HY60
 

"Dave Plowman (News)" wrote:

Woody wrote:
Point of interest: the larger the value of a capacitor the more
inductance it has, so it is a good idea to put some small value caps in
parallel to reduce any high-frequency content on the supply lines.
Something like a 0.1uF polyester will do, and if you live in an area if
high RF (i.e. near a transmitter site of any sort) you might even
consider another 10nF ceramic as well. Best location for these caps (if
they are not already present) is where the power leads connect to the
amp PCB.

I may get flamed, but in this high-noise environment in which we live
these days, such little bits of additional help, whilst probably not
making any audio difference may help prevent the clicks and bangs.

These sort of small value caps are also fitted to prevent RFI emission
*from* the device.

Wrong place though.

Graham

HY60
 

Phil Allison wrote:

"TonyL"
Eeyore wrote:
TonyL wrote:

I'll probably go for a
regulated supply simply because I have a nice transformer with a
27-0-27 volt secondary

VA rating ?


and a boxfull of 2n3055s and MJ2955s.

Do you also have a boxfull of heatsinks for them ?

Not since I raided my heatsink store for a previous project...a 13.8V 30A
transceiver supply. For this little project the metal enclosure will make
an adequate heatsink.

** Don't let Eeysore spook you with his BS.

Your regulator pass transistors do not have to dissipate much heat - maybe
up to 15 watts each, worst case. Long as the case is 1.5 mm aluminium, it
will be fine.

That's 60W of heat to get rid of. More in fact than the HY60 modules will
generate into 8 ohms by a factor of at least 2. The *thickness* of the case is
almost irrelevant. It's the SURFACE AREA that counts.

You are NOT a proper designer and stop pretending to be one.

Graham

HY60
 

"Woody"


Point of interest: the larger the value of a capacitor the more inductance
it has,

** ********.


so it is a good idea to put some small value caps in
parallel to reduce any high-frequency content on the supply lines.

** Purest Crapology.


Something like a 0.1uF polyester will do,


** Does absolutely NOTHING.

Very silly mythology ......



...... Phil

HY60
 

In article , Jim Lesurf
scribeth thus
In article , Rob
wrote:
Jim Lesurf wrote:
In article , Rob
wrote:



When Ted Rule designed the Armstrong 600 series amps he made them to
work up to about 40wpc continuous. But with small heatsinks, so you
could only get high levels for a modest time. Reason being that at the
time most audio fans listened to music with a high peak/mean ratio and
with a wide dynamic range. Generally with speakers that were not a
difficult load.


As it happens, I got one of those (1974, a receiver) on ebay recently,
works perfectly. I just use it for radio with some Dynaudio speakers.

I use one also for a radio in the room where I have the computer I've
typing on now. Use it with a Freeview DTTV box as a tuner. Gives nice
results with a pair of Spendor LS3/5A's. :-)

Dontcha tink they deserve better then the BBC artefact induced BBC
freeview distortion;-?...

--
Tony Sayer

HY60
 

"Eeyore"
Woody wrote:
"Phil Allison"

** Don't let Eeysore spook you with his BS.

Your regulator pass transistors do not have to dissipate much heat -
maybe up to 15 watts each, worst case. Long as the case is 1.5 mm
aluminium, it will be fine.

Use at least a 2,200 uF cap on the regulated DC output rails, so the
output impedance is low and the pass devices only see the average DC
current.

Nonsense.


** Both claims are 100% true.


The output Z of the regulated outputs is so low...


** False.

It depends very much on the type of regulator topology.

A zener controlled emitter follower is not very low Z

- PLUS cannot SINK any current at all.



that there won't
be enough ripple for those caps to do any useful job.


** You clearly have no idea how the idea works.

Large electros are essential.

****wit.


...... Phil

HY60
 

"Eeysore CRIMINAL NUT CASE LIAR "

Phil Allison wrote:


** Don't let Eeysore spook you with his BS.

Your regulator pass transistors do not have to dissipate much heat -
maybe
up to 15 watts each, worst case. Long as the case is 1.5 mm aluminium,
it
will be fine.

That's 60W of heat to get rid of.


** You have NOT done the math - you lying ss.

15 watts max, per device with BOTH channels running at full output.

The average DC current is under 1 amp per channel.


The *thickness* of the case is
almost irrelevant.


** No it is NOT you LYING ****wit.

**** OFF !!



....... Phil

HY60
 

"Eeyore" wrote in
message

Even pro amps with SMPSs don't make any serious attempt
to regulate the rails.

Why should they?

HY60
 

In article , tony sayer

wrote:
In article , Jim Lesurf
scribeth thus


I use one also for a radio in the room where I have the computer I've
typing on now. Use it with a Freeview DTTV box as a tuner. Gives nice
results with a pair of Spendor LS3/5A's. :-)

Dontcha tink they deserve better then the BBC artefact induced BBC
freeview distortion;-?...

Well, to me the results on R3 sound preferrable to the results via
FM. And of course Freeview is a more logical choice than FM for
World Service and R7 since they aren't available here on FM.

Maybe I notice the drawbacks of FM more easily than yourself.

But don't let me interrupt you using every occasion to re-grind
you personal axe... Just that your worries aren't mine. I just
enjoy the music, etc. :-)


Slainte,

Jim

[1] Primarily since I use this to listen to R3. Plus World Ser

--
Change 'noise' to 'jcgl' if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

HY60
 

"Arny Krueger"
"Eeysore Lying ****wit "

Even pro amps with SMPSs don't make any serious attempt
to regulate the rails.


** Shame how so many of them do - you know nothing ASS !!

Like all the ones with PFC corrected PSUs !!!!!!!!!!!!!!

The the whole Powersoft range, Crown CE4000 & some QSCs et alia .....



Why should they?


** Makes the power output independent of AC voltage sag for one.

Makes "universal" AC voltage operation possible too.



.... Phil

HY60
 

Arny Krueger wrote:

"Eeyore" wrote

Even pro amps with SMPSs don't make any serious attempt
to regulate the rails.

Why should they?

Indeed. No need whatever.

Graham