@ Mr Pass and Diyers
Thank You very much for superb Diy project, kind words and help in SE amp explorations
I do play more music with Schade 50W this evening and night.
First observations: start at power on with progressive up current rise for about -2 minute's.
Speakers are silencious without music.
I am happy camper with big heat sinks at 3A2 of the bias.
Time to try A, B, C, D taps of CCS and hear & feel subtle different harmonic distorstion signatures and phase.
Aoife O'Donovan - Red & White & Blue & Gold on Vimeo
Graph and schematic courtesy of NP
Get two tube preamps and one solid state to try
Thank You very much for superb Diy project, kind words and help in SE amp explorations
I do play more music with Schade 50W this evening and night.
First observations: start at power on with progressive up current rise for about -2 minute's.
Speakers are silencious without music.
I am happy camper with big heat sinks at 3A2 of the bias.
Time to try A, B, C, D taps of CCS and hear & feel subtle different harmonic distorstion signatures and phase.
Aoife O'Donovan - Red & White & Blue & Gold on Vimeo
Graph and schematic courtesy of NP
Get two tube preamps and one solid state to try
Attachments
C'est magnifique!
I was simply inspired by Mr Rothacher Diy builds perfection
Please any news about 2SK77B new MR amplifier and compare audio test's to the Schade 50W can be superb fun ?
I don't know Christophe...that looks too neat and tidy.
Cheers,
Dennis
That only amp prototype
Cheers
Thanks Walter
is two resistors with big ceramic core to keep them temperature stablenot far from the hot puck mosfet.
Oh it's all precisely like on the Papa schematic with IXFN140N20P.
Yes prototype is one channel only.
I get two bench psu 60 V | 5A max if connected in series just perfect for mono.
My thrue exotic component are huge 230V : 230V galwanic separation transformer.
Greetings
Attachments
2SK77B triode simulation with IXFN Schade Feedback
Few impresions after preamp's and taps test.
Jfet buffer 25 Ohm's source impedance or similar for this amplifier is the KEY.
First time I try passive Autoformer Volume Control AVC attenuator with this prototype. Clean sound.
After that i connect them to the solid state preamp and was BIG motor boat brrr bada boom.
One resistor value 50R ~ 500 R connected to the hot of the RCA and GRN and no more problem. All OK
It was delicious music with tube preamp at night.
~ 28V from IXFN drain to GRN show me +3A bias.
I solder 2 order or 3 order distortion switch between C and D tap's.
Difference is clearly audible
2 natural relaxed tone
3 nice dynamic tone
get the two options is COOL for match with specyfic audio source, preamp and drivers.
Great experience
Few impresions after preamp's and taps test.
Jfet buffer 25 Ohm's source impedance or similar for this amplifier is the KEY.
First time I try passive Autoformer Volume Control AVC attenuator with this prototype. Clean sound.
After that i connect them to the solid state preamp and was BIG motor boat brrr bada boom.
One resistor value 50R ~ 500 R connected to the hot of the RCA and GRN and no more problem. All OK
It was delicious music with tube preamp at night.
~ 28V from IXFN drain to GRN show me +3A bias.
I solder 2 order or 3 order distortion switch between C and D tap's.
Difference is clearly audible
2 natural relaxed tone
3 nice dynamic tone
get the two options is COOL for match with specyfic audio source, preamp and drivers.
Great experience
Attachments
Let's 
for Papa & play the song.
Fleet Foxes - White Winter Hymnal on Vimeo
In France is start begining of the spring season.
Wiring photos show for future FAB's
for Papa & play the song.Fleet Foxes - White Winter Hymnal on Vimeo
In France is start begining of the spring season.
Wiring photos show for future FAB's
Attachments
@ Gyuri
You make me feel shy
For sure I am a leader of my own soldering station haha
@ Diyers
Voltage at lead outs of two 1000 uF caps are less 10 V.
10 KuF output cap have 59V for short time at power on.
After few minutes at 3A2 full bias , tension go down to ~ 15 V.
Anyway 50 V rated big can is safe.
You make me feel shy
For sure I am a leader of my own soldering station haha
@ Diyers
Voltage at lead outs of two 1000 uF caps are less 10 V.
10 KuF output cap have 59V for short time at power on.
After few minutes at 3A2 full bias , tension go down to ~ 15 V.
Anyway 50 V rated big can is safe.
Attachments
No poof in my amp all OK.
I use 10000 uF | 50 V rated cap.
Useful info to edit in # 1 build wiki post beacause is not write on the schematic
Done.