Just finished building monoblocks of 211 driving a 211 SE amplifier. Took a total of 4 chassis, 2 per monoblock.
Parts used are:
- Monolith Magnetics 15K amorphous core output transformers
- Monolith Magnetics FeSi plate chokes for 211 driver
- Monolith Magnetics Power Transformers and Chokes
- Bartola Valves Source Follower
- Rod Coleman Bias Supply
- Daitron low noise SMPS supplies for 211 filaments
- VH Audio CuTF 0.1uF/1200V coupling Caps
- Elrog 211s on the output and using Psvane 211T on the driver, and ordered another pair of Elrog 211s to replace them
- Amphenol 14S-2 Connectors for filament supply and 22-34 HV connectors for B+ and Source Follower Supplies
- 55uF/1KV kemet film caps for power supplies
Hooked it into the system, which had a 211 driving a 805 in class A2 Shishido style with a source follower. Initial impressions, same nice big sound as the 805, I don't think I lost anything compared to the previous set up. Even without any breakin, it sounds great!. Will let it play in the system for a month before comparing.
Been thinking of this project since the initial days of sound practices when I got exposed to Sakuma San 🙂, finally got it after 20 years 🙂
Attaching the schematic
Parts used are:
- Monolith Magnetics 15K amorphous core output transformers
- Monolith Magnetics FeSi plate chokes for 211 driver
- Monolith Magnetics Power Transformers and Chokes
- Bartola Valves Source Follower
- Rod Coleman Bias Supply
- Daitron low noise SMPS supplies for 211 filaments
- VH Audio CuTF 0.1uF/1200V coupling Caps
- Elrog 211s on the output and using Psvane 211T on the driver, and ordered another pair of Elrog 211s to replace them
- Amphenol 14S-2 Connectors for filament supply and 22-34 HV connectors for B+ and Source Follower Supplies
- 55uF/1KV kemet film caps for power supplies
Hooked it into the system, which had a 211 driving a 805 in class A2 Shishido style with a source follower. Initial impressions, same nice big sound as the 805, I don't think I lost anything compared to the previous set up. Even without any breakin, it sounds great!. Will let it play in the system for a month before comparing.
Been thinking of this project since the initial days of sound practices when I got exposed to Sakuma San 🙂, finally got it after 20 years 🙂
Attaching the schematic
Attachments
Looks great! Since i am in a 211 project, feel free to share your listening experiences with the amp.What preamp/speakers are you using with them? i am planning to use the 801 tube as driver with an AZ or GZ type rectifier as well as 2 to 3 inputs(Ongaku type) Monolith is pretty near me here in Belgium, if i may be so curious, what did these transformers cost you?
Cheers! Filip
Cheers! Filip
This is the best amp I have build, its two stage, so requires a hefty preamp. I use benchmark LA4 preamp, RME ADI-DAC2-ProFS as the as dac, and Volumio Priomo as the streamer. For vinyl, I have technics new DD TT, with iphono3 - black label phono stage. Between RME and LA4, Ihave more than enough gain to drive the monoblocks to full power. With Cree Schottky diodes, I have not had the urge to go with a tube rectifier, I just the damper diode for slow turn on.
I can throw all kinds of music at loud volumes, and the amp just performs effortlessly. I also use really noise SMPS supplies from Daitron for the filaments, removing the need for hefty linear supplies. All I can say is - I went all out in building these monoblocks, and they are worth it. These are amorphous core 15K output transformers, best to reach out to Ward or Yves on the pricing.
Currently, I am ripping my vinyls 24/96 lossless wav files with the RME pro, and given my slight hearing loss, can't make out the difference between vinyl and these high res rips 🙂. BTW, I have built 3 high powered amps with 211 as the drivers -- 211 just has a magical sound about it. I use Elrog 211's. I converted by 211-805 to 211-845, using an old pair of magnequest FS-100's as the output transformers. All the amps have mosfet source followers that buffer the driver from the output tubes
All the best with the project
cheers
I can throw all kinds of music at loud volumes, and the amp just performs effortlessly. I also use really noise SMPS supplies from Daitron for the filaments, removing the need for hefty linear supplies. All I can say is - I went all out in building these monoblocks, and they are worth it. These are amorphous core 15K output transformers, best to reach out to Ward or Yves on the pricing.
