I'm looking at the Antek AS-1T230.
It has dual 230 secondaries with dual 6.3 secondaries.
I was thinking of running the 6.3's in series for the 12.6v heater supply of the Aikido and use the onboard jumpers to supply the 6.3v heater supply to my 6CG7's.
Having the 12.6v main supply will be handy if I want to try different tubes down the road.
It has dual 230 secondaries with dual 6.3 secondaries.
I was thinking of running the 6.3's in series for the 12.6v heater supply of the Aikido and use the onboard jumpers to supply the 6.3v heater supply to my 6CG7's.
Having the 12.6v main supply will be handy if I want to try different tubes down the road.
Is there a calculation for input coupling capacitor value?
I remember reading somewhere that you want the capacitor value should be selected for one decade below the "Knee Frequency" or something.
I would assume that is the F0 frequency, which I would say 20Hz???
One decade below that would be 2Hz correct?
I remember reading somewhere that you want the capacitor value should be selected for one decade below the "Knee Frequency" or something.
I would assume that is the F0 frequency, which I would say 20Hz???
One decade below that would be 2Hz correct?
The general formula for the -3db point is
C = 1/(2 x Pi x f x R)
So if R = 22k
f = 2Hz
Then C=3.6uF
But actually going down to 2Hz is excessive..it's perfectly OK to make it 10Hz, so that will give you a C of 0.72uF (close enough to 0.68uF)
If the Jantzens are too expensive, try these:
Obbligato Gold Series Film Capacitors
C = 1/(2 x Pi x f x R)
So if R = 22k
f = 2Hz
Then C=3.6uF
But actually going down to 2Hz is excessive..it's perfectly OK to make it 10Hz, so that will give you a C of 0.72uF (close enough to 0.68uF)
If the Jantzens are too expensive, try these:
Obbligato Gold Series Film Capacitors
Funny thing is the .82uf Silver-Z is cheaper than the .68 Silver-Z, price wise I don't mind if they are worth the extra money.
I was looking at the Obbligato caps this morning LOL.
BTW where did the 22k come from? We are talking about the input capacitor right? 22k is the input impedance of my chipamp.
OTOH I was looking at getting my Blue Velvet from partsconnexion so I could get the caps plus the pot for the same as just the Jantzen Caps.
I was looking at the Obbligato caps this morning LOL.
BTW where did the 22k come from? We are talking about the input capacitor right? 22k is the input impedance of my chipamp.
OTOH I was looking at getting my Blue Velvet from partsconnexion so I could get the caps plus the pot for the same as just the Jantzen Caps.
Last edited:
Well there's only one capacitor in the signal path in an Aikido - it's at the output of the aikido, which leads to the chipamp, hence the 22k of the chipamp.
It doesn't need a capacitor on the input of the aikido.
btw, if you want to add a volume control, this is the way to do it:
(Ignore the voltages, tubes, resistor values, etc. There are lots of ways to make an aikido, but the overall circuit stays the same)
It doesn't need a capacitor on the input of the aikido.
btw, if you want to add a volume control, this is the way to do it:
(Ignore the voltages, tubes, resistor values, etc. There are lots of ways to make an aikido, but the overall circuit stays the same)
Last edited:
The all in one kit PSU section allows for a voltage doubler for the heaters. This allows you to obtain 12.6V off a 6.3V secondary - and that is regulated DC for the finished voltage. I am running 3 amps in this manner and it works flawlessly. Just remember that you will halving the amps on the xformer 6.3V section.
6CG7s run 0.6A per tuber heater current
That Antek on one section provides 3A from the 6.3V
You can configure the board to run the heaters in series so if you were to use a voltage doubler 12.6V @ 1.5amps available current you would be just within your range(0.6X4 / 2) = 1.2amps draw running 12.6V with heaters in series.
Basically you will only need to use half of the sections on that toroid. Not that its a bad thing because they are relatively cheap.
Another option is the Allied 6K56VG its readily available and rumor has it its a Hammond. It has 270V secondaries though...you would need to drop about 80V in your first R...running 40mA (10mA X 4 tubes) would put it at a 2000 ohm 5W resistor for that duty.
6CG7s run 0.6A per tuber heater current
That Antek on one section provides 3A from the 6.3V
You can configure the board to run the heaters in series so if you were to use a voltage doubler 12.6V @ 1.5amps available current you would be just within your range(0.6X4 / 2) = 1.2amps draw running 12.6V with heaters in series.
Basically you will only need to use half of the sections on that toroid. Not that its a bad thing because they are relatively cheap.
Another option is the Allied 6K56VG its readily available and rumor has it its a Hammond. It has 270V secondaries though...you would need to drop about 80V in your first R...running 40mA (10mA X 4 tubes) would put it at a 2000 ohm 5W resistor for that duty.
I kind of figured that transformer would do fine.
As I understood the chart in the all in one kit it said that with 12.6v heater you could jumper to use the 6.3v heater tubes but not the other way around.
If what you say is true though maybe I should pick up the Aikido mono kit for two tubes and buy two of them.
Then I would use both 230v secondaries and each heater regulator would get a 6.3v.
As I understood the chart in the all in one kit it said that with 12.6v heater you could jumper to use the 6.3v heater tubes but not the other way around.
