I always found that Sugdens A21a and A21SE take around half an hour for the bass to assert itself and the sound to become something special
I haven't heard an Aleph 3, but contextually it seems very similar to my Pioneer M-22. Both are 30W class-A amplifiers and they have a beguiling yet solid presentation when paired with the right loudspeakers.
You can tell all this from the schematic?!
As far as it's possible to tell from a schematic I would say...
“Audiophiles seem to revel in minor controversies - vinyl vs CDs, tubes versus solid state, capacitor, wires, magic dots... and negative feedback.
At one extreme, the position is that "feedback makes amplifiers perfect". At the other extreme, "feedback is a menacing succubus that sucks the life out of the music, leaving a dried husk devoid of soul".
The former viewpoint usually belongs to so-called 'objectivists' who have a fine appreciation for electronic theory and measurements. Their opposites would be the 'subjectivists' who emphasize the listening experience and often own tube amplifiers. Accusations are occasionally made that objectivists can't hear, and conversely that subjectivists hear things that aren't there. This being the entertainment industry, I hope everyone is having a good time.”
From an interesting interview/discussion with Nelson Pass here on 6 Moons.
This could just be relevant, at a stretch. I 'won' a DIY Sony VFET amp in part 2 of the lottery.
Now I've had a chance to hear it solo with ESL57s/Townshends it's without question the best sound I've enjoyed in this room.
No, not at all - there is an awful lot of thermal mass to be brought up to temp; and while that happens- all of it is designed to reject heat efficiently (by convection.)
I think the more interesting question is to wonder why being 'warm' makes such an obvious difference - when it really, really should not. At all.
(to the extent that - if temp is the determinant - covering the thing with a teatowel, to bring it up in 10mns from a cold start should be no different to wasting 2hrs and 0.4KwH on 'warmup')
PS - This is no slight on what it may or may not be in terms of enjoyment!
There’s a service manual here with a schematic. Assuming it arrives safe and sound and works ok I’ll work on the assumption that I’ll eventually at least recap it, check the heatsink gloop is still gloop etc, and probably try and find a full set of the power mosfets to keep safe as a spare. Apparently it used very good quality Panasonic caps which seem to have lasted well/better than expectations, but even so they are likely getting tired by now. I’ve yet to find evidence of folk having issues these amps despite the age, but I’ve not read the whole internet yet. I’ll pop the lid and if nothing is obviously leaking or bulging and the DC offset looks reasonable I’ll assume it is safe for a while. I’ve also got a heat meter so I can spot if it is running too hot.
The MOSFETS are obsolete, about the only place I would trust is Rochester Electronics but they have a high MOQ. When I wanted some hard to find mosfets I had to try aliexpress and eBay, I got them eventually but about half the deliveries had to be scrapped as they were fakes, get a transistor tester and see how a kosher one measures with it, one that measures capacitance, threshold voltage, gm etc and you should be fine.
Given just how good Pass support is and the whole community around it I’m not going to bother. If it ever dies it can be fixed, of that I’m certain. I’ve been doing a real deep-dive of the DIYAudio Pass room and I have yet to find a single reference of a real Aleph 3 needing anything more than a recap, they seem remarkably robust for something that runs so hot. Pretty much bomb proof. There also seem to be several substitutions that people use when building clones with arguably better properties, so if it ever does blow up I could likely get it working nicely if Pass themselves didn’t have any of the Mosfets to sell me. I’m certain I’d get a lot of help and it would end up working again.
I’ve been reading a lot. I’m obviously way, way, way out of my depth lurking on DIYAudio (when it comes to electronics I’m neat and tidy, very careful, but I know nothing - I can just follow instructions, that is all), but I’m gaining huge respect for Nelson Pass. He has an amazing attitude. A very clever, generous and decent bloke. This industry would be a way better place with more folk like him in it.