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In Reply to: RE: The old no hum no fun posted by Kloss on November 09, 2015 at 06:13:17
You can disagree, fine with me. But alas, you have NEVER heard my implementations.I can share with you this, just YESTERDAY, Sunday, on ALTEC A-4s ( 110 db ) in Kansas City, we compared one of my implementations, ( with L1 500 mHY and L2 2.2 HY. ) to a Yamomoto A-08 - which sports a large 10 HY inductor.
That quieter B+ amp, with a 10 HY inductor, was bested - in EVERY parameter of music, rather easily.
This K.C. A-4 owner now is selling all his amps, and going to use what I proposed herein and we both heard on his system yesterday on his A-4s. Took him 1 1/2 A-B passes, twenty minutes, to hear it all !!
Since this happened less than 24 hours ago, AND on 110 dB speakers, I thought I'd respectfully report on our listening session.
Jeff Medwin
Edits: 11/09/15Follow Ups:
Owned at least 50 SET have 3 at the moment have enjoyed both those that hum and those that don't, of the 2 I prefer no hum low noise- I run horns. I also know a 45 SET does not do so well on theater horns unless biamped I have or had in my piles Altec a4- 5- 7, RCA Shearers, Lansings about so I do know what power requirements they have so not surprised the 45 did not give its best. Even my 300b amps couldn't get the best out of 4 15 inch woofers. I currently have a 45 SET in my office even in nearfield its struggles to drive my Community Leviathans 4-515B and TAD 4001.
Kloss,
Respectfully, you have "ordinary " SET amps, and what I have running now on A-4s are totally different than anything you have experienced.
Where do you live, I'll have to let you hear it on your system. I'm near KC, MO.
Jeff Medwin
S WI heard a lot of bold claims from amp builders over the years but the results I hear are more similar than different. Maybe you bring something to the party I haven't heard but I have heard much and am Jaded.
I appreciate your comments. Refreshingly right on !!I was mentored by Robert Fulton (1925-1988) and he and I concured, AMPS are the weakest link in the audio chain.
I think amps are far-worse than many speakers.
Amps are generally TURKEYS, ill-designed for a difficult task.
I've built my own amps, DHTs, since 1982, and honestly believe I DO bring something different to this audio art, to serve the music.
I'll likely put a few "out there" in the coming years. Its FUN to build and hear them.
Jeff Medwin
Edits: 11/11/15 11/11/15
!
The Mind has No Firewall~ U.S. Army War College.
You THINK you have the amplifier resolved. Not so, IMHO, from your supply's description and my experiences.
Jeff Medwin
I built many SETs with 45, 2A3, 300B, 845. I built some 45 SETs including direct coupled one.
After listening to A-08, again and again, my friend and I concluded that there's something strange with 6Moons, or their taste is strange, or their speakers are differently strange or strangely different.
Since A-08 was in kit form, we checked the wiring again and again. I even let other DIYer friend to check the wiring, just in case.
The sound is exaclty opposite to 'lively', we even thought that this may be the Japanese voicing. Or we talked about there is something we did not know at all about SET sound.
I think now simply that the review is exaggereated with pretty look. Do not blindly believe the review. Yes it makes sound, but I'd rather go for Jeff low DCR chokes, for similar gambling.
The Yamomoto A-08 we used had exquisite parts. It was a FACTORY built unit, and it was neatly wired, for sure.The Yamomoto tube sockets, as one example, were lovely, and it has C-Core Output trannies, power and chokes as I recall. The speaker wire's binding posts are special also, very nice feel with a fine-thread so tightening is progressive to the touch. Lovely.
If you look at the A-08 schematic on line, you will see they specify " RN65 " resistors, vintage American military spec types I presume these to be. Where they use an RN-65, for - say, the plate resistor or cathode resistor of the front-end tube, I would now very carefully (and expensively ) employ TWO closely-matched Caddock MK-132s or TF-020s, and such resistors' end-result is HUGE in "tone, transparency and purity".
