Forums :: Resources :: Features :: Photo Gallery :: Vintage Radio Shows :: Archives :: Books
Support This Site: Contributors :: Advertise


It is currently Nov Thu 23, 2017 5:45 pm


All times are UTC [ DST ]





Post New Topic Post Reply  [ 1652 posts ]  Go to page Previous  1 ... 4, 5, 6, 7, 8, 9, 10 ... 83  Next
Author Message
 Post subject: Re: A new 300B amp project
PostPosted: Aug Sun 13, 2017 7:06 am 
Member
User avatar

Joined: Nov Sat 26, 2011 4:09 am
Posts: 7988
Location: Texas. USA
john8750 wrote:
You guys
Could this circuit be modified for CCS and NFB? I like this circuit.
I need your help here. Without you I wont even try any 300B.
I am getting better educated on speaker building. The 15" is just to big. But I want the 12" with 6/8" mid and a good tweeter. I know that the best I can afford is still not the best.
For now, I would like to settle on the amp schematic. So I can order the iron stuff.
I will duplicate the Little Prince for the preamp, so the 300B will need to be all tubes. The power supply maybe not.
http://www.oestex.com/tubes/Circuits/AW ... ircuit.jpg
If you do enough mods anything can work. :wink: Feedback will lower the sensitivity too much and I think you want to stick with all triode seeing as how the output stage is triode.

This one has all triodes and 10 dB of negative feedback. 32 Watt. It's not sensitive enough either but using a 12AX7 on the front end, instead of the 12AU7, might be enough. http://www.bonavolta.ch/hobby/en/audio/300b_9.htm


Top
 Profile  
 
 Post subject: Re: A new 300B amp project
PostPosted: Aug Sun 13, 2017 7:07 am 
Member
User avatar

Joined: Nov Sat 26, 2011 4:09 am
Posts: 7988
Location: Texas. USA
Pbpix wrote:
... What's with those weird value resistors???
.05 and .25 and .01 ?
What the heck is that all about????????????

is that ohms? or some drafting shorthand for k ohms or megohms????
And especially for 1939... it just doesn't seem to make sense.
megohm


Top
 Profile  
 
 Post subject: Re: A new 300B amp project
PostPosted: Aug Sun 13, 2017 7:10 am 
Member
User avatar

Joined: Nov Sat 26, 2011 4:09 am
Posts: 7988
Location: Texas. USA
ab5ni wrote:
... Damn! Now that is a nice setup, Flip! Is that the setup you are using, dude? I really love the vaulted ceilings and all of the wood. The acoustics in that room must be amazing.

73,

Randy AB5NI
LOL Hell no. I couldn't afford that setup and a car too.


Top
 Profile  
 
 Post subject: Re: A new 300B amp project
PostPosted: Aug Sun 13, 2017 7:57 am 
Member
User avatar

Joined: Jan Thu 01, 1970 1:00 am
Posts: 21081
Location: Haledon, NJ, usa
Flipperhome wrote:
Pbpix wrote:
I wasn't asking about A2 though.

Something less.

Like AB1.

Could an op275 drive that transformer if not in call AB2 or A2?
No. Primary impedance is 30 Ohm.


Ok Flip:
So.. help me out here a little.
... so how about driving the 300b directly with an opamp that can swing Higher Voltage?
Like the opa454 I mentioned above.

http://www.ti.com/product/OPA454/datasheet

"If I could do this with ...... some easy & simple (non tube) way to get enough grid swing.. I might build it.

Is there an opamp that would be able to do that wide of a grid swing?
How about something like an opa454 ?? ... would it have good fidelity?
"
http://www.ti.com/product/OPA454

_________________
To be a man, Be a non-conformist, Nothing's sacred as the integrity of your own mind.
-Emerson


Top
 Profile  
 
 Post subject: Re: A new 300B amp project
PostPosted: Aug Sun 13, 2017 8:21 am 
Member
User avatar

