Good-looking setup that 
Latest effort - A pair or very small speakers using PRV full range drivers. Designed so that i can run them open backed if I fancy although they never worked well for OB in my systen before. The wood sides and top are from excess wood flooring and the rest offcuts. Eventually these are planned for desktop use but are about to be inserted in my main system after trying them out last night.
The graph shows the FR measured from listening chair. Green = closed baffle. Red =back open.
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Think I’m going to go with some 5k Lundahls and stick some 45 valves in the amp.
Will I just see a slight reduction in power if I use 5k rather than 2.5k and put the 2a3 back in the amp at some point?
Yes but probably a reduction in distortion too. And you don’t really need a full 3 Watts. What are you? Some sort of hooligan?
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Sometimes you have to turn Katie Melua up to 11 and let go 
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Pretty much.
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Is there going to be a difference in distortion between the 50mA and 100mA versions, the 50mA has a primary inductance of 35H and the 100mA is 17H
Think I can get away with the 50mA for both 2a3 and 45 as 50mA is around 10 Watts max?
I’d go for the 50mA version unless you’re chasing max. power with the 2A3, that will be better for the 45 (better LF response because of the higher Lp). For 2A3 50mA is a touch low, but there’s some headroom in there. The lower current might result in a bit higher distortion (usually more current = lower distortion) but that will be offset by the increased load resistance.
Then again, your speakers don’t do bass 
(I’d still go with the 50mA version anyway)
Yeah luckily I’m not bothered about all that bass 
Will go for the 50mA version then 
On the plus side I’ve finally found a decent use for an LP12, using a plinth as the amp chassis 
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How about using 2.5k and two 45’s in parallel vs one 2A3 ?
The First Watt J2 dates from ~2009, and when on, which is a lot, averages 65-75C on the heatsinks, depending on ambient temps.
With that in mind (and little else, TBH, it sounds fine), I decided I’d replace the 15,000uF smoothing caps which were rated at a stingy 25VDC and 3000hr/85C lifetime rating -
Popped a couple of caps off the board and, well, some naughty microfarads are AWOL -
Once all the caps were out, it became obvious the flush-mounted resistors were also cooking the PCB -
So I whipped 'em off…
Nice new caps (R) vs. slightly off-colour old ones (L) -
The new ones are 10,000hr/105C rated, so prolly see me out…
I’ve kept the old ones for charging-up and then chucking towards unsuspecting people to catch…
Here’s the board part re-populated with uprated Mills resistors stood well off the board -
I also pulled the fucking stupid T4L microfuses - sure they’ll probably never pop (and if they do, the amp is possibly scrap, 'cos dead silicon), but what a PITA to change if not! So, boggo 20mm cartridge holders and fuses into place instead.
Also binned was the X2/Y2 cap across L&E - completely pointless considering the filtering at the other end of the power cord - and more-pertinently, in the way.
That’s as far as I got today. I’ll pop the caps back in next time I get a chance to fanny-about with a soldering iron. No rush, waiting on some other parts anyway.
Meanwhile, I’m suspiciously eyeing the NTC thermistor (green disc) that couples system-ground to mains Earth. I get why he’s used it, it’s clever - in overcurrent situations its already token 10R resistance drops to nothing - but it won’t do so quickly (1 - 12s), it won’t do so repeatedly if its hit hard enough, and it’s kind of hard to derate sensibly across the amp’s operating temps - it’s probably sitting at closer to 2R most of the time, which makes it a mite pointless, so I may pull it and put something more conventional in there.
Grounding overall is also a bit random - e.g. the standoffs could ground to the chassis - except no-one removed any anodisation, same was true for the star-ground point on the chassis until I sorted it, and only one XLR socket was grounded, so I’ll get everything back to one point via as few routes as possible.
Not that it’ll make the slightest difference to the sound…
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sounds like you may as well have bought a new kit…
Tut!
FAR too easy.
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That’s a bit spooky, I just bought a mic off amazon and had a quick play with REW this afternoon.
Haven’t got a clue what it means but will try and have a read up on how it use it properly soon
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PS it was this one I bought…
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Think the one he is after has a calibration certificate.
The UMIK-1 is rocking horse shit secondhand but if you buy it from Minidsp in the US even including postage and VAT it’s still cheaper than the UK, should be just shy of £100
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His sister is on holiday in the states so was going to get it sent there but dates didn’t work out.