The Yamomoto sounded gray and artificial to us both, narrow band like a bad AM radio station signal playing through a cheap radio. It missed playing one octave higher and lower, versus my prototype's implementation. Also, it was TOTALLY outclassed in dynamic contrasting, and taking control of the large ALTEC A-4 speaker system. This is due to what holds almost ALL other SET amps back,
(1) poor internal wiring,
(2) high DCR chokes ( above 20 Ohms ) , and
(3) high amounts of capacitance in the power supply.
For example, the A-08 sports a "typical" / undesirable 10 HENRY ( about 80 to 100 Ohm ) choke in a C1/L1/C2 filter, ugh. Its DOA, by design, or should I more properly call it mis-design. I used L1/C1/L2/C2 - 10 Ohms and 8 Ohms for L1 and L2, 500 mHY and 1.8 HY respectively. Low Stored Energy Supply, aka LSES.One other thing, the A-08 used an electrolytic, (as I recall) to bypass the Rks. And noisy zeners on the Pentode's extra grid. No good. However, I used about EIGHT carefully chosen Rk bypass film capacitors in parallel - across each Rk, to ARTFULLY get the amp to play wide-band and with proper musical intent.
Yes, Yamomoto-San, ( had he been in front of those ALTEC A-4s ), may have rolled over and simply puked, if he heard the A-B. But maybe, he would learn something too, to apply into the future.
This amp build has been FUN so far, and I look forward to retrieving it from those A-4s, 55 miles away, and getting it playing on my now-silent A-7s, fifteen feet away. !! Need to finish re-wiring those A-4 woofers first, ( wanna' hear them properly ) that task coming-up this Sunday I hope.
Each ALTEC 210 bass horn weighs 440 pounds, unloaded, and each ALTEC 515C must be about 30 pounds, two per bass horn, so, we need to move about 500 pounds when loaded, just to access the enclosure's rear woofers' panel. Ugh.
Jeff Medwin
Edits: 11/24/15 11/24/15 11/24/15
Hi Jeff,
In fact I tried your low DCR concept in some different ways. I could feel the change in dynamics, etc.
But please use gentle and considerate words, or others may only see your definite writing and stick to that wording and may try to criticize it. You know what I mean. I've seen this before and feel sorry to see this again.
If you can offer the simplest combination of power tranny and chokes with proposed circuit, that will help, both you and others who are curious after all these years that you've been suporting that idea.
Cheers,
Chul
Hello Chul,I much respect the fact that you are a musician, pianist.
I do not mind others criticizing me.
I speak about what "I" hear and what "I" think.
There was plenty written previously herein about Flywheel, and LSES and one can peruse a Hammond catalogue and come up with decent alternatives, with a little effort, the use of PSUD and by listening.
In recent years, I more and more modify the leads of all power supply magnetics, ( see photo above ) to play back music's awesome peak instantaneous currents.
I still do not use chokes much over two pounds in weight, and over 2 HY or over 10 Ohms DCR. In 2015, I may employ LSES over a Flywheel, and in true LSES style, it will have L1 equal L2,..... but NOT always. Fastest settle is not my key PSUD priority ( as was written by John Swenson, John Hasquin et all ), smooth settle is the priority.
I still use 50 uF as the largest cap size, and typically use a lesser uF amount on C1 - than on C2. In 2015, I use WIMA DC LINKS as a main supply cap, and bypass it with four to eight smaller value, higher quality film caps, selected by ear, for full musical expression. Bypassing main film caps I find is a "must", in all C locations for decent full-frequency playback results. It must be done by listening and its an ART form IMHO, like musical expression on your piano.
Let people experiment on their own, by listening, and come up with a circuit they are happy with, and proud of to call their own.
Most important of all, do what pleases you and have fun in the hobby. If YOU like your results, that is ALL that matters. Have FUN.
