Advice for taking care of my Hybrid amp

[DaveMuadDib]

Ok people, I've got an Orange Terror Bass head in transit at the moment and according to their website:

[quote]Maintaining the size of the original Tiny Terror, the Terror Bass is a 500 watt hybrid amplifier with a Class D solid state power section and the AD200B twin-valve 12AX7 preamp.

Note: The Bass Terror does not require rebiasing when replacing tubes.[/quote]

I've never owned a valve amp before, so I really wanted to know how much care should I take with it? It's not like I'm playing volleyball with my current solid state markbass head or anything, but do I need to wait for the valves to cool down before I move it, etc? What situation should I ACTUALLY use the "standby" mode for, or is this effectively just a mute? And how much use would I be expected to get out of it before I had to replace the tubes? How would I know when it's time to replace? Is replacing the tubes expensive?

Also - what do they mean by "Class D"? And is the preamp really the same as the AD200B (their all-valve head)?

What does rebiasing mean?

Please help me

Edited July 3, 2010 by Dave_MuadDib

[Lfalex v1.1]

One bit at a time-

No need to allow it to cool before moving. Just treat it as you would any amp.

Without looking at specs and stuff, I would suggest that the standby is just a "Mute" as you suggest. My old Trace SMX is the same. Generally, amps with [u]power[/u] valves (rather than preamp ones like yours) have an [b]on/standby/off[/b] switch instead. Check your manual- you may find it may mute the DI out also.

Valve life varies. My first 12ax7 in my Trace lasted a year. The second has lasted since - well over a decade.
My first went microphonic- picked up all the vibrations in the air, and howled along in unison. If the OTB has a blendable solid-state/ valve preamp, just turn it to 100% solid-state until you can replace them.

12ax7s aren't expensive. Less than £15 each. When replacing them, treat them like automotive halogen bulbs- don't handle them directly- do it through a cloth or gloves. This stops grease deposits from your skin causing them to blow (I don't fully understand all the technicalities of this one. Maybe I'll wiki it!)

Class D amps are lightweight, switched power supply amp stages. Common applications? Lightweight bass amps!! Car stereo head units also. Class D as opposed to class A (Tubes, by definition, though transistor devices can run in Class A) Class A/B, Class B, Class C (used in megaphones, apparently) All to do with current/voltage consumption and the linearity of the resulting stage (blah blah- wiki it!!!)

Rebiasing: Power valves require a different biasing voltage to be applied to them depending upon their use in any given application, including in what class the amp is operating. Job for an amp tech or suitably experienced users, really.
Not a concern for you, as pre-amp valves don't need re-biasing.

Phew!
Hope that helped!

Edit for handling advice; Dont get any sand in it. Keep it away from sandworms, as rhythmic vibration attracts them. Nice username, BTW!

Edited July 3, 2010 by Lfalex v1.1

[escholl]

[quote name='Lfalex v1.1' post='885031' date='Jul 3 2010, 07:57 PM']When replacing them, treat them like automotive halogen bulbs- don't handle them directly- do it through a cloth or gloves. This stops grease deposits from your skin causing them to blow (I don't fully understand all the technicalities of this one. Maybe I'll wiki it!)[/quote]

It actually is perfectly ok to touch them with your bare hands -- it would only be an issue if the envelopes were made of quartz, but they're made of glass. Think of them like a regular incandescent -- ok to touch with your bare hands, but they might be hot if they've been on!

[DaveMuadDib]

[quote]Without looking at specs and stuff, I would suggest that the standby is just a "Mute" as you suggest. My old Trace SMX is the same. Generally, amps with [u]power[/u] valves (rather than preamp ones like yours) have an [b]on/standby/off[/b] switch instead. Check your manual- you may find it may mute the DI out also.[/quote]

There is a single switch on the OTB which goes off/standby/on from top to bottom, rather than a separate power on/off and standby on/off. I think you're most definitely right. So being that it's just a preamp valve, there's no need for me to wait for it to heat up, etc?

[quote]Valve life varies. My first 12ax7 in my Trace lasted a year. The second has lasted since - well over a decade.
My first went microphonic- picked up all the vibrations in the air, and howled along in unison. If the OTB has a blendable solid-state/ valve preamp, just turn it to 100% solid-state until you can replace them.[/quote]

I don't think the OTB has anything fancy like a blendable power amp, as far as I can tell it just has Gain and Master Volume! But I'll consult the manual when the thing arrives tomorrow.

[quote]12ax7s aren't expensive. Less than £15 each.[/quote]

VERY reassuring. Is it worth keeping spares, or are they the kind of thing that start to age as soon as they leave the factory and I'd be better off buying them as-and-when?

[quote]Class D amps are lightweight, switched power supply amp stages. Common applications? Lightweight bass amps!! Car stereo head units also. Class D as opposed to class A (Tubes, by definition, though transistor devices can run in Class A) Class A/B, Class B, Class C (used in megaphones, apparently) All to do with current/voltage consumption and the linearity of the resulting stage (blah blah- wiki it!!!)[/quote]

Gotcha. I'd had a quick peek at the wiki, but the articles I read didn't go into much from a bass perspective I always assumed "Class X" was about the quality of components rather than the actual fundamentals of the thing. Maybe there's a slight correlation, but meh

[quote]Rebiasing: Not a concern for you, as pre-amp valves don't need re-biasing.[/quote]

Unlike most of my technological endeavours, it's reassuring to know that at least ONE element is just plug and play!

