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Post by Deleted on Feb 17, 2018 14:39:38 GMT
D'Agostino Momentum Mono blocks I've heard them several times and have been supremely underwhelmed so far. Have to agree with you Martin, had these pass through our hands a few times now, other than looking like A JULES VERN throwback devices underwhelming. However the stereo version is much better imho, still not worth the outlay, but definitely better. Responds very well to different power leads quite a surprise really. The integrated version does suffer from troubles a few have had to go back for some TLC.
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steve
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Post by steve on Feb 17, 2018 17:15:45 GMT
At the moment I'm into taking low power, single-ended direct heated triodes and driving them with triode strapped pentode power valves, such as 6V6, 6AQ5 or EL84. Input stages are medium gain pentodes, again, triode strapped. Solid state rectification with high capacity choke input power supplies make up the rest of the equation. These things such as the 2A3 amp I have recently completed, may be low power, but the power drivers give a low-revving, torquey effortlessness to the presentation that belies the 4Wpc output power. High efficiency speakers are of course essential with this kind of power, and I've got these too. My current ones are omnidirectional room flooders, the best way to bring the music into the room IMO. I go for "they are here" rather than "you are there"
There is nothing new under the sun with valve amps but there are plenty of avenues to explore. The caveat is that these avenues are only explorable by the DIY community. Commercial valve amps makers are not interested in anything that isn't either a rehash of 1950s push-pull ultralinear technology or a SET amp with 300Bs driven by a 6SN7 cascade, to give that tubey midrange magic.
Not that there is anything wrong with that, but it's a pretty conservative attitude they have. Conservative amps sold to a conservative market of old men.
You can be an old fart or you can learn a bit of electronics, get soldering and create something unique. There's no better thrill than hearing high end sound coming from an audio system you built yourself. Educational, fun and rewarding.
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steve
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Post by steve on Feb 17, 2018 17:36:58 GMT
Here is my example of what can be done with valve amps if you put your mind to it: Cheap, fun, educational, rewarding and no need for expensive racks, cables or magic crystals. You know it makes sense.
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Post by TheMooN on Feb 17, 2018 17:38:02 GMT
I've heard them several times and have been supremely underwhelmed so far. Have to agree with you Martin, had these pass through our hands a few times now, other than looking like A JULES VERN throwback devices underwhelming. However the stereo version is much better imho, still not worth the outlay, but definitely better. Responds very well to different power leads quite a surprise really. The integrated version does suffer from troubles a few have had to go back for some TLC. The many contented D'Agostino owners around the globe must be feeling utterly crushed at this time. for my part the Momentum's made it through to the last round due to a warmth of tonality without the bleeding edge resolution and over etched detailing beloved of the Audiophile Bat. The SS contender bout featured DartZeal , Constellation and CH Precision, all of which bested the Dag in a number of areas however the Dag won out IMHO by scoring 8's consistently across the board over assorted 6-7>9 10's
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steve
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Post by steve on Feb 17, 2018 17:40:33 GMT
Jesus Christ, it's another world.
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Post by TheMooN on Feb 17, 2018 17:47:22 GMT
Interesting looking Omni's there Steve.
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steve
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Post by steve on Feb 17, 2018 18:01:07 GMT
Ignore the tweeter on the inside edge. It's not doing anything, it is just blocking a hole left by a lash-up I abandoned because it completely messed up the stereo, turning the presentation into a Phil Spector wall of sound. The omnis are excellent, but they are in the frame for a revamp this week.
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Bonky
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Posts: 156
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Post by Bonky on Feb 17, 2018 18:02:01 GMT
Here is my example of what can be done with valve amps if you put your mind to it: Cheap, fun, educational, rewarding and no need for expensive racks, cables or magic crystals. You know it makes sense.
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Post by TheMooN on Feb 17, 2018 18:17:35 GMT
Ignore the tweeter on the inside edge. It's not doing anything, it is just blocking a hole left by a lash-up I abandoned because it completely messed up the stereo, turning the presentation into a Phil Spector wall of sound. The omnis are excellent, but they are in the frame for a revamp this week. Interesting, I have been mulling upon Omni's for some time for a second system, You may think me certifiable however I have been thinking of a true Mono Vinyl/ R2R set up with a single monster Omni transducer hmmmmmmmm"!
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steve
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Post by steve on Feb 17, 2018 18:27:08 GMT
Sounds like a great project. Japanese valve amp maestro Mr Sakuma, wouldn't use anything other than mono, but he uses a big horn setup rather than an omni to entertain the punters in his restaurant. Omni would make perfect sense with a mono system if you wanted to fill the room with sound.