Jeff Medwin
Edits: 11/25/15 11/26/15 11/26/15
Pics, or it didn't happen! ;> )
Got pictures for you. L1, 500 mHY Stancor C-2708 is at the top, below three ( white , gray, yellow) doubled-up wires running horizontally, 1 1/2 inch lead length to rectifier tube. L2 is green, mid-right side of chassis.Note my (1) extensive use of doubled-up wiring, (2) extensive film cap bypassing across every cap location, all done by my ear.
This 45 amp totally ROCKS on the A-4 ( full range, Kloss ) !! "Killed" the fella's Yamomoto A-08 last Sunday, it's wideband playing - EASILY plays an octave higher and lower, with color and HUGE dynamic range and finesse. Its in a different league.
Next time I do some more work at the A-4 site in KC, I'll take speaker photos for you. I am having A-4 owner totally rewire his A-4s, for maximum transfer efficiency. Those ALTEC 210 bass-horn enclosures weigh 440 pounds each, with no drivers in them
Jeff Medwin
Edits: 11/11/15 11/11/15
Curious, what is the output iron? Series or parallel feed?
Steve,I am proud to report the output transformers were NOTHING SPECIAL at all !!!
Recall, myself and a designer friend, a few years ago on this Forum, saying we could build a SET with a doorbell transformer output, and it will outperform all others?? This, in a way, is it.
Only I am using an INexpensive BUDGET SE output transformer, with a multiple primaries, as I recall, 2.5K, 3.5K and 5 K. Of course, 5K used for Type 45.
With my wiring and multiple value film cap bypassing EVERYWHERE, we easily play an ocatve higher and lower, with great tone, finesse, and dynamics, that puts that fancy Yamomoto C-Core ( ?? ) output transformer into an irrelevant status. Mr. Yamomoto-San would have possibly gone into cardiac arrest Steve, it would have shaken him up, but good.
THIS was FUN to hear and do !! Wow !!
Jeff Medwin
Edits: 11/12/15 11/12/15
nt
Here is a link to a Stereophile review of those amps.
The specs indicate full bandwidth , but the circuit is a lot different from the drlowmu amps.
Look up Jeff Day's " glowing " review from 6 Moons on the A-08. Likely, that review made the Kansas City ALTEC A-4 owner buy the A-08. He told me it was a "big" purchase for him.
Now he will sell it !!
Jeff Medwin
Jeff Day waxes lyrical about most equipment he "reviews" - I don't place value in his advertorial.The Yammy looks pretty, but does not set the bar particularly high. Reviewers have used the Yammy as an example of fine build quality (?!) - but it looks to me to be designed for simple construction and troubleshooting while looking organised... "agricultural".
Still, people praised it... before moving onto other designs. I am guessing the Yammy is an example of "impressive first impression versus long term enjoyment" type of contention.
Cheers,
91.
"Confusion of goals and perfection of means seems to characterise our age." Albert Einstein
Edits: 11/12/15
No, yammy 08 is really a good sounding amp with well defined voicing.The problem is in general 45 type FR amp has a very restricted usefulness due to lack of capable speaker systems. Do not forget that yamy costs $3k and Serious stereo $15k.
Agreed, it is pretty decent value
Cheers,
91.
"Confusion of goals and perfection of means seems to characterise our age." Albert Einstein
One of those Yamaha amps paid a visit. I don't think you were by during its stay, but it completely delivered the verdict that flea power is not for me.
cheers,
Douglas
Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.
No , I wouldn't expect you to fall for Yammy 08 considering what you have there BUT keeping things in perspective , what you have there would be in a range of $50k + If it were commercially available.
I thing it is a really nice, limited purpose weekend amp. It was a hit on the market and I assume there were many sold. Not that many resurface on used market and they tend to sell quickly if the price is right.
Hello,
Very well said. I agree with you.
Jeff Medwin
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