sunnysal Posted July 26, 2003 Share Posted July 26, 2003 Congratulations erik! when you have a chance can you post the modified schematic with your mods? I would love to see it. I second the digital camera suggestion! Maybe Craig should build the 2A3 PP version, then he might not leave it on a shelf due to power limitations...what d´ya think craig? regards, tony Quote Link to comment Share on other sites More sharing options...
edster00 Posted July 26, 2003 Share Posted July 26, 2003 Congrats on finishing your Horus amps Erik...I am sure you did a bang up job on them! These Horus are a step up from the Moondogs IMHO, but I am not getting rid of my 'dogs anytime soon either. Get those photos to me Erik, and I'll get them on some webspace so you can post links to them. I know I am looking forward to seeing them. Quote Link to comment Share on other sites More sharing options...
Painful Reality Posted July 26, 2003 Share Posted July 26, 2003 I am really glad you enjoy the Horus. The transient handling and the ability of rendering the low level details while placing the music first is what makes this stong point of this amplifier. Using the 2A3 AVVT mesh plate bring it a bit further to my taste but the availability of these is a bit obscur. I guess the TJ 2A3 Mesh should be interesting too. As I stated in the MagneQuest web site, credits for this amp should be given to other than me. On the list are: Gordon Rankin who suggested me to use a parafeed configuration AND a grid choke when dealing with a 2A3 or a 45. Christian Phaneuf from Expériences Sonores in Quebec City (the guy that started me into this madness). I shamelessly copied the input-driver design he used in a nice 45 SET amp. I think he was himself inspired by a design from Steve Berger (from April Sound). Nothing new under the sun... And finally LeoK who suggested some modifications in the output section (mods he implemented in Chris's amps). So I'm left with nothing of my own in this amp I guess... Hurry up to show us these photos! Have fun listening to it in the meantime! Jeff L. P.S. Getting a digital camera would be a good thing!!! P.P.S. (editing time now) AHHHHHH! re-reading this post, I realised I forgot THE most important guy behind the Horus... Endless thanks to Kelly (Mobile Homeless) as he was the first one to bug me to write about the Horus on the MagneQuest website. I owe him a lot, especially for the exeptional coverage I received here. Quote Link to comment Share on other sites More sharing options...
Deang Posted July 26, 2003 Share Posted July 26, 2003 "So I'm left with nothing of my own in this amp I guess..." See...humble. He's worse than freaking Leo. Quote Link to comment Share on other sites More sharing options...
Deang Posted July 26, 2003 Share Posted July 26, 2003 Craig -- I'll want mine with a nitrous valve. Quote Link to comment Share on other sites More sharing options...
Painful Reality Posted July 26, 2003 Share Posted July 26, 2003 ---------------- On 7/26/2003 11:44:01 AM DeanG wrote: See...humble. He's worse than freaking Leo. ---------------- I may be a bit less humble about the 2A3 PP amp that is cooking in my head right now... In this amp I should steal from others only 98% of the concepts instead of the usual level of 100%!!! Jeff L. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted July 26, 2003 Share Posted July 26, 2003 Jeff, I may be a bit less humble about the 2A3 PP amp that is cooking in my head right now... In this amp I should steal from others only 98% of the concepts instead of the usual level of 100%!!! It still takes a special talent to know what to steal !! Craig Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted July 26, 2003 Author Share Posted July 26, 2003 Picasso once said, "Good artists borrow, great artists steal!" I am off to Target to pick up my picture CDs, and my wife says she should be able to figure out how to upload from our hard-drive onto this forum. We haven't done much of this sort of thing, but we'll give it out best shot, so stay tuned! Erik Quote Link to comment Share on other sites More sharing options...
NOSValves Posted July 26, 2003 Share Posted July 26, 2003 Erik, If you want just email the photo's to me and I'll host them on my server and put them up so they show right up on this thread. I have plenty of web space available. craigostby@comcast.net Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted July 26, 2003 Author Share Posted July 26, 2003 Thanks Ed and Craig. I don't even know how to email them. Let's see if Marie and I can figure this out...I really need to learn how to do some of this! We got the CDs back, and have them installed on the hard drive. We'll try to have them here soon. Erik Quote Link to comment Share on other sites More sharing options...
jhawk92 Posted July 26, 2003 Share Posted July 26, 2003 Now that I have heard a Scott 299B, as well as two sets of Moondogs and a pair of Paramours, I think I am a bit more qualified to talk about tubes than I once was. I have to admit, I don't think Craig will stay on the "Dark Side" too long. I was mightily impressed with GaryMD's 299B and heard more details on my audition CDs than on the 2A3 SET amps; there was more low bass as well as higher highs. This is just an initial observation, one based on a Moondog audition that was over a week old, so don't flame me too much. I think Reg and I will get together sometime this fall to pit 2A3 against 7189 with my K-horns and we'll see how things fall out. But if you can put more power through an SET amp, then maybe things would really sound good. Reg pointed out that Welborne had a 300B model, Laurel, that pushed up to 8W, so that may be a good option. Quote Link to comment Share on other sites More sharing options...
