DISCLAIMER

DISCLAIMER: Vacuum tube circuits work with dangerously high voltages. Do not attempt to build circuits presented on this site if you do not have the required experience and skills to work with such voltages. I assume no responsibility whatsoever for any damage caused by the usage of my circuits.

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Tuesday, December 31, 2013

Happy New Year!

Hi!

Yet another year comes to it's end. This has been the third year since the start of the VinylSavor blog. It was a very exciting and productive year for me. Since the beginning of the year, I am working full time in audio. This summer I moved my workshop to a separate location away from the private apartment. This gives me a lot more room for storage and workshop. The office also got an own system which is still in preparation. Once it is set up I will describe it in a separate post.






Many projects got completed this year. Most of them shown on this blog. The most fun project was the Sound Processor.  Above a photo of one of the UX201A tubes glowing in this device. And a shot of the mercury vapour 866A glowing away in it's magic color in the power supply:





Definitely the most interesting meeting of the year was my visit at the last german vacuum tube manufacturer ELROG. Since my visit there I have worked a lot with the company the ER211 became my favourite 211/VT4C tube and was used in the latest 211 amplifier build.




The tube which I used the most throughout the year was definitely the 6AX4, which finds it's way into most of my power supplies. Typically in a set of 4 for an all tube full wave rectifier bridge:




Not all of the projects which I planned for 2013 got finished or even started. The mighty 851 transmitting triode is still waiting to find it's way into an amplifier. Here shown with a 211 tube to give an idea of it's size:





I guess this tube has to wait unit somebody orders such an amp. Who really needs 150W of single ended glory? Would definitely be a fun project though. Or maybe a 75W amp with the smaller sister of the 851, the 849:





Also the fully differential EC8020 phono stage is still waiting to be built. Hopefully in 2014.





Definitely in the plan is finally a 300B amp especially since there is hope for a german made 300B tube!




Also definitely planned is a new power amplifier with the 801A as output tube, Probably two versions one with an indirectly heated driver and an all directly heated one with a second 801A as driver.




Silver transformers will be a big topic for 2014 with a 211/211 amplifier in the planning using all silver transformers as well as a 45/45 amp.

I'd like to thank all my customers, partners, friends and readers of my blog for a great year. Looking forward to an even better and more exciting 2014. Stay tuned!




All the best for the new year to you and your families!

Thomas







Friday, December 27, 2013

Making of a 801A / 211 Amplifier, Part 5: More Photos

Hi!

A few more photos of the newly finished mono blocks with the Elrog ER211 tubes.




First listening in the workshop system:




Tidying up a bit:




The amplifier sections:




I enjoyed these amps a lot. Now they are off to their new home. I have to build the next set of 211 monos to be able to enjoy those Elrog tubes again.




Best regards

Thomas

Wednesday, December 25, 2013

Making of a 801A / 211 Amplifier, Part 4: Listening

Hi!

Here some impressions of the  211 mono blocks, finished in a silver, black and white color scheme:




Although the 4 chassis take up significant floorspace (each chassis is 43cm wide and 31cm deep) fitting everything in was quite a challenge. Especially the power supplies are darn heavy. But the result is definitely worth it.

A close up of one of the amplifier sections:




The power supply of one channel:




Although the amplifier combo is quite large the white transformer covers and caps help to give a less overwhelming look when the set sits on the floor in front of the speakers:




A view from the side:




Some more photos:





So much for the looks, but how do they sound ?




Readers of my blog now that I am a bit reluctant to give sound descriptions of amplifiers that I built. After all the sound perception is quite subjective. So take these with a grain of salt.




Having built many different amps, I am not easily impressed by anything new. But these amps catched me by surprise. So far the flea power 45 has been my favourite output tube, with it's extreme finesse and colourful sound. But these 211 beasts are fully up to par to a 45 in the finesse and color arena! This is thanks to the Elrog tubes. I have noticed this feature of the Elrogs before when listening to them. But in these amps they fully show their potential. All the magic of the 45 but combined with the authority of 10 times the power.




The bass these amps reproduce is simply stunning. Even with the humble Haigner Rho speakers, the room is filled with the lowest registers. Fully controlled bass notes with fine details I have not heard before. The amps excel in layering the sound so that each voice or instrument can be easily picked out and followed. Yet everything plays together well integrated.




Voices are reproduced with full emotional impact. In a short summary: These are simply the best amplifiers I have built to date.

Best regards

Thomas



Monday, December 23, 2013

Making of a 801A / 211 Amplifier, Part 3: Signal Chassis Assembly

Hi!

In the last post about these mono blocks I showed the assembly of the power supply chassis. Now we will see how the amplifier section gets constructed.




The metal plate with sockets and connectors:




The red jacks above the tube sockets are bias test points. At these the bias current of the tubes can be measured with a DVM.

The back side:





Mounting the transformers and oil capacitors:




Output and interstage transformers are original Hirata Tango production:





All signal wiring is done with solid core silver wire, protected by additional sleeves:




Adding some B+ and filament wiring:




Chokes, additional oil caps  and bias resistors are added on a tier which is mounted below the metal plate:




Below the driver tube socket in the top right corner there is space left to add an input transformer if needed. These amplifiers will be used with a preamp which has very high gain, so the input transformers are left out, but can be easily added later if needed.


The amp is ready to be tested:




After testing the amplifier will be inserted into it's wooden frame.

Impressions of the finished amplifiers will be shown next. Stay tuned!


Best regards


Thomas

Saturday, December 21, 2013

Making of a 801A / 211 Amplifier, Part 2: PSU Assembly

Hi!

The first post about the creation of these 801A / 211 single ended mono block amplifiers showed how the layout was done. Part 2 will cover the assembly of the power supply chassis.





Everything starts with the top metal plate, here with connectors, sockets and switch mounted:




The bottom side:




While the filament transformer for the driver tube will be mounted on top of the plate, the other transformers are too high to fit under the cover. They need to be mounted slightly lower. Here a foto with the power transformers mounted:





View from below, which shows how the two larger transformers are mounted on rails:





Some foots showing details how the transformers are mounted below the plate:






Wiring of the transformers:





Adding the filament supply section:





Almost finished PSU with capacitors and chokes added for output and driver section high voltage supplies. The green resistors are only temporarily added for testing, and will later be replaced by aluminium cased resistors.







Testing the power supply:




One of the power supplies finished with final bleeder resistors. Ready for the transformer covers to be added and to be encased into the wooden frame.





The assembly of the amplifier chassis will be shown next. Stay tuned!

Best regards

Thomas