Moondogs and Klipschorns

[kev313]

"It's easier to build an "optimized" 2A3/300B amp than it is for a 45/2A3."

I think so too. That's why I said 'personally' that I would prefer one designed for a specific tube. The 2A3 is very much like two paralleled 45s -- if not nearly exactly -- something which is reflected in the plate resistance differences between the two.

I would have to check to confirm, but I think the EP output transformer primary windings on my Moondogs are 3.4K ohms. It's why I was seriously contemplating using them as 300B amps, with some minor changes that would include a regulated 5 VDC supply for the filaments.

Concerning the difference in sound: I have found the 2A3 to be probably slightly more balanced top-to-bottom, and one of the reasons for the perceived greater top end extension or clarity (just from my own perspective) of the 45 might have to do with the mildly lighter output in the LF range. Midrange quality of the 45 is really superb, IMO, and with the right speakers is really nice all around. Lots of people I know who began with the 2A3 have come to prefer the 45.

I have a friend who has had MANY SE 2A3 amps, and his long-time favorite is a Tucker-designed 45 with parallel-feed output and active plate loading.

Guy did mention he liked the Gemini, though, so it still must have been a great sounding amplifier.

Erik

After owning these Moondogs, the Wright 2a3's, and the DRD 45's, I found that the 45 based amp had a bit more clarity. A little more detail resolution and, oddly enough, better dynamics (micro and macro) across the spectrum. Bass was more detailed that the 2a3, IME, but there was a bit less of it. I have no idea if this was tube or circuit based, but given the simimlar findings from Korneff, Wavelength, and Yamamoto owners, I think it these may be traits of the tube. Not having heard any other 45's, I am not committing to that call! I was suprised, however, by the fact that the lower power amp had better control over the speaker.

Despite the above, I found that I preferred the Moondogs to the other two amps. In short, it just sounded like there was more "there" there. Bear in mind that I have been using Fostex based speakers, so it could be that I simply appreciated the bass bump, as it were. That may ultimately explain why I am now even happier using a 15 watt el84 PP on these speakers.

Anywho...I've got someone coming over in the very near future with his Fi 2a3 monoblocks using the Magnequest silver output trannies. Looking forward to listening to these on this system and comparing notes. Of course at this point, the above 2a3's and 45 having been out of the loop for a bit, it is difficult to make comparisons other than as to how they stack up against the Shindo el84.

[Erik Mandaville]

Kevin:

".I've got someone coming over in the very near future with his Fi 2a3 monoblocks using the Magnequest silver output trannies."

Really great looking amps! I'm curious about what you think about them, even though you haven't been using this kind of amp recently. Silver secondary windings on OPTs have always intrigued me, but I just haven't been able to go the extra di$tance. Please report on what you think!

Moondogs went to James today -- at IKEA, no less! I did some very minor touch-up, and that's really all. He was very nice, and we wandered around IKEA looking for good/functional component racks that didn't cost an insane amount of money. It's always funny to me when reviews of racks mention their 'sound,' which just, IMO (and I may be totally incorrect) seems kind of 'over-the-edge.' For turntables, I think this is a very important consideration, but neither he nor I bought anything.

I very much enjoyed having your Moondogs here, Kevin; and, once again, very good packing with all of that.

Erik

[jazman]

Erik,

Since these Moondog's former owner prior to Kevin was Thom Mackris, were the Kiwami resistors that Thom liked so well still installed? In addition, did you consider giving the new owner the option of upgrading the caps to Jensen PIOs while you had it on the bench? Just curious.

Klipsch out.

[jt1stcav]

Since several people have been thanking Erik for his generous contributions throughout these forums, I thought I'd throw in my two cents worth as well. Erik doesn't ask for anything in return for all his help, but he's eager to tackle any problem...big or small (or without a schematic as he did with my brother's no-name Chinese 6BQ5 amp last year).

And then when I offer to do something nice for Erik (like he always does for others) by giving him a pair of 300Bs for one of his many projects, he turns right around and thanks me by making custom length interconnects that I initially never asked for (but definately had a use for)...A simple "thank you" would have sufficed, but here's Erik in true "Mr. Nice Guy" fashion, going well above and beyond the call. Not because he has to, but simply because he wants to!

