Tube amp with cheap transformers 'useless' ?
Sep 24, 2012 at 7:12 PM Post #76 of 106
Yeah, probably, but:
 
1. I am trying to move the discussion away from economics, demonstrate that I do understand the subject at least to a degree and that I'm not merely arguing for the sake of it but doing something positive.
 
2. It's a sketch of a an unbuilt design and it specifically states on the schematic that values are subject to revision. It's 40 years since I designed a tube amp and I freely admit that I stuck in some of the values without a lot of consideration. I don't establish final values for SS designs at this stage in the process.
 
3. I don't put a lot of trust in the sim. myself, but as to exactly why, that's for me to know and you to wonder.
 
Now, I can go on and build this thing, or I can go back to working on the numerous other projects I've got going, it's no skin off my nose.
 
w
 
Sep 24, 2012 at 10:36 PM Post #77 of 106
Wow, I thought this thread was dead weeks ago... Wakibaki, build your amp and see if it really can be sold for less then $200.00; PCB + casework + R&D + shipping cartons + advertising on top of parts. Get back to us and let us know.
 
Sep 24, 2012 at 10:51 PM Post #78 of 106
Here's a little something that I dont think has been mentioned earlier in this discussion. Much easier to amortize compliance costs and insure yourself against lawsuits when you are shipping a container load of amps than when you are selling them one-by-one on e-bay. Mikhail may not have been too concerned about the risks his customers took with some of his amps, but clearly that doesnt apply to everyone in the industry. 
 
http://www.aksaonline.com/faqs/faqs_general.html
 
 

If the Aspen Amps products are so good and so simple to build, why don't you yourself manufacture them , even on a small scale?

[size=9pt]
In modern consumer societies, the economists describe business enterprises in terms of ‘barriers to entry’. In essence, this phrase describes the cost of infrastructure and production equipment necessary to create the product. Today we live in a highly regulated and litigious environment, and all electrical appliances, including amplifiers, must pass a number of rigorous safety and electromagnetic emission tests. No manufacturer can sell his product without passing these tests and winning proper certification. In a world market, each and every country has its own tests (but of course!!) and all consumer goods must be passed locally for sale within that market.
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[size=9pt]
A moment’s thought reveals that this is the major barrier to entry for the AKSA on world markets. Aside from the technical aspects, which are straightforward and easy to arrange, there is the matter of negotiating the various government agencies and bureaucracies. And then there is often a maze of complex trading and marketing controls, which make it difficult to mass market any complex consumer product – taken as a whole, these are substantial issues and at this point in time we are not able to negotiate them. Not yet, at least.
[/size]
[size=9pt]
That said, a commercial agreement has been reached with a Californian company to produce a retail product based entirely upon the AKSA design. A similar discussion is in process with a manufacturer in Turkey. Of course, it is too early to say when fully complete AKSAs will be available and at what cost, but they will certainly be marketed across the Internet, at first in North America and Korea, and then throughout Europe.
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Sep 25, 2012 at 2:38 PM Post #79 of 106
Quote:
Wow, I thought this thread was dead weeks ago... Wakibaki, build your amp and see if it really can be sold for less then $200.00; PCB + casework + R&D + shipping cartons + advertising on top of parts. Get back to us and let us know.

 
I never said under $200 for a valve amp, I said under $200 for a SS amp. What I did say about valve amps was that $1500 was unnecessary. I said $400 build price, 100% markup.
 
 
$1500 is just too much. Even with 100% markup.
 
(Output) transformers perform better (less distortion) when lightly loaded. How much lighter a load are you going to get than headphones? Admittedly interstage transformers have even lighter loading, but headphones are a light load. You don't need anything more than a low power (speaker) transformer, run at fractional power.
 
You can buy 2 Hammond 10W push-pull Hi-Fi output transformers for 125$. Even if you go single ended, 2*10W transformers will still only be ~$200. These are truly overkill in a headphone amp. You can probably use the lower grade guitar amp style transformers considering the light loading.
 
I'd expect to be able to build a pretty good (beyond reproach) tube headphone amp (that'll incidentally drive speakers), including buying transformers, for $400 at the outside. A manufacturer can expect some economies of scale when purchasing.
 
Still, you can probably build a couple of good quality 200WPC solid state amps for the same price.
 
