Power op amp driving valve in A2

If they glow, this is the place to be
User avatar
pre65
Amstrad Tower of Power
Posts: 21373
Joined: Wed Aug 22, 2007 11:13 pm
Location: North Essex/Suffolk border.

#1 Power op amp driving valve in A2

Post by pre65 »

I came across this P Millett web page and found it interesting.

Has anyone here tried this ?

http://www.pmillett.com/pwrop.htm

Here are the driver PCBs

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... _500wt_949
The only thing necessary for the triumph of evil is for good men to do nothing.

Edmund Burke

G-Popz THE easy listening connoisseur. (Philip)
User avatar
Paul Barker
Social Sevices have been notified
Posts: 8867
Joined: Mon May 21, 2007 9:42 pm

#2

Post by Paul Barker »

worth a go. doesn't the Electraprint man do something like this? And that hairy shirtless guitar player guy with an 833a amp has a mosfet design.
User avatar
pre65
Amstrad Tower of Power
Posts: 21373
Joined: Wed Aug 22, 2007 11:13 pm
Location: North Essex/Suffolk border.

#3

Post by pre65 »

I will see what a pair of 1626 (VT-137) cost first, unless anyone here has a pair to dispose of ?
The only thing necessary for the triumph of evil is for good men to do nothing.

Edmund Burke

G-Popz THE easy listening connoisseur. (Philip)
User avatar
Mike H
Amstrad Tower of Power
Posts: 20157
Joined: Sat Oct 04, 2008 5:38 pm
Location: The Fens
Contact:

#4

Post by Mike H »

Or TDA2050? Maplin have got Velleman kits I think. But they are single-sided supply (i.e. not split rail) but that may be an advantage as the output will be positive DC for bias into A2.
 
"No matter how fast light travels it finds that the darkness has always got there first, and is waiting for it."
User avatar
pre65
Amstrad Tower of Power
Posts: 21373
Joined: Wed Aug 22, 2007 11:13 pm
Location: North Essex/Suffolk border.

#5

Post by pre65 »

Mike H wrote:Or TDA2050? Maplin have got Velleman kits I think. But they are single-sided supply (i.e. not split rail) but that may be an advantage as the output will be positive DC for bias into A2.
Like this ?

http://www.ebay.co.uk/itm/TDA2050-IC-30 ... 2361wt_983
The only thing necessary for the triumph of evil is for good men to do nothing.

Edmund Burke

G-Popz THE easy listening connoisseur. (Philip)
User avatar
Mike H
Amstrad Tower of Power
Posts: 20157
Joined: Sat Oct 04, 2008 5:38 pm
Location: The Fens
Contact:

#6

Post by Mike H »

Not just like it, that is it. :D

OK maybe not Velleman then according to its PDF

Didn't think it came with a heatsink though?
 
"No matter how fast light travels it finds that the darkness has always got there first, and is waiting for it."
User avatar
pre65
Amstrad Tower of Power
Posts: 21373
Joined: Wed Aug 22, 2007 11:13 pm
Location: North Essex/Suffolk border.

#7

Post by pre65 »

Mike H wrote:Not just like it, that is it. :D

OK maybe not Velleman then according to its PDF

Didn't think it came with a heatsink though?
So Mike, do you think that is a better way (and cheaper/quicker to get) to drive a 1626 into A2 ?
The only thing necessary for the triumph of evil is for good men to do nothing.

Edmund Burke

G-Popz THE easy listening connoisseur. (Philip)
User avatar
Mike H
Amstrad Tower of Power
Posts: 20157
Joined: Sat Oct 04, 2008 5:38 pm
Location: The Fens
Contact:

#8

Post by Mike H »

It's a simple way, whether it's better than "whatever" is something else :D
 
"No matter how fast light travels it finds that the darkness has always got there first, and is waiting for it."
User avatar
pre65
Amstrad Tower of Power
Posts: 21373
Joined: Wed Aug 22, 2007 11:13 pm
Location: North Essex/Suffolk border.

#9

Post by pre65 »

Mike H wrote:It's a simple way, whether it's better than "whatever" is something else :D

I like simple. :wink:

PS it looks like the heatsink is extra on the Maplin thingie.
The only thing necessary for the triumph of evil is for good men to do nothing.

Edmund Burke

G-Popz THE easy listening connoisseur. (Philip)
Laurence
I am not a user, I am a free man
Posts: 73
Joined: Wed Oct 05, 2011 6:21 pm

#10

Post by Laurence »

But you are basically building a hybrid amp. Surely if you only want to drive the 1626 you would be better to keep purist with a CF :?:
User avatar
pre65
Amstrad Tower of Power
Posts: 21373
Joined: Wed Aug 22, 2007 11:13 pm
Location: North Essex/Suffolk border.

#11

Post by pre65 »

Laurence wrote:But you are basically building a hybrid amp. Surely if you only want to drive the 1626 you would be better to keep purist with a CF :?:
I was interested by the article, and sometimes it's just nice to do something different.

I have several amps driven by CF (833a, 811a, 300b) so different could be good. :lol:
The only thing necessary for the triumph of evil is for good men to do nothing.

Edmund Burke

G-Popz THE easy listening connoisseur. (Philip)
Lee S
Old Hand
Posts: 664
Joined: Fri Aug 10, 2007 9:39 am
Location: UK

#12

Post by Lee S »

Paul Barker wrote:And that hairy shirtless guitar player guy with an 833a amp has a mosfet design.
Aaaargh !!! Paul !!! I had just about forgotten about that bloke until you mentioned it again.... Horror !!! :pukeright:
©2020 Lee
User avatar
Paul Barker
Social Sevices have been notified
Posts: 8867
Joined: Mon May 21, 2007 9:42 pm

#13

Post by Paul Barker »

Well to be fair he was one of the first to provide insight into the 833a, but he did ought to have kept his clothes on.

However a friend of mine aparently wins the hairiest backside contest, I heard tonight when he was passed out naked on the bathroom floor his wife sent for her friend to lift him into bed. Must have been a very good friend!
User avatar
pre65
Amstrad Tower of Power
Posts: 21373
Joined: Wed Aug 22, 2007 11:13 pm
Location: North Essex/Suffolk border.

#14

Post by pre65 »

Andrew I is sorting out a couple of 1626 for me, so now I need to think about the driving stage.

Mikes idea is swaying me in the Maplin direction. :wink:
The only thing necessary for the triumph of evil is for good men to do nothing.

Edmund Burke

G-Popz THE easy listening connoisseur. (Philip)
User avatar
pre65
Amstrad Tower of Power
Posts: 21373
Joined: Wed Aug 22, 2007 11:13 pm
Location: North Essex/Suffolk border.

#15

Post by pre65 »

Whilst supping my late morning red bush tea, I had a thought. :shock:

That in itself is unusual, but here goes.

Instead of using that Maplin module, what about using my T-amp ? That would save quite a few petrol vouchers.
The only thing necessary for the triumph of evil is for good men to do nothing.

Edmund Burke

G-Popz THE easy listening connoisseur. (Philip)
Post Reply