Does this amp contain passive PFC?

[eem2am]

Does the Series One 200 Amplifier contain a Passive Power Factor Corrector Stage...?..........

Blackstar Series One 200 Guitar Amplifier

....it weighs 27Kg, and surely it could only be that heavy if it contained a Passive Power Factor Corrector Stage?

WEIGHT = 27Kg.............
Blackstar Series One S1-200 200W 4 Channel Valve Head at Gear4Music.com


The following is a 200W mains transformer, and it only weighs 2.7Kg, so the weight of the Series One 200 amplifier cannot be attributed to the mains transformer.........

200W UK to USA Voltage Convertor : Power Supply Convertors - Traditional : Maplin Electronics

..So therefore, i conclude that the Series One 200 Amplifier weighs so much because it contains heavy iron-core chokes which correct the power factor passivley.....

Am i right?

If not, whats inside this amplifier that makes it weigh 27Kg?

[pinkmouse]

I very much doubt it, most likely heavy pressed steel chassis, heater traffo, and huge output iron. It might have chokes in the PSU, but if so, they'll be for smoothing.

You do seem to be preoccupied with this brand of amp and PFC.

[Nigel Goodwin]

You seem obsessed by PFC?, what's your problem?.

I also very much doubt it has, it's heavy because the transformers are heavy (and not puny auto-transformers like you linked to).

A 200W amplifier will also have transformers rated higher than 200W, decent quailty ones are large and heavy, plus the chassis will be heavy as well.

[tinitus]

Originally Posted by eem2am

The following is a 200W mains transformer, and it only weighs 2.7Kg, so the weight of the Series One 200 amplifier cannot be attributed to the mains transformer.........

..So therefore, i conclude that the Series One 200 Amplifier weighs so much because it contains heavy iron-core chokes which correct the power factor passivley.....

Am i right?

no, you do not understand how it works

power supply trafo is much bigger than the rated output power
and even so is the output trafo

with 2x KT88 its pretty heavy stuff
I leave further calculations to the experts

btw, the stuff you link to makes no sense at all, nada

[eem2am]

tinitus:
I am not sure i know what you mean when you refer to a "power supply transformer" and an "output transformer".

....surely there is only one large transformer?

Surely there would be one transformer to transform the mains to the high voltage power supply required by the tubes.

I appreciate that there would be maybe a little flyback smps transformer for the filament supply.

But it wouldnt make sense to have more than one large transformer in there?

-And even if there were two transformers, they wouldnt weigh anywhere near 27Kg, even if good quality...after all, this is only a 200W amplifier.

And the chassis may weigh a Kg or two, but again, nowhere near 27Kg.

If its not PFC Chokes causing the heavy weight, then i am wondering what it is....

...the only other thing i can think of is post-regulators on the secondary of the main transformer with large heatsinks......?

[mctavish]

[QUOTE=eem2am;2796579]tinitus:
I am not sure i know what you mean when you refer to a "power supply transformer" and an "output transformer".

It is a big tube amp, they are HEAVY. It cannot function without a "power supply and output transformer". I suggest you do a little reading on tube amps.

[Nigel Goodwin]

Originally Posted by eem2am

tinitus:
I am not sure i know what you mean when you refer to a "power supply transformer" and an "output transformer".

....surely there is only one large transformer?

Surely there would be one transformer to transform the mains to the high voltage power supply required by the tubes.

No, two large transformers. There may also be a large HT smoothing choke.

I appreciate that there would be maybe a little flyback smps transformer for the filament supply.

But it wouldnt make sense to have more than one large transformer in there?

-And even if there were two transformers, they wouldnt weigh anywhere near 27Kg, even if good quality...after all, this is only a 200W amplifier.

It's a valve amplifier, they are massive and heavy - the two massive transformers will weight a large amount for a start, and the chassis and cabinet have to be larger and heavier to support their weight.

And the chassis may weigh a Kg or two, but again, nowhere near 27Kg.

If its not PFC Chokes causing the heavy weight, then i am wondering what it is....

As we've endlessly explained, mostly the transformers.

Why would you think it would even require a choke for PFC?.

...the only other thing i can think of is post-regulators on the secondary of the main transformer with large heatsinks......?

As mactavish said, you might try studying valve amps, they are crude, simple, big, and heavy.

EDIT:

Here's something you might like to study, it's the schemetic of a PA we used to use two of back in the 70's, it's similar to your Blackstar - 4xKT88's - and they weighed an absolute ton!.

Notice it has two massive transformers at the right, plus an HT smoothing choke (which looks small because it's only two wires, but is still a pretty big HT choke).

http://www.chambonino.com/carlsbro/carl2007pa.html

Even better, here's some pictures of it, the second one down shows exactly why they weigh so much, just look at those transformers (you can scale them by the KT88's they dwarf), also notice the HT choke behind the left most KT88, which probably weighs more than the auto-transformer you linked to.

http://www.chambonino.com/work/carlsbro/carl10.html

[tinitus]

clearly see at least two equally sized trafos
and could still be more than that

I looked up a trafo made fore 4x KT88
weighs in at 10 KILO

but in this amp, trafos might actually be a bit smaller
all the other smaller parts in there easily sums up to quite a lot more than you might expect

at least I hope theres not too much poisened lead in there

[Brian Oshman]

Capacitors are used for PF correction. Chokes would be used for LF noise reduction from the line voltage.

[Nigel Goodwin]

Originally Posted by Brian Oshman

Capacitors are used for PF correction.

Which was my point, about why he imagined chokes in the first place?.

However, to be fair, chokes 'could' be used for PFC, IF the load was excessively capacitive, which obviously isn't the case here.