Fair question. I wired it that way, for two reasons.What I don't understand, and maybe Mr. Heyne can explain it to me, why he wired the grid connection from the AC701 all they way down to the PCB pad and not directly to the insulated standoff right next to it?
Photo:© Klaus Heyne, 2022
I agree, so many good tubes out there. The only reason i'm interested is because the price of 6s6b, one of my favorites, might go balistic. But i just re-stocked at regular price, so whatever...My 2cents - a little too much obsession with the tube; as Decca found out decades ago, the transformer in the M49 and M50 has waaay more to do with the sound than the tube. When Decca replaced the tubes with a simple FET circuit, they found the change in sound insignificant.
So, the big question about these new '49s is, have they been able to come up with a transformer that can come anywhere near the big, big sound of the original?
It might not though, there are way more 6s6bś out there than ac701s and it seems 6s6b has a lot less rejection rate. Also the m49v looks like it will be produced in limited quantities ( which I think it’s part of the hype since it’s not really that hard for produce considering it’s pcb…the u67 or 87 are way more complicated to produce)I agree, so many good tubes out there. The only reason i'm interested is because the price of 6s6b, one of my favorites, might go balistic. But i just re-stocked at regular price, so whatever...
I think it has been like that since the war started . Now you can only get them mostly from Ukraine and Boulgaria.Well, that's what i thought before i went for a search some days ago. Russia-Ukraine situation doesn't help, and at least on eBay the stock is substantially reduced.
Probably the core alloy is not the same as the vintage Bv.11. So, generally speaking, ratio, inductance, DCR and capacitance can be "to the spec's", but it's hard to replicate the magnetics resistance of the alloy.What's so "sci-fi" or irreproducible about the original transformer, though? Surely they have all the core & winding data they'd need...
Interesting...It was not any version of a 6S6B. I honestly do not know the tube in the final series.