The 6cg7 tubes are great. They are basically a 9-pin version of the 6sn7 and work well in an aikido preamp.
Which ones to get ? Well I doubt that there would be much difference between them. Gold plated pins don't mean much. You might find there are some old ones that have the screen that separates the two triodes. If you can find these they are good.
As for the sound of an aikido, it's not what people think of as normal "tube sound", which detractors say is "soft and warm" and lovers say is "liquid and musical"
The aikido sound is hard to pin down. It's more solid state sounding that normal tube circuits, but mostly it comes across as fast, transparent, 3-dimensional and very musical. I'm sure it will be a great front end to your gainclone kit.
My own experiences are thus; in my 35 years of tinkering with hifi I've had and heard a lot of amps. I built a Peter Daniels kit to his exact specs and found that it was not up to the standards I was used to. I can see how people coming from mid-fi gear can latch onto the sound and think it's great, but there's really something missing imho. I don't want to poison this thread with any more comments. Let's keep it about preamps.
All I will say is that the aikido is an amazing circuit. Not only does it make a brilliant preamp, it can also be used as a voltage amp in a truly great power amp. I've seen power amps like this that use 300B tubes or mosfets as the output stage (eg moskido). Others use it with a 24Volt supply, special tubes as a headphone amp.
If you run into any problems there are plenty of people who can help.
Which ones to get ? Well I doubt that there would be much difference between them. Gold plated pins don't mean much. You might find there are some old ones that have the screen that separates the two triodes. If you can find these they are good.
As for the sound of an aikido, it's not what people think of as normal "tube sound", which detractors say is "soft and warm" and lovers say is "liquid and musical"
The aikido sound is hard to pin down. It's more solid state sounding that normal tube circuits, but mostly it comes across as fast, transparent, 3-dimensional and very musical. I'm sure it will be a great front end to your gainclone kit.
My own experiences are thus; in my 35 years of tinkering with hifi I've had and heard a lot of amps. I built a Peter Daniels kit to his exact specs and found that it was not up to the standards I was used to. I can see how people coming from mid-fi gear can latch onto the sound and think it's great, but there's really something missing imho. I don't want to poison this thread with any more comments. Let's keep it about preamps.
All I will say is that the aikido is an amazing circuit. Not only does it make a brilliant preamp, it can also be used as a voltage amp in a truly great power amp. I've seen power amps like this that use 300B tubes or mosfets as the output stage (eg moskido). Others use it with a 24Volt supply, special tubes as a headphone amp.
If you run into any problems there are plenty of people who can help.
GloBug, your new avatar is giving me nightmares.
I've built two Aikido line amps, one with 6SN7, one with ECC88. If you keep the supply voltage high (this is quite important!), the performance is very good. Sound? Nope- there's no particular coloration, they're as neutral as any other good preamp. The PC boards have outstanding quality. The gain is much higher than I need, so I gave them away and use my own unity gain design in my system.
6CG7 strikes me as a good choice, assuming you want 20dB or so of gain.
I've built two Aikido line amps, one with 6SN7, one with ECC88. If you keep the supply voltage high (this is quite important!), the performance is very good. Sound? Nope- there's no particular coloration, they're as neutral as any other good preamp. The PC boards have outstanding quality. The gain is much higher than I need, so I gave them away and use my own unity gain design in my system.
6CG7 strikes me as a good choice, assuming you want 20dB or so of gain.
it was harder to pick without the gym equipment
John was nice enough to send me some boards and critical parts (foil resistors, Teflon caps), so I put them together and played around with the circuit and operating conditions just to see what it would do- I posted my results a few years ago. It's a nice design, when set up properly, but as I said, WAY too much gain for my setup. The fellow who's using them now is quite happy.
Presumably, MOSFET followers wouldn't cause problems with the circuit, though I'm not sure why you'd need them- the output Z of the White CF is already low enough for any practical system.
Presumably, MOSFET followers wouldn't cause problems with the circuit, though I'm not sure why you'd need them- the output Z of the White CF is already low enough for any practical system.
I have a pair of Audiosector LM4780 chipamps that are configured for dual mono they have a 22k input impedance.
I have already ordered two matched pairs of Sylvania 6CG7 with two grey plates and one silver plate. They test 114/116 & 114/117 and 113/117 & 114/118.
I got a good deal on them so I won't be two devastated if I blow up a $10 tube.
Now it comes down to brass tacks; I'm about to place my aikido order and I'm wondering if anybody has experience with both the ACF-2 and the Aikido 9 pin All in One.
What are the differences?
Is the four tube really that much better?
What size input capacitors should I use since they seem to be out of a lot I will have to order my own (I'm thinking the Jantzen Z-Silver or Z-Superior 800V polypro's)?
Are Film Foil caps that much better? Since were not talking huge values they shouldn't be too expensive.
I have already ordered two matched pairs of Sylvania 6CG7 with two grey plates and one silver plate. They test 114/116 & 114/117 and 113/117 & 114/118.
I got a good deal on them so I won't be two devastated if I blow up a $10 tube.
Now it comes down to brass tacks; I'm about to place my aikido order and I'm wondering if anybody has experience with both the ACF-2 and the Aikido 9 pin All in One.
What are the differences?
Is the four tube really that much better?
What size input capacitors should I use since they seem to be out of a lot I will have to order my own (I'm thinking the Jantzen Z-Silver or Z-Superior 800V polypro's)?
Are Film Foil caps that much better? Since were not talking huge values they shouldn't be too expensive.
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I would go full Aikido.
As far as caps...
I am using in a few different amps and can reccomend:
Jantzen Z silvers
Auricaps
Russian PIO K40Y9 (Tubecad or Ebay)
RTI film caps (from tubecad)
Any value from 0.22uF to 1.0uF will work nicely at least 400V
The 4 tube Aikido will provide gain based upon the input tube selected - 6CG7 is around 10. The ACF is just a cathode follower which is "basically" an Aikido without the input tube section which provides the gain.
As far as caps...
I am using in a few different amps and can reccomend:
Jantzen Z silvers
Auricaps
Russian PIO K40Y9 (Tubecad or Ebay)
RTI film caps (from tubecad)
Any value from 0.22uF to 1.0uF will work nicely at least 400V
The 4 tube Aikido will provide gain based upon the input tube selected - 6CG7 is around 10. The ACF is just a cathode follower which is "basically" an Aikido without the input tube section which provides the gain.
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