Intact Audio

Shunt regulators almost always sound better than series regulators for whatever reason. As to whether it's practical and or worthwhile? Good question. They throw out a lot of heat, thus become impractical at some point. Not sure what the T-rex shunt reg looks like, but if its higher voltage you're m...

Somehow, that tester has come back to life. I've recently gotten some questions on it. No, no recent updates. Somewhere in my pile of things to do on a rainy day is a new tube tester. I was going to put in a small PIC processor asnd a small display to print out the read values. Ahhh, but for some ti...

Hi, My first comment would be the pass tube want more than the G2 voltage you provided them in order to provide the current output you want. The "107 volt" G2 supply looks to be too low, so that when you attempt to draw the required current you can't get enough output. Hope that helps. Reg...

Thanks Don, Sounds like you have it. I think you could use the tetrode symbol as that already has the 4 leads, but it looks as though you're set up OK. I'm more or less "back"... I hang out here occasionally, although my priorities are a bit different these days.... Since getting my health...

Oh... One additional point.... The "original" used the anode as reference point for the CF stage. That provides DC feedback, and stability for high gain circuits. The "rev 2" biases the screen from the supply... No DC feedback. I think you will find in practice, that will be impo...

Cute circuit. The points about noise and power supply rejection are all good advantages. In principle, there is only one functional disadvantage. The anode voltage cannot drop lower than the g2 voltage in this circuit whereas in a standard pentode or the first implementation not returned to the anod...

Hi All, Here's the video I did for the folks at ETF, since I couldn't make it this year. It discusses W.E.'s "harmonic equalizer" that is one of the few things intended to cancel ODD order distortion products. I uploaded it to my YouTube page (conway7734) but it is unlisted.. that is, it d...

Here's a couple mods of the schematic with a 10k to 8 ohm xfmr. You get about 30 watts out as shown.

I added voltages and currents, and made the tube values visible, and labeled a few test points.

Freq response 1dB points show as 10Hz and 45kHz

Enjoy,
Stephie <3

Cute stage, jc! The only electrical quibble I would have with it is that there will be occasions where you overvoltage the 2N4393, due to pops, ticks or whatever. Put in a large input voltage and not the drain source voltage on the FET. It'll work, but you might see short lifespan on those parts. En...

Hee Hee Hee. No need to insult me. I haven't been a guy for a few years now.

Let me know if those work out OK. They seem to follow the curves reasonably well, except for what I consider a drawing error on Raytheon CK6528 curves.

BTW, here's a recent "me".

Hugs,
Stephie

Here's both. Let me know how it works out. The 6336 is the "A" (5 amp heater) from the Raytheon tube curves. The 6528 likewise uses the Raytheon tube curves, although I strongly suspect those curves are in error for Vg=-20 volts and above 100mA and subtly incorrect for Vg=-50 volts, as the...

Hi Jeffrey and all, Dxxn Thai food is great. Picked up about 10 pounds on that trip, although some of that is associated with a better top end. (Yeah, I got my, er, uh, tweeters, yeah, that's it, tweeters, improved while I was under the knife so to speak). Those Thai street venders produce some real...

Thanks. I'll be here til the 21st. Couple of checkups to go

Stephie >3

Well, made it thru ok. Recouperating. Youse guys missed a good opportunity. Steve got whole Photoshop suite for $30 and new 2011 blackberry for $100

CU when I get back

Stephie >3

Hi, Concept should work reasonably. You can trade the high voltage relatively low current for lower voltage at 2x the current, and avoid needing to "turn around" the winding by placing the "current" device as a current sink in the "other half" of a push pull configurati...

Hmmm. Given the effect of the resistance, it would imply a large effect of input capacitance too. Hi gm parts are prone to this, as are any triode (the screen grid of a pentode effectively removes the "Miller" capacitance whose effect is roughly Cga*gain.) I also wonder if that's some of t...

I depart for Thailand Oct 2 and return Oct 20. Direct flight leaves LAX late in the PM Saturday, gets there Monday morning. Free room and Plane tickets provided. I'll need assistance with luggage on return...I imagine I'll be hurting. Anyone up for it? Ya get to wander around Thailand for a couple w...

Oh... sorry.

http://www.youtube.com/conway7734

In the intro video, I also introduced a few of my amps, including the 813 matrix and the 16 tube P-P 801 amp.

Stephie <3

A couple months back, Parts Express had a sale on powered subwoofers, and, on an impulse, I got one. It does indeed add heftiness to the bass, but interestingly, my t-lines produce better bass (and deeper bass), just not nearly as much of it. (you can get a view of my speakers in the background of a...

Check this elegant build of your RAT tube-tester that my friend Lars built after finding the "greygum" site: Beautiful. Really a first class job. I would love to see a picture of Stephie's own RAT tube tester, My own implementation pales by comparison to that beautiful job above. I'll tak...

Thanks Pete for hosting those pages and thanks for the kind words all! Indeed, moving forward, I'll have some nice things to publish, I hope.

Stephie <3

:lol: :lol: :!: I wish I *had* made this decision 20 years ago! Who knows? By now I might have had a whole series of beautiful amps out on the market with this wunnerful iron in them. 3 weeks *is* a long time, but for someone with the available time, it does give a chance for some serious parts and ...

'Tis I again. Well, indeed I have started in motion the stuff for my Thailand trip. I expect it to be for 3 weeks somewhere in the October timeframe. I'll post the days when I get confirmation. I think I've jumped through all the required hoops, and I have my new passport stuff in process. Seriously...

One of several. Two Heathkit models, an old Eico model that I've modified to cover up to 1MHz, and a little hand held unit I designed and built that uses an Analog Devices 9834 DDS chip as its base and controlled by a PIC. Also several "TIMS" (transmission impairment test set) used primari...

ooohhhhh. That could be interesting.

Besides, you folks know I'm still going through puberty, so I can't guarantee that horniness (especially 600Hz and above) might not somehow be involved.

Stephie <3

Oh dear! now I've scared them off.
Sigh. Always a bridesmaid, never a bride.

<giggle>

O wow, Escorted by gentlemen such as yourselves. I am honored. :D Hmmm. Public forum and all. Well, I AM a lot more open than I used to be.....(and I won't even use the "blushing" emoticon) You folks know why I'm planning to go to Thailand, right? Let's call it "corrective surgery&quo...

There's lots of approximations in all the models; the ones I've done are no exceptions. Because of R13, the distortion will definitely be strongly dependant on the linearity of the dynamic plate resistance of the 'AU6. Which is the better model for that application? It's usually a good idea to Spice...

Hi, At some point I may indeed reinstate those pages and start updating things. At this instant, between work (I love my current job, although I spend massive amounts of time here), and my own personal projects (hey, I have a lifetime of things to catch up on, now that I'm healthy and happy), that m...