For those into valves:

[geoffbyrne]

tests run on JJ 803S valves

[url="http://la-economy.blogspot.com/2012/02/tube-test-jj803s.html"]http://la-economy.bl...est-jj803s.html[/url]

& Tung Sol 12AX7

http://la-economy.blogspot.com/2012/02/tube-test-12ax7-tung-sol-reissue.html

G.

Edited February 27, 2012 by geoffbyrne

[Dood]

Ahhh superb. I've e-chatted with Myles before about valves. He's been a great help and incredibly knowledgeable. This makes for very interesting reading.

[bertbass]

I replaced the JJ ecc83s in my Mywatt 200 with a trio of Tung Sol 12AX7 and I did actually notice a difference for the better. In my opinion that is. Tighter bass and less middle which I like.

[bigbottomend]

Good info , thanks

[REDLAWMAN]

Terry,

Hi mate, hope you're well?

Daft question probably, but why did you replace only 3 of the 4 and did you retain the 4 JJ powertubes?

Incidentally- and slightly off beam- have you ever tried running it on 2 instead of 4 power tubes and if so, did you take out the 2 central ones or 2 end ones?

[charic]

[quote name='dood' timestamp='1330383877' post='1556746']
Ahhh superb. I've e-chatted with Myles before about valves. He's been a great help and incredibly knowledgeable. This makes for very interesting reading.
[/quote]

Did you ever try those other valves in the kilo?

[Dood]

Not yet mate! It's a job to do at some point to see how it sounds, but i've been pretty busy elsewhere! I'll start by rotating around valve one,the 'critical' position and see what difference it makes with my 'magic' valve and my rather spesh 5751.

[geoffbyrne]

Latest epistle from Myles:

[url="http://la-economy.blogspot.com/2012/03/vacuum-tubes-today.html"]http://la-economy.blogspot.com/2012/03/vacuum-tubes-today.html[/url]

G.

[geoffbyrne]

Another interesting instance of Amp Blueprinting:

http://la-economy.blogspot.com/2012/03/bit-of-amp-blueprinting-from-past.html

G.

[bertbass]

Sorry, a bit slow with this reply but only just seen it. I only replaced 3 because stupidly, I didn't realise that there were 4 preamp valves and only ordered 3. The only reason that I changed them in the first place is that I'd read that the Tung Sol 12AX7 were supposed to be better valves so I thought I'd give it a go. I haven't changed the KT88s as the JJs are new and it would have cost a lot of cash to replace them as well. Never tried running an amp with only 2 of the 4 output valves and doesn't the output impedance change with only half the output valves?