Alternately, there is the modified Morgan Jones OTL design using 6N1P Russian tubes.
 
http://gilmore2.chem.northwestern.edu/projects/showfile.php?file=bender_prj.htm
 
- drives reasonable current into 64 ohms, probably OK with pretty much anything since lower impedance phones tend to be efficient.
 
w
 

 
That's what I wrote - after that, uproar.
 
@estreeter, your last post has at least some merit to it.
 
I might build the amp, for all that.
 
w
 
Sep 25, 2012 at 6:08 PM Post #80 of 106
OK. With LCRC PSU @ 200VAC in
 
@tube-town.net - inc. shipping
 
Chassis 1440 - 10, 4*8*2 in.
OPT 125BSE 5W 45mA DC * 2
Toroidal PT 30VA 6.3V * 1.5A, 200V * 0.1A
Choke 156G 300V 9H 300 ohm 40mA
B9A sockets * 2
Res 10k 5W
 
[size=small][/size]122 ~ $157 US ~ £98
 
Need: various grommets, hook up wire, nuts & bolts, small tagboard, caps, res, pot, jack sockets, semiconductors, knob, power inlet, cable ~ $85?
 
In hand 2 * 6N6P ~ [size=small]€6[/size] ~ $7.50 ~ £4.80, punches, pillar drill & drills, soldering iron, sidecutters, pliers, spanners, screwdrivers, wire strippers, solder.
 
Total parts: [size=small]€194[/size] ~ $250 ~ £155. I bet if I built 20 I could get it down to $200.
 
To assemble the first one:- 2.5 hours. 1 hour thereafter. $40. Completed, to you: $500 + postage.
 
On 20 units: hours worked 40 inc. design time, packaging & shipping, outlay $4000 + banking costs + wear & tear on tools, sale price $10,000, income after outlay $6000 + 20% shipping skim.
 
Tax? What tax? I'm retired.
 
w
 
Parts ordered
 
Sep 26, 2012 at 7:50 AM Post #81 of 106
I admire anyone who can build an amp from scratch, but you wont have any of the costs faced by a commercial operation. No question that it's an interesting project, and I look forward to seeing the end result, but I dont see how it negates many of the points made earlier. 
 
Sep 26, 2012 at 10:56 AM Post #82 of 106
Never give an inch, huh?
 
Sometimes I live in the country.
Sometimes I live in the town.
Sometimes I get a great notion,
To jump in the river and drown.
 
Huddie Ledbetter, quoted by Ken Kesey in:- 'Never Give an Inch'
 
w
 
Sep 26, 2012 at 11:23 AM Post #83 of 106
This may be a Head-fi first. Never before has an argument over "Does X make a difference" lead to any measure of intellectual progress. If every cable, amp, dac, tube argument went this way, the market would be FLOODED with DIY plans in a way that I can't even imagine!
 
So for once: I vote the discussion continue to derail
beerchug.gif

 
Sep 26, 2012 at 11:59 AM Post #84 of 106
Quote:
This may be a Head-fi first. Never before has an argument over "Does X make a difference" lead to any measure of intellectual progress. If every cable, amp, dac, tube argument went this way, the market would be FLOODED with DIY plans in a way that I can't even imagine!
 
So for once: I vote the discussion continue to derail
beerchug.gif

 
The business plan or amplifier design has not yet been demonstrated to actually work. 
 
Sep 26, 2012 at 12:33 PM Post #85 of 106
I said progress, not success. Tested or not, i've never seen a break-in or cable or discrete vs opamp debate lead to any sort of a schematic. I'll hold my judgement for lack of progress until after this design is refined, tweaked, and tested.
 
Sep 26, 2012 at 12:46 PM Post #86 of 106
Quote:
This may be a Head-fi first. Never before has an argument over "Does X make a difference" lead to any measure of intellectual progress. If every cable, amp, dac, tube argument went this way, the market would be FLOODED with DIY plans in a way that I can't even imagine!
 
So for once: I vote the discussion continue to derail
beerchug.gif

 
This is an interesting thread, but it would be nice to see this discussion continue on a civil, respectful level.
 
Sep 26, 2012 at 1:14 PM Post #87 of 106
Quote:
 
This is an interesting thread, but it would be nice to see this discussion continue on a civil, respectful level.