Joined: Dec Mon 29, 2014 9:39 pm
Posts: 3302
Location: Los Angeles
Pbpix wrote:
john8750 wrote:
You guys
Could this circuit be modified for CCS and NFB? I like this circuit.
I need your help here. Without you I wont even try any 300B.
I am getting better educated on speaker building. The 15" is just to big. But I want the 12" with 6/8" mid and a good tweeter. I know that the best I can afford is still not the best.
For now, I would like to settle on the amp schematic. So I can order the iron stuff.
I will duplicate the Little Prince for the preamp, so the 300B will need to be all tubes. The power supply maybe not.
http://www.oestex.com/tubes/Circuits/AW ... ircuit.jpg

Hi John:
So what exactly is it you 'like' about it in particular... you didn't say why.
Explain please.
and btw...
What's with those weird value resistors???
.05 and .25 and .01 ?
What the heck is that all about????????????

is that ohms? or some drafting shorthand for k ohms or megohms????
And especially for 1939... it just doesn't seem to make sense.



I just want a doable circuit. All tube is preferred. That one looks straight forward. I think you and Flip could touch it up. Seems like that coupling transformer in the other amp would not be the best idea. But, I don't know. And I will be using a tube preamp so don't know about going from tubes, to IC, through a transformer, then back to a tube output.
Let me know, I could be wrong.

_________________
John Smith, over and out.
If I did something right, I made a mistake.


Top
 Profile  
 
 Post subject: Re: A new 300B amp project
PostPosted: Aug Sun 13, 2017 8:22 am 
Member
User avatar

Joined: Nov Sat 26, 2011 4:09 am
Posts: 7988
Location: Texas. USA
Flipperhome wrote:
ab5ni wrote:
Howdy Flip,

Flipperhome wrote:
How do you intend to "feel" 44 kHz?

That's a giant unfounded leap from frisson as there's not a single thing to suggest it's any particular frequency, much less "harmonics," much much less at 44 kHz, but at least now I know what you meant.

Btw, you can rest easy because most 'Hi-Fi' amps available today can do 44 kHz and above, even modestly priced ones.
Btw, I just had a frisson experience listening to Pinball Wizard, by the Who, on Youtube.


Top
 Profile  
 
 Post subject: Re: A new 300B amp project
PostPosted: Aug Sun 13, 2017 8:29 am 
Member
User avatar

Joined: Dec Mon 29, 2014 9:39 pm
Posts: 3302
Location: Los Angeles
Flipperhome wrote:
john8750 wrote:
You guys
Could this circuit be modified for CCS and NFB? I like this circuit.
I need your help here. Without you I wont even try any 300B.
I am getting better educated on speaker building. The 15" is just to big. But I want the 12" with 6/8" mid and a good tweeter. I know that the best I can afford is still not the best.
For now, I would like to settle on the amp schematic. So I can order the iron stuff.
I will duplicate the Little Prince for the preamp, so the 300B will need to be all tubes. The power supply maybe not.
http://www.oestex.com/tubes/Circuits/AW ... ircuit.jpg
If you do enough mods anything can work. :wink: Feedback will lower the sensitivity too much and I think you want to stick with all triode seeing as how the output stage is triode.

This one has all triodes and 10 dB of negative feedback. 32 Watt. It's not sensitive enough either but using a 12AX7 on the front end, instead of the 12AU7, might be enough. http://www.bonavolta.ch/hobby/en/audio/300b_9.htm



OK
What about a 12ax7, 12au7 instead of the 6sn7 also?
Isnt that a lot of NFB?

_________________
John Smith, over and out.
If I did something right, I made a mistake.


Top
 Profile  
 
 Post subject: Re: A new 300B amp project
PostPosted: Aug Sun 13, 2017 8:32 am 
Member
User avatar

Joined: Dec Mon 29, 2014 9:39 pm
Posts: 3302
Location: Los Angeles
Btw, you can rest easy because most 'Hi-Fi' amps available today can do 44 kHz and above, even modestly priced ones.[/quote][/quote]Btw, I just had a frisson experience listening to Pinball Wizard, by the Who, on Youtube.[/quote]

Naw, probably just gas.

_________________
John Smith, over and out.
If I did something right, I made a mistake.


Top
 Profile  
 
 Post subject: Re: A new 300B amp project
PostPosted: Aug Sun 13, 2017 9:14 am 
Member
User avatar

Joined: Jun Sat 17, 2017 4:22 am
Posts: 1106
Location: Lafayette, LA.
Howdy Flip,

Flipperhome wrote:
Btw, I just had a frisson experience listening to Pinball Wizard, by the Who, on Youtube.


