Hi,
Does any one have the schematic of the RM-1 Pre-amp?
If so please let me know !!Thanks a lot!!
Does any one have the schematic of the RM-1 Pre-amp?
If so please let me know !!Thanks a lot!!
Replacement for my Beveridge RM-1 and MD D-75?
I recently had a power surge that damaged my dearly loved Beveridge RM-1/RM-2 (pre-amp and DC regulated power supply). I need for insurance purposes a modern replacement. I called Beveridge and they plan on making this preamp again but this time at a price of $12k - $14k based on cost as it will be made in Chicago (or so I was told). I love the preamp and it was many thousands of dollars in the 80's and the phono-stage was the best I have heard even currently for under $1k.
The RM-1/RM-2 had AC pass to the capacitors as a result of the damaged rectifier. I built a quick rectifier from four 6-amp diodes (monsters - these were!) and replaced a shorted pass-transistor, all damaged capacitors with SPRAGUE 400-volt, 500uf capacitors and hard-wired all the vaporized silver/lead traces with no luck. I spent 15+ hours and about $80 in parts - I had them on hand, though - and still no output. I threw in the towel.
The Musical Design D-75 was also damaged. I am very technical and I repair gear for a a living (usually RF and lab equipment) so I tore into the RM-1/RM-2. The full-wave bridge rectifier was damaged from the surge (it must have been a monster as that rectifier has a SURGE rating of over 200-amps at 1/2 cycle!). The two resistors in-line with the RCA inputs (2.2 ohms 1/2-watt) were BLOWN and that caused a short so the amplifier kept blowing fuses. I replaced the resistors with 10-ohm 1/2-watt and brought it up slowly and at about 10-15 volts the fuses blew - and blew and blew again. The ground floats in the amplifier (bad idea in my opinion) from the initial design - it was not bad or damaged, that was just the way it was designed. Long story short the left and right channel were damaged but the resistor replacement corrected the RIGHT channel - the left channel has two bad MOSFETS and several damaged diodes and capacitors. Again - I threw in the towel. I will get around to fixing them sometime soon but for now I want to know the modern equivalent for the RM-1/RM-2 and possibly the D-75 amplifier even though a current D-75B is available. The amplifier was a glaring deficiency in my system.
It will be paired with my Musical Design CD-1 and MD DAC as well as a pair of my beloved Dunlavy SC-1's. I use NXG BLUE interconnects (I know - but they sound as good as my Nordost as 1/4 the price!) and Nordost Red Dawn speaker cable and USA stands.
Anyone know a current equivellent for the RM-1/RM-2 with equal phono-stage and D-75 replacement? I want to keep the quality the same regardless of price. I have been out of the game for some time (as you can tel from my set-up) so I would not know. The RM-1/RM-2 is the best preamp I have heard and I am disappointed the pre was damaged and not easily repairable. I am concerned all the point-to-point wiring I did can increase the resistance and noise pick-up in the PS leading the coloration of the preamp itself.
Thank you in advance - Darren
The RM-1/RM-2 had AC pass to the capacitors as a result of the damaged rectifier. I built a quick rectifier from four 6-amp diodes (monsters - these were!) and replaced a shorted pass-transistor, all damaged capacitors with SPRAGUE 400-volt, 500uf capacitors and hard-wired all the vaporized silver/lead traces with no luck. I spent 15+ hours and about $80 in parts - I had them on hand, though - and still no output. I threw in the towel.
The Musical Design D-75 was also damaged. I am very technical and I repair gear for a a living (usually RF and lab equipment) so I tore into the RM-1/RM-2. The full-wave bridge rectifier was damaged from the surge (it must have been a monster as that rectifier has a SURGE rating of over 200-amps at 1/2 cycle!). The two resistors in-line with the RCA inputs (2.2 ohms 1/2-watt) were BLOWN and that caused a short so the amplifier kept blowing fuses. I replaced the resistors with 10-ohm 1/2-watt and brought it up slowly and at about 10-15 volts the fuses blew - and blew and blew again. The ground floats in the amplifier (bad idea in my opinion) from the initial design - it was not bad or damaged, that was just the way it was designed. Long story short the left and right channel were damaged but the resistor replacement corrected the RIGHT channel - the left channel has two bad MOSFETS and several damaged diodes and capacitors. Again - I threw in the towel. I will get around to fixing them sometime soon but for now I want to know the modern equivalent for the RM-1/RM-2 and possibly the D-75 amplifier even though a current D-75B is available. The amplifier was a glaring deficiency in my system.
It will be paired with my Musical Design CD-1 and MD DAC as well as a pair of my beloved Dunlavy SC-1's. I use NXG BLUE interconnects (I know - but they sound as good as my Nordost as 1/4 the price!) and Nordost Red Dawn speaker cable and USA stands.
Anyone know a current equivellent for the RM-1/RM-2 with equal phono-stage and D-75 replacement? I want to keep the quality the same regardless of price. I have been out of the game for some time (as you can tel from my set-up) so I would not know. The RM-1/RM-2 is the best preamp I have heard and I am disappointed the pre was damaged and not easily repairable. I am concerned all the point-to-point wiring I did can increase the resistance and noise pick-up in the PS leading the coloration of the preamp itself.
Thank you in advance - Darren