Monkeybrains Posted February 2, 2011 Share Posted February 2, 2011 I just picked up a used pair of RF 7's about 8 years old and i noticed the sticker on the back say 150 watts Max Input . My RF 5's about 7 years old say 250 Watts Max input ??? The RF 7 can handle more power Correct ? are the sticker mixed up ? Im looking at a Emotiva amp do i get Two (UPA - 1 Mono blocks) 200W Rms @ 8 Ohm - 350W Rms @ 4 Ohm or One (XPA - 2 2 Channel) 300W s Rms @ 8 Ohm - 500W Rms @ 4 Ohm for my RF 7's . Thanks Quote Link to comment Share on other sites More sharing options...
jacksonbart Posted February 2, 2011 Share Posted February 2, 2011 Assuming your amp does not clip, you will damage your ears long before you damage the RF7s with clean watts. Quote Link to comment Share on other sites More sharing options...
Guest davidness Posted February 2, 2011 Share Posted February 2, 2011 I agree. Do not even worry about the watts rating. Your head will explode before the speaker. If it were me, i'd get the XPA2, or if your ready for the extra effort, get a nice tube amp, like Don's Dynaco ST70 over in the Garage Sale section. Quote Link to comment Share on other sites More sharing options...
Guest davidness Posted February 2, 2011 Share Posted February 2, 2011 PS; congratulations on the RF7's. I've had my pair for over a year, and they are the best single investment I've ever made. They sound frigin' awesome! Quote Link to comment Share on other sites More sharing options...
Monkeybrains Posted February 2, 2011 Author Share Posted February 2, 2011 Thanks Guys i keep reading about the Tube amps people are using but i know NOTHING About Them . If i buy a used tube amp and then later it may need repair does it cost alot of money to fix or update them. What about a new tube amp for the RF 7's can i get something under 2000 dollars in Canada ? How many watt tube amp is best for the RF 7. What other tube amp would work well with them . Thanks guys im going to research all about tube amps now . Quote Link to comment Share on other sites More sharing options...
Guest davidness Posted February 2, 2011 Share Posted February 2, 2011 I currently have a Bob Latino ST-120 tube amp, which is a modern, more powerful version of the Dynaco ST-70, the most popular tube amp ever made (about 300,000 sold) driving my RF-7's. The ST-70 is more than powerful enough for a pair of RF-7's. The ST-120 even more so! (the American need for excess!) The ST-70 for sale by Don in the Garage Sale looks to be in great condition and has all the modern updates you want, and for that price in that condition, it's a steal, and an excellent introduction to tube amps. It's what I'd buy if I were you. Or, I'd purchase a kit from Bob Latino and assemble it myself. This would allow you to really get to know something about something you don't know anything about, and you'd then be able to self-service the amp for life. Tube amps blow tubes. Tubes cost money. Figure the average power tube will last about a year, maybe more, maybe less. Figure $30-$50 for each tube. The smaller input tubes rarely go bad, but can be had for $15 (new) to $80 (premium vintage). The rectifier tube is the most likely to go bad, perhaps 1 or 2 a year. Maybe it'll last a lot longer. Figure $15 to $50 for the rectifier tube. Lots of service options, and in the long run, it's easier to service than a solid state amp. I just had my Bob Latino amp fully reconditioned by Bob Latino himself, with new capacitors and some resistors, and the bill was about $125 plus shipping. Lots of people out there service the old Dynacos. Lots, including some members of this forum (Craig at NOSValves for one). Sometimes, tube amps have a reputation for not delivering as much bass as a good solid-state amp, but I have no problems, but I also have a seperate subwoofer, so that certainly helps. Tube amps sound great, they look really cool (and run really hot), and are great conversation pieces. Let me know if you have any more questions. Quote Link to comment Share on other sites More sharing options...
Guest davidness Posted February 2, 2011 Share Posted February 2, 2011 they look really cool Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted February 2, 2011 Share Posted February 2, 2011 Thanks Guys i keep reading about the Tube amps people are using but i know NOTHING About Them . If i buy a used tube amp and then later it may need repair does it cost alot of money to fix or update them. What about a new tube amp for the RF 7's can i get something under 2000 dollars in Canada ? How many watt tube amp is best for the RF 7. What other tube amp would work well with them . Thanks guys im going to research all about tube amps now . Be careful about the tube amp that you choose as the RF-7 is reported to have an impedance dip down to 2.7 ohms (I have not seen any info about the phase angle, which would also be useful to know) which can result in increased distortion with some designs. I have to disagree with the comment above about the life span of tubes. It all depends on how the tubes are used- many vintage commercial amps pushed tubes beyond their safe ratings as tube replacement costs when these were made were fairly low. But, in an amplifier of good design, it's not unusual to have tubes last 10-50,000 hours (and that includes the power amplifier tubes). This is not an exaggeration- I've designed and built many dozens of amps for people over the years and this kind of life has been typical. The other issue concerning tube life is ventilation. Some vintage amps were notoriously deficient in that area- again the manufacturers were not overly concerned about excessive heat build-up. As far as the cost of repairing a vintage amp goes, it all depends on the amp and the problem that occurs. At times, the repair cost can exceed the value of the amp itself. So, be careful in making your choice and, if you decide to buy a new amp, call the manufacturer and discuss these issues with one of their technical people before you purchase...................... Quote Link to comment Share on other sites More sharing options...
Guest davidness Posted February 2, 2011 Share Posted February 2, 2011 I have to disagree with the comment above about the life span of tubes. I'll defer. I suspect Tube Fanatic's expertise far exceeds my own. I only have experience with one tube amp. I had been going through a lot of tubes, which is why I sent it to Bob Latino for a 'refurbishment'. He found the problem (some incorrectly installed PIO capacitors) and he says my abnormal experience with tube life is now behind me. So far, since it's return, I've had no further problems. Quote Link to comment Share on other sites More sharing options...
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