• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

world's heaviest 2A3 amp?

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
up and running

OK, I'm happy, the amp is running again and the 2A3's are vertical. How does it sound? Smooth and not annoying. Timbre is apparent. There is bass again. The room dimensions are bad. Only 11' across. Kind of hard to get the speakers 3' from the front wall and get yourself 3' from the back wall and be equilaterally distant from the speakers. But it's listenable, unlike the Accurus and Crowns. It sounds good at all volume levels.

So most of the weight is the iron. I had much of the iron laying around and felt it to be better used in the amp than taking up space with all the other unused transformers. Topology wise, I needed left and right filament supplies for the DHT. I didn't mono-block the HV supplies, but I did have an LC each for each 2A3 and ECC99 driver.

I paralleled the triodes in each ECC99 and am running them at about 14 ma. The extra triodes were there and paralleling lowers the driver output impedance. I would prefer to run at 18 ma but want to try an interstage coupling transformer first. I'm using a 6.5K load resistance.

My first and maybe last tube amp design. On to the the next project - room correction. The plan is to burn room corrected cds. No hw effort and nominal sw development. I "completed" this project in the spring but haven't implemented it yet. Maybe it will save me from working on another speaker project.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.