Yup. I don't understand how Steve Deckert gets away with some of his design's but they seem to work. Even his $12,000 mono-block amplifiers use cheap electrolytic caps in the power supply yet seem to sound very lively and realistic with a some-what acceptable black background. Nevertheless if I was going to charge over $10,000 for some amps, I would be using the ASC oil caps for sure!
I agree, I think he had that little transformer built custom specifically for line-stage kits etc. so why not build it slightly conservative like the Edcor 217? (50mA and 1A)
Please.read.this.thread:
http://www.diyaudio.com/forums/tube...box-looking-tube-buffer-mods-reduce-buzz.html
There are flaws in that device....like the use of the OC2... the abysmal wiring...the floating heater AC voltage...
Tip: first draw a complete schematic how your version will be and have it checked here.
http://www.diyaudio.com/forums/tube...box-looking-tube-buffer-mods-reduce-buzz.html
There are flaws in that device....like the use of the OC2... the abysmal wiring...the floating heater AC voltage...
Tip: first draw a complete schematic how your version will be and have it checked here.
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Jean,
Thanks for the thread link. I haven't read that thread in years!
DF96's comment at the end of page 1 really sums up my experience with Decware amplifiers and buffer products :
"It is quite amusing to compare the wonderful prose on the Decware website, and their prices, with the rat's nest of wiring in one of their simpler products. A newbie DIYer would be ashamed of that. Doubtless it has glowing reviews, although I remain quite baffled as to why people will spend 100's of dollars on a simple (and badly made) cathode follower."
My ZBox looked exactly like the photo on the right; a complete rat's nest!
I sent it back to Steve which cost me a fortune because I live in Canada and he "upgraded" the build which is the photo second to the right. Basically used shielded leads and common grounded them. Yet he still never employed grounding pin 9. My 2A3 SET was only 2.5 watts per channel so I never had any hum problems but my current amp is a Gainclone DalAudio Retro 3886 which will put out 68 watts into my 8" Silver Flute drivers :
I am going to make sure this custom ZBox is quiet, is built wonderfully and uses premium parts that will last a few decades! My choice of coupling capacitor's in the cathode follower are the Jensen 3.3 uF copper foil/paper in oil which are going to run about $140.00 each! You wanna play you gotta pay!
I was told by Eddie Vaughn that the Jensen Paper in oils are smooth as butter and one of the best choices to tame a cheap digital CD player; darn expensive though!
Thanks for the thread link. I haven't read that thread in years!
DF96's comment at the end of page 1 really sums up my experience with Decware amplifiers and buffer products :
"It is quite amusing to compare the wonderful prose on the Decware website, and their prices, with the rat's nest of wiring in one of their simpler products. A newbie DIYer would be ashamed of that. Doubtless it has glowing reviews, although I remain quite baffled as to why people will spend 100's of dollars on a simple (and badly made) cathode follower."
My ZBox looked exactly like the photo on the right; a complete rat's nest!
I sent it back to Steve which cost me a fortune because I live in Canada and he "upgraded" the build which is the photo second to the right. Basically used shielded leads and common grounded them. Yet he still never employed grounding pin 9. My 2A3 SET was only 2.5 watts per channel so I never had any hum problems but my current amp is a Gainclone DalAudio Retro 3886 which will put out 68 watts into my 8" Silver Flute drivers :
An externally hosted image should be here but it was not working when we last tested it.
I am going to make sure this custom ZBox is quiet, is built wonderfully and uses premium parts that will last a few decades! My choice of coupling capacitor's in the cathode follower are the Jensen 3.3 uF copper foil/paper in oil which are going to run about $140.00 each! You wanna play you gotta pay!
I was told by Eddie Vaughn that the Jensen Paper in oils are smooth as butter and one of the best choices to tame a cheap digital CD player; darn expensive though!
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OK then. Good luck
2 votes now!
I have been reading the King James bible for years now and this scripture came up :
"And for that the dream was doubled unto Pharaoh twice; it is because the thing is established by God, and God will shortly bring it to pass." Genesis 41:32
I think it takes about 3 days for the caps to get shipped from Ontario to Saskatchewan here, pretty shortly! Yeah!
Hi Corey,
For what it`s worth ... These expensive parts rarely make any difference beyond what a good industrial part would. The construction materials are more important. A good Polypropylene capacitor is probably overkill here, but that would be my choice. You don`t handle heavy current, so a foil isn`t required, a film would work well. Build it with these kind of parts. If you`re really curious you can try Teflon capacitors. That`ll eat up your bank account quickly enough! Just normal Teflon, not the audiophile grade stuff. Those parts are used in science and test & measurement applications - sparingly.