Woot! Did you try it again to see if you could repeat it, Flip? If you can, write down the time in the stream where it happens. Just out of curiosity, what were you thinking when this happened? Reminiscing? I'm starting to wonder if emotion has a lot to do with this. OTOH, if it is just a frequency response, as I've said before in another thread, and if the data analysis plays out, we should build an OPT and speakers that can pass a broad range of ultrasonic frequencies and sell them for gazillions so we can afford a sound room like the one you linked :D. I can see it now: "Goosebump Amplification, LTD." :D. Our first employees will be You, Peter, John, and me :D.

73,

Randy AB5NI

_________________
I eat spaghetti code out of a bitbucket while sitting at a hashtable - pay for the meal with cache!


Top
 Profile  
 
 Post subject: Re: A new 300B amp project
PostPosted: Aug Sun 13, 2017 9:18 am 
Member
User avatar

Joined: Jun Sat 17, 2017 4:22 am
Posts: 1106
Location: Lafayette, LA.
Howdy John,

Flip wrote:
Btw, you can rest easy because most 'Hi-Fi' amps available today can do 44 kHz and above, even modestly priced ones.
Btw, I just had a frisson experience listening to Pinball Wizard, by the Who, on Youtube.


John wrote:
Naw, probably just gas.

Man, if gas can do that, I'm going to make a stop over at Taco Bell later today and load up on bean burritos :D.

73,

Randy AB5NI

_________________
I eat spaghetti code out of a bitbucket while sitting at a hashtable - pay for the meal with cache!


Top
 Profile  
 
 Post subject: Re: A new 300B amp project
PostPosted: Aug Sun 13, 2017 9:36 am 
Member
User avatar

Joined: Nov Sat 26, 2011 4:09 am
Posts: 7988
Location: Texas. USA
john8750 wrote:
OK
What about a 12ax7, 12au7 instead of the 6sn7 also?
Isnt that a lot of NFB?
Plate voltage is too high for a 12AU7.

The more I think about this the more I'm convinced that the 300b, while not bad, isn't the best tube for this despite the fanboy accolades (hey, it's Western Electric). A triode connected KT88 has the more plate dissipation, a cathode heater (simpler to power), better linearity, over twice the gm (easier to drive, which reduces driver distortion), and cost less to boot. http://www.thetubestore.com/Tubes/KT88-Tube-Types

In addition, it can be used ultra linear, if one so choses. For example, this Dynaco (Dynakit) Mark III amplifier (sound familiar?) It's basically a scaled up Prince John. I know you can build that :wink:

Attachment:
dynaco-Dynakit-Mark-III-Schematic.png
dynaco-Dynakit-Mark-III-Schematic.png [ 119.63 KiB | Viewed 245 times ]


Top
 Profile  
 
 Post subject: Re: A new 300B amp project
PostPosted: Aug Sun 13, 2017 10:19 am 
Member
User avatar

Joined: Nov Sat 26, 2011 4:09 am
Posts: 7988
Location: Texas. USA
ab5ni wrote:
Howdy Flip,

Flipperhome wrote:
Btw, I just had a frisson experience listening to Pinball Wizard, by the Who, on Youtube.


Woot! Did you try it again to see if you could repeat it, Flip? If you can, write down the time in the stream where it happens. Just out of curiosity, what were you thinking when this happened? Reminiscing? I'm starting to wonder if emotion has a lot to do with this. OTOH, if it is just a frequency response, as I've said before in another thread, and if the data analysis plays out, we should build an OPT and speakers that can pass a broad range of ultrasonic frequencies and sell them for gazillions so we can afford a sound room like the one you linked :D. I can see it now: "Goosebump Amplification, LTD." :D. Our first employees will be You, Peter, John, and me :D.

73,

Randy AB5NI
Yes, although it wasn't as pronounced the second time around. It's right after the opening guitar when the bass kicks in, and then, to a lesser extent, again at the vocal.

Actually, I wasn't 'thinking', per see, which is why it was so pronounced the first time. It's been so long since I listened to that song it sort of caught me off guard in an "oh WOW" moment. The second time around I was more prepared and 'analyzing' it. It's definitely an emotional reaction.

