pucho812
Well-known member
outside of the burr brown chip opa604, are there any other opamp ic's that can handle and will run off +/- 24V?
48V opamp chips,
- Thread starter pucho812
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Balijon
Well-known member
A bit in the unobtainables...: Analog Systems MA-362 and MA-374 (used in the Jim Gamble EX56 desks)
Theo
Theo
That's easy enough to find out using the parametric search of any bigger distributor. Off the top of my head, TI has some more: OPA551/552, OPA445, OPA454 (high power).
If you're content with 44V, there is much more to find.
If you're content with 44V, there is much more to find.
pucho812
Well-known member
volker said:
44V is true, but would prefer 48V for a project that is a mix of doa's and chips, that way I can have 1 set of power rails
Kingston
Well-known member
you could run those DOA's at 44V. lose only 1dBu of headroom compared to 48V and you don't need to settle in for second rate or outdated opamps.
pucho812
Well-known member
Kingston said:
true
In a world of 5V and 3.3V A/D convertors, 44V rails seem excessive.
In console design I routinely ran most of the internals 6dB cooler than the final output stages, with their automatic + 6dB of voltage gain from 2x signal swing. There is no reason why this strategy couldn't instead run low voltage regions 10dB cooler or whatever.
I don't see much more than bragging rights from very hot PS rails.
Maybe we can have competitions, where people try to blow up other people's input stages with their overly hot outputs. 8)
JR
In console design I routinely ran most of the internals 6dB cooler than the final output stages, with their automatic + 6dB of voltage gain from 2x signal swing. There is no reason why this strategy couldn't instead run low voltage regions 10dB cooler or whatever.
I don't see much more than bragging rights from very hot PS rails.
Maybe we can have competitions, where people try to blow up other people's input stages with their overly hot outputs. 8)
JR
gemini86
Well-known member
I imagine that would resemble one of those car hopping contests...
Rob Flinn
Well-known member
My console is full of them Harris 911 aka MCI 2001
college101
Well-known member
Not everyone understands opamps yet...were in that chapter right now in class
pucho812
Well-known member
college101 said:
o.k.?
college101
Well-known member
Opamps can be used as Voltage amplifiers! BUT what we really need to know...what are you trying to do with the opamps at 48V...Like a few chaps on here suggested...Having a supply line at 48 volts is excessive...a better idea would be to run a lower line and then step it up...
pucho812
Well-known member
college101 said:
Yes they can.
48V max so bi-polar +/- 24V. anyway the idea was/is simple to it run from a single psu source of +/- 24V. since the units in question are a mix of discrete opamps and ic chips, why not have ic chips that run on the same voltages as the doa's and drive down cost a bit. however after some thought I am rethinking my issue.
Andy Peters
Well-known member
college101 said:
That's because they are voltage amplifiers. (BTW, what is commonly called an audio power amplifier is really a voltage amplifier.)
I don't quite get what you're on about there.
-a
Andy Peters said:
Perhaps run low voltage electronics at lower nominal audio signal level, then add voltage gain to step up signal for higher voltage sections?
Kind of academic since you step up noise floor along with signal that is typically dominated by input gain stage so S/N is unchanged, but high rail voltages looks good on paper.
JR
The Philbrick and Heath analog computer opamps ran +/-250V or +/-300V.
I've seen fully differential opamp with +1500V/-200V rails, but it was pretty special-purpose.
Most audio loudspeaker power amps are specialized opamps with rails well over +/-24V.
"Step up" with what?
I've seen fully differential opamp with +1500V/-200V rails, but it was pretty special-purpose.
Most audio loudspeaker power amps are specialized opamps with rails well over +/-24V.
"Step up" with what?
What would be the point of operating the DOA's at 48 and the rest at 44? Headroom would still be limited by the 44 rails.pucho812 said:
pucho812
Well-known member
abbey road d enfer said:
now someone is thinking on the same idea as me.
Asked and answered... If trying to optimize peak output level you can normalize voltage gain between them so they both saturate at roughly the same time.pucho812 said:
but why? 48 Vp-p will probably overload most line inputs.
For one possible justification, audio circuits that don't recover from clipping very well, might benefit from having extra voltage headroom so they never clip.
YMMV.
JR
