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Old 8th June 2012, 09:42 AM   #741
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I found, like Buzz, that active regulation is the next level. Not required for really good sound however. When it comes to the heaters, I found that simple AC is best.
Furthermore, another tweek that I am on the fence with is using a ccs as the anode load vs. a resistor. I am currently using a CCS and have been for many months. Others swear by the simple resistor.

Stiff power supply, I am not sure, however, I used the parts I had which turned into a massive looking thing. IMHO, I don't think they hurt but not required provided channel seperation can be maintained.

These are just my opinions. As usual measurements don't show significant difference.
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Old 8th June 2012, 10:22 AM   #742
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At the risk of being stoned, the only thing I have not liked is the tube rectifier. As I said earlier, I haev not touched it since finishing it, but when i added the Winged C 5u4g, i got something i dont quite like. NOt as clean as the SS. I would argue it added something negative vs something positive. Probelm is, I threwit together, so it could be layout related. I also changed from CRC to CLC. Too many variables. I got a big matching thing to go through and all will be redone. I am going to layout the entire internals on a pcb for neatness, i know heresy, and then set the psu up in such a way that I can switch from SS to tube rectification. I like Bas' idea of tube after SS for slow ramp of B+. Will try it all. Main point....its worth it. Makes me want to try other big tube pre's. Got some of the Russian tubes Wavebourn recommended earlier in the thread as well.
PS I love tubes as Pre's with SS as power amps, FWIW.
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Old 8th June 2012, 10:41 AM   #743
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I'll probably be stoned by the objectivists who maintain that different brands of rectifiers won't alter the sound. But the Russian 5U4G's aren't exactly the pinnacle of rectification. I found them in my amps to make the amps sound bright. Hence I've never used that rectifier ever again except for startup tests.

Its russian cousin 5AR4 is better already. The NOS 5R4 potato mashers is what I use most, since they can be bought for reasonable prices. Though I realize there must be better. They are perhaps not the best when it comes to bass and dynamics.

Though it would be cool to have a real Mullard GZ34/7. That is simply for people with a lot of money and no diy skills. The so called damper diodes are probably even better. I say probably because I have never compared them side by side.

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Old 8th June 2012, 10:51 AM   #744
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Distorted birght is how i would describe it. I can see them adding "detail" to some speakers that fall of up high and perhaps that s their attraction, but i dont need assistance there, just honest reproduction. Is nt the tube you are using sfter SS, a dmaper diode?
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Old 8th June 2012, 11:06 AM   #745
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Yep. The 6AX4 is a damper tube. Able to supply 165mA constantly.
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Old 8th June 2012, 11:10 AM   #746
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BAs, do you have a scehamtic of the SS/damper alyout?
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Old 8th June 2012, 11:43 AM   #747
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Sure. It might be worth your while to still add a RRSF (Reverse recovery spike filter).
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Old 8th June 2012, 01:20 PM   #748
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Quote:
Originally Posted by Bas Horneman View Post
Sure. It might be worth your while to still add a RRSF (Reverse recovery spike filter).
Beyond my knowledge base. Tubes are very new to me.
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Old 8th June 2012, 01:32 PM   #749
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Here is Voltsecond's version.
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Old 8th June 2012, 01:36 PM   #750
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Proponents of solid state rectification use this to tame the recovery spike of the rectifiers. This recovery spike excites the secondaries of the transformer. And couples into all other windings.

The RRSF is said to ameliorate solid state rectification. The advantages of ss (cheap/works for ever/no separate heater) remain ofcourse. And the disadvantage is removed (noise).

Since I'll have none of the switching noise because of the damper tube. I'll still have to solve the reverse recovery spike. So I'll implement it as well. But I was lazy last night. I'll probably get to it after a couple of listening sessions.

JC Morrison even uses big *** chokes in his Silbatone amps!!!

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