I really like crescendos (among other things). I go bonkers at the ending 'charge' passage in the 1812 Overture. I can see the troops scurrying around to their final positions, getting louder, louder, then... CHARGE! Cannon to right of them, Cannon to left of them, Cannon in front of them Volley'd & thunder'd. Oops, different battle. :mrgreen:

Another that does it is the quiet morning after passage in the William Tell Overture and then, out of the blue, THE LONE RANGER! Which is exactly how it hit me when raiding my parents record collection at the age of 10. :lol: I was an instant Rossini fan. (I found the 1812 Overture in the same raid).


Top
 Profile  
 
 Post subject: Re: A new 300B amp project
PostPosted: Aug Sun 13, 2017 1:52 pm 
Member
User avatar

Joined: Jun Sat 17, 2017 4:22 am
Posts: 1106
Location: Lafayette, LA.
Howdy Flip,

Flipperhome wrote:
Yes, although it wasn't as pronounced the second time around. It's right after the opening guitar when the bass kicks in, and then, to a lesser extent, again at the vocal.


Okay. That sounds like a normal frisson response to me. The great thing is that you weren't expecting it to happen.

Quote:
Actually, I wasn't 'thinking', per see, which is why it was so pronounced the first time. It's been so long since I listened to that song it sort of caught me off guard in an "oh WOW" moment. The second time around I was more prepared and 'analyzing' it. It's definitely an emotional reaction.


Hmmm. I'm going to go with my gut on this and say that it "could" be tied to an emotional response or trigger, but my gut is also telling me that it could just be certain frequencies, too. Maybe it might have something to do with certain audible frequencies mixing and creating audible harmonics, which leads me down another path, which would be vocal harmonies. To study this theory, we'd probably have to gather tons of data and use set theory to analyze things correctly, I'm thinking. Well, we could always write a multi-layered neural network and have it figure things out (grin). If we could nail something like this down, we'd make mega-ultra-uber bucks and could afford any sound room we ever desired, plus a 100-car collection to boot :D.

Quote:
I really like crescendos (among other things). I go bonkers at the ending 'charge' passage in the 1812 Overture. I can see the troops scurrying around to their final positions, getting louder, louder, then... CHARGE! Cannon to right of them, Cannon to left of them, Cannon in front of them Volley'd & thunder'd. Oops, different battle. :mrgreen:


I'm a classical fan myself. My father taught music (Jazz, Orchestra, and Percussion) at the local university, so I was attending his concerts while still in diapers. When I was a kid, I had a frisson response and asked my Dad about it, and he said, "Some frequencies of music do that to me as well, and it's one of the reasons I love music so much. (My Sister teaches music, and her daughter graduated in music works for ASCAP in NYC. My Mom taught chorus and elementary education at the local uni, and I'm the turncoat, going into physics and computer science, although I absolutely adore music. Basically, I didn't want to ruin the thing I loved so much by being an educator :D.)

Anywho, my Dad was telling me about frisson responses years and years ago (call it the 60's or there about), but I'm thinking there wasn't a definition at that time. He knew the response existed, though. He said that the best way to get that response was to listen to classical music live. He'd tell me about how he'd have those responses while conducting, and sometimes it was so moving that it nearly made him cry with pleasure, and he'd sometimes freeze on stage and absorb it for all it was worth :D.

All of that led me to talking about "physically feeling" the music and knowing that it caused goosebumps. That led to me searching this subject, which led me to that frisson article (and many others).

Quote:
Another that does it is the quiet morning after passage in the William Tell Overture and then, out of the blue, THE LONE RANGER! Which is exactly how it hit me when raiding my parents record collection at the age of 10. :lol: I was an instant Rossini fan. (I found the 1812 Overture in the same raid).


For me, it's Richard Strauss - Also Sprach Zarathustra / 2001 Space Odyssey; That, a lot of John William's music, certain passages in Rhapsody in Blue, and other types of songs and music too numerous to mention :D.

73,

Randy AB5NI

_________________
I eat spaghetti code out of a bitbucket while sitting at a hashtable - pay for the meal with cache!


Top
 Profile  
 
 Post subject: Re: A new 300B amp project
PostPosted: Aug Sun 13, 2017 6:52 pm 
Member
User avatar

Joined: Dec Mon 29, 2014 9:39 pm
Posts: 3302
Location: Los Angeles
It must be in ones brain, made up of memories, and set off in the form of a seizure and triggered by a certain sound. So it would be a person to person thing. And some gas.

