John Broskie’s Aikido Pre-Amplifier Blind Test Session – Jimmy's Junkyard
Interesting results from a nice aikido fan club builders.
Regulator with IRF seems to help the aikido. Without further info on the circuit and tubes it is hard to conclude anything. The tube seems to be also a small regulator replacing the transistor.
The power rectifier seems diode, the tubes all 9 pin .
Soo... I don't know how my aikido would situate in this.
Surprised that the 10Y was not in the best sounding aikido!!!!
Interesting results from a nice aikido fan club builders.
Regulator with IRF seems to help the aikido. Without further info on the circuit and tubes it is hard to conclude anything. The tube seems to be also a small regulator replacing the transistor.
The power rectifier seems diode, the tubes all 9 pin .
Soo... I don't know how my aikido would situate in this.
Surprised that the 10Y was not in the best sounding aikido!!!!
Hi Tix,
The Aikido is a great sounding amp. I am using 6CG7/6FQ7 to 5687
I experimented with the power supply when I built it. The clever design has an excellent PSRR and because of this does not need lots of capacitance.
I eventually settled on a diode bridge using FREDs (fast recovery epitaxial diodes) into 6uf > resistor > 20uf > resistor > 12uf The supply should have a Q=0.7 or lower and resonance below 3 or 4 Hz. Check out Duncan's PS calculator. Try for fast rise times without overshoot.
Avoid electrolytic caps.
I can't remember the values of resistors used, was built about 7 years ago. Do not use the cheap sand cast resistors anywhere in the amp or PSU. They are noisy and sound horrible. There are not many in the circuit so buy good ones. Mills are OK, they are quiet and mellow. Maybe a little too mellow
With low capacitance I have a fast, agile supply that sounds way better and more exciting than using large values.
I will build another one to replace the original because all the experimenting has left it looking like scrambled eggs. I will definitely use octals this time and stay with point to point wiring. I may use the Mundorf resistors this time.
The Aikido is a great sounding amp. I am using 6CG7/6FQ7 to 5687
I experimented with the power supply when I built it. The clever design has an excellent PSRR and because of this does not need lots of capacitance.
I eventually settled on a diode bridge using FREDs (fast recovery epitaxial diodes) into 6uf > resistor > 20uf > resistor > 12uf The supply should have a Q=0.7 or lower and resonance below 3 or 4 Hz. Check out Duncan's PS calculator. Try for fast rise times without overshoot.
Avoid electrolytic caps.
I can't remember the values of resistors used, was built about 7 years ago. Do not use the cheap sand cast resistors anywhere in the amp or PSU. They are noisy and sound horrible. There are not many in the circuit so buy good ones. Mills are OK, they are quiet and mellow. Maybe a little too mellow
With low capacitance I have a fast, agile supply that sounds way better and more exciting than using large values.
I will build another one to replace the original because all the experimenting has left it looking like scrambled eggs. I will definitely use octals this time and stay with point to point wiring. I may use the Mundorf resistors this time.
I found the Brimar E88CC to be excellent with a fantastic midrange and way better than the Mullard ECC88. Brimar stands for British Manufacture of American Range. CV2492 also very very good. The Telefunkens are way overpriced and in my opinion they sound different to the Brimars but not better.
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