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Post by TheMooN on Feb 17, 2018 19:07:28 GMT
That is absolutely my objective Steve, My first inclination was to go with a single horn ala WE however I just do not have the space at this time ergo a single Omni mono around the size of say an Tannoy Westminster is in the planning stage .
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Post by MartinT on Feb 17, 2018 23:55:57 GMT
The many contented D'Agostino owners around the globe must be feeling utterly crushed at this time. Don't take it personally. I'm sure the hundreds of Naim fans won't care about my opinion of their products, either. It takes all kinds and we are just offering opinions here. Just to quash my preference for solid state in this case, I'd have taken the Audio Research.
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Post by Chris on Feb 18, 2018 8:31:04 GMT
Here is my example of what can be done with valve amps if you put your mind to it: Cheap, fun, educational, rewarding and no need for expensive racks, cables or magic crystals. You know it makes sense. That's stunning
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Bonky
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Post by Bonky on Feb 18, 2018 9:15:00 GMT
Steve, You can't leave us all hanging in the air...
Is the 'Stateside' valve amp your own design? What are the specs? Valves? Did you build it all yourself?
Thanks
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steve
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Post by steve on Feb 18, 2018 9:38:30 GMT
Steve, You can't leave us all hanging in the air... Is the 'Stateside' valve amp your own design? What are the specs? Valves? Did you build it all yourself? Thanks Yes, it's my own design. It is a single-ended triode design with an output of 4Wpc There are three stages of amplification: Input stage - 6AU6, medium gain pentode, triode strapped Driver stage - 6V6GT, output pentode, triode strapped Output stage - JJ 2A3-40 direct heated power triode. Output transformers- Old spec Hammond 1625SE, 2.5K primaries. Manufactured in 2000 Power supply - high voltage, Schottky diode bridge rectifier feeding 10H, 400mA choke. Power supply split after choke - to twin smoothing capacitor banks (one bank per channel). Chassis was made by my son, from folded sheet steel, and has mahogany wood end cheeks. I did the layout and the spray job in rose gold. The idea of the rose gold was to give was a 50s retro vibe. Short tapered wooden legs complete the look.
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Bonky
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Post by Bonky on Feb 18, 2018 9:46:47 GMT
Wonderful Steve; thanks for that. Way beyond my capabilities...I'll stick with WD KEL84 kits I think
BW.
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steve
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Post by steve on Feb 18, 2018 10:21:43 GMT
Wonderful Steve; thanks for that. Way beyond my capabilities...I'll stick with WD KEL84 kits I think BW. I started off 12 years ago with a WAD Phono 2 and Pre 2 kit. That got the DIY bug going and I've been building my own equipment ever since. One purpose of my posts on this thread, is to try to show that valve amplifiers can provide a way into high quality, high end sound that does not come with telephone number price tags. The OP was asking whether valve amp design had reached its zenith, and yes of course it has; there is nothing new apart from the use of modern solid-state control electronics to regulate high voltage power supplies, provide hum free filaments, heaters, automatic bias, overload shut down protection etc. The basic circuit in modern push-pull ultralinear amps is the same as it was in the 50s and 60s. But.... the DIY'er can be creative, dig up long forgotten circuits and get high end sound quality for relatively little outlay. All it takes is a willingness to learn, from folk who know what they are doing and from perusing old books. OK...being realistic - the DC voltages involved are lethal and you need a basic ability to solder and one hand behind your back at all times when testing a live project, but there's nothing lke the thrill of listening to music on an amp/speaker system you built yourself, or the fear that grips you as you contemplate the moment of first switch on. A Variac helps enormously with the fear factor
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Post by MartinT on Feb 18, 2018 11:21:52 GMT
Great build, steve and a pleasure to see the workmanship.
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Post by Chris on Feb 18, 2018 12:05:14 GMT
Yeah,utterly lovely looking thing. Couldn't agree more about building either - the labour cost alone in a modern valve amp must add a good bit to the final price.
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Deleted
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Post by Deleted on Feb 18, 2018 21:41:18 GMT
Have valve amps reached there Zenith.
For me no, but as you are aware I do not make commercially available valve amps. But I do design transformers and odd things, I have a design for a output transformer for a single ended valve amp that would allow us to provide about 100W in a transformer a quarter of the size. Ad have low frequency roll of at 10Hz at -3dB. I am playing with this concept now, and having fun, ok a few electric shock did restart the old mech ticker in a funny mode, but I think I will soon have the magnetics sorted. I will keep you posted. Now style OK I will get Hugh to do that as biscuit tin look crap even with a tiny dog on the front.
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