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Denis Cornell.

springhead

Member
Joined
Feb 12, 2016
Messages
262
The "Our Class A design has less-cross over distortion". Surely if it were Class A it wouldn't have any!

No doubt a fine amp though and looking forward to hearing it if you can bring it along in January Paul. The only other Cornell I've heard in the flesh is Wilko Johnsons, from a position of ten feet in front of it with a silly grin on my face!
 

PaulD

Active member
Joined
Jun 25, 2007
Messages
673
"Our Class A design has less-cross over distortion". Surely if it were Class A it wouldn't have any!

Ha Ha good point, I didn't notice that! It seems someone wasn't thinking when they wrote their advertising hype! :rofl
 

ourmaninthenorth

Well-known member
Joined
Mar 28, 2009
Messages
7,119
The "Our Class A design has less-cross over distortion". Surely if it were Class A it wouldn't have any!

No doubt a fine amp though and looking forward to hearing it if you can bring it along in January Paul. The only other Cornell I've heard in the flesh is Wilko Johnsons, from a position of ten feet in front of it with a silly grin on my face!

The double bastid....:hee:hee

The last Cornell I played through I had Greeny in me hands, now that made me smile...:laugh2::laugh2:

I'm having the chassis out later, so we can have a mooch around the engine room....stand by...to the tools was the cry...this should do it..Class A? I'll give you bloody Class A..

KkF1obQ.jpg
 

springhead

Member
Joined
Feb 12, 2016
Messages
262
Yeah that'll open it. And maybe a wrecking bar to gently lever it out, mind you don't scratch the paint.
 

PaulD

Active member
Joined
Jun 25, 2007
Messages
673
The double bastid....:hee:hee

The last Cornell I played through I had Greeny in me hands, now that made me smile...:laugh2::laugh2:

I'm having the chassis out later, so we can have a mooch around the engine room....stand by...to the tools was the cry...this should do it..Class A? I'll give you bloody Class A..

KkF1obQ.jpg


Damn! All those years of experience building and repairing amplifiers and I thought my soldering iron was my most useful tool.... I need one of those!!
 

ourmaninthenorth

Well-known member
Joined
Mar 28, 2009
Messages
7,119
Here you go Lads...

I've dropped a right bollock here, the Wife's just come home from work..seen the tools out and issued forth the kiss of death..."while you've got those out, can you just...??" :laugh2::laugh2:

Ia7RzVE.jpg


KUZmD2y.jpg


39e5nDZ.jpg
 

Wally

Well-known member
Joined
Feb 27, 2003
Messages
3,535
PaulD wrote: "To summarise a single ended amplifier (one output valve) will always be class A, a push-pull amplifier (2 or more output valves) can be either class A, class AB or class B"

Fwiw and fyi, there are single-ended, Class A amplifiers with more than one power tube.
Ex: http://schematicheaven.net/gibsonamps/gibsonette.pdf

there are others..
 

springhead

Member
Joined
Feb 12, 2016
Messages
262
PaulD wrote: "To summarise a single ended amplifier (one output valve) will always be class A, a push-pull amplifier (2 or more output valves) can be either class A, class AB or class B"

Fwiw and fyi, there are single-ended, Class A amplifiers with more than one power tube.
Ex: http://schematicheaven.net/gibsonamps/gibsonette.pdf

there are others..

That Gibson is Parallel Single Ended, PSE. Both output valves are doing the same thing at the same time, i.e. Class A. More power out than one valve but not as efficient as push-pull. I've never understood the attraction of PSE. You save on a phase inverter but have to use a larger, heavier more expensive output transformer than a push-pull amp using the same pair of power bottles.

Paul - that's some busy innards, very nice. Quite a labour intensive build. I'll have to dock him some safety points for taking the live from the IEC socket to the side connector of the fuse holder - should be on the far end. Please be careful if you change/check the fuse - pull the mains plug out first or it could bite you.

And get those shelves put up for her...
 

Wally

Well-known member
Joined
Feb 27, 2003
Messages
3,535
That Gibson is Parallel Single Ended, PSE. Both output valves are doing the same thing at the same time, i.e. Class A. More power out than one valve but not as efficient as push-pull. I've never understood the attraction of PSE. You save on a phase inverter but have to use a larger, heavier more expensive output transformer than a push-pull amp using the same pair of power bottles.

