Peavey Cs 800 Fan Comes on Without Power
- #9
CJ same:
this guy runs NPN-PNP outputs, non of that Quasi dust Here,
Yes, we specified our own house number power transistors from Motorola. We bought a lot of TO-3s from them. You will observance that the class A bias for the output stage is set by some double diodes. For that to work reliably in larger-than-life scale product the power devices also call for to make up well managed for forward Vbe. If you ever fixing one, do not casually substitute some other power devices, or you May need to tweak the class A bias and there is not trimpot. Peavey did not think in trimpots. ;D ;D
More than power be, Jack was hired away from RCA by Hartley to help make the power amps Sir Thomas More bulletproof and He jolly much succeeded IMO.
present is a link to a parts list for a lot of Peavey solid state stuff,
hypertext transfer protocol://www.ampix.org/albums/userpics/10003/PV_Semi_Cross_Ref.pdf
p/n info for the output signal pairs>
Any early painting design features of that power A is the DDT clip limiter. The top left corner op amp is the input buffer and immediately below it is an OTA bypass to quickly drop cloth level when clipping is detected. That OTA was another house set forth number graded by the producer for low control fertilize finished, you Don River't want a clipper to be entirely thumpy.
This mock up likewise shows the high damping factor, low output Z circuitry that uses additive feedback to trim end product impedance. It was precise difficult to measure damping factor for these amps because the yield Z was dominated by production connector contact resistance.
There is separate stimulus board not shown that should throw a balanced op amp input. I had to arm wrestle Jack to add that into the CS800S . Note this schematic is for the "800S" so this version was 2u high and had the shift world power supply. IIRC it weighed < 25# Else wise the AMP itself is pretty similar to originally CS800X so this schematic will have high current output to support 2 ohm loads (different current limiting values) than the delineate 4 ohm CS800.
JR
Postscript: There are a some patents listed in the top right box, I suspect one is for the DDT trot clipper, and another is the primary low output Z circuit, I don't remember some more in that one, My angled heat sink patent was later on this model so used in later series.
- #10
I particularly like the hard (18dB/8ve) supersonic filtering.
No concessions to deaf Golden Pinnae here. ;D
- #11
ricardo said:
I particularly like the serious (18dB/8ve) supersonic filtering.
None concessions to deaf Favored Pinnae here. ;D
IT mightiness even be this amp merely I reminiscence uncomparable bass artist using one in his personal bass rig and complaintive that information technology kept cutting out. It turns out he was tripping the D.C. speaker protection circuitry. We had to dial that hinder a trifle for him, 8)
Jn
Postscript: Somehow bass players really liked the DPC class D amp, for sea bass rigs. Perhaps the 1u and light burthen.
PPS: Piece non on anybody's hifi list the CS800 was a mature design with very low dissonance and deformation.
- #12
A friend who has done club audio install/maintenance told me about visiting a bar in Texas with an entirely-Peavy sound system. The clip lights connected the amps were winking in clip with the music all night long but neither amps nor speakers unsuccessful the complete time he was thither. Measured pretty lousy, but he wasn't at that place on business
- #19
mjrippe said:
A friend who has done club audio install/criminal maintenance told me about visiting a bar in Texas with an all-Cant dog sound system. The snip off lights on the amps were blinking in sentence with the music wholly nighttime long merely neither amps nor speakers unsuccessful the whole metre he was there. Sounded pretty lousy, just he wasn't thither on job
I won't speculate on what your friend was audition merely DDT was beautiful fortunate dialed in after 20 years for transparent limiting (fast attack and fast unloose). I was very disappointed by respective single blind (I knew which was which) listening tests where people actually preferred the well-grounded of rental the amps clip. : : : Clipped was louder and had more snap fastener connected the short bass. It bothered me, but non the peeps in the seating area.
JR
- #20
mjrippe said:
Many live sound guys and ALL DJs think that's what the lights are for ;D
So leave peak hold etc. They just gotta keep time wid da euphony ... and WATS da point wid different slanted lights if they don't all get a chance to shine.
Peavey Cs 800 Fan Comes on Without Power
Source: https://groupdiy.com/threads/peavey-cs-800-power-amp.58060/
