Mods for Sophia Electric EL34?


Does anyone done, beside the cap changes the manuafacturer offers; know of any other circuit mods or favorite tube combinations used in this amp? Are there any owners of the amp? If so, what speakers are you using it on?

I made a change to 6u8 NOS Siemens input tubes [from the stock chinese units]...WOW! What a major difference in the sonics! I stumbled onto this via ebay.

Music_al1
music_al1
I am also looking at modifying this amp. I bought it so I could start learning about upgrades and tube circuits. I play it on my Adagios by Acoustic Zen at times and it is very nice. I also upgraded the tubes, it was a good move, I am using jj el34s and miniwatt ECF802s. I like them, I have few others to try, but haven't spent m8hc time doing it in a while.

Right now I am struggling to understand the circuit, hopefully to try to draw a schematic and be able to play around with it a bit. Mostly to stretch and expand my electronics knowledge from oh so long ago...

Somewhere I swear I saw a recommended and simple modification, something to do with the output transformer connections, but I recently moved and I can't locate it.

So far it seems that the manufacturer Cap changes are simple coupling cap upgrades, that should be easy.
I think there may be a few extra caps in the signal path or directly affecting it and if I can figure which these are I would replace them as well. There also may be a little benefit to upgrading and increasing the power supply caps a little.

If I do come up with a schematic, I will be needing help with it, perhaps from the awesome folks at the DIYforum.

I would love to stay in touch and share anything we figure out.
Change the main power supply capacitors to blackgate 100uf/500V would upgrade the amplifier to another league if you have funds to do it.

Look into Sophia Electric's more expensive amplifier would be the next step.