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Ella Amp


Brap

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Jeff, back on topic, I have two people writing me about building a 2A3 PP or 2A3 SET, both first timers. How hard was it to build that interstage 2A3 amp documented on Gizmo's site? I know you said it would be easier than other options but I wonder for someone that is a true first timer without the aid of a kit. Perhaps the Joplin would be good base for this interstage unit as you claim. But would the parts additions and circuit changes be problematic for the newbie? I think that Ralph Power amps was the first 2A3 amp you built, correct?

kh

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On 1/26/2004 3:05:28 PM painful reality wrote:

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On 1/26/2004 2:39:03 PM Are Friends Electric wrote:

there are no WMD in Iraq.

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Darn!

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This is interesting, too. So are you saying that Clinton and Senate Democrats said that there were, with the intent to set-up President Bush? Pretty diabolical, but considering that some people are claiming that the first President Bush killed JFK (and that Nixon found out and covered it up), who knows?

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Kelly, the Ralph Power design is really easy to build. But doing a kit first will definitively help to get a feel of what should a part layout may look like.

I think the Joplin has plenty of room inside to fit a Lundahl 1660 at a later stage. Providing one has a bit of 3D visualisation abilities, it shouldn't be a problem to install them.

This was indeed my fist PP DHT. Gizmo got me curious with all his raving. I couldn't resist to this simple little design. As I said though I would replace the 417A by a 6C45-Pi with a plate voltage at 150V and 40 mA of plate current. It's outside the specs of the tube but they are sturdy and besides, they are somewhat cheap. So I don't really care if they last 17 000 hours instead of 20 000.

Before doing so, it would be important to make sure that the PSU can give the additional current.

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On 1/26/2004 4:34:44 PM HEPA TITUS wrote:

Jeremy Epstein seems pretty fond of the 6C45pi in a phono amp.

You think this tube with transformer phase-slitting would fly with a 6BQ5 PP application?

Curious.

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It would be a bit overkill but I cannot say for sure as my experience with IT phase splitter on pentode amps is nil.

DHT PP amps with a IT phase splitter will require a driver with some cojones, hence the use of a 6C45-Pi runned hot. Working with High Gm tubes comes with their share of problems though and one should expect taming some oscillations at VHF. A look at the Kugelis preamp schematic on the Valve online magazine (available from the Bottlehead website) should give some idea on how to avoid those oscillations.

For the Kugelis click here

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Thanks Jeff,

I thought maybe you have tried this with Pentodes.

The article does kinda claim the 6C45pi as a RFI monster.

I knew ferrite beads would be mentioned, but not all the other tips.

Seems like that schematic wants that tube well regulated.

Have you had troubles with HF oscillation, or any RFI anomalies with use of 6C45pi as the article seems to threaten?

That Kugelis dish looks kinda scary.

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That Kugelis dish looks kinda scary.

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The 6C45 is definitively a RFI monster. I would try all the tips except for the regulation on the filament and look at the results. If there is some oscillations, only then would I go with filament regulation.

I used the 6C45-Pi in the past and you simply cannot avoid these oscillations. You won't have any choice but to adress those.

As for the Kugelis dish, nothing is more scarier (and horrible) than a plate of poutine.

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Sadly, Jeff and I have discussed and debated poutine many a time. PAthetic. And ole TAd found so many shots of poutine, we all called it quits.

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There is not much to debate...

It's gross and it would even have BBQ Jimmy hesitate about about having one. You have to be born around here to even consider eating this.

BBQ Jimmy and the bombshell

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Well- that took about an hour to get through the pain -- Hell those two should just get married. It all sounded like me and the wife when I havent played enough golf and she's at that time of the month!!!

Ella, WAD, Joplin, ZEN, hell I'm flipping a coin!! Seriously, I think I'll go with Joplin for what I've read here. Has roomo for upgrades, the Khorns will sound good, I can use it for the Forte's, it has some power for those beveraged nites requesting Aerosmith. Also, I read where the Zen's don't care for Khorn crossovers too much.

So can I get a concensus here???? At this pint, I'll take 3 out of 5!!

Thanks gang

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On 1/19/2004 12:47:15 PM Brap wrote:

After much discussion this weekend -- thanks to all who provided sane input, I've decided on the Ella to use with my Khorns. Also, I will be trying this amp with my 1986 Forte' speakers as a comparison WTH.

Comments are always appreciated.

Brap

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I'd go with your original decision, the very first post in this thread, copied above. You've decided a few times already.

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So can I get a concensus here???? At this pint, I'll take 3 out of 5!!

Thanks gang

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Brad, I think you should decide by yourself now. Providing you let the Zen out of your choices, everyone of these will be OK. Forget about a consensus you'll never get one. Time for an executive decision from you now.

But if you want my opinion, it's the Joplin first, then the Ella (based on the poor response time you got from WAD), then the WAD. But I'm a DHT freak so you may see me as biased, and like most of us clowns arguing here (instead of spending quality time with the missy), I didn't listen to any of those!

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