nikongod

I think you have the 2 flip-flopped. The original purpose of the WCF was driving cables. its performance is independent of load as long as its not too low. SRPP on the other hand is totally load dependent. SRPP can come out of class-A without clipping audibly, and gets wrecked driving anything but its optimal load. the idea of driving a 32 or 300 ohm load off of the same SRPP output stage frightens me... If the ES-1 is what everyone says it is, it has a long-tail-pair input stage. the disadvantage of a LTP is you dont get as much gain, BUT you gain PSRR. A "Williamson style" concertina has more gain, but practically no PSRR... LTP can take a balanced input and claim "fully balanced", not that that really matters on head-fi as long as it has XLR in and out. A concertina is also somewhat sensative to how the outputs are loaded. The 2 plate outs from a LTP have equal Zo, where the "plate" and "cathode" outs on a concertina are not even close. miller capacatances or a resistive load screws the balance up. A real designer would rough his design out on paper taking a few iterations if necessary, P2P his prototype, tune 3 parts, and make 1 circuit board.

way to derail a thread, I thought we left head-fi to keep clear of this shit. there are plenty of threads here and there to muckrake in. Most wallwarts integrate the fuse into the transformer in various ways: saying "no fuse" is incorrect. what you meant to cut and paste was DR. gilmore's recommendation elsewhere that a fuse be placed in the DC rails to the actual audio stage. with alarmingly few exceptions, no wall wart is more likely than ANY manufacturered PS to cause a fire. The safety of rail fuses in an amp with bipolar supplies and whether they would even blow predictably in a class-A circuit and in a way which would prevent further damage to the speaker and amp is very questionable. in fact, you only need to look at the raptor to see a case where the B+ fuse blows somewhat randomly, although generally at NYC meets. fortunately, its a single supply amp with cap coupled outputs... on the other hand with a dual supply (+ and - voltages) when you blow one rail, the output goes to the live rail... good luck with that across your headphones. back to bashing RSA, its much more fun.

If you have the headphones for it, there is absolutely nothing wrong with those plugs, and the plugs are outstandingly awesome. on the other hand, if you dont have the HE90, you paid for an expensive socket that you cant use. for these people (and I think that people who DONT have the HE90 are going to be the majority of buyers for this amp, on the assumption that people who DO have the He90 already have gear they are happy with) something else would serve their needs better. putting the HE90 plug on is impressive because its a statement that this amp is good enough for them. sort of like running the R10 out of a portable amp.... I dont have a source for chassis mount EXP-950 connectors. I was referring simply to the headphones.

the 6sn7 does not have enough juice, but the 500v is stator to stator, so its only 250v p-p per section, which the 6sn7 can do. it just cant do the current necessary for the O2 and that voltage swing at the same time. Im a little upset (although not surprised) that ray used the connector for the HE-90, rather than the connector for the more obtainable he60 or easily obtainable koss ESP-950. he could have really gone out on a limb, and sourced 5-pin XLR's for the jades directly [sarcasm]much harder to find than the stax connectors...[/sarcasm] bummer, it was made to look pretty and impress people who have never heard anything else.

IBTL

What values do you need? Rat-Shack has an OK selection in higher power ratings. Looking at the schematic, you should be able to get most of the resistors listed from them. The only issue is that the "part to part" matching may not be so good.

They can make oscillations or noise worse. It dosnt sound like the amp is running properly with 6SN7 as gain. Thats what the amp was designed around; if its not right on its best tube noting else stands a chance. I would take it into a shop.

I kind of disagree with DR gilmore's statement that the dyna(whatevers) and some of the others mentioned are op amps. I dont think they have enough open loop gain to satisfy the condition of opampishness. To Dr G's credit, im sure that if his only goal was to make 60dB or more of open loop gain he could have designed another gain stage into the amps only to cancel it out with more feedback later on. there are no free rides: are the more complex harmonics worth it? I'd say not. on that note, not everything in an IC package is an opamp either. With a discrete design you can do a couple things you CANT with an IC. At the end of the day, it boils down to the designer having control over what goes into his (her...) product VS selecting the best part that may be made for something else. 1: You can unconditionally guarantee that EVERY transistor in the gain stage(s) runs class-A no mater what. Many IC opamps run the internal transistors class-A but who really knows how hard? 2: In the design stages you can "roll" transistors in a discrete design, where you just swap the whole IC. 3: Since all of the parts are separate, they can dissipate much more heat individually. You can safely "burn" off a couple watts in the gain/driver stages of a discrete design if thats what it takes to make the amp work well... you only get a hair over a watt TOTAL dissipation with a dip-8 package. 4: If you are designing an amplifier as opposed to an op amp, you can build to suit a specific gain. you also have access to the internal transistors, so smaller local feedback loops (around 1 stage) can be used rather than 1 big one which is typical with an op amp.