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Hoerninger
05-05-2007, 03:13 AM
When studying the JBL Array series I have come across Class D amplifiers. I wonder what they are good for.
Are these heavy duty amps for bass and PA as JBL offers them?

Cited from somewhere in the web:


"The 1500 Array incorporates an advanced-technology, 1000-watt Class D digital-switching amplifier to deliver powerful bass output under the most-demanding conditions of continuous high-volume use, ..."

"The JBL PRX512M is a 12" 2-way stage monitor or front-of-house self-powered speaker system with both a 400W low-frequency and a 100W high-frequency Crown Class D amplifier. It has a DSP-controlled input section with selectable EQ."
Or are these amps a choice for high end usage?

Some more information:
http://www.hardwareanalysis.com/content/article/1822/
There is a online shop from Netherlands with some interesting offers and informations:
http://www.hypex.nl/
___________
Peter

grumpy
05-05-2007, 10:39 AM
They are an amplifier type that when implemented well, can be used for
any audio purpose. Claims to fame are low weight and waste heat, and
potentially small size. Past warts have been RFI, ultrasonic output, and
reliability problems... though with better designs, chip sets, and output
semiconductors available now, cost/performance/reliability has improved.

Many folks swear by them (in a good way). I don't have any in use at home
to comment on. There are high quality versions available for home/car/pro
use.

-grumpy

scott fitlin
05-05-2007, 10:51 AM
For sub bass, they have pretty good sounding, and tough Class D amps these days.

timc
05-06-2007, 02:06 AM
I think that classD (ICE for me) Is good as long as the load is easy. They are a bit rolled of in the highs (ASP version) and the dont sound as transparent as more expensive gear (McIntosh, Pass, ML ++) But for their price they are good.

Using them for subs i dont like. They sound too slow and slugish for my taste....Didnt manage to kick life into my L65's or SVA1800's. A Crown PA amp costing a third sounded way better.

Best regards.

Hoerninger
05-08-2007, 02:01 PM
After reading here and following all the links I think a Hypex is worth trying.
They have announced a swtched power supply.

@ Scott
With your writing about CROWN (http://audioheritage.org/vbulletin/showpost.php?p=167659&postcount=56) I suppose it is best to stick to the old style PS with a lot of capacity.
____________
Peter

scott fitlin
05-08-2007, 02:06 PM
After reading here and following all the links I think a Hypex is worth trying.
They have announced a swtched power supply.

@ Scott
With your writing about CROWN (http://audioheritage.org/vbulletin/showpost.php?p=167659&postcount=56) I suppose it is best to stick to the old style PS with a lot of capacity.
____________
PeterTry it, you may like it.

In my application, you have to understand, I am open 12 to 14 hours a day, 7 days a week. Its a demanding application.

Most importantly, even though I dont always love todays technology in amplifiers, I DO still prefer the Crown sound above everything else. Thats the key right there, I "LIKE" the way Crowns sound.

Hoerninger
05-08-2007, 02:20 PM
Try it, you may like it.
... Its a demanding application.
... Thats the key right there, I "LIKE" the way Crowns sound.

Thank you for encouraging me.

You are a professional - I am hobbyist. While planning a new home system the fortune is my wife having on my side this time. She has liked a MARANTZ SC-7S2 + MA-9S2 as well - till a certain point of insight.

Crown has a good reputation here as well.
__________
Peter

Rusnzha
05-09-2007, 11:01 AM
Originally posted by Hoerninger



After reading here and following all the links I think a Hypex is worth trying.


I'm real happy with mine!

DS-21
05-15-2007, 11:57 PM
I've been using class D amps to drive my main speakers (subs are currently driven by Class G amps) for quite a while.

A Panasonic XR55 receiver has anchored my main system (~91dB/w/m 8" Tannoy dual concentrics across the front and side surround channels, KEF Q-Compacts for the rear surround channels) since the fall of 2005. It uses TI DAC-amp chips that are a commodized form of the TacT amps. These amps do amplification and D/A conversion (PCM->PWM) in a single step. It cost ~$230 or thereabouts from Amazon, or a little bit more than a third of the asking price for the subwoofer EQ (Velodyne SMS-1) in the system.