-Chris
For what it`s worth ... These expensive parts rarely make any difference beyond what a good industrial part would. The construction materials are more important. A good Polypropylene capacitor is probably overkill here, but that would be my choice. You don`t handle heavy current, so a foil isn`t required, a film would work well. Build it with these kind of parts. If you`re really curious you can try Teflon capacitors. That`ll eat up your bank account quickly enough! Just normal Teflon, not the audiophile grade stuff. Those parts are used in science and test & measurement applications - sparingly.
-Chris
Maybe less cannabis, religion maybe later and now think of a device that is better than a ZBox ?! I mean, when all the design flaws are out it is not a Zbox anymore (I hope )
You don't need any gain with "digital" sources that have 2V outputs. So a device like this would be more appropriate. Not in my book as I try to solve problems at the root but anyhow::
http://www.ebay.com/itm/6N3-5670-Tube-Buffer-Amplifier-DIY-Kit-/270472007841
Device will have no gain, will cost less than one of the Jensen caps you want to buy and it will serve the purpose better. You will get regulated B+ (a relatively safe B+ too!), regulated DC heater voltage with slow start and a muting relay as a bonus.
)You don't need any gain with "digital" sources that have 2V outputs. So a device like this would be more appropriate. Not in my book as I try to solve problems at the root but anyhow::
http://www.ebay.com/itm/6N3-5670-Tube-Buffer-Amplifier-DIY-Kit-/270472007841
Device will have no gain, will cost less than one of the Jensen caps you want to buy and it will serve the purpose better. You will get regulated B+ (a relatively safe B+ too!), regulated DC heater voltage with slow start and a muting relay as a bonus.
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Okay guys, one more question then I got to run out and buy a gallon of milk.
What is better for this cathode follower; a C-R-C or C-R-C-R to get the final 100 VDC?
Basically what I am asking is if I should fine tune by trial and error my resistor choice between to caps to get 100 VDC or split the resistance up between 2 resistors; one after each cap?
Note: whatever choice you recommend, the resistor(s) will be 5 watt Kiwame carbon films :
KIWAME - 5 Watt Carbon Film Resistors
What is better for this cathode follower; a C-R-C or C-R-C-R to get the final 100 VDC?
Basically what I am asking is if I should fine tune by trial and error my resistor choice between to caps to get 100 VDC or split the resistance up between 2 resistors; one after each cap?
Note: whatever choice you recommend, the resistor(s) will be 5 watt Kiwame carbon films :
KIWAME - 5 Watt Carbon Film Resistors
Maybe less cannabis, religion maybe later and think of a device that is better than a ZBox ?! I mean, when all the design flaws are out it is not a Zbox anymore (I hope
No, my cannabis is only 0.77% THC and I haven't even ingested any yet today.
Scripture is not religion. In fact most religions; like Catholicism don't even read the bible!
Hey thanks for the advice on the buffer, appreciate it!
I like the sound of the ZBox philosophy; dropping the filament voltage to 10.5 on the 12AU7 tube to improve cheap digital players; nevertheless the power supply and layout can be greatly improved!
Yeah that "10V heater voltage" is exactly the part that makes little sense. Anyway, the suggested buffer can be set to lower heater voltage too if you believe in that.
The Zbox philosophy seems to be to throw some randomly chosen parts together combined with some "design peculiarities" and sell it at quite a price. There apparently is a market for that which keeps amazing me. Like an audio seller I know told me: "As long as a reviewer says a device is OK it wil be sold like mad. People don't even listen to the stuff I sell"
I repeat it: you don't need any gain. In fact gain might be your enemy here. The Zbox has lots of gain (at least in the schematic I saw). A "CD buffer" as they were once called gets 2V at its inputs and it better puts out 2V too and not higher. Many power amps are not the best friends of too high input voltages. You don't need a stage with gain, you need a stage with no gain which is called a buffer. Your Gainclone DalAudio Retro 3886 has enough gain, if not more than enough. Having a superfluous device with lots of gain in the chain might lead to strange unwished side effects. I think you tried the Zbox thingy with a different amp in the past....
Last replies on the Zbox thingy:
No you need regulated DC by means of, for instance, a modern regulator IC. In some way you want to put your precious signals through an extra device in the chain without harming them. Low noise and ultra low ripple are a must to preserve those signals. Keep "trial and error" for when you are baking an apple pie.
Did it ever occur to you that wattage of resistors is based on Ohm's Law ? So a 5W resistor can be overkill or it can burn away when dissipating 10W. There is a mechanism for that which is called Ohm's Law. Tool of choice is a calculator. Part are not chosen on brand but on value after calculation. The part with the "right" value can of course be replaced for mucho $ gold foil caps but they also need to have the right value in µF and the right voltage ratings. There is no way trail and error and randomly choosing parts and values will work out optimally.
