There's something wrong in Colorado...

[n_maher]

Maybe I'm looking at it wrong, but it looks like (at lest the pair I can see) are going to pin 6: the cathode. Why put them in series, when parallel would help with the heat dissipation?

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.

I have a European version of the Extreme with the out board power supply.It is not designed to run 6528 tubes.

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.

[JBLoudG20]

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.

Well less current yes, if we are talking doubling the resistance. I was more referring to putting 2 500 ohm resistors in parallel, giving the same equivalent resistance, but helping to better dissipate the heat, by halving the current through each resistor.

I agree, I'm scared if that is 500ohms. Hell I'm scared if its 1k: I used 1K on my VanTOTL and I used 2 25 watt resistors in parallel to deal with the heat.

[kevin gilmore]

The Extreme does not have the FET to which Kevin referred. Kevin really knows his shit but he does make mistakes so don't take everything he says as gospel. It isn't.

Well if people would send me better high res pictures and tell me what they are

pictures of, i would make less mistakes. If you think i'm going to ever buy any

mikhail crap, you gotta be kidding.

As far as the extreme pictured above, better pictures are needed from a couple

different angles, taken with as much flash power as possible to see thru to the

other side. With a better side shot, its easier to determine the resistor power,

but sure looks like 5 watts each. Maybe only 3 watts each.

And i definitely like the acetate changing color around R54...

But here is my best guess. The output resistor to ground is 2 x 250 ohm in series.

500 ohms... REALLY... The zanadeux uses a 330 ohm resistor. The other 2 resistors

probably also in series are probably in the plate to lower some of the tube output

power. And you bet the thing runs stinkin hot.

So depending on what the value of b+ is (something in the 150 to 200 range)

the cathode resistor has 50 volts across it. So about 5 watts.

And i definitely like the acetate changing color around R54

[n_maher]

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.

[spritzer]

OTL sure sounds better then transformer coupling when fed through some of those luxurious caps...

Nice of Mikhail to save me from looking over the Hammond catalog for a filament transformer to add to the ES-1's. That 8A unit will do just fine...

[penger]

I guess I'll go look at getting new hex screws that are larger... and harder to strip.

Here's what Mikhail told me about what tubes I could run. (I can send him an email if to see about running higher power tubes and see what he says.)

5998, 6080, 7236, 7802, 6AS7 for output

6SN7, 6SL7, 6188, 6SU7GTY for driver without adapter.

With adapters:

5965, 7AU7, 12AU7, 6211, 5814, 12AT7, 12AV7, 12AZ7, 12AY7, 739, 749, ECC82, ECC81 and more. But, these are the best for ECC1

2C51, 396A, 5670 for 2C51 adapter

6922, ECC88, E88CC, 6CG7, 6GU7, and a few other for ECC2 adapter.

And Mr. Gilmore, in the interest of knowing more about this amp, let me know specifically what angles you would like to see, and I will take pictures tonight.

-Eric

[kevin gilmore]

values on all the resistors and electrolytic caps would be very handy in

drawing up a complete schematic. And the voltage ratings on the caps.

Getting a good picture of the bottom of the board thru the top of the board

is quite tricky, and you typically need a very good camera and a ring flash.

But in general, close the lens down as much as possible, and crank the flash

as much as possible. Then a slight angle and the bottom of the board shows up.

Put the camera on a tripod, and make sure the focus is perfect.

Also shining a light under the board, and photographing from the top at

high sensitivity usually works...

Now that i have the time to stare at it a while i really think all 4 resistors

are in series, so that it is probably 1k ohm, and there is probably 100 volts

across those resistors, making for a total of 10 watts which is 2.5 watts

per resistor, and if they are the same as the other resistors of that type

they are rated at 5 watts each.

See this is why good pictures are so important

[kevin gilmore]

lets see

C51 and C?? 390uf 400v

C52,C53 200uf 220v or is it 220uf 200v

R54 .15 ohm 5 watt

R50,R51,R52 50 ohm 5 watt

C56,C57 22000uf 25v filament cap

C4,C104 470uf 250v output capacitor

R4,R104 47K ????

R10 2102 == 21k

C1,C101 cathode capacitor

r106,R107,R108,R109,R6,R7,R8,R9 250 ohm 5 watt

R5,R105 ??

R56 ??

R57 ??

R58 ??

R53 ??

R1,R101 1004 == 1M

R55 ??

How am i doing ??

[guzziguy]

Well if people would send me better high res pictures and tell me what they are

pictures of, i would make less mistakes.

So what you are saying is that it's somebody else's fault when you make a mistake?

If you think i'm going to ever buy any

mikhail crap, you gotta be kidding.

Now you're inventing things that I never said. Why? You quoted my post so you must have read it. So you know that nowhere does it say anything about you buying anything of Mikhail's? It's a nice use of a straw man argument though.

As far as the extreme pictured above, better pictures are needed from a couple

different angles, taken with as much flash power as possible to see thru to the

other side. With a better side shot, its easier to determine the resistor power,

but sure looks like 5 watts each. Maybe only 3 watts each.

And i definitely like the acetate changing color around R54...

But here is my best guess. The output resistor to ground is 2 x 250 ohm in series.

500 ohms... REALLY... The zanadeux uses a 330 ohm resistor. The other 2 resistors

probably also in series are probably in the plate to lower some of the tube output

power. And you bet the thing runs stinkin hot.

So depending on what the value of b+ is (something in the 150 to 200 range)

the cathode resistor has 50 volts across it. So about 5 watts.

