i hear many things about tube rectifiers being better than solid state diodes. I tend to use them in the near future but just don't know which tube rectifier is good to go for. I hear that differents models have different sound.
i tend to use the tube rectifier for a pre- amp stage deliver juice to 2* 12 ax7 and 12at7
any help would be great
i tend to use the tube rectifier for a pre- amp stage deliver juice to 2* 12 ax7 and 12at7
any help would be great
I have a great fondness for the TV damper diodes like 6D22S, 6CH3/6CJ3, EY500A etc because they sound the best out of everything I've tried. Cheap too ($US5-7/tube). The two drawbacks are they are single diodes so you need 2, and they have a healthy heater requirement. If your power trans has a 5V 3A heater winding the 6D22S/6CJ3 will work fine even though it's under the 6.3V 3.6A nominally required. They are way overkill for the application, but are cheap and available.
If you just want an octal dual diode, 5AR4/GZ34 in whatever flavour you can afford.
Do yourself a favour and use a choke input irrespective of the diodes chosen.
Cheers
If you just want an octal dual diode, 5AR4/GZ34 in whatever flavour you can afford.
Do yourself a favour and use a choke input irrespective of the diodes chosen.
Cheers
RECTIFIERS
Hello,
In case you want to stick with the more classic types for preamp use:
The 6AX4/EZ81 and 6X4/EZ80 are both duo-diode types that were often used for this apllication.
Prices will vary so look around before you decide.
The TV damper types are an alternative and offer low voltage drop due to lower Ri but you'll need more of them:
I like to use them where I draw sufficient current and use a Graetz bridge full wave rect.
I would even say don't bother with tube rectifiers if you don't want to use a good choke PSU.
Happy trails,
Hello,
In case you want to stick with the more classic types for preamp use:
The 6AX4/EZ81 and 6X4/EZ80 are both duo-diode types that were often used for this apllication.
Prices will vary so look around before you decide.
The TV damper types are an alternative and offer low voltage drop due to lower Ri but you'll need more of them:
I like to use them where I draw sufficient current and use a Graetz bridge full wave rect.
I would even say don't bother with tube rectifiers if you don't want to use a good choke PSU.
Happy trails,
The bad things about tube rectifiers include cost, power consumption, heat, reliability, and inferior regulation.
The good things about tube rectifiers include slow warm up, which can extend the life of the other tubes in the circuit, and that they can look quite cool.
Sonic differences beyond the ability (or inability) to regulate? I'm skeptical.
The good things about tube rectifiers include slow warm up, which can extend the life of the other tubes in the circuit, and that they can look quite cool.
Sonic differences beyond the ability (or inability) to regulate? I'm skeptical.
REGULATE
Hi guys,
Whether using solid state rectifiers or tubes to do that I will always provide good shunt regulation (lowZ) on a per stage basis.
I then rely on the capacitance put behind the regulated stage to provide the necessary current, not the rectifiers and the transformers which will be too slow for the task in most cases.
One major advantage of tube rectifiers is that they don't throw back all the switching noise into the powerlines.
And that is something that can be heard as well as measured.
Cheers,
Hi guys,
Whether using solid state rectifiers or tubes to do that I will always provide good shunt regulation (lowZ) on a per stage basis.
I then rely on the capacitance put behind the regulated stage to provide the necessary current, not the rectifiers and the transformers which will be too slow for the task in most cases.
One major advantage of tube rectifiers is that they don't throw back all the switching noise into the powerlines.
And that is something that can be heard as well as measured.
Cheers,
Hello all,
I have said it before (or maybe not here) and I will say it again... the rectifier shouldn't make the amp sound like anything but itself. If a different rectifier makes your amp sound different, then the power supply is badly designed. The power supply should not make the amp sound different. It should be transparent to the quality of the amp itself, which is what does the actual work.
Someone somewhere here said it before, and I have also heard it from school: an amplifier is nothing more than an adjustable voltage regulator. But the source voltage (power supply) should be stable (fixed unchangeable voltage) and have a theoretical infinite current capability.
As for the fast or slow startup... solid state rectifiers have been used in tube equipment since the fifties (selenium rectifiers) with little if any apparent reduction of tube life.
But I may be all wrong about this, in spite of the fact that I have a few items with the original tubes in my collection with SS rectification.
I use SS rectification in my amps and hear no difference, mainly because I use a large filter cap after the choke, so PS impedance is consistently low, even when I do use tube rectifiers. Also, I have been using it for at least three years with no degradation of sound quality, with hundreds of hours of use, powering on and off every day.