 
I would like to see it continue on a level that is respectful of people trying to make a living selling the audio gear that they build. 
 
Sep 26, 2012 at 5:22 PM Post #88 of 106
Quote:
 
I would like to see it continue on a level that is respectful of people trying to make a living selling the audio gear that they build. 

 
I enjoy reading this thread.
Interesting stuff.
 
I'm sure most of us realize you can't compare a mass producted commodity like a stove. a fridge, or a toaster which you can buy at numerous stores in any large urban centre to a boutique product like a vacuum tube headphone amp.
Everyone I know has a stove.
Must people I know have no idea that a vacuum tube headphone amp even exists.
The tube headphone amp and the stove are two completely different business models.
The stove manufaturer MUST build high volume on an assembly line to succeed.
The OTC vacuum tube amp will always be an extremely low volume shop.
Even Fender builds way more tube guitar amps than Woo builds tube headphone amps.
And if Jack Woo has to put in a big mark-up to succeed in business, that's OK with me.
He still has to make money and sell at a competitive price.
When you buy Woo, you do not expect a cheap transformer set.
 
If you don't like Woo, then think of your favourite brand.
Personally, I think a tube amp with cheap trannys is uselss.
May as well buy an OTL with appropriate cans.
 
And as for Wakibaki, in some ways, I see where you are coming from.
 - Simulate the best you can
 - build a prototype or two or three........etc.
 - figure out why it doesn't work
 - and eventually finesse your prototype until it Actually works the way you had envisioned.
 
Sep 26, 2012 at 5:26 PM Post #89 of 106
Quote:
 
I would like to see it continue on a level that is respectful of people trying to make a living selling the audio gear that they build. 

 
Respect. Yes.
 
Does that include objecting to the misquotation and misrepresentation of my views as detailed in post #79? Somehow I don't get the impression that it does.
 
I have every respect for the people at JDS labs trying to make what I see as an honest and proportionate return on their investment of time and money. One moderated by genuine competition.
 
In common with more than one of the respondents here, I think you're partisan and hostile, nikongod, either because I'm challenging your world view, because I'm challenging your financial interests or because I'm challenging the comfortable and entirely undeserved sense of superiority that comes from conspicuous consumption, or for some other obscure reason I haven't yet figured out.
 
Since, however, I can point to my past support for the pricing levels at JDS labs, I completely fail to understand what twisted logic is being applied to my views to see them as being disrespectful of people trying to make a living selling the audio gear they build.
 
I only object to what I see as excessive markups on costs or the promotion of overengineering and cost as necessary, the more so since anyone with an iota of rationality wanting transparent reproduction would not choose a tube amp in the first place.
 
Come to that, it would almost certainly be cheaper to model tube amp distortion in a DSP, preprocess the signal from the source and feed it to a quality SS amp, but I'm entirely convinced that no matter how convincing the result, be it completely indistinguishable in blind testing, it would be found wanting in some respect, if none other than simply that it didn't cost enough, although this could never be admitted and some other objection would of necessity be dreamed up as a pretext.
 
Do I respect people who expect to garner respect by spending money? No. For all I know their daddy gave it to them. Do I respect the people who fawn over such? Try to imagine how little.
 
w
 
Sep 26, 2012 at 6:01 PM Post #90 of 106
Quote:
Personally, I think a tube amp with cheap trannys is uselss.

 
Ah, well. You and I disagree there. I just don't think that a tube headphone amp needs to have expensive transformers, for the technical reasons I have already stated. I think that the limit of performance of tubes can be achieved at these power levels without expensive iron. That's all.
 
Nice to see a good-tempered post though.
 
As to the Woo amps. No, I have designed some overkill amplifiers. There's a certain satisfaction to producing (or owning) an amplifier with a diminishingly small level of distortion, or overkill qualities in some respect or other. Is it necessary for it to be transparent (or in the case of tubes for it to reach the limit of performance)? Almost certainly not. You probably can't produce a headphone amp of any description with audible quality better than an O2. You can build heavier, lighter, with more feaures, longer battery life, any number of distinguishing features including better measurements, almost all more expensive given the current state of the art, but you probably can't make one that is audibly better, because there is a limit to human perceptions. A lot of people think that that limit hasn't been reached, but what scientific evidence there is suggests that it has.
 
 
w
 

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