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In Reply to: RE: A challenge to you all posted by SteveBrown on January 19, 2017 at 20:22:49
I am not sure if bickering is the correct term. It seems to me that there exists here, a base of very tube savvy individuals who can call up information regarding amplifier circuits and tube operating points as second nature. While the rest try to follow along. I think that it is wonderful that they are willing to share their hard earned knowledge with those who are seeking answers to problems. And speaking for myself, i find that while build threads don't seem to have a high priority here as on some other forums, but that doesn't bother me. But i find that whenever i do have a problem with a project, that the inmates give their thoughts and solutions in a manner that is courteous and friendly and sincere. And to me advice that is given in that manner is hard to come by.
But on to practical matters, If you are good at building and soldering then a diy'er can make a better amplifier. Without an accountant to make sure you are only spending X amount of time for each amp and X amount of dollars for each part one can do a much better job. Almost all commercial amps use circuit boards. This is so there are no mistakes and robots can assemble the cb in just a minute at very little cost. The early kit built amps from the "golden age" of tube audio serve as examples of how to build an amp with point to point wiring. There are different ways or styles of wiring an amp. There is the military style with neatly bundled wiring, there is "The Fisher" style which is neat but unbundled, There is the Scott style, not so neat, and the post 1960s oriental style which can be described as an explosion at the "lo mein factory". And the funny thing is they all work, more or less.
As far as posting about your amp projects, Check my last post "fixed problem fixed" which shows my last amp that i just finished building. And i am looking forward to more build stories from other inmates. cheers, Dak
Edits: 01/20/17Follow Ups:
That is funny. I think just the opposite of you.I think most DIY below-the-deck shots I see photos of are atrocious, and circuit implementations, are a waste of the person's time and money, compared to a good commercial product.
Most DIYers do not KNOW how to lay out an amp really really well ( me included ) and most make horrible choices, by penny pinching, or not KNOWING what is a good sounding or a poor sounding part to use from the onset.
Some are SO amateurish and go so far as to think a bread board is a viable amp...it isn't !! Lay out is huge factor in making a great amp.
I will mention just two products, commercial audio amps. In the solid state realm, a Spectral DMA-200S and in the tube world, my good friend Dennis of Serious Stereo, his latest 2A3 amps. Think a DIYer at home can beat either commercial amp ?? If so, you will be 100% wrong.
Some others come to mind, the people at Berkeley Audio, and the great sounding MBL amps and speakers.
There are many good reasons to do DIY, and I ENJOY it, but don't think for one millisecond, you will outdo the folks in the San Francisco area, and Montana, Germany, etc, the Professionals.
Of course, one must be able to discern, the good from the bad in the commercial realm.
All the names I've mentioned off the top of my head, have superior products, to ANY DIY implementations. Get REAL !!
Cheers,
Jeff Medwin
Edits: 01/24/17 01/24/17
Jeff,
When and where did you hear the "Spectral DMA-200"? On what speakers? What length of time where you able to evaluate said amp?
Have you heard Boulder, the other example you have sited?
Sure, a 3000.00 amp better sound better than my 500.00 amp. But comparing my 500.00 cost amp to commercial products? Up to 1500.00 Not even close. Who are you Kidding?
Actually I compared a 3500.00, SE 845 Raphaelite amp to my SE pentode KT90 amp which costs about 500 for the parts, and they both sounded very close with the Raphael amp having a miniscule edge in resolution while my amp was better at bass and dynamics. So i think your statement isn't in left field, not even in the ballpark, maybe in the parking lot, at the end of the row.
Hi DAK,Neither that amp you compared yours to, nor the amp you built, ( if its an 845 ), would "I" ever want to be stuck with, to listen to.
First of all, there is NO need for an 845 amp on 98 dB or better speakers.
Second of all, there is NO need for a three stage amp, when a well designed two stage, especially Direct Coupled, will CREME it.
You are, thus far, unable to discern that !!
As I have said, in all my posts in this thread, it has NOT much to do with money, but the ability to DISCERN the good from the MANY MANY audio also-rans.
My amp references remain, the four amps I have mentioned. Any 845 amp is KIDDIE stuff compared to those, and low in overall fidelity to boot.
I do commend you for building DIY amps. I enjoy doing that myself. But I try to at least copy the best available. I DISCERNED " what end is up ", what was the best, years ago, by going to CES and RMAF shows, etc. You DAK, need to do that, and learn what end is up, so that you, too, will discern better.
Ever hear a MBL amp, playing their Radialstrayler ( sp ??) speaker?? Oh my goodness. You should !!
Have fun, continue to broaden your audio horizons, I do that myself, all the time. Live and learn.
Jeff Medwin
Edits: 01/26/17
DAK, you are on the right track. Commercial stuff is nutty expensive, and if it is making money, it is either even nuttier, or bean-countered.
