• 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.

EL34 Baby Huey Amplifier

Interesting Zintolo, I'm running Svetlana winged c el34 on this build and the new build will run KT90's. I have to admit, I've not tried many of the Russian equivalents.

As mentioned, I also cant try the 6N2P-EV with the EL34 as the boards don't have the option to swap out the ECC83.

Agree the Brimar tubes sound better with Rock, I've settled on the Telefunken's at the moment as they sound amazing with female vocals, once we are out of lockdown ill grab a few NOS Mullard's
 
Another option could be to modify the board and redo the heater connections like this:

6n2p_rewire.jpg


This evening I will check if it can be easily done or not.
 
Looks great! Satin finish?

Is the wheel paint a hard wearing type? Ended up using engine paint on mine, for the heat resistance and also fairly hard wearing. I painted a couple of transformers with Hammerite after a friend gave me a few pointers, light coat and wait a few minutes and repeat until nice solid coat. (I ended up doing 3) He said don't let it dry between coats. I was impressed with the results but nervous of doing a whole chassis as well!

I got the bottom cover plates powder coated as they went in with a job for my work which is in the black textured finish that Kenwood used on there cases in the 70's :D love that finish, just not on the front or tube amp chassis top plate
 
Welcome KelloGsX,

Output at this stage would depend on many factors though mainly, output tubes and B+ voltage.

GB info here
GB: EL34 Baby Huey Amp and PSU MK2 PCB

Great project but would suggest you read the entire thread, there have been issues and errors along the way, also some great tweaks to the original design. Safe to say the current run of PCB's are tried and tested.

Also great start to this thread for current builders
EL34 Baby Huey Kit GB 2021 Builders

Happy reading
 
Question guys, has anyone fitted a switch between the input on the PSU PCB and the two HT outputs on the Toroidy Power transformer so that you can switch between the low and high B+?

Last night I found a sleeve of NOS Sylvania 6L6GC tubes in my "stock" so decided to drop a pair into one of my Monoblock's. The sound was not great I have to admit but wonder if its because I was running them too low with 380v on the plates? Spec suggests 450v plus.

In essence Id like to be able to tube roll with the flick of a switch and a quick re-bias.

Any thoughts from the experts?
 
Question guys, has anyone fitted a switch between the input on the PSU PCB and the two HT outputs on the Toroidy Power transformer so that you can switch between the low and high B+?

Last night I found a sleeve of NOS Sylvania 6L6GC tubes in my "stock" so decided to drop a pair into one of my Monoblock's. The sound was not great I have to admit but wonder if its because I was running them too low with 380v on the plates? Spec suggests 450v plus.

In essence Id like to be able to tube roll with the flick of a switch and a quick re-bias.

Any thoughts from the experts?

I have a 3 position switch on my BH EL34 so I can adjust the B+ to 450, 425 or 400v. I set all bias currents to 0 before changing B+. I find the 400v setting with about 65-70ma works nicely for KT88s . The biggest caveat is to make sure your power supply and coupling caps can take the highest voltage setting. Running 450v means you need at least 500v caps in the PS.