Newbie Valve head question.

[drlargepants]

Why are bass all valve heads so heavy ?

Guitarist in our band has bought one of those all valve Orgin heads, and it’s lighter than my ABM 500 head. 

They’re also much cheaper it would seem. 

Just curious really. 

[Reggaebass]

I’ve been reading up on valve heads lately and the transformers weigh quite a bit, and they are normally constructed very solid which also adds to the weight 

Edited January 18, 2019 by Reggaebass

[drlargepants]

2 minutes ago, Reggaebass said:

I’ve been reading up on valve heads lately and the transformers weigh quite a bit, and they are normally constructed very solid which also adds to the weight 

The Marshall Orgin 50 guitar head is 12kg from memory. An Orange AD200B bass head is is 27kg. 

There’s a Peavy all valve bass head that’s pretty light. I’m not sure you can get that in the UK though. 

[drlargepants]

lol the Ampeg SVT Classic is a whole 10kg heavier than the Orange. 

It weighs more than my son !

[Reggaebass]

I found this picture the other day of a AMPEG "SVT"

[drlargepants]

It has a PCB ?

[drlargepants]

You can see where the weight comes from. Also those valves are huge !

[Reggaebass]

It wouldn’t let me copy the link but here’s the page 

[Guest oZZma]

20 hours ago, drlargepants said:

Why are bass all valve heads so heavy ?

Guitarist in our band has bought one of those all valve Orgin heads, and it’s lighter than my ABM 500 head. 

They’re also much cheaper it would seem. 

Just curious really. 

Because the bass' sound is heavier 😂

[Reggaebass]

3 minutes ago, oZZma said:

Because the bass' sound is heavier 😂

Massive 😂

[Woodinblack]

20 hours ago, drlargepants said:

Why are bass all valve heads so heavy ?

Guitarist in our band has bought one of those all valve Orgin heads, and it’s lighter than my ABM 500 head. 

Valves are voltage amplifiers, unlike transistors, that are current amplifiers. What this means in practice, that when you take a small signal of a bass and amplify it a lot with transistors, you end up with a low voltage and a hell of a lot of current, which is luckily what you need to put in a speaker.

With valves on the other hand, you end up with not much current and a very high voltage, which is not what you can put in a speaker, so you need an output transformer to take it down to the sort of voltage and current you can put in a speaker, which obviously has to handle the full current of the output you want (and get rid of the heat). As you need a transformer to get the power for the amplifier in the first place it means you need two large transformers in a valve amp, which by their very nature are pretty heavy. And then you obviously are going to need a big bit of metal to mount them on.

Edited January 19, 2019 by Woodinblack

[cattytown]

22 hours ago, drlargepants said:

The Marshall Orgin 50 guitar head is 12kg from memory. An Orange AD200B bass head is is 27kg. 

There’s a Peavy all valve bass head that’s pretty light. I’m not sure you can get that in the UK though. 

That’s a 50 watt guitar head against a 200 watt bass amp.

There will be more valves and heftier transformers to deliver that power.

 

i must weigh my bassman 135 sometime...

 

Paul

[drlargepants]

3 hours ago, Woodinblack said:

Valves are voltage amplifiers, unlike transistors, that are current amplifiers. What this means in practice, that when you take a small signal of a bass and amplify it a lot with transistors, you end up with a low voltage and a hell of a lot of current, which is luckily what you need to put in a speaker.

With valves on the other hand, you end up with not much current and a very high voltage, which is not what you can put in a speaker, so you need an output transformer to take it down to the sort of voltage and current you can put in a speaker, which obviously has to handle the full current of the output you want (and get rid of the heat). As you need a transformer to get the power for the amplifier in the first place it means you need two large transformers in a valve amp, which by their very nature are pretty heavy. And then you obviously are going to need a big bit of metal to mount them on.

Brilliant. Thank you. 

[doomed]

Can't look like that and not be heavy...

[Newfoundfreedom]

4 hours ago, Woodinblack said:

Valves are voltage amplifiers, unlike transistors, that are current amplifiers. What this means in practice, that when you take a small signal of a bass and amplify it a lot with transistors, you end up with a low voltage and a hell of a lot of current, which is luckily what you need to put in a speaker.

With valves on the other hand, you end up with not much current and a very high voltage, which is not what you can put in a speaker, so you need an output transformer to take it down to the sort of voltage and current you can put in a speaker, which obviously has to handle the full current of the output you want (and get rid of the heat). As you need a transformer to get the power for the amplifier in the first place it means you need two large transformers in a valve amp, which by their very nature are pretty heavy. And then you obviously are going to need a big bit of metal to mount them on.

Brilliant explanation of the difference between valve and solid state amps. Thanks.

I've got one of those Mossfed amps. I think they're organic. 

[Beer of the Bass]

On 18/01/2019 at 20:52, drlargepants said:

The Marshall Orgin 50 guitar head is 12kg from memory. An Orange AD200B bass head is is 27kg. 

There’s a Peavy all valve bass head that’s pretty light. I’m not sure you can get that in the UK though. 

The Ampeg PF-50T is 8.8kg, and might be a better comparison as it's also a 50 watt amp.  It saves quite a bit of weight by just having a cage on top of the chassis rather than a full wooden cabinet.  Mesa had a couple of surprisingly light valve bass heads too. 

[Paddy515]

On 18/01/2019 at 20:56, Reggaebass said:

I found this picture the other day of a AMPEG "SVT"

SVT II non-pro. Heavy, yes, but a tone monster - Ooooooohhhh yes!!! The 30Kg lift is worth it!!

[Quilly]

Because valve amps are for real men and are meant to be heavy, that’s why 😃

[Guest oZZma]

2 minutes ago, Quilly said:

Because valve amps are for real men and are meant to be heavy, that’s why 😃

A manly man would effortlessly carry It under his arm anyways!

 

 

[Quilly]

1 minute ago, oZZma said:

A manly man would effortlessly carry It under his arm anyways!

 

 

The lethality of valve amps and all the warnings etc . Checking valves by banging them with a pencil etc. they are the equivalent of steam locomotives.