Decoupling...

If they glow, this is the place to be
User avatar
Mike H
Amstrad Tower of Power
Posts: 18326
Joined: Sat Oct 04, 2008 5:38 pm
Location: The Fens
Contact:

Re: Decoupling...

Post by Mike H » Tue Oct 08, 2019 5:58 pm

pre65 wrote:
Mon Oct 07, 2019 7:21 pm
IslandPink wrote:
Mon Oct 07, 2019 6:24 pm
Oh, Mike - I thought you were going to solve the puzzle for us ?
He's probably giving it some deep thought first.
First, during and after, still have no answer to the orginal question.
 
I never make the same mistake twice. Instead I prefer to fill my day with a variety of different mistakes

RhythMick
Old Hand
Posts: 533
Joined: Fri Jun 23, 2017 12:24 pm

Re: Decoupling...

Post by RhythMick » Tue Oct 08, 2019 9:28 pm

izzy wizzy wrote:
Tue Oct 08, 2019 1:51 pm
Foot in mouth time. I think I see what is being said. Say using my amp as an example, at idle the HT is 1000V @ 180mA = 180W. At say a power out of 30W the HT delivers the 180W plus 30W so the HT bounces around to the dynamics of the music not so much to the frequency changes but a little as the load is non-linear as are the valves and all other things coz nothing is perfect. Class A amps do increase the HT current draw depending on power out. Prolly explains why low Z rectifiers have an effect esp on dynamics and bass, IME anyways.

As the HT bounces around to the dynamics not so much frequency variation, then maybe caps in the HT are not so "critical" as say a SE amp where usually the AC signal is coupled to the OPT via the HT cap.

And so the idea is a seperate front end power supply is still advantagous coz HT still bouncy.

I'll be interested to try this but I just stuck my 10H chokes in the bias supply ... hmmm ...

Cheers,
Stephen
I have a box full of chokes I'm not using. Literally. Your welcome to borrow them.

User avatar
IslandPink
No idea why I do this anymore
Posts: 6959
Joined: Tue May 29, 2007 7:01 pm
Location: Denbigh, N.Wales

Re: Decoupling...

Post by IslandPink » Tue Oct 08, 2019 10:01 pm

izzy wizzy wrote:
Tue Oct 08, 2019 1:51 pm
Foot in mouth time. I think I see what is being said. Say using my amp as an example, at idle the HT is 1000V @ 180mA = 180W. At say a power out of 30W the HT delivers the 180W plus 30W so the HT bounces around to the dynamics of the music not so much to the frequency changes but a little as the load is non-linear as are the valves and all other things coz nothing is perfect.
I'm relieved this does actual happen - but disappointed we haven't found a source of CO2-free energy .
"The bass is the king of the instruments - it has no known natural predator" (Wobble)

izzy wizzy
Old Hand
Posts: 840
Joined: Fri Nov 02, 2007 7:02 pm
Location: Folkestone
Contact:

Re: Decoupling...

Post by izzy wizzy » Tue Oct 08, 2019 10:25 pm

RhythMick wrote:
Tue Oct 08, 2019 9:28 pm
I have a box full of chokes I'm not using. Literally. Your welcome to borrow them.
Thanks. Just had a rummage in the shed and have a tx, choke for choke input and mercury to give it a go in one channel to see if there's something to go forward with. This has the advantage of getting rid of some heat; the decoupling resistors disappate about 50W.

Cheers,
Stephen

RhythMick
Old Hand
Posts: 533
Joined: Fri Jun 23, 2017 12:24 pm

Re: Decoupling...

Post by RhythMick » Tue Oct 08, 2019 10:28 pm

Ok but if you decide you'd like the chokes let me know. I have audio note probably around 20 or so sat doing nothing.

Post Reply