_________________
John Smith, over and out.
If I did something right, I made a mistake.


Top
 Profile  
 
 Post subject: Re: A new 300B amp project
PostPosted: Aug Sun 13, 2017 6:55 pm 
Member
User avatar

Joined: Dec Mon 29, 2014 9:39 pm
Posts: 3302
Location: Los Angeles
Flipperhome wrote:
john8750 wrote:
OK
What about a 12ax7, 12au7 instead of the 6sn7 also?
Isnt that a lot of NFB?
Plate voltage is too high for a 12AU7.

The more I think about this the more I'm convinced that the 300b, while not bad, isn't the best tube for this despite the fanboy accolades (hey, it's Western Electric). A triode connected KT88 has the more plate dissipation, a cathode heater (simpler to power), better linearity, over twice the gm (easier to drive, which reduces driver distortion), and cost less to boot. http://www.thetubestore.com/Tubes/KT88-Tube-Types

In addition, it can be used ultra linear, if one so choses. For example, this Dynaco (Dynakit) Mark III amplifier (sound familiar?) It's basically a scaled up Prince John. I know you can build that :wink:

Attachment:
dynaco-Dynakit-Mark-III-Schematic.png




Now, that's an idea. I like it. What about adding a CCS? And that should power my Genesis speakers.
I noticed a connection from the lower UL tap connecting to the NFB. That's a new one to me. Is it for a good reason?

_________________
John Smith, over and out.
If I did something right, I made a mistake.


Top
 Profile  
 
 Post subject: Re: A new 300B amp project
PostPosted: Aug Sun 13, 2017 7:07 pm 
Member
User avatar

Joined: Dec Mon 29, 2014 9:39 pm
Posts: 3302
Location: Los Angeles
Flipperhome wrote:
john8750 wrote:
OK
What about a 12ax7, 12au7 instead of the 6sn7 also?
Isnt that a lot of NFB?
Plate voltage is too high for a 12AU7.

The more I think about this the more I'm convinced that the 300b, while not bad, isn't the best tube for this despite the fanboy accolades (hey, it's Western Electric). A triode connected KT88 has the more plate dissipation, a cathode heater (simpler to power), better linearity, over twice the gm (easier to drive, which reduces driver distortion), and cost less to boot. http://www.thetubestore.com/Tubes/KT88-Tube-Types

In addition, it can be used ultra linear, if one so choses. For example, this Dynaco (Dynakit) Mark III amplifier (sound familiar?) It's basically a scaled up Prince John. I know you can build that :wink:

Attachment:
dynaco-Dynakit-Mark-III-Schematic.png



Flip
I also see the low negative bias tap on the PT. Could we get that somewhere else? Or is that transformer available?
I don't see a B+ voltage on the transformer. Guessing it is 800vct.
I will find info on this amp and study it.
Thanks Flip.

_________________
John Smith, over and out.
If I did something right, I made a mistake.


Top
 Profile  
 
 Post subject: Re: A new 300B amp project
PostPosted: Aug Sun 13, 2017 7:27 pm 
Member
User avatar

Joined: Jun Sat 17, 2017 4:22 am
Posts: 1106
Location: Lafayette, LA.
Howdy John,

john8750 wrote:
It must be in ones brain, made up of memories, and set off in the form of a seizure and triggered by a certain sound. So it would be a person to person thing. And some gas.


Who knows, but it would be a ton of fun trying to figure it out, especially if it involved gas :D. Seriously, can you imagine if they do narrow it down? Besides the killing you'd make in the audio world, imagine piping the sounds or frequencies that cause a frisson response into a store every so often, like once a minute or so. They'd either think the place was haunted, they had magical powers :D, or it was the best store ever! Also, if the researchers found out that most people enjoyed frequencies in a certain range of hearing, the advertising industry would bombard us with them.

Thinking about this a bit deeper, I wonder if some group of individuals would complain and sue because they were being programmed by the media and advertisers :D. "Yesterday, the Such-and-Such corporation had a massive class-action lawsuit filed against the company for playing sounds and music in their stores that give their customers goosebumps, and this reaction caused them to stay in the store longer and spend more money than they intended." :D.