And i definitely like the acetate changing color around R54

I've never said that you don't know what you are talking about with regards to circuits, both your own and analyzing others'. What I said is that not everything you posit as fact necessarily is. That is undeniable as even you now admit, abeit in a round about way, that the Extreme really doesn't have the FET that you claimed it had when it was "designed to fail". I'm sure that you are correct the vast majority of the time, but was you say isn't gospel and shouldn't be taken as such. Too many people on HC do seem to take it that way.

[kevin gilmore]

Now you're inventing things that I never said.

No... I never said that you said that. It is just that i'm working from pictures

that people send me. If i was going to be consistently more accurate drawing

schematics from units than i am now from pictures i would have to actually

have the real thing to look at. That means someone would either have to send

me a unit, or i would have to buy one. The chances of me actually purchasing

a unit from mikhail is zero.

It took me 3 tries to get the singlepower squarewave circuit exactly right... For example.

If i make a mistake and someone points it out, then i will admit to the mistake.

OK, the power fet on the extreme was a mistake.

The cathode sitting at -350 volts on every single ES1 and ES2 is not a mistake.

[penger]

C51 and C51 390uf 400v

C52,C53 220uf 200v

R54 .15 ohm 6.5 watt

R50,R51,R52 50 ohm 5 watt

C56,C57 22000uf 25v filament cap

C4,C104 470uf 250v output capacitor

R4,R104 47K ????

R10 2102 == 21k

C1,C101 cathode capacitor 16V 1000uf

r106,R107,R108,R109,R6,R7,R8,R9 250 ohm 6.5 watt

R5,R105 Dale-M 2002F

R56 Dale 0507 J

R57 Dale 0507 J

R58 Dale 0637 J

R53 I believe says 3.75W

R1,R101 1004 == 1M

R55 15 ohms 5%

Can't get you pictures of the bottom of the circuit board... my camera sucks too much.

[kevin gilmore]

R56 Dale 0507 J

R57 Dale 0507 J

R58 Dale 0637 J

those are date codes, i'm looking for the number with typically an "F" after it.

R53 I believe says 3.75W but what is the resistance...

don't rotate any of the resistors if you can't read them. If you have an ohmmeter

you could measure them

r4,r104 is the color code yellow, purple, orange... very hard to tell from the picture

as the camera probably skewed everything to green.

[RockCity]

Hey Kevin, can you answer this question please? Your expertise is appreciated.

Kevin mentioned some of the imminent dangers with the design flaws in the ES-1 and Extreme. Are there any problems with the MPX3 and PPX3?

[blubliss]

The cathode sitting at -350 volts on every single ES1 and ES2 is not a mistake.

According to Mikhail, wrong again.

How come you have such a big boner for Mikhail?

And why don't you call him and discuss the supposed problems with him instead of spewing false accusations around the forums.

[Dreadhead]

Quick someone buy the mythical Singlepower 8 channel amp:

FS: Singlepower Squarewave and Squarewave XL - Head-Fi: Covering Headphones, Earphones and Portable Audio

[riceboy]

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.

I have a European version of the Extreme with the out board power supply.It is not designed to run 6528 tubes.

Thanks Penger for posting up the pics. I actually was interested in an external power supply for the Extremem as you know because of the 6528 tubes. I really like those tubes in my other SP amp and I have talked to Mikhail and he did let me know that the external power supplies he has now with the Extreme would run the 6528 tubes. He did tell me that the Extreme without the external power supply won't run 6528 tubes. Thanks again Penger for taking your time to post up the pics and for everyone who has commented Aloha

[n_maher]

According to Mikhail, wrong again.

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?

[n_maher]

Thanks Penger for posting up the pics. I actually was interested in an external power supply for the Extremem as you know because of the 6528 tubes. I really like those tubes in my other SP amp and I have talked to Mikhail and he did let me know that the external power supplies he has now with the Extreme would run the 6528 tubes. He did tell me that the Extreme without the external power supply won't run 6528 tubes. Thanks again Penger for taking your time to post up the pics and for everyone who has commented Aloha

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.

[luvdunhill]

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.

just checked my precious 500v Black Gate stash. No ratings. I'd guess 85C if I was pressed for a guess.

[blubliss]

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?

Are you kidding? He stated his assertion as a fact. That's silly. Why would you defend him knowing that he hasn't even measured anything.

I do have a big boner for people who act as they are truth incarnate, and it is especially disturbing when respected individuals in the community do it.

[riceboy]

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.

Thanks Nate for your input. I really do appreciate it. I've been holding off on getting the external power supply and will probably just not get one. The Extreme I use at work has so far been working great so I'll keep my fingers and toes crossed. Thanks again

[n_maher]

Are you kidding? He stated his assertion as a fact. That's silly. Why would you defend him knowing that he hasn't even measured anything.

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?

I do have a big boner for people who act as they are truth incarnate, and it is especially disturbing when respected individuals in the community do it.

You must often find yourself uncomfortable while browsing Head-Fi, no?

[Pars]

<snip>

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.

AFAIK, all BGs are 85

[Guest sacd lover]

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.

The ZD runs the 6c33 with 6.6 amps of heater current per tube without any trouble. The amp does get really hot but reliability seems fine. So, IMO, a 5.0 amp 6528 shouldnt be any trouble. Also, the Extremes high voltage supply is in the outboard power supply and the heaters are on the amp section. The big amperage Plitron should be running the heaters on pengers amp.

That said, I tried 6528s in my one box Extreme with the 14 amp transformer a couple times and I didnt like the heat buildup at all. The chassis is to small to dissipate all the heat. I have a tube rectified outboard power supply, two box Extreme coming someday and I plan to atleast give the 6528s a try. But, honestly, I really like the inexpensive 6AS7G.

[luvdunhill]

AFAIK, all BGs are 85