Class A OPamp, or Class AB 24 transistor?

[Pearlworld]

"What's the difference between the Beyond and Encore?
The Beyond is a Class 'A' amplifier and uses an OPamp for the main amplifier. The Encore is a Class 'AB' amplifier and uses 24 transistors per channel." Thats quoted from here http://www.firestoneaudio.com.au/pro.../headamps.html
Looking to buy a Firestone Cute, and im wondering what the difference is inbetween the Beyond and Encore ? Ill be using the amp for my AKG k501's , MS-1's and Mylarone X3's.
Can someone explain this to me, and point me in the right direction, i still don't understand any of this tech stuff... (couldn't find anything on this in the search, would also appreciate being pointed towards a thread that explains vocab and stuff), Cheers fellas

 

[majkel]

They don't state what kind of op-amp they used, so it is not much informational. Class A is smoother with better clarity and transparency in general but on the other hand, good diamond buffer while being class AB solution, might sound very well, preserving all aspects of class A. Class AB gives better impact and bass thump.
The only way is to listen to both of them or ask people who have listened these models and could describe the differences. Trying to guess the sound signature by technical solutions makes no sense IMHO. Here you can only trust company's statements, however they say nothing about soundstage, details, warmth and smoothness of sound. For regular headphones I would use the other solution than recommended for bass-shy AKG K1000.

 

[Pearlworld]

If it helps, im more after a warm, bassy sounding amp, because ive already got the AKG k501's which are crisp and analytical, hoping to mix the two sounds to get to a midpoint... thanks, for the help, more needed

 

[RatFarm]

Opamps generally cannot deliver current the way transistors can. If you have demanding headphones then descrete (transistor) is the way to go.

 

[jcx]

Impressed with the reading ability displayed above? I am

-on the pages for each amp the Beyond is described:

• OPA2227 for main amplifier
• Current boosters made by NPN/PNP power transistors
• Class A amplifier
• Extra low output resistance (Zo less than 0.05 ohms)
• High current capacity (200mA per channel)
...
• Max. output 6Vrms (24VDC adaptor)

I always think the 1st question is can the amp drive the headphones with enough I, V to reach real world dynamic peak SPL without the amplifier clipping

the 6 Vrms, 200 mA spec is fine for the 32 Ohm MS-1

for the 120 Ohm AKG K501 I would look for more V, but this is probably just adequate (7 Vrms required for K501 to reach 120 dB spl)

but 6 Vrms would not really do the best job with 300 or 600 Ohm cans despite the assertion in the marketing blurb

the op amps are socketed so those inclined could "roll" if you believe the claims about opa227 "sound" that will inevitably follow


I'm not sure what the 500 mA output of the Encore is useful for when coupled with the same 6 Vrms spec of the Beyond - driving speakers?


Some buffered op amp designs can do more V, similar A in the same price range:
Xenos 1HA; Meier Headfive, Arietta; or various PPAV2

also some op amps could give more output without the external buffer: AD8397, TPA6120 are two that have been used in headphone amps

 

[kipman725]

can't say without schematics.

 

[majkel]

OK, so...
1) I hate OPA2227's sound. It's veiled, dark, laid back, bassy and boring. For me - awful.

2) Good discrete buffer gives better current output than AD8397, being 310mA maximum peak. From BC337/BC327 you can draw 1A peak and I'm sure in the amp are bigger transistors than these.
3) I often realise that people understand "warm" sound differently. Probably you'll find the discrete AB version warmer. Class A gives better clarity which make people prefering "smoky" club atmosphere find this clarity cold. On the other hand class A makes music sound more colorful, heavy AB class makes it "gray" and uninvolving. If you often listen to live music (not amplified), you'll realize class A advantages but, boy, not with an OPA2227. You can buy this model with future op-amp upgrade in memory.

 

[Pearlworld]

How much do op-amps cost alone? I wouldn't upgrade it for sevral weeks, but i'm wondering how much it'll cost, if its hard to do, and if they're easily available in australia... thanks for the help guys