · 3rd December 2007, 11:48

Quote:

Originally Posted by low_bass_makker

Navin Ji there is a T class also coming up.

that is just a version of class D (based around a Sonic Impact's Tripath chip) just as Sound Craftsmen's class H and Carver's (class G) Magnetic Field amp were versions of Class AB and Crown's Class I was a version of the Class E (switching amp). PWM/Delta-Sigma (Switching amps) operate at 200kHz and above and have not proved to offer any significant advantages to the audiophile. However for PA and Sound Reinforcement they do have applications.

Bass&Trouble · 3rd December 2007, 12:09

Quote:

Originally Posted by low_bass_makker

Navin Ji there is a T class also coming up.

The Blau PA 275 is a Class T amp. Like Navin said, the T stands for Tripath, derived from the owner of the company, a Mr. Adya Tripathi. Indian, of course.

So when are we going to the see the Class R amps?

determinus · 3rd December 2007, 13:05

Enlightening indeed. That was more like a 1 minute primer on past, present and future of classes in amps. Thanks Navin.

@LBM, since you are the king of high power amplifiers, what's your opinion on the Xtant monos? Also, old school Rockford has a class BD that churns out 1500rms (very small foot print). I also found some Orion, Phoenix Gold, and Diamond above 1kw and with damping factors above 2000!! Any inputs on the above brands, models etc? All from a sub amp point of view.

@B&T: I actually thought it was Tri-Path, part of the key circuitry!

navin · 3rd December 2007, 13:11

Quote:

Originally Posted by determinus

@B&T: I actually thought it was Tri-Path, part of the key circuitry!

B&T, see what you've done.

sh@rpshooter · 7th December 2007, 08:23

If I may add, the only problem with Class T is low power (not more than 15W ito 4 Ohms and 8 into 8 ohms) making it suited for high sensitivity speakers. also they do have a propensity for oscillation (hence minor distortions in the 15Khz range, though can be caught only on revealing systems)

Bu ICE modules (ex B&O) are more into the digital setup and have had Jeff Rowland, Kharma pretty interested..although yet to catch on. also lots of other manufacturers amps like Flying mole, Nuforce have found a good following of their amps.
Again the term digital may be misleading as the amplification is still in the analogue domain..but fall more into the category of switching amps.

las head Mr triparthy was reeling under litigation. not sure of the future of class T.

For Home Hi-fi duties I do have a Sonic Impact and must say it is a very good alternative to my pure Class A amp

gunbir · 7th December 2007, 10:06

Well here's what Mr. Eric Stevens (Image Dynamics USA) has to say on this matter:

"Class D or switching amplifiers can sound good when done right but cost even more than a class A/B amp when they are done correctly. Most of the class D amps are made because they figured out how to make a lot of power cheaply using that amp topology. The cheap class D amps sound like crap plain and simple and I would recommend a cheap class A/B amp over a cheap Class D every day of the week.

At full power the class D and class A/B are very similar in overall efficiency. It is at lower power levels that the class D is more efficient."

omishra · 7th December 2007, 12:54

Quote:

Originally Posted by sh@rpshooter

If I may add, the only problem with Class T is low power (not more than 15W ito 4 Ohms and 8 into 8 ohms) making it suited for high sensitivity speakers. also they do have a propensity for oscillation (hence minor distortions in the 15Khz range, though can be caught only on revealing systems)

For Home Hi-fi duties I do have a Sonic Impact and must say it is a very good alternative to my pure Class A amp

I am using 100W RMS /channel (Amp1) in my home 2.1 system. Ofcourse from 41Hz audio amp kits. Sounds good to me! Tripath based amplifiers for DIY:ers. . Also available for 400W RMS / channel.

It has audiophile sound quality. But...

Again they have one problem, radiation which disturbs FM/AM reception. From many days I am trying to shield my AMP, that is why not trying in my SX4.

DerAlte · 7th December 2007, 15:04

Quote:

Originally Posted by omishra

Again they have one problem, radiation which disturbs FM/AM reception. From many days I am trying to shield my AMP, that is why not trying in my SX4.

