If you're considering a single-ended amplifier...

[Erik Mandaville]

...consider one the DRD amps from Welborne Labs. The first CD is Bach's Goldberg Variations -- in this case, a transcription for guitar by Kurt Rodarmer. Guitars were custom built for this project, and two are used, since the lower octaves required can't be reached with a conventional 6 string. This recording won an award in Guitar Player magazine, and is one anyone interested in Bach and/or classical guitar might want to consider. Rodarmer is a really, really good guitar player!

I used Jensen PIO coupling capacitors in my parallel feed monoblocks, but the DRD doesn't use them -- or any coupling capacitor, for that matter. A very large 50mf oil capacitor is used in the Ultrapath position, though.

My feeling is that comparing amplifiers of already very high quality is not going to be obvious in terms of striking differences. The Horus was certainly 'faster' sounding than the Moondogs in terms of transient response, but the Horus and DRD seem, at least at this very early stage, quite on par with one another in that respect.

If you want to build a pair, the instructions are excellent and have clear pictorial diagrams throughout. The only part that might be a bit challenging for someone new to electronics work has to do with the paralleling of the sections of the 6N1P -- just not a whole lot of space to work with there.

Very impressive! Clear, excellent bass response, and so quiet even with AC heaters on all tubes. This is a very pure design in that sense -- just simple twisted filament wiring with gounded center taps. It works very well. Kudret did very well for his investment, I think.

[Marvel]

Erik,

It looks like, from the pics you posted, that the top plates are painted on both sides so that you can easily flip one over so that you can make the amps as mirrors of each other. Was that actuall the case, or do they sell a left and right top plate?

Marvel

[Cut-Throat]

Marvel,

The plates are identical. They are made that way for simplicity. You simply reverse the plates for the mirror image. Same for the plates on the bottom of the amp.

[mike stehr]

What brand of 45 tubes came with these DRD's?

[Cut-Throat]

Mike,

I am going to answer this because Erik built a 2A3 kit.

I built a DRD45 and the 45's do not come with any tubes. There are limited new production tubes right now, and Ron W. did not want to supply NOS tubes, because as he said - He did not want to spoil the fun for us of scrounging around for NOS tubes.

[mike stehr]

My mistake. I thought Eric built 45 amps.

OK. I would gather your using NOS 45's.

What did you manage to find? Cunninghams? Marconi's?

(I don't think you'd have Marconi.)

I know the new production 45's are limited, and I think they are pretty expensive as well.

I can't remember what brand they were, but they make a rather spendy mesh-plate 45.

[jazman]

Kevin,

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2205843234&category=7275

Klipsch out.

[mike stehr]

Good price. It's still got 4 hours, however.

[Tom Mobley]

Got a feeling it will go up some towards he end. There's probably a dozen guys with sniper bids already in.

Tom

[Cut-Throat]

Edmond and Mike,

Thanks for the link Edmond, but I do have a stash of used 45 tubes. If I decide that I like the 45 amp (when I get my other one back from Welborne) I probably will get of a pair of the TJ Meshplates 45s.

Oddly enough Mike I do have one Marconi! as well as a pair of GEs, a Silvertone, and an RCA

[Kudret]

Erik, Thanks for your initial impressions.

I am glad that you liked the DRDs and they are on par with your Horus amps. A three way detailed comparison (Moondogs, Horus and DRD 2A3) will be very valuable for all, whenever you have the

time. I look forward to your future remarks.

kudret

[Erik Mandaville]

Hi, Kudret:

The comparing of the three amps is actually complex and depends on a number of variables. Not all Moondogs are the same, and I have heard a couple (Edster's and LonStar's)I thought were more revealing and transparent than my own. Both of those had upgrades -- power supply filter caps, different coupling capacitors, Teflon sockets -- that mine didn't. The same is also true for the Horus amplifiers. Many built by the designer (JFL)have cobalt output transformers, which mine do not; and that factor is one that could have a cosiderable impact on the characteristic sound of the amplifier. Many of the Horus built by Jeff also have higher quality parts throughout than mine. Being under a fairly strict budget when I built my own version of the Horus, I had to pick parts carefully, and made an effort maximize the quality where I believed it would make the most difference. The power supply electrolytic I chose for my own Horus is actually the same that came with the DRD kits, and while they are not nearly as expensive as Black Gate capacitors, still do a good job. But I think the sound of an amplifier is not just dependent on one or more of its parts, but rather something influenced by the over all, sort of cumulative effect. Others who have the cobalt parafeed OPTs, including Leo's extensive modification of his Moondogs, say that the cobalt is hard to improve upon. I just didn't have the money for them at the time. Those things are expensive OPTs! I did have Jensen PIO coupling capacitors in the Moondogs, and those were removed to use in the Horus. They have a liquid and rich quality that I very much liked.

So, there are some great Moondogs out there, as there also Horus amps that could be described as being pretty different in an important way from my own. I also still really like my Moondogs, but they are just different sounding than the Horus. Obviously the Moondogs are only available used now, and the quality of any one of those is directly related to the ability of the person who built the amps. I've seen some fantastic wiring jobs, and others that were kind of not so great. You should see the first amp I made -- what a rat's nest! But I leave it like that as a kind of personal record (or something....I don't know why. Maybe I'm just too lazy to go in a tidy things up!).

I'm tired....

[Daddy Dee]

Erik,

I know from our earlier conversations that you anticipated that the DRD's would be excellent. From your description so far, I'm wondering if you'd say they exceeded your expectations.

[Erik Mandaville]

Hi, Dee:

I've had the DRDs on for several hours, and they sounded great with everything we listened to. I began to have the impression that they may have slightly more bass impact than the Horus, although I can't say that for sure. The DRDs, like the stock Moondogs, also have by-pass capacitor in the first stage, which might have something to do with this impression. It's not a striking difference though. This is something I also noticed between the Horus and the Moondogs. The cathode resistor in the Horus isn't bypassed, but I have the capacitors to do that.

I can say for sure that the DRDs are outstanding for the money. Even for the extra $300 spent on a factory wired version, that labor cost is actually very, very reasonable. I was going to charge much more than that for the Horus, but I would have also had to punch and drill the chassis myself with basic hand tools and chassis punches. It's alot of work.