No, just a bridge in the linear rectifier. SMPS also has own rectifier, so I see no reason in adding more diodes.
I got 2pcs of Mark Levinson phono preamp module,it should be used in JC2 preamp.there is a no signal information in the module,it should be bad one,but I would to try to connect the pin and do some testing,there are six pins in there. Any one can help how to connect cable to testing this module? whichi pin for the power supply and which pins for input/output.Any comments and suggestion will be great appreciate.
Attached the picture for you reference.
Attached the picture for you reference.
Attachments
Yes, I am sure 5kVA+ transformers are cheap, small, and lightweight. A 2.5kVA toroid from Triad weighs 43 lbs.
Bet your Crown I-Tech 5000HD amp with the JBL M2 uses an SMPS. It can only do 2000W into 2 ohms though
.There is a lack of higher output voltage SMPS off-the-shelf yes. In automotive they are probably using boost regulators like PMP9637.
Hypex is selling their 3000W SMPS for about the same amount of money your transformer costs.
Hypex Electronics webshop
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And you probably worked on some Chris! I know I did, which is how I picked up a Sony TA-86 with a dead power supply in college working as a stereo tech (I bought it from the owner cheap because no other tech in the Amherst, MA area was willing to mess with a SMPS):
Sony TA-N86B on thevintageknob.org
It was the first piece of stereo equipment I ever saw with a SMPS, at the time called a "Pulse Power Supply." I really liked that amp, and although I lacked the test equipment at the time to verify the ripple amplitude, I never heard anything wrong with the amp, such as intermod products between the PS ripple and HF signal. Sure, some may not consider it ultimate audiophile stuff, but it was a very competent amp with switchable Class A/space heater mode. I drove it with a Luxman C1000 preamp and a Luxman PD-441 TT and it was a marvelous sounding setup for the late 70's...I still have the Luxman TT..
I ought to compile a record of all the stereo equipment I have had since I started building systems...it all started with a KLH 27 handed down from my Dad...
Sonic history trivia...
Howie
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Hi Howie,
Yes, and I have a Sony integrated amp in for repair now that uses an SMPS. It was "struck by technician". It even has a T.I.M. that I have to trace on top of the original failure. No one else would touch it, and silly me accepted the job.
I suspect that your list might be as long as mine. No one should have had that many over time.
Cheers!
Yes, and I have a Sony integrated amp in for repair now that uses an SMPS. It was "struck by technician". It even has a T.I.M. that I have to trace on top of the original failure. No one else would touch it, and silly me accepted the job.
I suspect that your list might be as long as mine. No one should have had that many over time.
Cheers!
In late 70'Th my mentor come from some closed expo in Moscow and described a Sony amp that they demoed there among other things. I quickly designed my switching power supply. The problem was, to find high voltage transistors in USSR then. I found some prototypes, with "factory" names, without official designations. To drive them I used CMOS logic ICes. I divided the frequency twice to get a clean meander, then using a logic combined it with delayed by monostable multivibrators then divided the same signal. It was just an exercise, of course nobody was thinking them about using such exotics in production.
Aaah. The relevant part --- I tried a Hypex. But could try the 3KW one, also. Could be useful for something.
That is Thee problem... higher voltage models.
If I was satisfied with the Crown digital amps with smps, I would be done now. Great for stadiums but not very High-End performance. Details missing. Sound is not very sophisticated or refined.… more like good mid HiFi. But, powerful mid fi. Best part is the DSP/xover.
THx-RNMarsh
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I would disagree with that! All the profesional audio power amplifiers have DSP options. Many sound better, but the killer is reliability.
In one site it is basically a full day travel to and fro. Figure in airfare, hotel etcetera and the cost of service is about $3,000 per visit. Tolerence for even a single failed amplifier just ain't there. Not surprisingly DSP units have higher failure rates. At first running close to 20%. Even if the amplifiers were free, the true costs would be too high.
Did one auditorium with Crown amplifiers and Vertec loudspeakers. Simple problems like with a pair of fans one was installed backwards so noise but no airflow. Close enough service only used a long day. After three years of the system often being sub-par all the amplifiers replaced by Ashly, one of my favorites. Very noticable improvement in quality and no failures so far.
Hi... not sure what you disagree about. seems that we agree on the sound of the Crown Amps. I wasn't talking of reliability but that has been a known weakness in many smps. I don't know if an Ashly is good enough even if better than Crown.
The dsp is still the best part for me because I can input all the speaker parameters from the front panel USB port and let the dsp/uP/firmware do the rest. I don't need the most current SOTA DSP at the moment when the PA part is so bad in sound. I just hope the amp/dsp doesn't fail before I can replace it.
As far as my experience is concerned, the digital amps and smps still are not SOTA sound wise. BenchMark PA may be an exception as it is very good but not the best of the best. And we don't know about its reliability yet... too new. For my application, I would need 4 of them... Bi-amp'ed speakers and PA set for mono operation. For 1/3 their cost, I can have two of Damir's designs which do the job and give SOTA sound. But then that's at my cost. But even at estimated retail, they still sound better.
IMHO of course.
THx-RNMarsh
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I bought a pair of Behringer NU3000DSP to drive cardioid bass arrays that I am building for upcoming festival in October. I almost finished one section, will try tomorrow. 7 more sections to go, after I test it and adjust properly acoustic resistance...
I hope I can set up crossover from a front panel, without connection to Windows computer that I don't have.
I hope I can set up crossover from a front panel, without connection to Windows computer that I don't have.
Sounds like Ed had more of a Crown problem than DSP problem. Should be one of the more reliable parts of an amp.
A DSP for 2 channels of audio is going to be pretty cheap. If they use something like an AD SigmaDSP maybe $20 in qty 1 at Digikey.
Actually, I was looking at a SigmaDSP recently. Looks like needing to do SRC is pretty common when doing DSP between different clock domains, but they are not as low distortion for that as something like SRC4392 or AK4137. Dedicated chips could be added for SRC, but that would add to cost and complexity. The Crown amps have Sharc chips, which may be better than SigmaDSP parts for SRC, not sure.
I'm not clear on the concept of THD in isolation with a purely mathematical process. There are compromises at any point in time to account for computational limitations to achieve real time results. I usually see these as a total artifact/noise floor rather than concentrated in harmonics. I might be wrong, the data sheets these days are very sparse and don't offer much insight.
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