The Zbox philosophy seems to be to throw some randomly chosen parts together combined with some "design peculiarities" and sell it at quite a price. There apparently is a market for that which keeps amazing me. Like an audio seller I know told me: "As long as a reviewer says a device is OK it wil be sold like mad. People don't even listen to the stuff I sell"
I repeat it: you don't need any gain. In fact gain might be your enemy here. The Zbox has lots of gain (at least in the schematic I saw). A "CD buffer" as they were once called gets 2V at its inputs and it better puts out 2V too and not higher. Many power amps are not the best friends of too high input voltages. You don't need a stage with gain, you need a stage with no gain which is called a buffer. Your Gainclone DalAudio Retro 3886 has enough gain, if not more than enough. Having a superfluous device with lots of gain in the chain might lead to strange unwished side effects. I think you tried the Zbox thingy with a different amp in the past....
Last replies on the Zbox thingy:
No you need regulated DC by means of, for instance, a modern regulator IC. In some way you want to put your precious signals through an extra device in the chain without harming them. Low noise and ultra low ripple are a must to preserve those signals. Keep "trial and error" for when you are baking an apple pie.
Did it ever occur to you that wattage of resistors is based on Ohm's Law ? So a 5W resistor can be overkill or it can burn away when dissipating 10W. There is a mechanism for that which is called Ohm's Law. Tool of choice is a calculator. Part are not chosen on brand but on value after calculation. The part with the "right" value can of course be replaced for mucho $ gold foil caps but they also need to have the right value in µF and the right voltage ratings. There is no way trail and error and randomly choosing parts and values will work out optimally.
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Hey Chris,
Is this using the 6N1P tube?
A guy by the name of Terry went very in-depth taking the ZBox cathode follower to the next level and ended up using the 6N1P. He used Auricaps and a very clean power supply.
I think he had vinyl source though. He actually wrote to me a few years ago and said sticking with the 12AU7 might be better for a cheap CD player source.
I am going to install a bypass switch to flip from 10.5-12 volts, effectively by-passing the resistor. Whatever sounds better, I will use.
I am anticipating 12 volts should be more aggressive and weighty for male vocals and 10.5 volts more laid back and smoother for female vocals.
That is another reason why I wanted to raise the B+ from 95 to 100 VDC. May add a slightly more lively presentation, though I doubt it.
Interesting enough, 95 VDC in the original ZBox I had really never took much away from any part of the music. It did add a slight veil but my HDT speakers(vinyl only speakers really) were so transparent the veil was welcome and actually could have used more sweetness than that device provided. Jensen coupling caps and Allen Bradley carbon comps should improve the design much for a cheap Onkyo 7030 source.
Talk to you guys in a few hours!
Corey
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For the first time in 30 years I now need cannabis ! Do you even read what is replied to you ?
Ok, had my share of trolls today. Back to my new commercial project called the "Thickbox Milliwatt" which I think will sell like crazy as it has Mundorf silver foil paper in oil caps (randomly chosen values for less aggressivity) and 9.9V heater voltage to make it more laid back. It has a gain of 33 which makes female voices at extremely low volumes sound like silk. By trial and error I found that Kiwame resistors 1 MOhm 5W make for a very black sound stage. Of course I upped the B+ with 5V for a more lively presentation. It uses 6N16P gold grid tubes which take it to the next level but only so with expensive CD players. OMG !
Bye.
Do you even read what is replied to you ?Ok, had my share of trolls today. Back to my new commercial project called the "Thickbox Milliwatt" which I think will sell like crazy as it has Mundorf silver foil paper in oil caps (randomly chosen values for less aggressivity) and 9.9V heater voltage to make it more laid back. It has a gain of 33 which makes female voices at extremely low volumes sound like silk. By trial and error I found that Kiwame resistors 1 MOhm 5W make for a very black sound stage. Of course I upped the B+ with 5V for a more lively presentation. It uses 6N16P gold grid tubes which take it to the next level but only so with expensive CD players. OMG !
Bye.
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Hi Corey,
No, it uses a 12AT7. Some even use the 12AX7. I see no need in using yet another type of tube when we have ones that work as well.
The difference between 95 and 100 VDC is NIL. Run the tube at full heater voltage as it was intended.
Carbon resistors are the worst types. You would be far better served with a nice wire-wound. You are going to use a zener diode, aren`t you. Otherwise there is nothing to talk about. You asked for a little direction, and got some from some extremely smart members. Then you decide to continue down this garden path anyway.
If that`s your game, there isn`t any sense in talking about anything more on this project. Just go build it.
-Chris
No, it uses a 12AT7. Some even use the 12AX7. I see no need in using yet another type of tube when we have ones that work as well.
The difference between 95 and 100 VDC is NIL. Run the tube at full heater voltage as it was intended.