Now, if you do use a tube rectifier, I recommend the 5U4 for its low internal resistance and voltage drop. This way you get the most power from the supply. Other tubes tend to have a more radical voltage drop change for the load draw (AKA poor regulation). This is what makes the amp sound "different". But that is not a good thing. Not for accuracy and trueness of fidelity, IMHO. It merely puts the characteristics of the devices in different modes.
But that is only my opinion... based on fact.
Gabe
I have said it before (or maybe not here) and I will say it again... the rectifier shouldn't make the amp sound like anything but itself. If a different rectifier makes your amp sound different, then the power supply is badly designed. The power supply should not make the amp sound different. It should be transparent to the quality of the amp itself, which is what does the actual work.
Someone somewhere here said it before, and I have also heard it from school: an amplifier is nothing more than an adjustable voltage regulator. But the source voltage (power supply) should be stable (fixed unchangeable voltage) and have a theoretical infinite current capability.
As for the fast or slow startup... solid state rectifiers have been used in tube equipment since the fifties (selenium rectifiers) with little if any apparent reduction of tube life.
But I may be all wrong about this, in spite of the fact that I have a few items with the original tubes in my collection with SS rectification.
I use SS rectification in my amps and hear no difference, mainly because I use a large filter cap after the choke, so PS impedance is consistently low, even when I do use tube rectifiers. Also, I have been using it for at least three years with no degradation of sound quality, with hundreds of hours of use, powering on and off every day.
Now, if you do use a tube rectifier, I recommend the 5U4 for its low internal resistance and voltage drop. This way you get the most power from the supply. Other tubes tend to have a more radical voltage drop change for the load draw (AKA poor regulation). This is what makes the amp sound "different". But that is not a good thing. Not for accuracy and trueness of fidelity, IMHO. It merely puts the characteristics of the devices in different modes.
But that is only my opinion... based on fact.
Gabe
don't believe the hype
The whole idea that different rectifier tubes have different "sounds" comes from the (technically illiterate) guitar player community. They plug a 5AR4 into an amp designed for a 5Y3, and then claim the rectifier sounds different. No, it's the amp that sounds different, because you've just increased the B+ by 25 to 30 volts. "Thicker", "warmer", "louder", are the adjectives that follow - and are exactly what I would expect.
I use tube rectifiers as heatsinks and voltage droppers when I have spare power transformers with too much voltage. They also look cool. But there is no "tube rectified" sound, trust me.
Regarding "soft start" and all that - there are hundreds of examples of 30+ year old hi-fi's out there, with their original tubes intact. And I've never seen a single tube stereo with a "standby" switch. That's odd, isn't it? If cathode stripping were such a problem, wouldn't they incorporate that design?
Joel
The whole idea that different rectifier tubes have different "sounds" comes from the (technically illiterate) guitar player community. They plug a 5AR4 into an amp designed for a 5Y3, and then claim the rectifier sounds different. No, it's the amp that sounds different, because you've just increased the B+ by 25 to 30 volts. "Thicker", "warmer", "louder", are the adjectives that follow - and are exactly what I would expect.
I use tube rectifiers as heatsinks and voltage droppers when I have spare power transformers with too much voltage. They also look cool. But there is no "tube rectified" sound, trust me.
Regarding "soft start" and all that - there are hundreds of examples of 30+ year old hi-fi's out there, with their original tubes intact. And I've never seen a single tube stereo with a "standby" switch. That's odd, isn't it? If cathode stripping were such a problem, wouldn't they incorporate that design?
Joel
CATHODE STRIPTEASE
Hello guys,
Stanby switches are there to kill the tubes so the industry can sell some more tubes.
Only to be installed on the gear of those customers you REALLY hate and know to be loaded.
OTH I love tubes too much to do that to them.
You could also poison them with some selenium rectifiers (if you can still find any)
Cheers,
Hello guys,
Stanby switches are there to kill the tubes so the industry can sell some more tubes.
Only to be installed on the gear of those customers you REALLY hate and know to be loaded.
OTH I love tubes too much to do that to them.
You could also poison them with some selenium rectifiers (if you can still find any)
Cheers,
A lot of guitar amps have standby switches, probably more of a convenience thing though. I know when I have played a stadium gig, I dont want to blast everyone with feedback when I drop the guitar...
Why would standby switches kill tubes anyway? I realise they slam the B+ onto them, but tubes are pretty tough I think!
Why would standby switches kill tubes anyway? I realise they slam the B+ onto them, but tubes are pretty tough I think!
STANDBY SWITCHES
While it's true tubes can withstand the surge of a nuclear blast... how many blasts would you want to live through to find out how durable the tubes are?
I think the point is that all electronic components suffer when slammed too often with full B+.