A Pioneer Elite EX500, with class D amp chips of unknown provenance, drives the 3 12" Tannoy dual concentrics (~94dB/w/m) up front and two 8" Tannoy dual concentrics in my home office system. I have no complaints about it, either, except that the autosetup routine wanted to set the mains-sub crossover at 200Hz.

While I've not done any serious listening (i.e. level matched and double blind comparisons) with the Pioneer gear, I could not tell the difference between the XR55 and an a separate system using a Marantz preamp and Adcom amplifiers. That Marantz/Adcom setup had previously shown themselves to be sonically identical to a pricey Meridian/Classe pre/amp combination on speakers with far more demanding impedance curves than my Tannoys, so I'm confident in the ability of the cheap little Panasonic at least to drive moderate efficiency speakers with benign impedance curves as well as anything else. If anything the JBL amps built into their speakers, which don't have to work as hard due to being downstream of active crossovers, should do a better job. And they should equal a good Class AB amp that weighs a whole lot more.

scorpio
05-16-2007, 02:14 PM
I am using a trends TA-10 to drive the mid high on my system, it replaces a hand made 2A3 SET, just as musical if not more and much better high, I'm just still chasing a slightly highish background noise, but not obtrusive. For the 100 euros it costed me shipped, unbeatable. Beside it weighs nothing and holds in one hand, very practical.

Tom Brennan
05-19-2007, 02:11 PM
Some chip-amps sound very good to me. I'm using a DIY gain-clone to drive Altec 605As and a Teac chip amp to drive my Model Nineteens. Other Altecs in the house are driven by a Jolida tube amp and a rebuilt Fisher 500B tube receiver.

A friend who has some excellent JBL pro 3115s uses a Panasonic chip receiver while his Monarchy, Conrad-Johnson and Audio-Note amplifiers gather dust.

jandegr
05-20-2007, 02:44 AM
My LSR32 are very happy being driven by a sony DA1200ES.
Bi amped (this receiver has 7 channels, and can be reconfigured in to
2 main channels with bi-amp and a further center and back-left an back right).
before i bought the receiver I was very reluctant to go class D, but it has
been the best combination with the lsr32's so far,

best regards,
Jan.

Hoerninger
09-07-2008, 10:44 AM
I looked for an amp for my office (?, Arbeitszimmer), not too elaborated and pricey for listening and experimenting.

In another thread (http://www.audioheritage.org/vbulletin/showpost.php?p=214744&postcount=14) TD mentioned the receiver Panasonic SA-XR10. There is a slightly bigger 7.1 version XR55 (http://www.panasonic.de/html/de_DE/156474/index.html) with a similar design, I did not expect that the class D amplifiers are any different. I got a good deal for a next to new receiver.

The specification says up to 7 x 100 W (DIN). 4 Ohm speakers can be driven, that is important for me as I am useing vintage BRAUN L710 and L810 and a small CANTON as center (very similar sound characteristics) - two more L710 are in the pipeline.
The receiver has no automatic calibrating. There is no HDMI, but I am not so much the guy for video.

When using the receiver in stereo mode than automatically two amps are used for each channel, which gives more power and performance.

The above mentioned combination speakers - receiver gives a very neat sound. It reminds me of my class A amplifier - electrostatic headphone combination.
____________
Peter

Mannermusic
09-08-2008, 06:08 AM
As mentioned at the top of the tread (Grumpy, #2), RFI is a problem. If you use an indoor TV antenna, you will have RFI interference. JBL knows this but has no concrete solution, for example, for the Venue series subs. It appears to me their chief advantage is simplicity and low cost. For home hi fi, I'd rather purchase an all-purpose amp with no limitations. So, be careful of your intended application. Mike

Hoerninger
09-10-2008, 10:58 AM
... RFI is a problem. If you use an indoor TV antenna, you will have RFI interference.

It depends ...
The Panasonic SA-XR55 has a FM and AM tuner. Both work with an indoor antenna.

For AM there is a loop antenna with a shielded cable. AM is very sensitive to RFI. About two feet between loop and receiver, the cable is longer, there is no digital hiss or distortion to hear. But if the loop is right in front of the receiver it is a no go.

Things evolve...
___________
Peter

Audiobeer
09-17-2008, 07:39 PM
A lot of older amps were built as Class D such as the Sansu "Au" line in the late 70s.