xoundmind Posted July 7, 2020 Share Posted July 7, 2020 In the hope of learning more about tube HiFi, what is the rationale for having two rectifier tubes in a circuit? Is this more prevalent in SET amps? (I know that some - particularly Mesa Boogie - guitar amps have two rectifiers, but it is not at all common.) Thanks for any wisdom on the matter. Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted July 7, 2020 Share Posted July 7, 2020 It's possible they want dual rectifiers for 2 different power supplies. One of each channel, or in the case of the Mesa Boogie, maybe one for the pre amp and one for the power amp. Quote Link to comment Share on other sites More sharing options...
xoundmind Posted July 8, 2020 Author Share Posted July 8, 2020 Jeff: Is it actually lowering the resistance too...which would have the combined effect of lowering the voltage. I’m possibly not following what you’re saying. thanks Quote Link to comment Share on other sites More sharing options...
babadono Posted July 8, 2020 Share Posted July 8, 2020 Ain't it just like solid state? 1 rectifier = half wave rectification, 2 rectifiers = full wave rectification, 4 rectifiers = full wave bridge rectification? 1 Quote Link to comment Share on other sites More sharing options...
babadono Posted July 8, 2020 Share Posted July 8, 2020 So most tube rectifiers are like a three terminal two diode SS package with a common cathode(and yea they make them). Cool. Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted July 8, 2020 Share Posted July 8, 2020 20 hours ago, xoundmind said: In the hope of learning more about tube HiFi, what is the rationale for having two rectifier tubes in a circuit? Is this more prevalent in SET amps? (I know that some - particularly Mesa Boogie - guitar amps have two rectifiers, but it is not at all common.) Thanks for any wisdom on the matter. Tube rectifiers drop a certain amount of voltage which, generally, is proportional to the dc current drawn. Two tubes are sometimes used in parallel to limit the voltage drop in amps in which the current draw varies quite a bit. In amps like SETs, in which the dc current draw Is quite constant, it is unnecessary. Manufactures sometimes used 2 rectifier tubes for marketing purposes. In guitar amps voltage sag is sometimes preferred as it can result in a distortion characteristic which some like. You can’t compare that with high fidelity applications. This topic can get involved and can be discussed in more detail if needed. Tubes like the 5U4 are full wave, not dual, rectifiers and were made for use with a center tapped transformer secondary. Maynard 2 Quote Link to comment Share on other sites More sharing options...
xoundmind Posted July 8, 2020 Author Share Posted July 8, 2020 Many thanks for all of the responses. Quote Link to comment Share on other sites More sharing options...
ned Posted July 9, 2020 Share Posted July 9, 2020 Fisher used dual rectification with the 50-a platform (including the 55a and 200a) mono blocks. 1956-1959 1 Quote Link to comment Share on other sites More sharing options...
Jim Gregory Posted July 26, 2020 Share Posted July 26, 2020 Since rectifier was brought.... I have Cary 805C monoblocks that have one rectifier in each amp. Cary states as 1629/6U5. Researched and find that the 1629 and 6U5 is the same “if I am understanding it correctly”. One of the amps has the rectifier going out. Should I replace both ? They are both the same age. Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted July 26, 2020 Share Posted July 26, 2020 7 hours ago, Jim Gregory said: Since rectifier was brought.... I have Cary 805C monoblocks that have one rectifier in each amp. Cary states as 1629/6U5. Researched and find that the 1629 and 6U5 is the same “if I am understanding it correctly”. One of the amps has the rectifier going out. Should I replace both ? They are both the same age. The 1629 and 6U5 are not rectifiers. They are “tuning eyes.” Their filament voltages are not the same, and require different sockets. Maynard Quote Link to comment Share on other sites More sharing options...
Jim Gregory Posted July 26, 2020 Share Posted July 26, 2020 5 hours ago, tube fanatic said: The 1629 and 6U5 are not rectifiers. They are “tuning eyes.” Their filament voltages are not the same, and require different sockets. Maynard Thanks Maynard Read some more and find that the tube is used as a visual voltage indicator. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.