Clik here to view.
C3g Line preamplifier part 2
Power supplyFrom the beginning this preamp was intended to be an exercise in the 6J5 way of simplicity and I calculated bias such a way they both could share the same power supply. The two units are...
View ArticleClik here to view.
LCR Phono preamp Part 1
Building a phono preamp is a difficult exercise in the way we have to deal with very small signals that must be greatly amplified without any loss and/or unwanted noise.If, like me, you enjoy the...
View ArticleClik here to view.
LCR Phono preamp Part 2
In the last post I described a constant coupled stage with a gain of 53 and low output impedance.For my project I need a gain of 2800 to compensate the LCR setup insertion loss (0,158_see part 1),...
View ArticleClik here to view.
LCR Phono preamp Part 3
Power supplyA good sounding preamp or amp always means a well calculated power supply, this is the circuit heart. Too often neglected or subject to approximations because calculation is time consuming...
View ArticleClik here to view.
LIE Belin line preamp revisited
Back on the air.In an older post, I detailed a line preamplifier using outstanding LIE Belin transformers. The study was made around the C3g tube, triode wired, but despite the good results in terms of...
View ArticleClik here to view.
Visseaux A710 SE amplifier Part 1
New post, new tube. Time to discover one of the finest directly heated triodes ever.One that favorably compares to the very best and sought-after tubes like PX4, AD1, RE604 and RS242. One that belongs...
View ArticleClik here to view.
Visseaux A710 SE amplifier Part 2
Power supply and partsCLC filter along with RTC Philips 5R4GYS rectifier. From my humble experience this is one of the best choices for the money when you have to deal with medium voltage/current.One...
View ArticleClik here to view.
C3g Phono preamp Part 1
A while ago browsing the web to enrich my knowledge, I stumbled on a phono schematic around the C3g. Well known in the hobbyist world and a must try for many, this tube just average in triode mode is a...
View ArticleClik here to view.
C3g Phono preamp Part 2
Supply and more Classic C input supply with two LC cells for excellent ripple attenuation.  Two other RC cells will floor the rectifier residual to negligible value. Especially important for the...
View ArticleClik here to view.
41MXP SE amplifier Part 1
Among the numerous triodes suitable for an audio project few are indirectly heated ones. Saying they are sonically inferior to the directly heated ones or less audiophile would be restrictive and...
View ArticleClik here to view.
41MXP SE amplifier Part 2
Supply Choke input is the way to go for most SE A1 amplifier with moderate current (below 100mA). Two good reasons: 1- Ripple is very low behind a choke, equal to V Ripple = Vout / 6 π2 f2LC√2 almost a...
View ArticleClik here to view.
46 SE amplifier Part 1
New tube, new sound. A while ago I stumbled on a little batch of NOS Visseaux 46. This tiny valve has the same size and shape than the world famous 45. A few aficionados have used it, but despite very...
View ArticleClik here to view.
46 SE amplifier part 2
Like the 41MXP SE amplifier, a choke input filter is the way to go. Excellent hum rejection, almost a perfect sin wave easy to smooth out and by far a less stressing load for the power transformer...
View ArticleClik here to view.
LCR Phono preamplifier revisited
A few month ago I sold my E88C/E86C LCR Phono preamp, playing the recently build C3g/E182CC RC one. I soon realized I couldn’t live without. Not to say the C3g is inferior, it is the most enjoyable...
View ArticleClik here to view.
GEC DA41 SE A2 amplifier part 1
Marconi Osram company, a GEC subsidiary, made some of the finest and thought after valves, from the scarce and super expensive PX family to the world famous KT one. These magnificent tubes were...
View ArticleClik here to view.
GEC DA41 SE A2 amplifier part 2
Power supply My long time favorite for smooth filtering is a LC supply. Not only the mains residual is almost a perfect sine wave, but transients response is better than with a capacitor input. With a...
View ArticleClik here to view.
STC 5A/180M Phono preamplifier Part 1
The story begins with a FR1/Mk3 cartridge bought from a Japanese seller. This Ikeda San masterpiece brought me to heaven when I heard it for the first time many decades ago. At that time, the poor...
View ArticleClik here to view.
STC 5A/180M Phono preamplifier Part 2
Once in a while doesn’t harm, I built a tube-regulated supply. The reason was to precisely set the tetrode anode voltage and see if it changes or not sonic signature compared to a classic CLCLC...
View ArticleClik here to view.
Sylvania 6A5G conversion
A few months ago, I built a 41MXP amp with the intention of using it with my tweeters along with an active crossover. The results were not as expected. Not to say this amp sounds bad, the 41MXP is a...
View ArticleClik here to view.
STC 5A/152M variation on a theme
There was no objective reason to modify the good-working RLC E83F phono preamp except this insatiable curiosity, which is mine. In fact, there is one, and it is a corollary to the development of the...
View Article