• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Check my first design, 6900/2A3 IT

Status
Not open for further replies.
Jump to Latest
#41
Re: subjective results cannot be repeated

Joel said:
Well, yes, that is what everyone seems to fall back on - "I can hear a difference - if you can't, don't do it". That really shuts down the learning process though, doesn't it?
Click to expand...
LOL.
By every objective measurement we have a SET is much worse than any other topology, yet many advocate them as superior. You may prefer them, and that's fine, but you can't have it both ways.

As for not being able to measure the difference between PSU topologies, well, I've done it and it's quite obvious.
And, yes I do advocate a certain minimalist apporach - but isn't that the essence of what makes a tube amp sound better than a Sony?
Click to expand...
Not IMO. The inherent linearity of many tubes and their ability to swing voltages far greater than most SS stages can (no overload and relatively constant distortion spectrum vs level) are two of the main reasons for it's clarity.
However, there are people who like rubbish like 12ax7's which have a lot of distortion due to a poor transfer.
Be careful not to forget Eistein's maxim (paraphrased here): as simple as neccessary, but no simpler.
Everyone always asks "why do tube amps sound different than SS amps"??? Look at the topologies! A williamson sounds a lot more like my 150W Soundcraftsmen MOSFET amplifier, than a single ended triode with 9 parts in it.
Click to expand...
There are lots of reasons why tubes are often better than SS. I agree that the average Williamson isn't very good, but it would be a very poor one that sounded like a Soundcraftsman. However there are other topologies in PP than a Williamson.
So, I think active regulation, OTL designs, current sources, and complex PSU's are heading in the wrong direction.
Click to expand...
Have you tried any of these, or are you merely extrapolating a thought process?
 
#42
Hmmmm, that's a lot to chew on...

I don't like 12AX7's either - but mostly because so many other people do! 🙄

transistors are current devices Brett. They don't swing voltages much at all.

tubes are not very linear compared to even poor ss devices. Thank god music is not a test signal, eh?

The Soundcraftsmen amp is pretty damn good sounding, BTW. :nod: But it is missing something..... [tubes]

No, of course I have not built all of those - so maybe I should just keep a lid on it.... but who has?
 
#44
... and back to the topic

Arnach,

I know a simplified power supply would be fine for this amp. Why not try that first, and then if you don't get the results you're looking for, go for the larger, more costly one? (especially if you're considering BG caps).

As Brett said, as simple as needed, but no more.

The black gates do look cool though, I have to admit. I'm not above picking parts because of pretty packaging... :drool:
You should see the 1MF oil coupling caps I used in an '01-A preamp.
 
#45
DIY

Hi,

If I'm on a budget I don't design for my own use,I design for someone elses budget.
Think they call that "engineering".
What's so wrong with getting it right first time?

I don't care much about BG caps unless I need big values for cathode bypass.
Which I try to avoid in the first place.
And MKV or PIO will outperform the BG anyway,so why bother?


Feed an opportunity. Starve a problem.

Peter F. Drucker.

Cheers,😉
 
#46
Poo. Thanks for the advice, but the power supply I ended up with above simulates very, very well, and I will be using it. I am using Solen for the 100 uF values, and two in parallel for the 200uF value. Power supply w/o caps is costing me around $550.. Not bad.

Anyway, what I am really wondering is if the Tango NC-14 is suitable for this circuit? It has an Rp=5K and handles 30 mA.

Thanks,

Aaron
 
#50
Re: ... and back to the topic

Joel said:


The black gates do look cool though, I have to admit. I'm not above picking parts because of pretty packaging... :drool:
You should see the 1MF oil coupling caps I used in an '01-A preamp.
Click to expand...

They are not cool anymore, when you strip them out of the plastic jackets. And in the light of recent posts, I'm sure that arnach will do that.😉
 
#51
build it your way then... I don't care.

aaron,
I'm not suggesting you skimp, or build a "cheap" amplifier, or compromise in any way. That would be absurd. I'm merely suggesting you use the right tool for the job. There is no prize for building the most expensive amp, and money does not gaurantee good sound - although you seem to be equating the two.

I was just trying to help offer a viable alternative. And I think $550 for a SET power supply is a lot of money. Sorry if pointing that out annoyed you. :no:

Finally, I would just add that I have PSUD installed on my computer - and it does not perfectly model reality.
 
#52
Joel said:


There was a guy in another section of the forum that claims he hears a difference when he places 3 cd's on top of his player, as opposed to only 2 cd's. :whacko: I'm not kidding. I will not keep an open mind about that.:cop:
Click to expand...

I could hear the difference when I placed 5 CD jewel boxes on my player as opposed to nothing on top of the player, no kidding. I'm not sure if this smilie is not reserved for moderators use only :cop: 😉
 
#54
Peter Daniel said:


I could hear the difference when I placed 5 CD jewel boxes on my player as opposed to nothing on top of the player, no kidding. I'm not sure if this smilie is not reserved for moderators use only :cop: 😉
Click to expand...

Have you tried placing random items from around the house on top of your cd player to see if you can get it to sound better? A friend of mine has a cat that likes to sit on top of his cd player... I wonder how that effects the sound.

--
Brian
 
#56
Was that you Peter??? Haha, sorry for making an example out of you - it just struck me as amusing.:cheeky:

I have learned to place my dog on top of mine. The 100Hz region seems more warm and "wooly" now.
 

Attachments

  • casey-small.jpg
    casey-small.jpg
    13.1 KB · Views: 348
#57
Well, this whole tube amp DIY thing for me started out with the Baby Ongaku, and it was Gordon Rankin who sent me the initial power supply schematic with two chokes, and I trust his ears 🙂

The total is costing far too much, but I think it's worth it..

Power supply $550 (Tango MX-175, LC-10-200, LC-15-150)
Interstages $264 (Tango NC-14)
Capacitors $180 (all Solen)
Resistors $50 (Audio Note)
Tubes $200 (6900 pr, Sovtek 2A3, Mullard 5AR4)
Output Trannys $600 (Tribute amorphous)

around $2k for the project. :-( .. But alot of the cost is getting some of those components from Japan, for instance, the power supply is only really US $380.

Getting real african ebony wood pieces for the chassis and copper plate.. but that's not for a while.

No complaints with the Tango NC-14?
 
#58
Here are the simulation of my PSU (bottom) versus Joels (top). I do believe mine is worth the extra money.

Please keep in mind the following qoute from Joel: "Finally, I would just add that I have PSUD installed on my computer - and it does not perfectly model reality." .. Obviously this is true, but the differences are large enough that even a significant margin of error on the part of the simulation can be overlooked.

Finally, Joel, I wasn't annoyed, no worries 🙂
 

Attachments

  • power.jpg
    power.jpg
    45.2 KB · Views: 365
Status
Not open for further replies.
Top Bottom