On the other hand... I have SS equipment over 25 years old...
Now we're getting a little off topic.
The coke bottle Sovtek 5U4 sure does look sweet in among my tubes.
Gabe
While it's true tubes can withstand the surge of a nuclear blast... how many blasts would you want to live through to find out how durable the tubes are?
I think the point is that all electronic components suffer when slammed too often with full B+.
On the other hand... I have SS equipment over 25 years old...
Now we're getting a little off topic.
The coke bottle Sovtek 5U4 sure does look sweet in among my tubes.
Gabe
KILLING TUBES
Hi Shifty,
It's the reverse operation that does most of the damage.Heating up the cathode too long before any B+ is present can damage the cathode.
Also if that standby switch halves the B+ the same problem occurs.
Alot of it was discussed here:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=6082]
Sure tubes are pretty tough.
If they weren't they wouldn't survive in the rockscene,would they?
Most of these guitar amps use tube rectifiers so switching the on all of a sudden should not cause any problems.
Cheers,
Hi Shifty,
It's the reverse operation that does most of the damage.Heating up the cathode too long before any B+ is present can damage the cathode.
Also if that standby switch halves the B+ the same problem occurs.
Alot of it was discussed here:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=6082]
Sure tubes are pretty tough.
If they weren't they wouldn't survive in the rockscene,would they?
Most of these guitar amps use tube rectifiers so switching the on all of a sudden should not cause any problems.
Cheers,
Slow diodes vs fast diodes vs tubes
I'm sure tube rectifiers are a lot quiter than yucky old slow mains grade diodes, with their terrible reverse recovery time "twanging" the leakage inductance of the power tranny secondary, but are they really that much better than "fast" diodes? I've seen the difference between slow and fast diodes on a scope and it was amazing, but it was only on a bench psu, not an amplifier so I can't give a complete answer. I'll have to look again and post some scope pics.
GP.
I'm sure tube rectifiers are a lot quiter than yucky old slow mains grade diodes, with their terrible reverse recovery time "twanging" the leakage inductance of the power tranny secondary, but are they really that much better than "fast" diodes? I've seen the difference between slow and fast diodes on a scope and it was amazing, but it was only on a bench psu, not an amplifier so I can't give a complete answer. I'll have to look again and post some scope pics.
GP.
RECTAL ANALYSIS.
Guys,
I'm starting to feel I'm rehashing the same ole' thing over and over.
Alright,so here we go again:
Semi conductor diodes,be they fast or slow will inevitably pollute the PSU and throw back spikes into the mains.
Use them or leave them it's up to you.
Look at what they can do to your audio and decide for yourselves.
Think of a good PSU as a two stage design:
#one with the xformers,rects,smoothing,choke.
# with the power demand storage,regulation, coping with the instant demands of your circuit under dynamic circumstances.
The choke and regulator will effectively decouple one from the other and stage #two should present low Z out.
You can further isolate your depencies on the PSU by using choke loaded anode or CCS devices.
Cheers,
Guys,
I'm starting to feel I'm rehashing the same ole' thing over and over.
Alright,so here we go again:
Semi conductor diodes,be they fast or slow will inevitably pollute the PSU and throw back spikes into the mains.
Use them or leave them it's up to you.
Look at what they can do to your audio and decide for yourselves.
Think of a good PSU as a two stage design:
#one with the xformers,rects,smoothing,choke.
# with the power demand storage,regulation, coping with the instant demands of your circuit under dynamic circumstances.
The choke and regulator will effectively decouple one from the other and stage #two should present low Z out.
You can further isolate your depencies on the PSU by using choke loaded anode or CCS devices.
Cheers,
fdegrove and the other guys
could u provide or share the schematic you are talking about please?
thanks guys
could u provide or share the schematic you are talking about please?
one of the reasons for the swap in rectfying method
one of the biggest reasons for the swaping looks cool
familar with ccs for solid state but do share some ccs schematics for tube and what is choke loaded anode? do share some light on topic
thanks guys
QQ
Hi,
These links should answer most of your QQ and probably raise many more:
http://www.diyparadiso.com/othello1.htm
http://www.tpub.com/neets/book6/22l.htm
http://www.geocities.com/Tokyo/5913/reg.html
http://members.aol.com/sbench/reg1.html
http://www.tubecad.com/may99/page5.html
http://www.vt52.com/diy/tips/tips_chokeload.htm
Happy reading,
Hi,
These links should answer most of your QQ and probably raise many more:
http://www.diyparadiso.com/othello1.htm
http://www.tpub.com/neets/book6/22l.htm
http://www.geocities.com/Tokyo/5913/reg.html
http://members.aol.com/sbench/reg1.html
http://www.tubecad.com/may99/page5.html
http://www.vt52.com/diy/tips/tips_chokeload.htm
Happy reading,
CCS
Hi,
I forgot this one:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=7082
Mr.Gary Pimm has done a lot of work in this field.
