What are the extra under chassis valves doing?
Absolutely no idea, you would have to ask Glenn.
These were run with a Croft Super Micro.
I had a 1989 full spec LP12, Koetsu Red, Croft Super Micro, Leak TL12 Plus, ProAc Mini Towers.
The imaging was astounding, the top and mid was outrageous, the bass was ok.
Sold it all in ‘92, except these amps, it paid for two years of university.
The shame of it exposing those internals and built in Asia too must sound horrible!!!
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It is cooked in Asia since it looks like a pot of noodles 
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We moved just a week ago and I’m tired of emptying boxes so I thought I’d post something here. Noticing an almost complete absence of speakers on this thread I thought I would add mine and talk about them a little bit. Excuse the mess.
PureAudioLogic Trio 15 Classic:
An open baffle speaker with 3 drivers … 2 X 15" woofers and a Voxativ AC-PiFe full range driver
Front screen off:
Solid oak frame … each speaker weighs around 60lbs … the grills are magnetically attached to both the front and the back of the speaker.
The Voxativ driver construction is very interesting in that the all the white/light material you see here is either wood veneer, solid wood or paper
The back:
The speakers are around H:50" (125cm) x W:23.5" (56cm) x D:15" (38cm) … Sensitivity 96 db making them easy to drive, Impedance 8 ohms and a frequency response of 29hz to 20Khz
Backless:
I have upgraded the internally cabling replacing it with the foil/ribbons you see here. If you look carefully you can see the magnets embedded in the side wall of the frame …
Back of the Voxativ driver … and yes, I installed it at an angle … looks great from the front.
Here’s the Mundorf cross-over installed on the base of the speaker frame … all the components are attached via screws, no soldering at all, meaning you can swap and replace components … a speaker equivalent of “tube rolling”
another perspective …
Back to the boxes … and the unpacking …
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Very interesting speakers there John. How long have you had them ?
Almost exactly a year to the day James …
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Wow amazing speakers
Open baffled how do you find them and what do you have to do as in room treatments I’ve often looked at the concept off them but never took the plunge
I think over the pond they are more popular than in the UK we still like our boxes so there not seen that much I first came across them in a article on hifi pig I was blown away buy the concept off no box
Archie: Like you I had spent quite some time being intrigued by the concept … I had gone to 2 or 3 HiFI shows where OB speakers were being demo’ed and had loitered around the rooms talking to the presenters but couldn’t quite bring myself to pull the trigger.
I must say though, they sounded tremendous at the shows … and I think that’s not always the case as the acoustics sometimes leaves a lot to be desired in those rooms.
Very early last year, after reading everything I could get my hands on about the technology, I read that Nelson Pass (of Pass Labs) had a pair of Open Baffle PureAudioProject (PAP) for his personal use.
Also Harry Westfield, owner of VPI no less, has a pair and speaks glowingly. In his own words they are *“…the answer to where did the dynamics go, where are the goosebumps and it has become my go to speaker for musical enjoyment…that special something that makes it sound real”.
PAP has a money back offer so I thought why not? Nothing to lose … and that’s the end of the story … wonderful experience … and still vey much enjoying them to this day.
But to answer your specific question … I didn’t use treatments in my last house and, even though I’ve only been here a little over a week, I’m not sure I’m going to need any here. The absence of a cabinet and there being no longer a need to put the air in the cabinet under pressure changes the entire dynamic of how the music sounds. The speakers provide omnidirectional music … the music doesn’t appear to emanate from anywhere it’s just “there” … in the room.
OB speakers are particularly sensitive to the distance from the back wall … in my last house I had them about 36" … I’m just in plonk and play mode at the moment … whenever I get 15 minutes to sneak away I’ll listen to a track and move a speaker a bit, then a bit more. I’ll find the right spots eventually.
The sound initially takes some getting used to … it’s effortless … and with my pair, having 4 x 15" woofers they are NOT wanting for bass. End game speaker for me. Hope this answers some of your questions.
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They’re just lovely!
I think OB speakers have a gentle roll off, from what I remember of speaker design, so as long as they’re away from rear walls the bass is supposed to sound much nicer than the steeper roll off, if more extended bass, from infinite baffle or bass reflex designs. Those bass drivers look like they shift a lot of air regardless 
Anyway, they look awesome.
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Not my photos, but photos of the inside of an Icon Audio 25 MkII Valve Amplifier, which is part of my office system.
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That looks very neat compared with many valve-based systems.
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Yes. Beautiful point to point wiring. 
Thank you so much for your response to my questions much appreciated
Yes I can imagine the 4 15"woofers produce plenty off bass, I do like the effortless sounding bit just as imagine how they would sound
Again thank you it appreciated
One off the best amplifiers I’ve ever had was made by icon audio I loved that amplifier it was few models up on yours, unfortunately I had to sell to help towards funds for something else more important at the time maybe one day I’ll get another, also had there valve cd player that was brilliant as well
My virgin Nait 1 (top) and unit serviced by Plurison a few years ago, Still marvel at sound quality of this amplifier. Wish I would have had WBT connectors installed on phono section but wanted to keep stock.
Would love to see shot of n-Sats innards as have one which exhibits a slight noise when moved an indication of something loose inside. Have refrained from opening up as does not affect sound but still discerning. In all likelihood crossover components which are often glued in-place in many speakers …
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This is an updated - show us what’s inside - of my 1986 Linn LP12, now that the upgrade project is nearing completion at my dealer.
So, an “afterwards” picture, to compare and contrast with first “before” post of the original inside, back in October 2020 at the start of the works
.
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This inside view of a Linn reminded my of a couple of pictures I took when I replaced the built-in under chassis power supply with an external Atlas power supply on my Alphason Sonata Gold turntable, which I still have of course.
Here is the inside of the Atlas Power Supply
And yes I know I should not have used mains coloured cable for the low voltage cable connecting to the motors as you see here.
The turntable had two motors, and the “7 on its side” shaped sub-chassis is cast from pig iron and is very heavy, and of course makes a rigid base for the bearing and the arm mounting. The three support suspension springs hang down to support this sub-chassis so are in tension, and are adjusted from above so no jig needed for setting up. High mass and damping design, and adding to the weight is the massive record playing weight. The only drawback is the difficulty fitting the flat belt over the two motor pulleys, hidden under the solid single piece platter. Could be considered a no compromise design!
Also apologies for the barrel distortion, the sides are straight!!
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