Push/Pull vs two tubes parallel (Single Ended)

[schaublin65]

Hi,

the short story is no

The long version is that the only disagreement in this thread is between you and the poster you insulted.

Take care....

John

[54Goldtop]

I would agree that those participating are being cordial and contributing allot of opinions that overlap to some degree - I wouldn't go as far as to say you all agree, or a general consensus is being formed. As to the issue of a poster being insulted I would point to cause and effect... It's very unfortunate really.

[matt h]

What it says:

I would agree that those participating are being cordial and contributing allot of opinions, but I don't see a general consensus or conclusion being formed - As to the issue of a poster being insulted I would point to cause and effect... It's very unfortunate really.

What it means:

Troll.
Troll.
Troll troll troll troll.

Troll troll troll troll troll troll.

[54Goldtop]

Matt - Affirmations?

[54Goldtop]

A horse is a horse of course of course
unless of course if it's a talking horse

[matt h]

(deleted)

[jazbo8]

To the OP - upon reviewing the old posts, it seems that you were asking two different questions: 1) class A PP vs. PSE, the answer of which you already provided here; and 2) class AB PP vs PSE, which you claim that there is no consensus by the various posters.

Since you come across to be more than a "layman" as suggested by your answer to 1), could you please put forth your take on 2)? You seem to be fixated on the slight differences between the various posters' responses instead on their common points, to some, it may come across as flame-bait...

[pdf64]

This all becomes more relevant to power output when we realize that it affects the load that each tube sees. PP transformers are spec'ed 'plate-to-plate'. An output transformer might be wound so that 8 ohms across the secondary appears as 5k ohms across the entire primary from one end (plate) to the other. We're told that with pure Class A each tube sees 1/2 of that or 2.5k while with pure Class B each tube sees 1/4 (1.25k). What do they see in Class AB? (Notice that 1/4 the entire plate-to-plate load requires that one tube is cut off completely during each 1/2 cycle so that that half of the transformer primary is an essentially an open circuit.)

Yes, you've summed up a conumdrum!

However, from http://www.valvewizard.co.uk/pp.html does it matter, as two methods of estimating output power are put forward, the latter is more of an estimate but doesn't appear to require cut off?
And we know that transformer action should cause each PP plate to swing between 0v and 2VB+ (ignoring losses).

Much abbreviated summary -
Output power:
P = (HT-Vmin) * Ipeak / 2
= 17.9W
Alternatively
P = 2 * (HT-50)^2 / Rload 15.6W

Maybe the second formula is why amps never seem to put out as much power as they should (or is that just me)?

[Structo]

Hi

I'm kind of new to this forum.

Since this seems to be the right thread to ask for spoonfed information I was wondering if my amp works the same if it's upside down?

Please don't be harsh and abrasive if you reply

I'm much too lazy to read RDH3 & 4.

Take care....

John

If you look up a tube's data sheet there will be a notation stating the tube "Mounting position".

Usually they state "any position" for the tube

But some tubes are designed to be mounted horizontal
But guitar amps are not as picky about tube position.

The only difference is that the amp with the tubes hanging down, such as Dumble amps and Fender heads, tend to get hotter because the heat is rising to the chassis.

Marshall amps of course use the tubes up method.

But to answer your first question, the amp will work right side up or upside down.

[Tony Bones]

Yes, you've summed up a conumdrum!

Yeah, well, it doesn't keep us from understanding why we can potentially get more power from a pair of tubes PP than PSE. It prevents us from performing an exact calculation but I'm more interested in understanding than numbers.

None of this serves the OP but I don't care; I'm not here to serve the OP.

[Jana]

It's better to have the tubes pointing up. If they are pointing down, then the electrons tend to pool in the tube.

[cbass]

It's better to have the tubes pointing up. If they are pointing down, then the electrons tend to pool in the tube.

Not a big deal I just pull the glass off and wipe out the excessive electrons with a clean. Cloth

[johnnyreece]

Hi

I'm kind of new to this forum.

Since this seems to be the right thread to ask for spoonfed information I was wondering if my amp works the same if it's upside down?

Please don't be harsh and abrasive if you reply

I'm much too lazy to read RDH3 & 4.

Take care....

John

If you look up a tube's data sheet there will be a notation stating the tube "Mounting position".

Usually they state "any position" for the tube

But some tubes are designed to be mounted horizontal
But guitar amps are not as picky about tube position.

The only difference is that the amp with the tubes hanging down, such as Dumble amps and Fender heads, tend to get hotter because the heat is rising to the chassis.

Marshall amps of course use the tubes up method.

But to answer your first question, the amp will work right side up or upside down.

I'm sure the original question was in jest, but for those who are curious, rectifiers like the 5Y3 and 5U4 are examples that are sensitive to horizontal mounting (the filament can sag and short spectacularly). It can be done, but they need to be oriented in a certain way to avoid potential catastrophe.

Derailed thread? Check.

[pdf64]

None of this serves the OP but I don't care; I'm not here to serve the OP.

Exactly, I'm here to due to tube amp fixation, OPs are just the starting point, any benefit to thread starters is kinda supplementary.

[matt h]

(deleted)