What cabinet are you using for the amp? A couple of photos would help visualize.

omishra · 8th December 2007, 22:49

Quote:

Originally Posted by DerAlte

What cabinet are you using for the amp? A couple of photos would help visualize.

These are photos, 41Hz Audio Forum , Cabinet is thick aluminium (2.5mm) cabinet with face plate 5mm thick and internal compartment is made from 18swg thick iron sheet. This cabinet costed me Rs.4500

I know I can shield the specific frequency, the switching frequency I am using is 600 kHz(L) and 650KHz(R). But disturbance comes for multiple of this frequency and only when the headphone jack is connceted to amp input using RCA cable.

This may this same case for all switching amps

3rd December 2007, 09:35	#1
determinus BHPian Join Date: Dec 2004 Location: Pune Posts: 279 Thanked: 16 Times View My Garage	Full range class D amps? Was browsing through eBay on old school amplifiers and one chrome finished mono caught my attention. It was Xtant x1001. Specs and reputation was truly amazing. I also found that Xtant has a Class D amplifier with full range called 1.1i. CarAudioMag has given some excellent ratings for the product. A little more googling revealed that Class D for full range is patented in 1999, and even Pioneer (Premier range) has one that is full range. Would request gurus to comment on this type of amps. And also on the Xtant series. Are they as good as they sound? EDIT: (PS: I generally look for reputation by the number of bids on eBay, and the average rate of completed listings. Xtant is high on that scale) Last edited by determinus : 3rd December 2007 at 09:39.
	() Thanks

3rd December 2007, 11:38	#3
low_bass_makker Senior - BHPian Join Date: Mar 2006 Location: Faridabad Posts: 6,813 Thanked: 306 Times View My Garage	Navin Ji there is a T class also coming up.
	() Thanks

3rd December 2007, 13:05	#6
determinus BHPian Join Date: Dec 2004 Location: Pune Posts: 279 Thanked: 16 Times View My Garage	Enlightening indeed. That was more like a 1 minute primer on past, present and future of classes in amps. Thanks Navin. @LBM, since you are the king of high power amplifiers, what's your opinion on the Xtant monos? Also, old school Rockford has a class BD that churns out 1500rms (very small foot print). I also found some Orion, Phoenix Gold, and Diamond above 1kw and with damping factors above 2000!! Any inputs on the above brands, models etc? All from a sub amp point of view. @B&T: I actually thought it was Tri-Path, part of the key circuitry! Last edited by determinus : 3rd December 2007 at 13:07.
	() Thanks

7th December 2007, 08:23	#8
sh@rpshooter BHPian Join Date: Jan 2007 Location: Bangalore Posts: 130 Thanked: 43 Times View My Garage	If I may add, the only problem with Class T is low power (not more than 15W ito 4 Ohms and 8 into 8 ohms) making it suited for high sensitivity speakers. also they do have a propensity for oscillation (hence minor distortions in the 15Khz range, though can be caught only on revealing systems) Bu ICE modules (ex B&O) are more into the digital setup and have had Jeff Rowland, Kharma pretty interested..although yet to catch on. also lots of other manufacturers amps like Flying mole, Nuforce have found a good following of their amps. Again the term digital may be misleading as the amplification is still in the analogue domain..but fall more into the category of switching amps. las head Mr triparthy was reeling under litigation. not sure of the future of class T. For Home Hi-fi duties I do have a Sonic Impact and must say it is a very good alternative to my pure Class A amp
	() Thanks

7th December 2007, 10:06	#9
gunbir Senior - BHPian Join Date: Sep 2005 Location: New Delhi Posts: 2,465 Thanked: 33 Times	Well here's what Mr. Eric Stevens (Image Dynamics USA) has to say on this matter: "Class D or switching amplifiers can sound good when done right but cost even more than a class A/B amp when they are done correctly. Most of the class D amps are made because they figured out how to make a lot of power cheaply using that amp topology. The cheap class D amps sound like crap plain and simple and I would recommend a cheap class A/B amp over a cheap Class D every day of the week. At full power the class D and class A/B are very similar in overall efficiency. It is at lower power levels that the class D is more efficient."
	() Thanks