Richard:
Have you listened to the Benchmark AHB2?
What did you think of it, relative to what you're looking for in amps?
No secret agenda, just curious ....
mlloyd1
Have you listened to the Benchmark AHB2?
What did you think of it, relative to what you're looking for in amps?
No secret agenda, just curious ....
mlloyd1
They're fairly good. I think they're probably the smartest home theater choice. But do they sound like a CFA amp or a VFA treated very well? No, not quite.
Why Home Theater? Well, they're not harsh on the ears, sound fairly powerful, and they're tiny so you can place them anywhere, right at the speakers if you so wish, or even in a wall. And I think they out pace most classD options by a good margin.
I just got back from The Office and tested a sample CFA originated by Damir.
JC.... yes, I think it is more than SR but aligned with the fact that the distortion doesn't rise within audio BW as most typical of high gnfb VFA will do. Talking power amps here. The constant distortion with freq and power and load is very impressive to measure, let alone hear. No dynamic changes. Rock solid and pin-point imaging.
Here are a few of many tests done today to illustrate the small variances --- 2, 4 and 8 Ohms.
2 and 4 Ohms
2 Ohms ! >600W
----------
----------
8 Ohms
same with freq... very low and little change.
The above is in all cases 2H only. 3H is <-110dB
THx-RNMarsh
JC.... yes, I think it is more than SR but aligned with the fact that the distortion doesn't rise within audio BW as most typical of high gnfb VFA will do. Talking power amps here. The constant distortion with freq and power and load is very impressive to measure, let alone hear. No dynamic changes. Rock solid and pin-point imaging.
Here are a few of many tests done today to illustrate the small variances --- 2, 4 and 8 Ohms.
2 and 4 Ohms 2 Ohms ! >600W----------
----------
8 Ohmssame with freq... very low and little change.
The above is in all cases 2H only. 3H is <-110dB
THx-RNMarsh
Attachments
Last edited:
Not a CFA, something about what is right and what is wrong. Audio PA's are designed to operate at a very narrow range of closed loop gains and are set up that way. The buffered CFA at 20dB more closed loop gain would have 20dB less BW (VFA).
Nope... not here any way. Using current mode operation only then will add -B, later.
-RNM
-RNM
Last edited:
I guess EE's are wasting their time with audio. Just about any input topology outputs a current, if that makes it current mode OK by me.
Last edited:
I am referring to Current-Mode circuit operation with buffer added to - input port. But the tests shown here are NOT with the -B input port added on... later for that mod.
THx-RNMarsh
THx-RNMarsh
Last edited:
No I haven't. For myself, the power is too low and I would have to buy two and bridge them. Way too expensive. But certainly would like to hear it on my system.
THx-RNMarsh
RE: Richards new amp
Very nice!
😎
More internal photos, please.
I'd really like to see/hear about the construction details that help get those impressive measurements.
🙂
mlloyd1
Very nice!
😎
More internal photos, please.
I'd really like to see/hear about the construction details that help get those impressive measurements.
🙂
mlloyd1
That's fantastic Richard - built like the proverbial out house - that's going to be around for many years!
🙂
🙂
I think you've nailed the whole design preference thing. You find a topology you like and feel comfortable with (and you of course like the sound as well) and then you keep working with it and refining it. JC likes complementary input folded cascade designs, DS likes blameless, I am happy with symmetrical CFA and so it goes.
I think Waly is into RF amps. But he hasn't quite worked out that they aren't really suitable for audio. You know, the stuff between 20 Hz and 20kHz.
😀
(I've calmed down now Scott 😉 )
Last edited:
- Status
- Not open for further replies.