Thank you very much for all you have done for the members of this forum, Erik.[]

[Erik Mandaville]

Edmond:

"Since these Moondog's former owner prior to Kevin was Thom Mackris, were the Kiwami resistors that Thom liked so well still installed? In addition, did you consider giving the new owner the option of upgrading the caps to Jensen PIOs while you had it on the bench? Just curious."

Yes. Before the amps arrived, we had discussed the possibility of coupling capacitor upgrades, but found that Thom had already installed PIO caps (Angela branded), as well as the green Kiwamis throughout the circuit except for the power supply and cathode bias on the 2A3. On Kelly's advice, I had also installed Jensen PIO caps in my amps, and he was right that they sounded very good in this design. When I built JFL's parafeed amps, I took the Jensens out of the Moondogs for the new amps, and used some Kimber capacitors I happened to have for the Moondogs. There are some designers who seem to really dislike oil caps in coupling positions, and there was one brand that I tried that IMO sounded really muddy and dark. Not so the Jensens.

These were also a pretty early pair of Moondogs, earlier than mine, and had MagneQuest transformers. They are physically a bit smaller than E-P iron, but otherwise very similar visually. I was also expecting to find the so-called 'Ultrapath' connection that Thom and I had talked about years ago, but he had brought the amps back to the original design before selling them.

Erik

[Erik Mandaville]

Jim:

"Erik doesn't ask for anything in return for all his help, but he's eager to tackle any problem...big or small (or without a schematic as he did with my brother's no-name Chinese 6BQ5 amp last year). "

Thanks. I had started out just doing some of this to help forum members, but started to get far more 'business' than I could keep up with. Since then, I have agreed to build amplifiers for about half of what might be charged for factory wiring. For minor repair work, it's often not a problem at all, and it gives me something challenging and enjoyable to do on weekends or school breaks from teaching.

That little Chinese amp became a personal battle for me![] I can say it absolutely is NOT a representative example of some of they very high quality work I have seen in other products from that country. It was an amplifier based on another design, which had been hacked to shreds in order to create the new one, so it was hard to figure out what was what. It wasn't even deisgned for U.S. voltages, and needed a step-up transformer to put the voltages where I estimated they should be for its tube types and general design.

As for the awesome pair of 300Bs you gave me (thanks a million for that!), I'm going to have some time fairly soon to do something with them. Looking again at the Moondogs, it really would be pretty easy to use them as a 300B amp, and I can use an inexpensive regulated 5 VDC supply (already built) for its filaments.

Erik

[Daddy Dee]

I also have received a lot of help and tips from Eric as well. I still have my Moondogs that Eric helped me quiet down.

I have not visited this forum very often in the last couple years, until a few days ago, one of my friends pointed me to the Bob Crites Tweeter thread. After reading this thread, I ordered a pair of the Tweeters for my Khorn/Altec Speakers. I may be visiting this forum more often, when I finish my Khorn listening room in the next few weeks.

Cut-Throat,

Great to see you posting. I hope you hang around here a little more.

Erik,

I want to add my thanks for the several projects you have worked on for me and the many times you have offered good counsel and advice. You have a generous heart, my friend.

[jt1stcav]

All I can say is you still got that little 6BQ5 amp to sing! Even after my bro later sold the amp to a friend of a friend, just recently the new owner contacted my bro again proclaiming how much he loves the sound of this no-name amp (thanks to you, Erik). You tackled the impossible with that project, and you still wouldn't accept anything in return. That's just the kind of guy you are...yer da man![]

If I ever have you upgrade/mod my 300B SE amplifier in the future, you WILL be compensated for it, whether you like it or not![]

[jbsl]

I made it back from Houston with the Moondogs and want to add my thanks to Erik also!! The only thing he would let me do for him is buy him a 99 cent cup of coffee at Ikea.

His attention to details when looking over the amps was outstanding and always kept me updated on everything he was doing and answered all my questions.

I have been playing with the amps over the last 12 hours and will post what I think Monday night after I have had a couple of days to play with them. I defentely like these amps! But for anyone thinking about SET amps you need to make sure you met the criteria or SET amps will not work. I'll go more into that when I post on Monday night.

Thanks again Erik!!