Not sure this is the right place but here goes anyway. Warning, very basic question below.
I have a pair of Rotel RB850 power amps that look like they are a dual mono design and have two transformers. I like their sound but wondered if there were any simple mids to make them better. Was thinking about a beefier toroidal transformer as a first step, anyone go suggestions of what to go for?
From online diagrams looks like the transformers are 30v-0-30v? What Iva should I be looking for and do I keep it with two transformer or go with one with dual secondaries.
I have a pair of Rotel RB850 power amps that look like they are a dual mono design and have two transformers. I like their sound but wondered if there were any simple mids to make them better. Was thinking about a beefier toroidal transformer as a first step, anyone go suggestions of what to go for?
From online diagrams looks like the transformers are 30v-0-30v? What Iva should I be looking for and do I keep it with two transformer or go with one with dual secondaries.
Doing a bit of googling-
Am I better with two of these
Vigortronix VTX-146-300-230 Toroidal Transformer 300VA 0-30V | Rapid Online
Or one of these
1pcs 500VA Black cloth Toroid Transformer for NAP200 amp 28V-0-28V 28V-0-28V | eBay
Stupid question alert - what is the difference between a 2 x 30v and a 30v-0-30v transformer and can the former be used as the latter by connecting the two 0v lines?
Am I better with two of these
Vigortronix VTX-146-300-230 Toroidal Transformer 300VA 0-30V | Rapid Online
Or one of these
1pcs 500VA Black cloth Toroid Transformer for NAP200 amp 28V-0-28V 28V-0-28V | eBay
Stupid question alert - what is the difference between a 2 x 30v and a 30v-0-30v transformer and can the former be used as the latter by connecting the two 0v lines?
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Hi,
Not sure what would you like to achieve by replacing transformers?
Do you have a hum from existing transformers?
Best regards.
Not sure what would you like to achieve by replacing transformers?
Do you have a hum from existing transformers?
Best regards.
No problems with the current amps they are running fine, no background noise so very happy with what were a £50 each purchases!
I have two running in bridged mode feeding a pair of B&W CDM1SE's as a desktop system, they seem to like a bit of power (plus NAD 1240 preamp and Fostex A3 DAC usb to PC running Spotify mainly but also have an AR EB 101 turntable with AT110E cartridge).
I found the sound more controlled when moving from single amp to bi-amped to bridged and thought that more headroom on the power side may bring even more control? Please correct me if my thinking is not right, what else would you suggest ?
I have two running in bridged mode feeding a pair of B&W CDM1SE's as a desktop system, they seem to like a bit of power (plus NAD 1240 preamp and Fostex A3 DAC usb to PC running Spotify mainly but also have an AR EB 101 turntable with AT110E cartridge).
I found the sound more controlled when moving from single amp to bi-amped to bridged and thought that more headroom on the power side may bring even more control? Please correct me if my thinking is not right, what else would you suggest ?
Much much better than other trafos: connect all the psus - all amps with ONE psu-character: much much finer and homogenious than with channel separated psus.
Renew all solder joints. Solder as less as possible.
Remove all bridging little caps - if existing.
Renew all solder joints. Solder as less as possible.
Remove all bridging little caps - if existing.
This thing is old.
I would replace all caps with hq parts and just upgrade the psu caps if sufficient space is available.
I would replace all caps with hq parts and just upgrade the psu caps if sufficient space is available.
Many thanks again, will look into that and do a quick costing, can you suggest any particular Cap manufacturer that I should look for ?
For future info service manual is here - http://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=12&cad=rja&uact=8&ved=0ahUKEwiFnIOToMjYAhWCIsAKHbHjCr8QFghTMAs&url=http%3A%2F%2Fwww.vintageshifi.com%2Frepertoire-pdf%2Fpdf%2Ftelecharge.php%3Fpdf%3DRotel-RB-850-Service-Manual.pdf&usg=AOvVaw1bC5Ot2ELu1uvR1MRFXw1K
For future info service manual is here - http://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=12&cad=rja&uact=8&ved=0ahUKEwiFnIOToMjYAhWCIsAKHbHjCr8QFghTMAs&url=http%3A%2F%2Fwww.vintageshifi.com%2Frepertoire-pdf%2Fpdf%2Ftelecharge.php%3Fpdf%3DRotel-RB-850-Service-Manual.pdf&usg=AOvVaw1bC5Ot2ELu1uvR1MRFXw1K
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Rotel UK sold the "B" version of many of their amplifiers for the UK audience. These were tuned to suit the average of the typical British listener. They did charge a premium for these factory built versions.
If you can find what the B version of the 850 had in there it would give you some pointers to what parts might give what you are looking for.
If you can find what the B version of the 850 had in there it would give you some pointers to what parts might give what you are looking for.
Don't bother changing the transformers.. that won't really give you any benefit.
Replace the main filter capacitors if you must do anything. Brand doesnt matter as long as it's a quality one like Rubycon, Nichicon, Nippon Chemicon, Vishay, Kemet etc.
Check and re-adjust the bias current as stated in the service manual.
Replace the main filter capacitors if you must do anything. Brand doesnt matter as long as it's a quality one like Rubycon, Nichicon, Nippon Chemicon, Vishay, Kemet etc.
Check and re-adjust the bias current as stated in the service manual.
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