Creative amplifier. Can it be and is it necessary?

[SVS]

It is unusual to see the combination of the words "creative amplifier", but it is real and we have been working on this project for some time.
It started even before the COVID-19, now the war stands in the way of it, but despite everything, we plan to complete this project.

What is a creative amplifier?
All users of tube amplifiers know that each tube has its own sound. There is even such entertainment, which consists in rolling tubes in search of their sound. But it will not always help to find it.
As usual, we do not use general feedback, so the sound is as close as possible to the real thing.
In general, this is a tube SET amplifier with a maximum output power of about 60W.
This device will have 11 own voices and its owner will be able to choose the one he likes the most now with a simple push of buttons. This leads to the formation of one voice from 4 different voices in different combinations.

In addition, the device also has an energy-saving function. Power consumption can be reduced by reducing the output power. At the same time, the electrical modes of the tubes do not change and the sound quality does not deteriorate.

I start this topic to find out how interesting this idea is to lovers of good sound. Maybe new interesting ideas will appear.

 

[Solypsa]

It is unusual to see the combination of the words "creative amplifier", but it is real and we have been working on this project for some time.
It started even before the COVID-19, now the war stands in the way of it, but despite everything, we plan to complete this project.

What is a creative amplifier?
All users of tube amplifiers know that each tube has its own sound. There is even such entertainment, which consists in rolling tubes in search of their sound. But it will not always help to find it.
As usual, we do not use general feedback, so the sound is as close as possible to the real thing.

Hard to say. Audiophiles tend to distrust adjustability, despite using other less direct methods to tune their system ( cables etc ).

In the pro world it is common to swap discreet opamp modules to tailor a preamp sound for example but I don't see this very often in hifi...

Love to see pictures

 

[SVS]

Hard to say. Audiophiles tend to distrust adjustability, despite using other less direct methods to tune their system ( cables etc ).

In the pro world it is common to swap discreet opamp modules to tailor a preamp sound for example but I don't see this very often in hifi...

Love to see pictures

The time has not yet come for the photo, this is still a project, but almost more than half of it has already been implemented.

This project did not appear out of nowhere, it has a history.

Ten years ago, we needed to make a SE tube amplifier with a power of about 50 W without general feedback and with the ability to reproduce sound microdynamics very accurately. Amplifiers on large tubes such as 833 (GU-48) or GU-81 cannot do this, so we used a pair smaller tubes, these were 811A.
In parallel, we did not connect the tubes, the output transformers did the power addition.
The project was very successful, we received 47W of very high-quality sound.

The second step was a similar project, but a pair of different lamps worked there, not the same. We used 811A and 6C33C. As a result, we got a sound that was not similar to the sound of component tubes, the sound was much better.

A little later, the idea of this project arose. Now we plan to use 811?, 6?33? and GU-72 tubes. GU-72 can work in triode or tetrode modes.
As a result, we will get a sound with handwriting:
1. 811A
2. 6?33?
3. GU-72 in a triode
4. GU-72 in a tetrode
5. 811?+6?33?
6. 811A+GU-72 in a triode
7. 811A+GU-72 in a tetrode
8. 6C33C+GU-72 in a triode
9. 6?33?+??-72 in a tetrode
10. 811A+6?33?+GU-72 in a triode
11. 811A+6?33?+GU-72 in a tetrode
The user will be able to easily choose the mode to his liking.

I think the idea is clear. We have already produced the most time-consuming and expensive components and will do assembly work.

I am attaching a photo of the prototypes.

 

[Solypsa]

In parallel, we did not connect the tubes, the output transformers did the power addition.
The project was very successful, we received 47W of very high-quality sound.

Nice. So did you stay with the method of using the output transformer for making these various connections?

 

[SVS]

Nice. So did you stay with the method of using the output transformer for making these various connections?

Thank you, we are trying.

Not quite so. I wrote about output transformers in the plural.
I also have a visual example of practical implementation.
More recently, we made a pair of SE monoblocs on 6?4?/6B4G. Each monoblock can work as a stereo amplifier with an output power of 2x5W, or a mono amplifier with a power of 10W.
That is, two output transformers are used and the addition is made by switching the secondary windings of the output transformers. Someone in electrical engineering does such manipulations every day, but no one uses it for SE tube amplifiers.

Thanks to this, instead of one huge output transformer with its gigantic parasitic capacitance and dissipation inductance, which significantly worsen the sound, we use several small transformers for which there are no complaints about the sound.

I believe that problems with sound microdynamics in powerful CE amplifiers are not due to tubes (833 or GU-81), but due to large output transformers, but we eliminate this problem.

I am attaching a photo of the combined monoblocks.

 

[christoph]

Wow, this sounds very interesting

 

[SVS]

Wow, this sounds very interesting

You have no idea how much. Photo in the system, McIntosh in front, a couple of which they easily pushed out.

 

[bonzo75]

You have no idea how much. Photo in the system, McIntosh in front, a couple of which they easily pushed out.

what speakers/drivers?

 

[Dogberry]

The 811A doesn't get the love it deserves. I used to have a pair of AES SE-811 monoblocks, and I often wish I still had them. Only 12W/channel, but extremely musical. And cheap!

 

[SVS]

The 811A doesn't get the love it deserves. I used to have a pair of AES SE-811 monoblocks, and I often wish I still had them. Only 12W/channel, but extremely musical. And cheap!

Yes, a very underrated tube. I consider its sound better than 845, 211, I'm not even talking about GM-70. The reason is that it is technically more difficult to use than other tubes.

 

[Dogberry]

What makes it difficult? I understand it was used (this may be apocryphal) in the MIG-25 Foxbat!

Chris

 

[SVS]

what speakers/drivers?

I don't know the drivers, the speakers are in the photo.