It does not take a genius to do this; it is for the most part just solid engineering( like any other product ). I've played and A-B'd with some talented folks. That in and of itself is entertaining. Learned a bit from each of them.
As to the traditional insults leveled at this opinion, like 'you just can't tell the difference'...there is no argument to be won. That is why it is used so often...LOL I take its use as an admission of defeat.
That argument is widely used to part fools from their money with techno-babble in a well documented fashion you've no doubt read about and seen in action by salesmen of any sort. LOL...if you are good enough, you will be admitted to the club where you can spend even more money. No thanks.
cheers,
Douglas
Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.
Hi Doug, and thank you for commenting. I will not be baited into a blatant attempt at trying to stir up the pot of controversy over something as obvious as night and day. The doc (sic) should take some of his own medicine. With comments such as "trust your ears" and "have fun, i am". It seems that those terms should be amended with, which can not happen unless you are "experienced" which accordingly, can not be attained without listening to specifically recommended equipment.
I wonder why a person with such beliefs would be part of the DIY community? It is obviously a waste of time for someone with that "experience". sincerely, Dak
Yep...don't get baited. It took me a while to recognize that, 'you aren't good enough to hear the difference' argument as an admission of defeat...LOL
I love some of the Irony presented in the arguments. In one paragraph, they tout some EE PhD, and in the next claim all such knowledge is worthless.
And then there is the techno-babble...'transfer efficiency' indeed.
cheers,
Douglas
Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.
**** But I said you have to be able to discern, DISCERN, what is a good commercial product. *****You have not enough experience, have no clue !!!
Since you are talking tube amps, I referred to Dennis' Serious Stereo, latest 2A3 amp. If you compared your " close " 500 dollar amp, to that much more expensive Serious Stereo amp, you would slink away from the A-B like a doggie, with his tale between his legs. Solid State amp, try a Spectral DMA 200S, or an MBL.
If you WANT the best, you have to first KNOW what it is, then you pay for it. If you are unable to DISCERN, and accomplish either, that is not my problem.
Jeff Medwin
Edits: 01/25/17
DIY audio is a leisure activity into itself. The idea that it's possible to make something in your garage which will compete viably with a highly praised $10k commercial product is of course complete insanity, unless there's a genius at work.But it's certainly possible to build something which will compete performance wise with gear in lower price categories.
I liken it to people who build cars in their garage. No person in his right mind believes that his home made car is going to be objectively better than a commercial product.. I think that just isn't the point.
It's an outlet to express creativity and enjoy solving some puzzles. And there's a feeling of accomplishment when the end product is satisfying. I strongly suspect that many people in the DIY community enjoy thinking about amplifiers and working on them as much as they enjoy using them... and what's wrong with that?
How to mitigate hum? In my experience, the nastiest, worst, sneakiest thing in an amplifier is the connection between the power transformer and the negative side of the first filter capacitor. If this isn't a direct connection, even a milliohm will introduce hum into the amplifier. And if the capacitor is over sized off a solid state rectifier, it won't be hum, it will be buzz.
Edits: 01/24/17
Good observation! You want your grounds short, and made from VERY heavy current conductors.
-Dennis-
I have achieved decent results paralleling specific circuit board traces on a couple commercial amps which were not that well designed with bare #14 from Romex - not the stuff of high end, sure, but it made a noticible reduction in background noise.
So let me get this straight... you're bickering with the use of my word bickering? :-) Just kidding. I love the description of the different styles you mentioned. I look at some of that vintage stuff and I'm just amazed it is as quiet as it is. I think for those new to DIY, doing a close study of existing, working designs is highly instructive. I'm also guessing companies like Fisher, etc. took the time and money to prototype designs to work out bugs.
My problem is none of my DIY amps are "Truly Done ".assembled , Yes
but not done.
There's always an added cap or resistor change after assembly. Then there's the break-in time for all new parts.
That's DIY if you don't like it you can always change it.
Fun stuff eh!
Willie
That's what I love about bread boards. Put the whole thing together in a couple of hours and change anything you want in a couple of minutes. Try doing that with a fully assembled amp!
I have seriously thought about trying to build the ultimate bread board platform as my next project. Just leave it up full time and have every thing easy to change but a little better than clip leads. I like those European style terminal blocks that let you put a wire in and tighten down a screw in just a very short time. Use universal output transfromers and have adjustable psu and filament voltage capabilities. I might have to start an "amp of the month club" if I do that. : )
Ground is simple, no schematic needed. I place a separate ground wire across the chassis on ceramic standoffs. Connect all transformer leads at far end. Next, I connect audio transformer grounds. Rest of various grounds are next, Then ground this wire at input jacks & chassis. 120 volt power ground is at transformer.
Never had a hum issue.
You posted you're reply to the wrong post methinks. At least I do not see how it relates to my post in particular. You might want to re-post to the correct one and delete this one.
Edits: 01/20/17
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