The OP did not buy the amp, he just heard it and was impressed.
I don't see the problem. Sure I question whether it is really worth over 10x as much as a DIY SET amp but I've never heard it and this is all subjective anyway.
The DIY Challenge is to do something similar for 1/10 the price. Not including the fancy case.
Regulated B+ supply for $70:
Hoefer Scientific Instruments PS500XT Adjustable DC Power Supply 500v 400mA 200W | eBay
The JJ 2A3-40 for 10 Watts output $130 More power out, no matching, and can use a lower primary Z OT for better performance. (Higher BW OT)
One -could- use a P-P OT with a CCS on one side for improved primary inductance and lower Zout. Or put a modulated CCS on one side for doubled power output. 20 Watts.
Hey, for 1/10 of $9000 you can build one hell of a DIY project.
Regulated B+ supply for $70:
Hoefer Scientific Instruments PS500XT Adjustable DC Power Supply 500v 400mA 200W | eBay
The JJ 2A3-40 for 10 Watts output $130 More power out, no matching, and can use a lower primary Z OT for better performance. (Higher BW OT)
One -could- use a P-P OT with a CCS on one side for improved primary inductance and lower Zout. Or put a modulated CCS on one side for doubled power output. 20 Watts.
Hey, for 1/10 of $9000 you can build one hell of a DIY project.
You really have to hear this thing. He has very large open baffle speakers. Forget the name. But he went to great pains to design every inch of this amp down to cables. TVC as opposed to stepped attenuators. Direct coupled. I mainly posted this so if anyone llives near hear they would take some time ouf their day and go have a listen. it really is worth your time. And I am not saying its the greatest amp in the world whatever that is. I am just saying it impressed the hell out of me and I really think its something special.
And furthermore, have you even seen one of our beavers up here???
things are startin to fall into place now😎
As I read all the opinions, and level of knowledge, I think that the group should get together and design and build the very first (I think the first) "Group Tube Amplifier of diyAudio".
Just a few $ dollars from each designer, and a group design project could do that.
Just a few $ dollars from each designer, and a group design project could do that.
It is indeed a great idea! Design a 2a3/300b amplifier that's not too difficult to build. It's the input section that needs the design - the outputs and OPTs should be straightforward. I'm sure we could get a handful of us to breadboard it and give feedback.
Also about interaction of the chain link. There is a way for engineers to partially counter speaker driver generated H2 exploiting appropriately tuned amplifier generated H2 at listening level.
How to have improvement in valve gear if we use the same topologies and ideas over and over again?
If you want to have an OBJECTIVE comparison of valve vs solid state amp, you have to do ALL measurements. Distortion plus frequency response is 1/10th of them at best. Maybe 1/20th.
Plus everybody is measuring to an resistive load which will tell you nothing about real performance of the amplifier. You have to measure at real speakers with their complex crossover etc. You are not listening to a resistor as dummy load, remember.
And noone bothers about some loudspeaker/amplifier synergy.
Correction to my earlier post (#22).
Checking the datasheet for the JJ 2A3-40, the Watts rating is increased, but the current rating is NOT! So the 2A3-40 version will NOT allow one to use a lower primary Z OT. Bummer.
I was thinking I could use my Hammond 1640 SE OT (1250 Ohms) long sitting on the shelf here, but it would still need a parallel set of tubes.
So I will do a 36LW6 "new" series Schade (UnSet, CED - Tubelab) "triode" setup to use it, with a 2nd Harmonic adjust to "fit" the 2A3 curves instead.
So it will be continuously adjustable thru the 3 example curve sets below.
Checking the datasheet for the JJ 2A3-40, the Watts rating is increased, but the current rating is NOT! So the 2A3-40 version will NOT allow one to use a lower primary Z OT. Bummer.
I was thinking I could use my Hammond 1640 SE OT (1250 Ohms) long sitting on the shelf here, but it would still need a parallel set of tubes.
So I will do a 36LW6 "new" series Schade (UnSet, CED - Tubelab) "triode" setup to use it, with a 2nd Harmonic adjust to "fit" the 2A3 curves instead.
So it will be continuously adjustable thru the 3 example curve sets below.
Attachments
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The builder runs local Craigslist ads and does repair as well. I plan to check it out post-covid. McIntosh Marantz "Classic Tube Audio" Vintage Stereo Sales & -...
indra1 and MikyK,
Indra1,
If you want to use the amplifier’s 2nd harmonic distortion to reduce the total amplifier plus loudspeaker total system distortion, you have to pay attention to the connections of the loudspeaker to the amplifier.
Essentially, 2nd harmonic distortion is caused by an increase in the amplitude of the alternation that is in one direction, and by a shortening of the amplitude of the alternation that is in the other direction.
Connecting the + and- of the loudspeaker one way, decreases the system 2nd harmonic distortion. Good.
The directions of the increased alternations and shortened alternations of the amplifier versus the loudspeaker are connected so that they are opposite, and so there is some cancellation of the 2nd harmonic.
Connecting the + and - of the loudspeaker the other way Increases the 2nd harmonic distortion. Bad.
The major problem is that you have to know (or measure; or hear) which connection polarity either decreases the 2nd harmonic distortion of the system, or increases the 2nd harmonic distortion of the system.
