Discussion in 'Power Amps' started by purr1n, Jan 12, 2020.
Yeah. Maybe its Class H or G, with the variable power rails and traditional output.
Modded used workhorse pro amps and Adcoms have long been super bang for buck. The Adcoms MUST BE MODDED and the fans MUST be changed on many pro amps for domestic use in the same room.
if anyone is a lazy piece of shit and doesn’t mod and complains, then they are a lazy piece of shit.
Should be fine with this newer Class D, H, G stuff. The fan(s) aren't audible and if the amps are pushed into hundreds of watts, the parts inside are going to sing louder than the fan! I'm sure most home speakers will melt by then. The older class AB amps with linear power supplies and big transformers, those fans can be loud at idle.
Is there any reason to expect that the benefits heard with the very efficient JBL's would extend to less efficient speakers with more complex crossovers?
I'm intrigued by this as an option to push 87 dB / 8 ohm nominal floorstanders.
Of course. With less efficient speakers, stuff like this is ideal. This is where the incredible crazy power comes in handy. Even more so if the impedance drop low in certain spots. Unfortunately, I don't have any moderate or low efficiency speakers around.
It's the really opposite of the Aegir, which I think would more ideally be suited to wide-banders (which never dip below 8-ohms) which never dip below 8-ohms and let a something else (like this for instance with its built-in DSP) power the subs.
Ah. Reading the comments before about synergy with high-efficiency speakers made me wonder if there were rules of thumb I wasn't aware of.
I'm generally looking to be punched in the face by the sound produced by my 2-channel setup, on the cheap, so this really looks like it's worth a try. Thanks for bringing awareness about options like this.
Maybe it's just the Canadian part of me, but I still like Bryston amps. They've suffered from price creep because they still try to do everything in Canada and that suuuuuucks because the manufacturing isn't cheap here. It's even worse on their digital products because getting all the required certifications up here is ugly-cry expensive.
On the used market, I think their amps are still good bang for the buck. I had a tri-amped stack with a 4B/3B/2B (actually two 2B's bridged into mono for each side) that was a lot of fun. Ultimately I took it apart, because my rack was not meant for that kind of weight. Bryston's 20-year warranty is also nothing to scoff at. I've had fantastic service from them sending in amps for checkups (not the original owner on any of them), upgrading components for cheaper than I could have done on my own, and just great communications throughout the process.
The class G and H stuff isn't a variant on class D. It's a variant on class A/B where the power rails modulate higher during peaks of music so you don't have as much wasted energy. G has multiple rails, while H actively varies the rail just ahead of the peak (I might have G/H swapped, I don't remember).
More power is *usually* desirable, but after a certain point more power comes at a price. Either literally more $$, more gain/noise, larger physical size/weight, or sonic sacrifices to get the kilowatts, etc. Get as much power as you need for a more-than-comfortable-amount of headroom, and call it a day.
@purr1n I used them for a time with pair of a old B&W DM3000's and also as Crossover/DSP/Amps for a two way horn system using klipsch K402/La Scala bass horn. Neither actually super bright systems. They were not terrible on the B&W, but certainly worse sounding than the nCore 500s I had later. That's why I'm assuming they have improved the design, even the Drivecores sounded better to me when they first came out.
The new version of the XTi is the XTi1002 right? Might will pick one up and compare to CDi1000 to make sure they sound the same. The binding posts and XLR would certainly be easier to deal with.
Used CDi1000 is available for $200 + $8 for two adapters from Sweetwater.
Used XTi1002 is $450
I can deal with fiddly wires for 240 bucks
Yes that's correct. No clue why the Xti1002 are so expensive used.
Indeed. I bought the CDi1000 for less than used XTi1002 prices. I would surmise it's the ease-of-use factors. Most people won't want to deal with Phoenix / euroblock and terminal strips.
Get this amp and a used passive Dynaudio. Most will come in active configuration, but if you can find something like a used passive BM15 with the 10" woofer or X16 with the 7" woofer, you will definitely be good to go. They aren't the most efficient, but they will take a ton of power and react accordingly - that is punch you in the face. Expect to pay $800-$1000 for the speakers.
On the Crutchfield product page for the CDi 1000, the fourth bullet under Product highlights suggests Output eq is not bypassable
“output EQ: 8 parametric filters per channel with adjustable Q, ±15 dB boost/cut, and adjustable shelving filters (not bypassable)”
The front panel has a DSP bypass. I think Crown is saying that once DSP is on, the 8 PEQ bands are always there are cannot be selectively bypassed, like on dedicated digital EQ boxes.
Looks to me like a typical AB with some CM coils to relieve from the sins of the switcher before it, (probably also G/H at higher demand), probably mosfets for such power in so few parts count.
I'm surprised to see TO-3 (still the best casing for thermals) parts in so recent design. Can you read the dev name or get a close up?
I admire your courage. This resistor without heatsink would be around 60W rated.
Short term it can take 10x more and it will take a while to burn it down.
I burned hole into a desk with a 100W unit without heatsink and it was in spec afterwards.
Those are great. The passive Dynaudios designed by Andy Munroe are pretty much indestructible. The active plateamps have had some durability issues and were cheaped out after the initial (and still available) BM15 a and BM6a. Too bad Dyn went downhill in the 2000s. I heard the Lyds and went WTF
Doesn't seem a problem with quick few second bursts (enough to get a good FFT) such as the THD+N vs voltage level plots, but sustained more than a few seconds at 375W, those things get mighty hot. Might need to build something mounted to fireproof plate with fans. I figure I'll take a voltage reading at lower wattage to confirm, and then to do the math from there.
MJ21194G for the NPN
MJ21193G for the PNP
They sure will take a ton of voltage. Could be fun to put these direct coupled after a tube and add a big cap after the transistors for a headphone amp. Sort of a tube / transistor hybrid OTL. Haha.
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