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Silver Member Username: GamerdudeOntario Canada Post Number: 531 Registered: Apr-06 | http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=300-958 Next gen t-amp |
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Gold Member Username: NuckPost Number: 8856 Registered: Dec-04 | Is yours in the mail, Kyle? |
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Bronze Member Username: HawkbillyNova Scotia Canada Post Number: 37 Registered: Jul-07 | "# Offers Class AB amplifier fidelity with Class D amplifier efficiency" It seems everyone is taking a shot at class D amps. There are some very good class d's out there. No need to stereotype.....pardon the pun.} |
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Gold Member Username: NuckPost Number: 8863 Registered: Dec-04 | The T-amp is based on a Tripath chip, CH, not class D really. When Tripath went toes up a while ago and were for sale, some European company bought them up and doubled it's stock value in a week. No, I did not have any. Frank A. told me to look at it. |
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Silver Member Username: GamerdudeOntario Canada Post Number: 533 Registered: Apr-06 | Haha No Nuck I havent gotten one. I allways thought that if I went active I'd get the pro t-amp and use it for some klip horns. like the k-55 or something. I wouldn't mind trying to mod one of these little amps. But the bank just doesn't seem to have the fund now that I have gotten myself into other smaller projects. |
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Gold Member Username: Frank_abelaBerkshire UK Post Number: 2418 Registered: Sep-04 | Nuck, I was under the impression that class T is a refinement of class D... Interesting to hear they were bought - who did the buying? I can't find any info on the web. Chris, traditionally, class D amplifiers have had their share of detractors because the amps are pretty noisy. Better voltage regulation and cleaner power supplies have accounted for much improvement in their fidelity, but there are many poor implementations (just listen to any modern TV panel). Regards, Frank. |
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Bronze Member Username: HawkbillyNova Scotia Canada Post Number: 38 Registered: Jul-07 | I'm far from the expert, but I think you're right Frank, there is some element of Class D in Class T. However, I don't buy into much of the Tripath literature which denotes itself as an improvement on Class D...ie better than. I've heard some of both that sound good, and as with everything, it's in the implementation. There are some poor implementations of every technology however, not just T and D amps. I've heard my share of crappy A and AB amps as well. I've read some wonderful reviews of current Class D amps from the likes of Channel Islands Audio, Nuforce, and even Rotel. I don't have any bias either way, I just don't like statements which imply one or the other technology doesn't have "fidelity". Many toob fans will claim the same about Class A or AB than some AB advocates are now claiming about T or D. As always, it isn't about the technology. It's about the sound. And I really couldn't care how anyone does it. As long as they bring it. |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 11525 Registered: May-04 | . I do hope you understand that the use of tubes does not automatically alter the operating mode of the amplifier or gain stage. Tubes run in class A and A/B (and class B and C also) just as do transistors. A single ended gain stage, whether solid state or vacuum tube, is inherently class A operation. By its definition, nature and design it can run in nothing but class A operation. Virtually all pre amplifiers, utilizing any gain device, will run in class A. Yet many manufacturers tout this operation as belonging only to their unique product. The analog output stages of virtually any digital playback device will also operate in class A. It is when we enter into the push-pull world of high gain and large amounts of current that other modes of operation even enter into the picture. As to class D and T, both are essentially analog amplifiers passing analog signals. The power supplies for both "classes" are switching types which, to many people, implies a "digital" amplifier. (Keep in mind class "T" is a marketing term chosen by Tripath to separate their product from other "digital" amplifiers and by electrical definition there is no such beast as class T whereas class A is a distinct mode of operation in electrical terms and is not in many ways similar to class B.) On-off-on-off, etc. 1,0,1,0, etc. While class D amplifiers can be built from discrete components, class T can only be constructed from Tripath's large scale chip gain stages. Both D & T have seen many refinements on the past few years and the use of far better air core inductors on the amplifier's outputs has minimized the high speed switching noise problems (of the modulated power supply) so common among lower performing class D amplifiers as used in subwoofers and car systems. As to disliking claims for higher fidelity than the competitors, this must make for an aggravating read through the advertisements of any audio company in any of the number of specialty audio magazines on the rack and available on line. . |