AnalOg Posted July 26, 2003 Share Posted July 26, 2003 Erik, All this computer stuff is easier than you think. Tom Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted July 26, 2003 Author Share Posted July 26, 2003 Jhawk: You know, I have heard some PP amps that I think are fantastic! I appreciate your contribution with this, since you have had the opportunity to do some really close comparison between the SET and PP. My tube old-timer dad asked me, "What the hell is all this about single ended outputs??? you'll get more distortion, poor THD figures, low power output..." I just said, "Dunno, I just like how they sound through my horn speakers." I think a PP 2A3 or 300B could be amazingly good...but listening to music has truly changed since I built Jeff's amplifiers. That Leok had the notion to redo the output connection was a very smart thing. He and I both did this on Moondogs, which was in their favor. Moreover, the parallel output transformer has very obvious merits. Increased bandwidth was supposed to be one of the results of the design, and that is surely the case with the Horus amplifiers. Sunnysal: I can surely post a revised schematic. That wouldn't take anytime at all. If you don't have your equipment plugged into a transient spike protected outlet, I would also install MOVs across the power transformer primary winding. Jeff's hand-drawn schematic was/is fine. Quote Link to comment Share on other sites More sharing options...
sunnysal Posted July 26, 2003 Share Posted July 26, 2003 Hey Jeff, If you have a new 2A3 PP cooking in your head right now might it be an improvment over my current configuration? let me know... Erik, I have double protection on the electricity that goes to the amps, a traditional monster spike and surge protector followed by a slow start circuit with breaker for the amps, they should be safe form the Salvadoran power company! tony Quote Link to comment Share on other sites More sharing options...
dubai2000 Posted July 26, 2003 Share Posted July 26, 2003 Yes, PP designs can be fantastic too and I certainly love my Eico or, at a different level, my 8B/MX-110 combo, BUT somehow a good SET amp seems to pull you into the music a tad more easily. I suppose in the end we should be happy that there are so many roads to musical bliss - as long as external factors don't get in the way . Wolfram Quote Link to comment Share on other sites More sharing options...
Painful Reality Posted July 26, 2003 Share Posted July 26, 2003 ---------------- On 7/26/2003 5:13:26 PM sunnysal wrote: Hey Jeff, If you have a new 2A3 PP cooking in your head right now might it be an improvment over my current configuration? let me know... tony ---------------- Didn't you said your PP was your last amp? Or was it your last chassis? Quote Link to comment Share on other sites More sharing options...
leok Posted July 26, 2003 Share Posted July 26, 2003 Erik, Congratulations. I've been off line for a few days trying to figure out what's going on between the parafeed Moondogs and the Chorus-IIs. Jeff's amp is a very nice design, and with the output storage cap relocated, even nicer. I'm interested in Jeff's gain/driver stage. 6SN7s are very quirky, and not at all uniform. Jeff's choice looks good. I think, on Monday, Chris will bring his Horus amps by and I can hear them on the Chorus-IIs. I'm sure your amps are a great match with the La Scalas. leok Quote Link to comment Share on other sites More sharing options...
Deang Posted July 26, 2003 Share Posted July 26, 2003 How is a rookie like me supposed to keep all of this straight? I thought the 6SN7 was soooooo linear? What did you find with the Moondogs Leo? Something simple hopefully. You did a very nice job on those Erik. I think those Chassis' could stand to be a little bigger though. Quote Link to comment Share on other sites More sharing options...
Painful Reality Posted July 26, 2003 Share Posted July 26, 2003 ---------------- On 7/26/2003 10:53:16 PM DeanG wrote: How is a rookie like me supposed to keep all of this straight? I thought the 6SN7 was soooooo linear? What did you find with the Moondogs Leo? Something simple hopefully. You did a very nice job on those Erik. I think those Chassis' could stand to be a little bigger though. ---------------- The 6SN7 is really linear if you hit the jack pot. Generally speaking (all right, you 6SN7 devotees, generaly means err... generaly!). But even you die hard 6SN7 fans will have to admit that the sound of a 6SN7 will vary from brand to brand. Used in CASCADE like in the Horus or the Moondog, I've found them to vary from piss poor to excellent, excellent ones being the ones that will cost you a bundle. The 5687 doesn't exhibit this dramatic brand to brand differences in sound. Most examples I know of sounds excellent at the very least. Plus they are dirt cheap... Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted July 27, 2003 Author Share Posted July 27, 2003 The 5687 is a great small signal tube! I have a 6SN7s that sound like absolute (insert word of choice), and horribly microphonic. The new Sovtek 6SN7s, like their 2A3s, are quite good in my opinion. But I enjoy the 5687 so far very much -- more than enything else, it's quiet. Dean: The chassis I bought for the Horus are actually quite close to that of the Moondog; and the space inside would be similar if not for the chokes and transformers. I honestly prefer an amplifier that has an integrated or unified appearance, with parts within close enough proximity to work together, visually. There is over an inch between the tubes, which is plenty for heat dissapation. Believe me, I had to seriously stretch the budget in order to get these...any larger would have added to the cost. On top of that, I am genuinely interested in solving some of the design constraints (Ok, problems!!!) I encountered as I went along. The main issue was the inclusion of the output stage capacitor and the large cap Jeff uses as the input cap from the power supply to the 5687 plates. As is, all PSU parts are at the rear, and don't come anywhere close enough to the front portions -- the signal side of the circuit. And the chassis still are not done. The pictures show vent holes in the top plate in the area of the output tube and rectifier, but I still need to drill the holes in the bottom. This will allow a sort of updraft for cooling. But yeah, in the end it would have been easier with an inch or so more in terms of length and width. I was building from scratch, and had to estimate the size chassis I would need. Thanks Leo! I hope you get that problem solved with your new speakers. Do you have the same thing with the RF-7s? Quote Link to comment Share on other sites More sharing options...
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