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Just finished some big mods on my MkIII's

W

Wungun

Active Member
Finally got around to installing my Poseidon boards!!
Used Obbligato caps on 'em. Tung-Sol gold pin 12ax7's and ElectroHarmonix 12au7's.

While I was in there, upgraded the power/ground leads to the board, added some capacitance to the 80uF section of the can (big thanks to Craig!!), grid stopper resistors (or are they screen stoppers?!)

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Next job will be to disassemble and polish the chassis, replace all the old tube sockets and upgrade more wiring maybe.

How does it sound...? I've been running the JJ's for awhile now, so the change this time around was the boards and wiring and grid stoppers...
I finished one amp and ran it with my unmodded amp...
Was almost like somebody was covering one of the drivers and partially covering the tweet on the unmodded amp! The clarity and definition of the mid to upper ranges was immediately apparent.
Bass is much more revealing as well...RIGHT there, but still tight and punchy. Certainly seems like more bottom end, which I wasn't expecting.

When I finished both and had a listen, it really became apparent, how much nicer my setup sounds.
Can't wait til tomorrow and have a real good listen.

I really need to start listening to some other systems now...I know mine sounds really good to me, but, that's just me!
 
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Thanx.
The only thing I dislike about the MkIII...?
There's no perfect way to orient it so you can actually see all those beautiful tubes!
Something is always hidden :S
 
Congrats! Glad you're finally getting them lined out. Sounds like a great improvement for ya. Enjoy!
 
costerdock - Any issues with vibration causing microphonics or other problems with the amps on top of the speakers?
 
Thanks Rick... Yeah, Iam really pleased with the Poseidon's.

Thinking about it, I think the wire upgrade made a noticeable improvement as well. I mean, apart from the transformer wiring, everything uses thin gauge, solid core copper wire with thin jacketing (dunno if that's original or changed by someone else) ...
Probably fine for line level and heater circuits...
But for carrying 195 to 500+ volts, I gotta think a bigger , multi strand wire can do a better job...and I think it most definitely does.

I'm basing this off my car audio experience...large gauge power wires, beefed up grounding, short common grounding...

Though, I could be way off the mark when it comes to tube amps!
 
etet said:
costerdock - Any issues with vibration causing microphonics or other problems with the amps on top of the speakers?
Click to expand...

No - not at all. I had them in my audio rack - on the bottom shelf for quite a while and decided to move them back to the top of the speakers (where I had them prior to my new rack) - they sit on heavy rubber - and the Cornwalls being 100 lbs each - sit on rubber cups - I didn't notice any difference when I moved them back - even at extremely loud volumes - dead quite. I'm happy with this configuration.

Thanks,

Chris
 
Seeing that horn, I kinda thought those were Klipsch's.
I run KG4's myself... Recapped with Ti tweeter diaphragms.
I thought about speaker mounting my amps...but I'd rather have short RCA's and longer speaker wires than the other way around.
 
Very nice job on the Mark IIIs , i miss mine but i have a very sweet ST70 now . Not the same power but still love it.

More pics when ya get em all cleaned up and dialed in ok ,

Thanks
 
Yup...an Asus Essence STX. Probably the best, consumer grade, analogue soundcard out there, IMHO.
The clock was a group buy kit on the DIYAudio forum...$30, easy to build...
Couldn't of done it without the forum help of other, much more smarter peeps than I!
There is a whole underground of modders for these soundcard...pretty cool. :)

Next, I gotta put together my "super regulator" board and run external power to it, get away from the noisy, switching PC PSU.
 
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