Carbon resistors are the worst types. You would be far better served with a nice wire-wound. You are going to use a zener diode, aren`t you. Otherwise there is nothing to talk about. You asked for a little direction, and got some from some extremely smart members. Then you decide to continue down this garden path anyway.
If that`s your game, there isn`t any sense in talking about anything more on this project. Just go build it.
-Chris
C-R-C or C-R-C-R?
Chris or other,
What do you recommend :
1) C-R-C
or
2) C-R-C-R
Example:
A) A single 30K resistor between two capacitors?
or
B) A 15K resistor between the two caps, then another 15K resistor after the second cap?
Wouldn't half the resistance split up between two separate resistors be faster than one large resistor between the caps?
Thanks for any replies!
Corey
Chris or other,
What do you recommend :
1) C-R-C
or
2) C-R-C-R
Example:
A) A single 30K resistor between two capacitors?
or
B) A 15K resistor between the two caps, then another 15K resistor after the second cap?
Wouldn't half the resistance split up between two separate resistors be faster than one large resistor between the caps?
Thanks for any replies!
Corey
Hi Corey,
It depends on how much extra voltage you have to get rid of. You have to look at all the factors together to make up a solution that works for what you have in front of you.
If you need 240 VDC and you are starting with 280 VDC, you have a 40 VDC cushion to work with. Where possible, I use an active regulator, or a stack of Zener diodes. Therefore I could start with a resistor before the first capacitor. That would likely be an R-C-R-C setup. If there is less voltage to start with you'll see a C-R-C circuit. With even less voltage to start with, I'm forced into either an L-C type circuit. I'll typically use active regulation for all but the most simple circuits that are non-critical.
For your situation, try the C-R-C-R that ends up with too high a voltage. Then hang a zener string on that to fix the voltage. Always calculate the power dissipation in all the resistors and any zener diodes and transistors.
-Chris
It depends on how much extra voltage you have to get rid of. You have to look at all the factors together to make up a solution that works for what you have in front of you.
If you need 240 VDC and you are starting with 280 VDC, you have a 40 VDC cushion to work with. Where possible, I use an active regulator, or a stack of Zener diodes. Therefore I could start with a resistor before the first capacitor. That would likely be an R-C-R-C setup. If there is less voltage to start with you'll see a C-R-C circuit. With even less voltage to start with, I'm forced into either an L-C type circuit. I'll typically use active regulation for all but the most simple circuits that are non-critical.
For your situation, try the C-R-C-R that ends up with too high a voltage. Then hang a zener string on that to fix the voltage. Always calculate the power dissipation in all the resistors and any zener diodes and transistors.
-Chris
I just typed up this response in another Thread
This applies specifically to Solid State Power Amplifiers but with some re-scaling of component values applies to High Voltage supplies just as well.
But there is a big difference between tube/valve and SS.
ClassA tube/valve amplifiers can have a lowish PSRR. These require a low mains ripple to make the Hum at the sensitive speakers to be inaudible.
There is quite a bit to be gained in helping the PSRR by attenuating the ripple at source. That's why we see the front end with multiple cascades of ripple filtering.
rC(L+R)C(L+R)CRcRc is even seen in extreme examples.
One simply has to make the quiescent Hum inaudible.
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Hi Andrew,
The starting R has been criticized for being "heavy handed". But from a ripple reduction point of view it has the huge positive of reducing the repetitive current surges. This, as you noted, reduces ripple right at it's very source. As a side benefit it makes life a lot easier for rectifiers, capacitors and the transformer. One thing to be aware of is that it does worsen voltage regulation, but this isn't a concern in most signal level stages as the current draw doesn't change much from instant to instant. This circuit also performs really very well when you have a DC source for heater current. If you can drop the voltage a bit just at the start, the voltage lost can be well worthwhile. Certainly when you look at the current spikes that end up in other winding's from the same power transformer.
It must be said that a power supply should be designed with the actual circuit that depends on it for energy. Certain trade-offs in one application may not apply to another.
-Chris
The starting R has been criticized for being "heavy handed". But from a ripple reduction point of view it has the huge positive of reducing the repetitive current surges. This, as you noted, reduces ripple right at it's very source. As a side benefit it makes life a lot easier for rectifiers, capacitors and the transformer. One thing to be aware of is that it does worsen voltage regulation, but this isn't a concern in most signal level stages as the current draw doesn't change much from instant to instant. This circuit also performs really very well when you have a DC source for heater current. If you can drop the voltage a bit just at the start, the voltage lost can be well worthwhile. Certainly when you look at the current spikes that end up in other winding's from the same power transformer.
It must be said that a power supply should be designed with the actual circuit that depends on it for energy. Certain trade-offs in one application may not apply to another.
-Chris
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