I think you might be better off with a filament transformer, rather than stressing a 70 volt line transformer with low frequencies and 2X voltage overload. I do have a 200 watt 70 volt transformer with several taps and a low impedance output so perhaps I could use that to step up the voltage enough.
#Carver cm 1090 wont power off full
I use this set-up with the Tesla fan, because it requires 100 volts, and I need the full output of the Elgar supply at start-up of the fan motor.īecause these power supplies have large audio transformers, they are heavy and can be expensive to ship. In order to obtain the full output at a lower voltage, a variable auto-transformer can be used, up to the frequency limit of the latter. This means that the full rated power output is available only at the full voltage setting. Note that on many of the older types, the voltage control is essentially a “volume control†on the drive to the power amplifier. Later models have numerical entry for frequency and voltage selection. I think that the Models 251 and 501 are the most commonly found of the older models, but you will need one with an analogue wide-range oscillator installed, unless you are willing to use a separate function generator. Elgar called these power supplies “A.C. These power supplies can be found on eBay, and with patience, a listing with a low price can be found.
There is also a miniature phone jack to permit the use of a signal or function generator.
My 121B came with a 300 – 500 cycle plug-in oscillator, which I modified to add a second range. I use one to power an 1896 Westinghouse “Tesla†electric fan, which has ten poles and was made for the 133-cycle lighting systems that Westinghouse had installed in the U.S. I also have one in my studio along with other brands and some home made amplifiers and gear.Elgar Corporation have been a leading brand of variable frequency power supplies. I still use this amp daily as it is on my home listening room stereo. I've also done studios and other facilities though my career.
#Carver cm 1090 wont power off pro
I'm a broadcast and audio engineer with plenty of experience in FOA audio, pro sound, and system design and installation in many different venues. Plenty of loud clear audio.īTW, none of the preselect styles fit me. It did quite good on a pair of A-T VOA A-7As. I even used this amp as a back up on one of my jobs after I made the changes. I pulled my folder on the amp and decided to write a review. How do I remember this? I was searching on line for something and came across this site. Looking at Fresponse I found the amp to exceed ratings and Pout (into 8 ohms/C) was flat over the range at better than 100W/channel with each channel being within a few tenths of a percent of each other. I then looked at waveforms for cross-over and THD distortion. Finally I added good computer grade electrolytics with a better capacitance and voltage rating. I replaced a few of the small electrolytics with better tantilums, some of the cheaper coupling capacitors with a better grade and increased the power value of some of the resistors. I wanted to beef up the entire supply, but there is no room in the enclosure. On the bench I found the poorly designed supply. Same thing when driven to any decent level.
So I tried the amp on some Apogee ribbon speakers. The first thing I found when I started to use my amp was it would shut down on my Altec-Lansing 1204Bs I had on my main stereo. The original design used cheap under sized filter capacitors. The other reason this amp gets a 4 is the cheap power supply design. Ok, I will stop my anti-not made in the USA or Europe tirade. Even Crown and many other once fine products are made cheaply in China and sold at very inflated prices. Now would I consider any high priced China anything. For what these amps cost new and all the raves about Bob Carver I would never had bought a new one. I rated the amp a 4 only because it is made in China. Mine has done a great job ever since I picked one up used in the early 90s.