Bare with me for a moment as it is more of a theoretical question rather than something I want to actually build.
If one wanted to parallel SE a bunch of low powered triodes to get a "decent" amount of power without having to buy a big expensive one, lets say 10 of them in parallel.
If one tube has an output impedance of 5k, OT's are readily available.
In our hypotetical case the output impedance is around 500 ohm. There aren't many OT I can seem to find which would have the necesary characteristics. What would be the real life solution to match these impedances? Would you need to make a custom transformer?
Lets take it a step further and parallel 625 tubes together, this gives us an 8 ohm output impedance..Could it theoretically be connected directly to a speaker without the use of a transformer?
If one wanted to parallel SE a bunch of low powered triodes to get a "decent" amount of power without having to buy a big expensive one, lets say 10 of them in parallel.
If one tube has an output impedance of 5k, OT's are readily available.
In our hypotetical case the output impedance is around 500 ohm. There aren't many OT I can seem to find which would have the necesary characteristics. What would be the real life solution to match these impedances? Would you need to make a custom transformer?
Lets take it a step further and parallel 625 tubes together, this gives us an 8 ohm output impedance..Could it theoretically be connected directly to a speaker without the use of a transformer?
Yes, there are such amplifiers, called OTL. Typically push pull, not single ended though. There are several threads here about OTL amplifiers.
600 ohm : 8 ohm / 4 ohm transformers are available, usual impedance for SE 6C33C based amps: https://www.tme.eu/en/details/ttg-6c33cse/toroidal-transformers/toroidy/
For Toroidy transformers is better to buy directly at Toroidy (https://sklep.toroidy.pl/en_US/p/TTG-6C33CSE-Tube-output-transformer-600-Ohm-6C33C/610).
It is cheaper.
It is cheaper.
Don't forget the DC idle current - a 6V6 will idle at 35 mA; x 625 is nearly 22 amps! 2.4 kilowatts will light up the voice coil of the speaker nicely! Since we're speaking theoretically, a choke could carry that DC current, and a large capacitor could couple the AC signal to the speaker. Or a 8 Ohm to 8 Ohm transformer could be built with a primary and core that can carry 22 amps... Good luck with that!
No need to parallel 600 tubes.
8 x 6С19П / 6s19p in SE cathode follower can do the job.
Here's a design from Japan:
https://www.diyaudio.com/community/attachments/6d5acd37-eb1e-4e2e-93c4-324f5ec10749-jpg.779702/
https://www.diyaudio.com/community/attachments/e32f3d70-6556-4ece-a385-023f83add0a1-jpg.779704/
8 x 6С19П / 6s19p in SE cathode follower can do the job.
Here's a design from Japan:
https://www.diyaudio.com/community/attachments/6d5acd37-eb1e-4e2e-93c4-324f5ec10749-jpg.779702/
https://www.diyaudio.com/community/attachments/e32f3d70-6556-4ece-a385-023f83add0a1-jpg.779704/
