spritzer

So true, the few times I bother to read it these days it just makes my head hurt. So much ignorance and stupidity... Fuck that, this is the Mk3. I got them in a trade.

Yup, get a DY294 but those do look real or very good fakes.

Mine came from New Zealand so a proper Mk2 and not an "A". I've done that comparison countless times. The HV is more linear, more neutral and clear while the older KGSS is warmer and not as defined. Can't go wrong with either one but the HV is the superior amp. The treble is smooth but there is more of it so they can slide into brightness a bit faster/easier than the Mk1. This is nowhere near the 009 let alone the horror of the old 009's. It's a bit like the old SZ2 units, when modified they had a touch more treble than the Mk1's. I'm keeping them stock for now and just enjoying them. They are silly good off the KGST, rocking the new mix of Thick as a Brick...

Good point... As for the new 007, now that the last BHSE in fully operational condition has been packed up I had to revert to the KGST. It's not quite as bass crazy as the BHSE so here the effect of the port is minimized. I have to hand it to Stax how well the port works on this set. It did take them some 8 years to get this working but still, it does what it is supposed to do with minimal side effects. Still no way I'll leave them like this...

He's asking about classic KGSS (no ccs for the third stage and +/-350V rails) vs. KGSSHV with 2SA1968. I'm not ready to call it just yet but it sure looks like it. I've seen the counter argument being that the designer factored this into the component so only used parts that would get better with use.

The highs were never the problem with the 007Mk2.5, it was the midrange. Replacing transistors and not the resistors is not a good idea. This was built in the 70's so still 5% carbon comp resistors which will drift.

Confirmation bias is tied into the new toy syndrome and I don't see how the caps would be a factor in the channel imbalance. Something is wrong somewhere and has to be fixed.

Even those of us "burdened" with experience (paraphrasing my favorite saying in Icelandic) still get a bit lost sometimes by just how good this stuff is. What bothers me about the whole burn in crap is this assumption that our senses and auditory memory are perfect but components made to tight specs somehow drift in a way that can't be measured but is clearly audible. It took me two weeks for the shine of the HE90 to wear off and I've only become more critical in those 10 years.

The ESP950 cables were something around 10$. Haven't bought any in probably 10 years though...

You do have a point there and I know that this is a purely psychological phenomenon. It doesn't exist in the sense that we can't measure it, caps don't magically change after being charged/discharged a few million times (100 hour burn in). It is also a pure fallacy to think that a one 5 minute session with any component will give you an an accurate impression of its signature, our senses simply aren't that good. They also just make up shit and lie to us... those fuckers...

There is no such thing as run/burn-in

I've been putting them through their paces this morning and my only complaint is the slightly overblown bass. Plugging the port should fix that issue.

Koss ESP950 extension cable works just fine. Ask somebody in the US to order a few for you and drop in an envelope.

They don't ship internationally... at least they didn't. Ebay might have something like that.

Yup, and they sure can rock. Bass has that slight reverb to it which suits rock perfectly. I'll reserve final judgement until I've plugged the ports and played with the pads. This is a bloody good start though...

An hour or so ago I got a brand new SR-007Mk2 delivered to me serial SZ3-2029. First impressions are positive, the fit out of the box is good and the midrange issues I had with the older Mk2.5 are gone now. The bass is a joke as is to be expected from a ported design but it is at least mostly controlled and only falls apart at a limited range. The top end is not as smooth as it should be but it might just be due to the earpad position. More updates coming and we'll see how long I'll last until I've ripped them apart to mod.

More than half of my SumR transformers buzzed and about a quarter are simply unusable. One of them melted through the insulation and shorted to the chassis... I've had some up and downs with Toroidy but they are mostly good.

I just want some large film caps right on the rails.

I don't think there is anybody who will match these for you. The amp will work just fine with unmatched ones though

The transformers are over spec so line fluctuation should never be a problem.

Poly caps always beat ceramic in my book so go for it. As for the 4.7uf caps, I can't find the layput files here for this board but I'm pretty sure they are the bypass caps I wanted Kevin to put in. Any value that fits is fine there but moar is moar bettah!!!

Indeed!!!!

Should be ok at lower voltages.

Been there, done that. It's a waste of money in this circuit.

It can be wired as both 117V and 230V but why would you order a transformer like that. You need a switch to wire them either in series or parallel but no simple solution springs to mind. Nothing wrong with doing this but watch the phase. I had to do this on the KGDT's that I'm working on and used this transformer: 553-FS36-350 with these custom PCB's: It was the neatest way of doing it. I have some spare PCB's listed on my site if anybody needs one.