Hmmm. Maybe this isn't a good idea afterall! LMAO!

73,

Randy AB5NI

_________________
I eat spaghetti code out of a bitbucket while sitting at a hashtable - pay for the meal with cache!


Last edited by ab5ni on Aug Sun 13, 2017 7:31 pm, edited 1 time in total.

Top
 Profile  
 
 Post subject: Re: A new 300B amp project
PostPosted: Aug Sun 13, 2017 7:29 pm 
Member
User avatar

Joined: Dec Mon 29, 2014 9:39 pm
Posts: 3302
Location: Los Angeles
OK, I found a list of Dynakit parts. I didn't know the parts were available. The trannys seem on the hi side, but still not so bad. I could go with Edcor, but don't know about the 55v neg bias tap. Any ideas about that Peter, Randy?

_________________
John Smith, over and out.
If I did something right, I made a mistake.


Top
 Profile  
 
 Post subject: Re: A new 300B amp project
PostPosted: Aug Sun 13, 2017 7:34 pm 
Member
User avatar

Joined: Dec Mon 29, 2014 9:39 pm
Posts: 3302
Location: Los Angeles
ab5ni wrote:
Howdy John,

john8750 wrote:
It must be in ones brain, made up of memories, and set off in the form of a seizure and triggered by a certain sound. So it would be a person to person thing. And some gas.


Who knows, but it would be a ton of fun trying to figure it out, especially if it involved gas :D. Seriously, can you imagine if they do narrow it down? Besides the killing you'd make in the audio world, imagine piping the sounds or frequencies that cause a frisson response into a store every so often, like once a minute or so. They'd either think the place was haunted, they had magical powers :D, or it was the best store ever! Also, if the researchers found on that most people enjoyed frequencies in a certain range of hearing, the advertising industry would bombard us with them.

Thinking about this a bit deeper, I wonder if some group of individuals would complain and sue because they were being programmed by the media and advertisers :D. "Yesterday, the Such-and-Such corporation had a massive class-action lawsuit filed against the company for playing sounds and music in their stores that give their customers goosebumps, and this reaction caused them to stay in the store longer and spend more money than they intended." :D.

Hmmm. Maybe this isn't a good idea afterall! LMAO!

73,

Randy AB5NI



Now you might have something there Randy. What about using it in the medical industry, you know, promote gas and ease constipation.

_________________
John Smith, over and out.
If I did something right, I made a mistake.


Top
 Profile  
 
 Post subject: Re: A new 300B amp project
PostPosted: Aug Sun 13, 2017 7:56 pm 
Member
User avatar

Joined: Jun Sat 17, 2017 4:22 am
Posts: 1106
Location: Lafayette, LA.
Howdy John,

john8750 wrote:
OK, I found a list of Dynakit parts. I didn't know the parts were available. The trannys seem on the hi side, but still not so bad. I could go with Edcor, but don't know about the 55v neg bias tap. Any ideas about that Peter, Randy?


I have some ideas on this, but I will defer to Flip's sage advice. Although I know a good bit about tubes from reading voraciously on the subject, I have no practical experience with such things.

With that in mind, like Flip mentioned, I'd go with a PP circuit, the KT88, mainly because of the in-directly-heated cathode, which would allow you to use AC for filament voltage (Read: cheaper), and I'd design the rest of amplifier using mil-spec components which would allow it to run in CCS (Continuous Commercial Service). I'd also like another CCS, as in Constant Current Source for a biasing mechanism.

As far as the -55V bias goes, I'll have to scroll up and take a look at the schematic, but remember that Peter and Flip know WAY more than I do when it comes to actual design of the circuit and its application.

73,

Randy AB5NI

_________________
I eat spaghetti code out of a bitbucket while sitting at a hashtable - pay for the meal with cache!


Top
 Profile  
 
Post New Topic Post Reply  [ 1652 posts ]  Go to page Previous  1 ... 4, 5, 6, 7, 8, 9, 10 ... 83  Next

All times are UTC [ DST ]


Who is online

Users browsing this forum: No registered users and 8 guests



Search for:
Jump to:  


















Privacy Policy :: Powered by phpBB