Hello,
The Anzai preamp i bought in the eighties had a slightly different riaa filter.
The riaa stage had 2 tubes each with a decoupling capacitor in the power supply. The line stage with one tube was also decoupled. If i remember right the power supply at the line stage was around 280 volts, then a 3k3 wirewound plus a 22µF for the output tube of the riaa section. Then another 3k3 plus 22µF for the input tube.
There was another design by Hiraga published in number 21 of l'audiophile magazine. I was told to copy this power supply and use it for the Anzai. Later i changed it into choke input which is always a good thing if done right.
greetings, Eduard
The Anzai preamp i bought in the eighties had a slightly different riaa filter.
The riaa stage had 2 tubes each with a decoupling capacitor in the power supply. The line stage with one tube was also decoupled. If i remember right the power supply at the line stage was around 280 volts, then a 3k3 wirewound plus a 22µF for the output tube of the riaa section. Then another 3k3 plus 22µF for the input tube.
There was another design by Hiraga published in number 21 of l'audiophile magazine. I was told to copy this power supply and use it for the Anzai. Later i changed it into choke input which is always a good thing if done right.
greetings, Eduard
Hello,
That one is from l'audiophile magazine too!
And here you the use of higher voltage power supply too.
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Hello,
The one i got was deliveredid with E83cc input. second tube ecc83 and line stage ecc82.
Usually there will be something missing in the french magazines.
Jean Hiraga RIAA Phono
This is the power supply i start using after using the original one for a few months and after talking to people in the shop in Paris. As said before later i changed it into choke input.
Hiraga Preamp
You see google is easier than going up the attic lol.
greetings, eduard
The one i got was deliveredid with E83cc input. second tube ecc83 and line stage ecc82.
Usually there will be something missing in the french magazines.
Jean Hiraga RIAA Phono
This is the power supply i start using after using the original one for a few months and after talking to people in the shop in Paris. As said before later i changed it into choke input.
Hiraga Preamp
You see google is easier than going up the attic lol.
greetings, eduard
Totally agree with you, ECC82 and ECC83 have Vkf=180V (!) ECC81 Vkf=90V and you must be careful elevating their voltage reference.
As for SRPP detractors, my suspicion is that they never was careful elevating the heaters.
No problems in 30 years is great, and consistent with my experience too, thanks a lot.
Posting any copyrighted materials such as Elektor schematics is a violation of forum rules. Please read and familiarize yourself with the rules.
You did follow the right way, as the Achilles heel of Anzai circuit is the change on plate resistance of the first SRPP when the valve ages, the RIAA EQ changes in time.
On my next preamp I will use a hybrid cascode 6922/2SK369 for the input stage, a la Allen Wright.
I would suggest shunt regulators for both +B and heaters PSUs.
When I did build the preamp, the TL783C was unobtainable here, so I did a regulated series supply based on CA3130 Op Amp, STP6N60 power MOSFET and LM385 1.2 voltage reference and the result was very good, I did the same for the heaters because the LM317 is very noisy, both PSUs had a soft-start.
Against most usual practice, I hate chokes because they are bulk, noisy and their magnetic field is horrendous into a phono preamp.
A power transformer designed to work at low magnetic field should be a good idea too, potting it in a ferromagnetic case (cheap iron) is paramount.
It's schematic version from Mr. Shibata
Attachments
John Broskie write interesting articles about SRPP circuits
SRPP+ All-in-One & Impedance Multiplier Circuits
SRPP+ Part Two
SRPP+ All-in-One & Mu Followers
Sonic Gold & More Google Patent Search
All-Tube SRPP on Steroids
http://www.tubecad.com/2005/February/blog0037.htm
http://www.tubecad.com/2004/blog0016.htm
http://www.tubecad.com/articles_2002/SRPP_Deconstructed/SRPP_Deconstructed.pdf
http://www.tubecad.com/december2000/page7.html
http://www.tubecad.com/june2000/page16.html
http://www.tubecad.com/june2000/page6.html
http://www.tubecad.com/may2000/
http://www.tubecad.com/june99/page2.html
SRPP+ All-in-One & Impedance Multiplier Circuits
SRPP+ Part Two
SRPP+ All-in-One & Mu Followers
Sonic Gold & More Google Patent Search
All-Tube SRPP on Steroids
http://www.tubecad.com/2005/February/blog0037.htm
http://www.tubecad.com/2004/blog0016.htm
http://www.tubecad.com/articles_2002/SRPP_Deconstructed/SRPP_Deconstructed.pdf
http://www.tubecad.com/december2000/page7.html
http://www.tubecad.com/june2000/page16.html
http://www.tubecad.com/june2000/page6.html
http://www.tubecad.com/may2000/
http://www.tubecad.com/june99/page2.html
For those interested, I created a spreadsheet for calculating the voltage amplification (gain [dB]) and output impedance (kohm) for various tubes. Input parameters are µ (voltage gain of tube), gm (transconductance), Rk (cathode resistors, lower tube Rk NOT bypassed!), and Rl (load resistance).
It's about Tim Mellow OTL 25W amplifier It pairs verry well SRPP preamp, sound special and is verry reliable concept. Not to tell you about Tim, which offer his project with lots of detaills and practical explanations. A nice person too. http://www.mellowacoustics.com/articles/Tim_Mellow_25w_OTL_Tube_amplifier.pdf For me it was a turning point into my personal project consisting in how esl speakers can be driven better.
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