DIY Audio General - stuff you're making, tips, advice sought, etc


What do you estimate the power output to be in watts/ cwt? :smile:


The correct units are Kg/Watt

This ratio is known as the Backfuck factor


If you’re interested and have the time this series of videos is very interesting. The fella knows his stuff. I’ve watched the lot and learned loads.


Phono stage on test…


Is that your kitchen? :laughing::ok_hand::heart_eyes:


Lol, no. Utility room, aka workshop.


E810F input stage? That was on the list of things to try here if a cascode stage didn’t cut the mustard (which in the end it has).


Looking forward to hearing this :grinning:


Ah ok, don’t look like you do much utilitying in there :+1:


I’ve noticed, that you do like the odd Trafo.


BBC news reports of widespread power outages across Luton…


Yes, E810F as pentode. A cascode would work as well, though, but the supply voltage requirement gets a bit out of hand.


Should be down in Brighton soon!


Today in ridiculously oversized heatsinks, this is for a pair of LM4780s.


Now wired up, now need to rewire the Pre 3 for balanced output and remake the pre/power ICs.

Edit: oh, and splatter blue LEDs everywhere, obviously.


Once I’ve sold 4,000000 pet twigs I would like to commission ‘Coco Loco’ AKA ‘Towering inferno’. x2 Mono blocks + Pre + Phono + SUT + Crossovers encased in a steel erection a bit like this, but taller than my ceiling


Assume these will power a single massive horn which will also provide your living accommodation.


Done, with the new knowledge that mini XLRs are a pig. Unfortunately, given the space constraints on the Pre3 they are necessary.

Good, but not quite there.
That’s better.


Slight behinds the scenes change to the NAGA-J LCR3. Originally wired up the second stage/cathode follower as a valve per side rather than per stage, so connected the heater referenced to ground. As it has ended up with the cathode followers in the same valve, I have swapped that to feed from the heater supply referenced c. 40V above ground to reduce the heater/cathode potential. Not that it was excessive, but it might increase valve life there.

Not that this will change sound quality of course. What will do that is the addition of this.


Took this to Jim’s bake last weekend, made for a Lenco lover in London, a nice coincidence to deliver it Sunday.

Unusually, the ply is Beech, nearly 4x’s the cost and twice as heavy with Corian top plate bonded on to create a CLD.

No numeric controllers, jig-sawn templates and a horse power router with a bit of sweat ensure no 2 are the same.