So, i will expect so flat SPL vs.frequency as possible (quality driver selection..) ,even so flat impedance curve. Compensate for dips and peaks is much more effective (and possible) and box performance will be amp DF independent. And speaker Q compensation should be made inside speaker box, not to rely on low DF of amp. This i find "intelligent".
Exactly. Especially, when DSP tries to compensate not only resonant peaks, but also dips.
Hi John,
Look up the Revox B-242 amplifier.
Mosfet driving BJTs. Cool idea, and pretty clear as to what they were trying to do. Of course, NFB is required as the mosfets themselves suffer non-linearity. They just don't reflect that back to the Vas. Just another twist to get to the same end, imaginative though.
-Chris
Look up the Revox B-242 amplifier.
Mosfet driving BJTs. Cool idea, and pretty clear as to what they were trying to do. Of course, NFB is required as the mosfets themselves suffer non-linearity. They just don't reflect that back to the Vas. Just another twist to get to the same end, imaginative though.
-Chris
The ear related problem, different with different persons, is really too complex
. That's why some need output transformers with horrible frequency response, and high and non-linear output impedance supported by high, amplitude dependent distortion, that masks speaker distortion and heavily modifies frequency response. Many people just do not want perfect responses (of any kind). But almost no one is willing to admit this fact
PMA, I have never found that added distortion was a good thing. However, I have heard sound systems that have significant measured distortion that sound pretty good, in spite of the measurements. There is a significant difference between your opinion and mine. Yet others here don't believe that most of the differences that you and I care about, really exist. How about that?
Free from here:
STUDER REVOX B242 Service Manual free download, schematics, eeprom, repair info for electronics
first page on google.
John,
link removed due to potential copyright violation
You may have to look a little for the download link.
There is not much special, it is pretty bog standard these days.
Fully Rail symmetrical cascoded frontend with some serious degenration, buffered and cascoded VAS with some significant degeneration, if i see right Hawksford Error Correction and multiple layers of VAS Buffering. The choice of the Driver V-Fets strikes me as subideal, three parallel pairs of BJT's as outputs.
Ciao T
link removed due to potential copyright violation You may have to look a little for the download link.
There is not much special, it is pretty bog standard these days.
Fully Rail symmetrical cascoded frontend with some serious degenration, buffered and cascoded VAS with some significant degeneration, if i see right Hawksford Error Correction and multiple layers of VAS Buffering. The choice of the Driver V-Fets strikes me as subideal, three parallel pairs of BJT's as outputs.
Ciao T
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John,
I do not know the date of this unit, however in the 1980's German PA Equipment Maker Zeck promoted their "BiMos" Amplifiers as being superior to classic Bipolar Amplifiers, like the Peavey CS800/1200 Series which had some real grunt in the bass but sounded edgy in Mid and treble and the then heavily promoted Mosfet Output Amp's, which sounded "foggy" in upper mid and treble applications and invariably failed completely to drive Bass cabinets well (not enough mosfet pairs, insuffcient lack of drivers for the Mosfets).
Zeck's "BiMos" used the small Hitachi Drivers and the usual banks of Bipolar Transistors. They did sound at the time considerably better than the alternatives (in PA Applications).
Ciao T
I do not know the date of this unit, however in the 1980's German PA Equipment Maker Zeck promoted their "BiMos" Amplifiers as being superior to classic Bipolar Amplifiers, like the Peavey CS800/1200 Series which had some real grunt in the bass but sounded edgy in Mid and treble and the then heavily promoted Mosfet Output Amp's, which sounded "foggy" in upper mid and treble applications and invariably failed completely to drive Bass cabinets well (not enough mosfet pairs, insuffcient lack of drivers for the Mosfets).
Zeck's "BiMos" used the small Hitachi Drivers and the usual banks of Bipolar Transistors. They did sound at the time considerably better than the alternatives (in PA Applications).
Ciao T
Actually in most of the drivers I play with, the "Mass Break" comes into play first and gives that nice level line of the frequency response graph that many mistake for a good thing!
(Mass Break is not time out for a religious service!
)Last night I realized that for my current DSP project if I change the order of the processes I can reduce the work by 75%! So I have quite a project for today!
Yes, perfect, ideal "massless" piston with ideal "motor"
. But of course I was talking about whole loudspeaker box, not about stand alone speakers.
I don't know algorithm of Audissey from Denon, but it works quite well!
How yours work?
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