Paul - that's some busy innards, very nice. Quite a labour intensive build. I'll have to dock him some safety points for taking the live from the IEC socket to the side connector of the fuse holder - should be on the far end. Please be careful if you change/check the fuse - pull the mains plug out first or it could bite you.

And get those shelves put up for her...

+1 on that fusing situation, Spring. good eye.

As for the parallel single-ended....maybe they were interested in what true Class A does compared to Class AB??? I cannot bring to mind the more modern amps that do PSE...but iirc one design has 3 tubes in parallel and one or even two can be pulled out of the circuit for lower output levels.
 

PaulD

Active member
Joined
Jun 25, 2007
Messages
673
PaulD wrote: "To summarise a single ended amplifier (one output valve) will always be class A, a push-pull amplifier (2 or more output valves) can be either class A, class AB or class B"

Fwiw and fyi, there are single-ended, Class A amplifiers with more than one power tube.
Ex: http://schematicheaven.net/gibsonamps/gibsonette.pdf

there are others..

Yes, I left out parallel single ended just to keep things simple as they are not very common.
 

ourmaninthenorth

Well-known member
Joined
Mar 28, 2009
Messages
7,119
That Gibson is Parallel Single Ended, PSE. Both output valves are doing the same thing at the same time, i.e. Class A. More power out than one valve but not as efficient as push-pull. I've never understood the attraction of PSE. You save on a phase inverter but have to use a larger, heavier more expensive output transformer than a push-pull amp using the same pair of power bottles.

Paul - that's some busy innards, very nice. Quite a labour intensive build. I'll have to dock him some safety points for taking the live from the IEC socket to the side connector of the fuse holder - should be on the far end. Please be careful if you change/check the fuse - pull the mains plug out first or it could bite you.

And get those shelves put up for her...

The treble bastid..now the bugger's trying to kill me.... :laugh2::laugh2:
 

PaulD

Active member
Joined
Jun 25, 2007
Messages
673
I'll have to dock him some safety points for taking the live from the IEC socket to the side connector of the fuse holder - should be on the far end. Please be careful if you change/check the fuse - pull the mains plug out first or it could bite you.

It may well be that it is this type of fuse holder:-

http://uk.rs-online.com/web/p/panel-mount-fuse-holders/0563784/

In which case neither contact is accessible when the fuse is removed so it would be perfectly acceptable to wire it that way.
 

Pat Boyack

Well-known member
Joined
Oct 19, 2011
Messages
4,510
Congrats and welcome to the family!! Class A, Class AB.........I prefer CLASS ACT!! Love my Cornell and I'm looking to sell enough of my blood to get the 48/50 Plexi for the big stages.

My amp guy says my Cornell is the best build he has ever seen. You can't beat the quality Denis provides.
 

ourmaninthenorth

Well-known member
Joined
Mar 28, 2009
Messages
7,119
Congrats and welcome to the family!! Class A, Class AB.........I prefer CLASS ACT!! Love my Cornell and I'm looking to sell enough of my blood to get the 48/50 Plexi for the big stages.

My amp guy says my Cornell is the best build he has ever seen. You can't beat the quality Denis provides.

Give us British lads a shout when the time comes Pat, we'll find you a used 45/50. :salude
 

Big Al

Well-known member
Joined
Apr 24, 2002
Messages
14,537
That Gibson is Parallel Single Ended, PSE. Both output valves are doing the same thing at the same time, i.e. Class A. More power out than one valve but not as efficient as push-pull. I've never understood the attraction of PSE. You save on a phase inverter but have to use a larger, heavier more expensive output transformer than a push-pull amp using the same pair of power bottles.

Paul - that's some busy innards, very nice. Quite a labour intensive build. I'll have to dock him some safety points for taking the live from the IEC socket to the side connector of the fuse holder - should be on the far end. Please be careful if you change/check the fuse - pull the mains plug out first or it could bite you.

And get those shelves put up for her...

The attraction is that pesky ol' thing called TONE. I've used late 50's Gibsonettes since '77. A '57 with field coil Jensen, a '58 an '59. I've seen players weep when trying them and had to deal with the whining and begging to sell, NOPE!

Along with the much recorded Champ and other single ended amps these Class A Amps have great tone. It is one of the great amp designs and singular voices among tube amps. One of the holy trinity of tube guitar amp designs along with cathode bias no negative feedback push/pull and fix bias negative feedback injected push/pull.
 
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