If what you say is true though maybe I should pick up the Aikido mono kit for two tubes and buy two of them.
Then I would use both 230v secondaries and each heater regulator would get a 6.3v.
How would one attach a headphone jack to the preamp?
I'm thinking that all I would need is a 1/4" stereo jack and a 2 source selector switch.
How would the Aikido do driving a 50Ω pair of Sennheiser's?
There are a couple of 600Ω cans that they make, would the Aikido fare better driving those?
I'm thinking that all I would need is a 1/4" stereo jack and a 2 source selector switch.
How would the Aikido do driving a 50Ω pair of Sennheiser's?
There are a couple of 600Ω cans that they make, would the Aikido fare better driving those?
So, I'm looking over the Aikido build sheet and it seems that for 6cg7 input w/ 6cg7 output they say 200-300V B+.
That puts me at 200v secondary for 288v B+ correct?
These are rough numbers obviously and I have no problem running close to 300 since my equipment will run on a line conditioner I maintain stable 115+- .25v.
Any thoughts?
That puts me at 200v secondary for 288v B+ correct?
These are rough numbers obviously and I have no problem running close to 300 since my equipment will run on a line conditioner I maintain stable 115+- .25v.
Any thoughts?
An output transformer, with a turns ratio of something like 6:1 to 10:1. One of the headphone guys can probably suggest some specific ones.
edit: The Cinemag CM-9661A looks like it would work.
Your 230V secondaries will give you 324V raw B+. You will run roughly 10mA per tube or 40mA total. to drop 25V you will need 25/0.040 = or 625ohm R in the RC filter @ 1W...I would use at least a 3W or maybe even a 5W resistor here in case you tube roll down the road.
I would not go much below 300V for your B+.
I have looked at toroids in the past for tubes...I was never 100% on how to handle the dual secondaries as a best practice. Most HV PSU's call for a center tapped transformer...230-0-230 for example. What you have is a 230-0-230-0 transformer.
You will need obviously the 2 230V secondaries...but then what to do with the two 0 legs? Tape them off for no connection? Connect them together? Connect them together and connect as a CT? Maybe folks that have used toroids in these cases will chime in for what is the best practice...
For the second 230v winding I would just tape it off or attach it to a terminal strip and not connect it to anything.
For the 6.3's if you take the second wire of the first 6.3 and attach it to the first wire of the second 6.3 you should measure 12.6v across S1-1 to S2-2 just insulate the connection of the two 6.3's in series.
At this point in time, Output transformers are too expensive since I would need two of them for stereo headphones.
What about a headphone mixer box that has balanced & unbalanced input with 4 headphone outputs, I would just make the RCA connectivity internal to the preamp?
For the 6.3's if you take the second wire of the first 6.3 and attach it to the first wire of the second 6.3 you should measure 12.6v across S1-1 to S2-2 just insulate the connection of the two 6.3's in series.
At this point in time, Output transformers are too expensive since I would need two of them for stereo headphones.
What about a headphone mixer box that has balanced & unbalanced input with 4 headphone outputs, I would just make the RCA connectivity internal to the preamp?
No, I believe you will need both 230 windings...the Queston is what to do with the two zero windings. ERRR...I think anyways....PSU's are not a strong point for me yet
Last edited:
You can use a CT or non-CT transformer with the all in one board - its pretty much just a matter of stuffing two diodes or four, and the CT connection.
On your toroid you can connect the two secondaries in series, effectively making the two windings in to one with a CT - the CT being the two wires you connected together to join the windings in series.
Or, you can connect the two windings in parallel which will give you double the current.
Using the all in one HV supply I don't think either method has an advantage over the other - just a matter of preference.
On your toroid you can connect the two secondaries in series, effectively making the two windings in to one with a CT - the CT being the two wires you connected together to join the windings in series.
Or, you can connect the two windings in parallel which will give you double the current.
Using the all in one HV supply I don't think either method has an advantage over the other - just a matter of preference.
OK, I'm just about to kick this Pig.
How about this transformer AS-05T240.
It has a 240v secondary w/ a 220v tap @ 100mA.
These transformers are said to produce 20% more current at 60hz since they are rated at 50hz.
That would put me at 120mA.
The Aikido would use about 90 mills with my 6CG7's so I should be good right?
The 220v secondary puts me in at 311V raw B+?
Is this looking correct?
I am ordering my Alps, Obbligato's & RCA's tonight, I will make a choice on my transformer and probably order it tomorrow.
The Aikido will be ordered probably on Saturday and I will hardly sleep until it gets here.
The chassis I will make with my mad woodworking skills and an aluminum top.
How about this transformer AS-05T240.
It has a 240v secondary w/ a 220v tap @ 100mA.
These transformers are said to produce 20% more current at 60hz since they are rated at 50hz.
That would put me at 120mA.
The Aikido would use about 90 mills with my 6CG7's so I should be good right?
The 220v secondary puts me in at 311V raw B+?
Is this looking correct?
I am ordering my Alps, Obbligato's & RCA's tonight, I will make a choice on my transformer and probably order it tomorrow.
The Aikido will be ordered probably on Saturday and I will hardly sleep until it gets here.
The chassis I will make with my mad woodworking skills and an aluminum top.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.