Cheers,
Hi,
I forgot this one:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=7082
Mr.Gary Pimm has done a lot of work in this field.
Cheers,
Ok, we've somehow gone from a simple evaluation of rectifier tubes into never-never land.
Can we come back down to reality please???
Why in the world would the amp care how it's DC got rectified??? A properly designed PSU does not reach the bottom of its reserves, so please tell me how I would ever "hear" how the capacitance is recharged.
And Frank, seriously, sometimes I think you are just playing with us, with all this talk about "switching noise back into the mains", and regulating every stage. I think you need to lay off Stereophile magazine for a few months.
Joel
Can we come back down to reality please???
Why in the world would the amp care how it's DC got rectified??? A properly designed PSU does not reach the bottom of its reserves, so please tell me how I would ever "hear" how the capacitance is recharged.
And Frank, seriously, sometimes I think you are just playing with us, with all this talk about "switching noise back into the mains", and regulating every stage. I think you need to lay off Stereophile magazine for a few months.
Joel
STEREOPHOOL
Hi,
Whatever makes you think I would read that stuff?
If any of you want to stick with the fifties than that's fine by me.
It is not me asking questions here and neither is it you as far as this thread is concerned.
Which doesn't mean you can't but if you're dismissing things off hand I can't be happy with it and my face goes a bit like this:
Whatever anyone's perception of it may be,no?
If you would log the HT rails while playing music loudly and never see it sag then you will probably have a decent PSU with regard to your highly effecient speakers.
In the real world I can not predict what LS is going to be hooked up,hence....
May I suggest some literature from the past twenty years:
Audio Anthology,Audio Amateur,Glass Audio,John Broskie's Tube Cad Journal,Speaker Builder etc.
And those are just the English spoken ones from the US.
Cheers,
Hi,
Whatever makes you think I would read that stuff?
If any of you want to stick with the fifties than that's fine by me.
It is not me asking questions here and neither is it you as far as this thread is concerned.
Which doesn't mean you can't but if you're dismissing things off hand I can't be happy with it and my face goes a bit like this:
Whatever anyone's perception of it may be,no?
If you would log the HT rails while playing music loudly and never see it sag then you will probably have a decent PSU with regard to your highly effecient speakers.
In the real world I can not predict what LS is going to be hooked up,hence....
May I suggest some literature from the past twenty years:
Audio Anthology,Audio Amateur,Glass Audio,John Broskie's Tube Cad Journal,Speaker Builder etc.
And those are just the English spoken ones from the US.
Cheers,
Well Joel, what can I tell ya. The Dynaco MkIIIs I have were modified about 20 years ago. The tube rectifier was removed and semiconductor diodes used in there place. 5 ohm 25 watt dale resistors in series with the diodes to reduce the spikes. Larger cap installed (330uf) Choke removed and cap multiplyer with a zenor reference installed in it's place.
Before mod: B+ = 425 VDC @ idle 360 VDC @ 60 watts output (just before cliping).
After mod: B+ = 425 VDC @ idle (set by zenor reference) 425 VDC @ 85 watts output (just before clipping)
Before mod: 1.5 VPP ripple on B+ @ idle.
After mod: .025 VPP ripple on B+ @ idle.
Before mod: 15 VPP hum and load induced modulation of the power supply @ 60 watts output.
After mod: .15VPP hum and load induced modulation of the power supply @ 85 watts output.
Me, I think regulators are a good thing, even simple ones.
Oh, by the way I used a slow turnon with these amps. A series resistor and a relay to short the resistor out in the transformer primary. after the B+ was at 75%.
Later Bruce
Before mod: B+ = 425 VDC @ idle 360 VDC @ 60 watts output (just before cliping).
After mod: B+ = 425 VDC @ idle (set by zenor reference) 425 VDC @ 85 watts output (just before clipping)
Before mod: 1.5 VPP ripple on B+ @ idle.
After mod: .025 VPP ripple on B+ @ idle.
Before mod: 15 VPP hum and load induced modulation of the power supply @ 60 watts output.
After mod: .15VPP hum and load induced modulation of the power supply @ 85 watts output.
Me, I think regulators are a good thing, even simple ones.
Oh, by the way I used a slow turnon with these amps. A series resistor and a relay to short the resistor out in the transformer primary. after the B+ was at 75%.
Later Bruce
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