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Gold Member Username: NuckPost Number: 8894 Registered: Dec-04 | I lost it Frank. My broker apparantly did as well, since I didn't buy any. I will look sommore. Good post, JV. |
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Gold Member Username: Frank_abelaBerkshire UK Post Number: 2423 Registered: Sep-04 | Jan, Actually, not wishing to pick on you or anything but in fact the power supplies of class D or T amplifiers do not need to be switching types. Arcam's class H (another refinement of class D) amplifiers in the Solo Movie and P1000 use linear supplies. The class D and H nomenclature relates directly to how the output devices are switched on and off continuously. The power supply can do this how it wishes. It's more usual to use a switching supply (also called a switched mode power supply), but not strictly necessary. Class T is a patented refinement of class D which Dr. Tripathi invented. It is a misnomer (as you say) since it doesn't actually relate to a particular class but is more of a branding exercise. That said, most class T amplifiers seem to be more successful implementations than traditional class D so there's something to it. Chris, you make an excellent point. It's not what you've got but how you use it that counts. Arcam's P1000 7-channel class H power amplifier is a quite disappointing listen. It offers much in pure paper terms but ultimately it's an unsatisfying unit to listen to. On the other hand Arcam's own Solo Movie HTIB also uses class H and is a resounding success. Another interesting observation (I think) is that the Naim n-Vi HTIB is the only item in Naim's range which uses both switched mode power supply and class T amplifiers, and yet it sounds very much like a Naim unit and quite unlike other class T amplifiers. Nuck, I thought you took a $20 punt! I was actually very close to taking a $500 punt but never did...! Regards, Frank. |
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Bronze Member Username: HawkbillyNova Scotia Canada Post Number: 39 Registered: Jul-07 | As to disliking claims for higher fidelity than the competitors, this must make for an aggravating read through the advertisements of any audio company in any of the number of specialty audio magazines on the rack and available on line. Not so much JV. I don't mind the "mine's better" you find in most ads. You expect that. It's the implication in some statements that one technology or the other is fundamentally flawed in some way that another isn't. They've all got their challenges I suppose. Of course, it may be that I'm just cranky. |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 11527 Registered: May-04 | . Right, Frank, the Auotcostruire T amp kit that I own had several options for a ps. I chose a sealed lead acid 12VDC battery with a floating charger. All total it cost about $65 for the ps portion of the amplifier, not counting the small cost of connectors. No noise of any kind from a SLA ps. I've never run the battery dead but it was estimated at about 5-6 hrs. playing time when the charger is disconnected. More than a few of the lower priced - and even a few of the higher priced - T amps give the user the option of ps choice. And, I've read nothing that says one style of ps is definitely better than another. However, the choices seem to come down in favor of the SLA battery or a switching type supply. . |
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Gold Member Username: Frank_abelaBerkshire UK Post Number: 2430 Registered: Sep-04 | Chris, Actually class D has been around for an awfully long time (early 20th century I believe) and pretty much all HiFi manufacturers ignored the technology because of noise implications in the switching process. It's only because the latest class D devices have developed such low noise in the last 10 years that class D amplifiers have become a viable alternative. Jan, indeed, the Arcam choice of linear supply is particularly surprising given the fact that they were shoe-horning this into an HTiB when a similarly specced switched mode would be lighter, smaller and run cooler. |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 11533 Registered: May-04 | . CH - Do you understand how the various classes of operation are defined and what sets each apart from the other? |
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Gold Member Username: NuckPost Number: 8896 Registered: Dec-04 | http://en.wikipedia.org/wiki/Electronic_amplifier |
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Bronze Member Username: HawkbillyNova Scotia Canada Post Number: 40 Registered: Jul-07 | "CH - Do you understand how the various classes of operation are defined and what sets each apart from the other?" Only in a rudamentary way JV. I don't have enough grounding (pardon the pun) in electronics to understand half of what I read. I do know it's tough to find two designers to agree, fully, on how to make good sound. Which makes life interesting. I've recently upgraded my digital source components and am looking at amplification next. It took me months to arrive at a conclusion on the front end, and I expect I'll be just as long on an amp. Lots of options. I'm trying not to get too hung up on design, just sonic characteristics, price, and service. One option I don't have locally here are amps incorporating tube implementations. No one carrys them. Only purely solid state options here. |