MikyK,
I have been preaching for years about measuring amplifiers into a real loudspeaker load.
(Instead of a resistor, or even a “loudspeaker simulator load”).
I measured amplitude and phase of amplifiers into loudspeakers with a $50,000 Vector Network Analyzer that I could use at work.
First you measure the impedance & phase of the loudspeaker.
Then you measure the amplifier into a load resistor, and get amplitude & phase graphs.
Then you measure the amplifier into a loudspeaker, and get amplitude & phase graphs.
Careful! Do not burn out the loudspeaker.
I do not have that kind of equipment at home.
Now I measure amplifiers with real loudspeaker loads, using an impulse.
Not nearly as nice, but it gives a reasonable quick indication of the frequency response, from upper bass to high frequency.
You do what you can with the equipment you have.
I think that those who have solid state amplifiers that have damping factors of 50 or more might say, who cares?
That often will be true.
But even a whiz-bang solid state amplifier had problems with real world loads . . . Loudspeakers!
All of the first production output were sent back by the owners, the amplifiers all burned up, killing themselves when attached to real loudspeakers!
Indra1,
If you want to use the amplifier’s 2nd harmonic distortion to reduce the total amplifier plus loudspeaker total system distortion, you have to pay attention to the connections of the loudspeaker to the amplifier.
Essentially, 2nd harmonic distortion is caused by an increase in the amplitude of the alternation that is in one direction, and by a shortening of the amplitude of the alternation that is in the other direction.
Connecting the + and- of the loudspeaker one way, decreases the system 2nd harmonic distortion. Good.
The directions of the increased alternations and shortened alternations of the amplifier versus the loudspeaker are connected so that they are opposite, and so there is some cancellation of the 2nd harmonic.
Connecting the + and - of the loudspeaker the other way Increases the 2nd harmonic distortion. Bad.
The major problem is that you have to know (or measure; or hear) which connection polarity either decreases the 2nd harmonic distortion of the system, or increases the 2nd harmonic distortion of the system.
MikyK,
I have been preaching for years about measuring amplifiers into a real loudspeaker load.
(Instead of a resistor, or even a “loudspeaker simulator load”).
I measured amplitude and phase of amplifiers into loudspeakers with a $50,000 Vector Network Analyzer that I could use at work.
First you measure the impedance & phase of the loudspeaker.
Then you measure the amplifier into a load resistor, and get amplitude & phase graphs.
Then you measure the amplifier into a loudspeaker, and get amplitude & phase graphs.
Careful! Do not burn out the loudspeaker.
I do not have that kind of equipment at home.
Now I measure amplifiers with real loudspeaker loads, using an impulse.
Not nearly as nice, but it gives a reasonable quick indication of the frequency response, from upper bass to high frequency.
You do what you can with the equipment you have.
I think that those who have solid state amplifiers that have damping factors of 50 or more might say, who cares?
That often will be true.
But even a whiz-bang solid state amplifier had problems with real world loads . . . Loudspeakers!
All of the first production output were sent back by the owners, the amplifiers all burned up, killing themselves when attached to real loudspeakers!
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I found Eduardo de Lima papers a few years ago and learned quite a bit since then.
I'm not sure my eyes are giving high points, to be honest. I find the look to be hideous. YMMV.
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Since I haven't heard it so I have no opinions of its sound. But even if I heard it and liked it, I'm still not sure it justifies a thread on this forum. What are supposed to do with a post like that in the context of a DIY forum when no technical details are provided, no schematic, no construction or innards pictures. I come here for education and sometimes amusement but I must ask: what's the point?
There is a half schematic in the owner’s manual.
http://whammerdyne.com/wp-content/uploads/2018/04/2018-04-07-Whammerdyne_Owners_Manual.pdf
http://whammerdyne.com/wp-content/uploads/2018/04/2018-04-07-Whammerdyne_Owners_Manual.pdf
Looks like a common DC Coupled stage, easy to do when there is a negative PS on board. If by resister alone some gain is lost. Otherwise to avoid SS the coupling can also use a selected NE51 0r 991 Neon lamp, just as the ancients did.🙂
I guess what you heard is a decent tube amp paired with efficient speakers. It's not surprising that you liked that.
Apart from this, I'd be surprised if his commercial amps would be fully conform to todays safety regulations. Just from looking at the photos: hot tubes exposed to humans fingers with no protection at all is a no go. Selling "unsafe" devices on a commercial basis is a risky business.
But hey, if you want an amp like this: make one! It will be a lot cheaper, and you can also make something better, with the looks that you like. That's what DIY is all about!
...looking a bit more at the website, I saw that he seems to use Speakon connectors to hook up the high-voltage side of the "remote" output transformers. Ouch! These connectors are made for loudspeaker connections, not for high voltage! This looks like it's not safe -- stay away from this stuff!
Also, take a look at the text on the website. Just one of the many examples: "These heralds of a new golden age are steadfast sentinels on our way to the realm of the Olympus of Truth." WTF!? Give me break! I'd suggest Zen Mod to revise this with some "proper" gibberish! 😀
Also, take a look at the text on the website. Just one of the many examples: "These heralds of a new golden age are steadfast sentinels on our way to the realm of the Olympus of Truth." WTF!? Give me break! I'd suggest Zen Mod to revise this with some "proper" gibberish! 😀