n_maher

Thanks for that, even if it's really not good news. I'm hoping they are conservatively rated. I would say that he misspoke in this case. Even if he's still running the 6SN7 heater off of the original, chassis mounted trafo you still don't have anywhere near the current capacity that you need for the 6528s. That's ignoring the previously mentioned heat issue as well.

I'd say that those are different enough that it's not exactly a fair comparison. The Zana is larger, and at least has some ventilation at the base of those tubes. Does the Extreme have any? I'd respectfully ask that you go back and look at the pictures and notice that the trafo in the outboard supply is a 12.6V/4A - 6.3/8A unit. You and I both know that this is not the HV supply. Mikhail may have built other Extremes where he's moved the HV out of the main chassis (that sounds like what he told me at Canjam) but that is clearly not the case here. I'm guessing that this Extreme didn't start life as a Platinum and therefore doesn't have the Plitron trafo, but I'm guessing there. The 5998 is my personal favorite in this type of amp, but the right 6AS7G sounds pretty darn good for $10 tube. The 7236 can also be good and not break the bank as well.

I'm not defending Kevin, he's perfectly capable of doing that himself if he feels it's neccessary. I'm saying that individuals with either a) insufficient technical ability to fully comprehend the scenario (myself included) or no further first hand information should just be quiet for now. Your post, saying you talked to Mikhail is worthless. So, like I said, I don't really care to hear from anyone about this till there's some first hand, picture documented evidence to go along with it. Get it? You must often find yourself uncomfortable while browsing Head-Fi, no?

Honestly I'd be pretty concerned about running 6528 tubes w/ their 5A heaters in the Extreme, regardless of power supply. The amount of heat strikes me as borderline unhealthy as it is. I know Vicki does it pretty regularly and should I ever find myself in Florida again you can bet I'll be cracking open her amp to check for signs of heat stress on some of those components. Minor tangent - does anyone know what the operating temp range for BG's is? I've never worked with their HV caps and can't find a pic on the web that shows the label clearly enough to show it.

How about we just wait for Kevin to get the amp and take some measurements and then post up. Or do you have a big boner for Kevin and feel the need to keep posting the same thing on multiple sites?

SiK had a line out dock long before ALO was buying camo hats. I had to point this out one time when he was defending his ingenuity a little too vehemently. He countered that his was the first dedicated LOD that didn't have the firewire port on it... oh, so yours is less functional and therefore the more noteworthy...

Based on limited research and advice from others I don't think the top of the line Freq's are very desirable. Word is that they're simply too sensitive. If/when I sell my stat setup I'll finally be ordering a pair of The Freq of Natures.

Seriously, did you not read Dan's last post? We Don't Care Fat, skinny, or otherwise.

Your sarcasm detector is broken. She hasn't been bullied by anyone here as far as I know and don't know why she's claiming to have been. She sent me a PM in response to my question, that's as much as I know. If she got bullied by anyone I suspect it might have been at Head-Fi and even then bullied is probably the wrong word. She is working on a commercial venture and attempted to position her and her company by pseudo-innocent posts in several sub-forums at Head-Fi when she's been telling people for a while about what she was working on. What did she expect? She has only herself to blame for her venture becoming public. The only secret kept secret is the one you don't talk about with anyone.

Feel free to PM grawk or I with the details. Bullying of any kind is not acceptable. Well, unless it's aerius.

Yeah, WTF? I thought I was pretty nice about it actually. \

You sure you have that right? Careful now, remember what I said, think before you post. We've been nice so far, well, mostly.

Someone is also going to have to explain to me the logic of having Black Gates in the power supply and on the cathodes of the 6SN7 but not having them for the output coupling caps. Also, the unbypassed output caps (which I believe are C4 and C104) seems kind of weird to me too.

I know you said you didn't want used, but I'd suggest trying to find a deal on a pair of ER4Ps or see if you can't find someone selling some IM716s.

Do you guys/gals refer to yourselves as professional engineers, or just software engineers (or other nonsense). To me a PE is a PE, which means you're licensed and registered with the appropriate board. But there are lots of jobs that carry an "engineer" title that operate in a gray area. -=she=- is referring to herself and her friends as professional engineers which take it to another level in my book. In some states unfounded claims like that can land you in a lot of hot water.

Because series would actually get the value up and flow less current, right. I can't tell if he has it setup so that both pin 3 and pin 6 both have what would be the equivalent of 500ohm or if he's got all 4 in series which would be 1kohm. If it's the first I'm scared, if it's the latter I'm still pretty concerned. Now I haven't taken the time to see how close the amp section of this is to the Menace/HA-2 but assuming it is those resistors are both in series and used in a similar fashion then the 4 are in series and dropping ~150V (depending on the B+ used) and trying to dissipate some 20W or more (total). Now they look like 5W resistors which would put them right on the brink. In the Menace I use two 50W resistors in parallel, sinked to the chassis w/ additional external heat sinks in the same situation and that amp runs fracken hot. Hell, even if he's running a lot lower B+ and there's only 100V across them it's still 10W which is going to get hot in a closed chassis. I'd love to know more about the B+ and circuit of this thing. Then what is the point of the external PS if it can't run any different tubes from the stock version? I know for Vicki he said the external PS was so that she could use the 6528s. And penger, I'd stick with the hex screws honestly, I hate phillips head screws.

I would like to officially state my desire that not all of Vicki's advice be followed. This thread is fine without pictures.

As someone who's earned both degree and title I take particular offense to her claim of being a professional engineer. Not that the title means a great deal, the list of idiot engineers is not short, but to make the claim when it's not true is just .

Yeah, there is. Look for Todd's thread from when he first got it.

Could you post the resistor values for the groups that are near the tubes? I'm specifically talking about the ones that are oriented vertically in pairs near each output tube. (Like R6, R7, R8 and R9) I'm really interested to see how hot those might be getting if he's running the current at Menace levels. Love the off-board mounted pot, led and headphone jack too. And, uh, I'd have to check but I don't think that external PS is up to running the 6528s like Mikhail claims it should be. Unless of course the Hammond trafo is rated to run 25% over its rated capacity.

Next time I'll PM you, I honestly thought you had to have seen it when you mentioned you were looking for one. I mean the odds were just outrageous... Sorry Vincent.

Go to the hardware store and ask them if they carry things like "easy-outs" or other similar products. It'll involve a small diameter drill bit and a reverse threaded stud/bit. You should be able to get just about any, non grade 8 bolt out with something like this without harming the surrounding threads. Well, if you're careful anyway.

I think putting them here would be just fine. If they spawn some kind of large scale discussion we can always split off that conversation.

I think, but don't hold me to this, that the external PS is the filament supply.

Now that's funny.