Currently, I am ripping my vinyls 24/96 lossless wav files with the RME pro, and given my slight hearing loss, can't make out the difference between vinyl and these high res rips 🙂. BTW, I have built 3 high powered amps with 211 as the drivers -- 211 just has a magical sound about it. I use Elrog 211's. I converted by 211-805 to 211-845, using an old pair of magnequest FS-100's as the output transformers. All the amps have mosfet source followers that buffer the driver from the output tubes
All the best with the project
cheers
All the best with the project
cheers[/QUOTE]
Much thanks!
While in the process of finding info on the power supply section , i came across this review:
Super 211 SET
For the past few days, i have seen so many takes on the power supply design(for instance mercury vapor rectifiers?) and the differences in voltages of running the 211 tubes...Same actually for the 845 and GM70 tubes designs. Described in the article above the tubes seem to run on 1300 volts. Same goes for the design in OPT. There's quite a lot of "commercial" designs that opt for 10K, 12K, 14 ,16 even up to 20K primary which are in my opinion pretty big differences. As described in the link above the owner/designer likes the 211 to be run at high voltages (more voltage gets the best out of the tubes?) while other designs opt for lower voltage run tubes. Take for instance the original Ongaku design which had 15K OPT , yet a lot of Ongaku "clones" just have 10K transformers(like Tango X10SF) ??? These are very different both in power supply and OPT, and they are critical design spots for an amp of this amplitude.Since i love 2 stage designs I might need some time to figure out a proof design. 😀 😀
cheers[/QUOTE]
Much thanks!
While in the process of finding info on the power supply section , i came across this review:
Super 211 SET
For the past few days, i have seen so many takes on the power supply design(for instance mercury vapor rectifiers?) and the differences in voltages of running the 211 tubes...Same actually for the 845 and GM70 tubes designs. Described in the article above the tubes seem to run on 1300 volts. Same goes for the design in OPT. There's quite a lot of "commercial" designs that opt for 10K, 12K, 14 ,16 even up to 20K primary which are in my opinion pretty big differences. As described in the link above the owner/designer likes the 211 to be run at high voltages (more voltage gets the best out of the tubes?) while other designs opt for lower voltage run tubes. Take for instance the original Ongaku design which had 15K OPT , yet a lot of Ongaku "clones" just have 10K transformers(like Tango X10SF) ??? These are very different both in power supply and OPT, and they are critical design spots for an amp of this amplitude.Since i love 2 stage designs I might need some time to figure out a proof design. 😀 😀
I have a mental block crossing 950V, hence stayed around 950V. I have had very good success of 211 driver and wanted to stay with it. But this requires a high gain preamp though. Finally, monolith folks told me they have a 15K design, so I went with it 🙂.
The precursor to this 211 amp was a 805 amp with 211 driver. I used the learning lessons there and finalized the design and components for this 211 amp.
There is no one way to build this, as you pointed out, you have to charter your path 🙂
all the best
The precursor to this 211 amp was a 805 amp with 211 driver. I used the learning lessons there and finalized the design and components for this 211 amp.
There is no one way to build this, as you pointed out, you have to charter your path 🙂
all the best
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Thx, I repurposed my 805 amp to 845 amp with the same 211 driver, and used Magnequest FS100 I had bought like 10+ years ago. Both these amps sound very good.
Few things to note are, I used the source followers made by Ale from Bartola valves and the bias supplies from Rod Coleman. The pre-build modules combined with SMPS supplies, makes the building of these beasts a little easier 🙂
Few things to note are, I used the source followers made by Ale from Bartola valves and the bias supplies from Rod Coleman. The pre-build modules combined with SMPS supplies, makes the building of these beasts a little easier 🙂