[quote]Phew!
Hope that helped![/quote]

It certainly did, thank you very much for your reply!

[quote]Edit for handling advice; Dont get any sand in it. Keep it away from sandworms, as rhythmic vibration attracts them. Nice username, BTW![/quote]

I must not fear; fear is the bass killer :-) You see, this is the exact reason that I have this username, because it always warms me deep inside when people comment on it. It helps remind me that there really are people out there who know what I'm talking about, and that everyone is not just reading about wizards that go to wizard school, or emotional vampires that don't bite people or remotely abide by any of the rules of vampirism. Kull Wahad! ;-)

-Dave

(Note to Harry Potter/Twilight fans: Don't get angry - get a copy of Dune :brow: )

Edited July 4, 2010 by Dave_MuadDib

[Lfalex v1.1]

No worries!
(I'm currently reading "Paul of Dune", having read all the others so far!)

[DaveMuadDib]

[quote name='Lfalex v1.1' post='885424' date='Jul 4 2010, 12:59 PM'](I'm currently reading "Paul of Dune", having read all the others so far!)[/quote]

It's the only book in the series that i haven't read - I've even read the Dune Encyclopedia! As much as I really did like the new dune novels, i'm not entirely sure that i can forgive the authors for crowbarring their robot characters into the series finale as marty and daniel - who were very clearly described as face dancers in chapterhouse! - and then quite literally dropping a deus ex machina final ending on us :-/ How are you finding Paul so far? I will have to give it a read at some point...

[GarethFlatlands]

You might as well keep some spares although they've don't blow like power tubes in my experience. It should be pretty bulletproof.

I'm partway through Children of Dune, heard the ones after weren't great. Someone needs to make a really good film out of Dune! The David Lynch one is impossible if you've not read the book.

[nick]

[quote name='Dave_MuadDib' post='885352' date='Jul 4 2010, 11:45 AM']VERY reassuring. Is it worth keeping spares, or are they the kind of thing that start to age as soon as they leave the factory and I'd be better off buying them as-and-when?[/quote]

Definitely good idea to have spares. I whipped out the crappy Chinese ones that came with my Trace V-Type & replaced them with something better.
Keep them as spares in my gig bag, in case the nice Harma ones ever go.

Worth treating yourself to a good preamp valve, it will make improve the tone. Many to choose from... all different flavours

[DaveMuadDib]

[quote name='GarethFlatlands' post='885784' date='Jul 4 2010, 08:42 PM']You might as well keep some spares although they've don't blow like power tubes in my experience. It should be pretty bulletproof.

I'm partway through Children of Dune, heard the ones after weren't great. Someone needs to make a really good film out of Dune! The David Lynch one is impossible if you've not read the book.[/quote]

I once read here (I think) that tubes start to degrade almost immediately, but I don't know if this was after production or after they're installed.

Children of Dune is a great novel, a fantastic end to the trilogy. Admittedly, God Emperor of Dune is a little bit long-winded, and this is where most people get lost and give up. But stick with it, it gets good towards the end, and it all makes sense with Heretics of Dune after that (my favourite book in the entire series, if not EVER) and Chapter House Dune is excellent too. Apparently they ARE making a new movie, but I'm not holding my breath for it to be any good. I love the Lynch movie so much, even if it is a bit :wacko:

Edited July 4, 2010 by DaveMuadDib

[GarethFlatlands]

[quote name='DaveMuadDib' post='885887' date='Jul 4 2010, 10:14 PM']I once read here (I think) that tubes start to degrade almost immediately, but I don't know if this was after production or after they're installed.

Children of Dune is a great novel, a fantastic end to the trilogy. Admittedly, God Emperor of Dune is a little bit long-winded, and this is where most people get lost and give up. But stick with it, it gets good towards the end, and it all makes sense with Heretics of Dune after that (my favourite book in the entire series, if not EVER) and Chapter House Dune is excellent too. Apparently they ARE making a new movie, but I'm not holding my breath for it to be any good. I love the Lynch movie so much, even if it is a bit :wacko:[/quote]

I've had the same pre-amp tubes in my Matamp for about 2 years and they're still going strong. Still, I assume they heat up and could potentially crack so it's probably wise to carry some spares around. I'm a fan of JJ tubes but they're pretty cheap so get a few and try them out to see what suits.

I'll try the next 3 books too, I have a pretty high boredom threshold so a bit of meandering in the middle shouldn't put me off.

[4 Strings]

Valves can last for years and years, some outlasting many transistors. Bit like wooden windows, looked after properly they can outlast their modern, plastic equivalent by several times.

HOWEVER! They are, of course, made of glass. You don't need to wear gloves as they don't reach the heat of the quartz envelopes of some car headlamps (where the extreme heat burns the grease from your fingermarks and cracks the quartz) and so, as has been mentioned, perfectly safe to handle. Also, they are large for electronic components and are normally just a push fit into their sockets and here is where they can be unreliable if things get knocked around. Many have spring wire clips to keep them in place, but there are still unsoldered contacts.

Your valve will require replacement at some stage in its life. As they are pretty cheap, if you want to maintain reliability pop in a new one every 5 years or so before it goes microphonic etc. I have a similar situation to yours in that my Hartke has one valve in the pre-amp, never keep a spare for mine, doesn't mean I'll not get caught out but I don't expect to be (I DO carry spare fuses!). If the valve goes mid-performance I'll not have time to change it anyway - can just turn up the transistor preamp anyway.

Just as an anecdote, my wife's dad made a 2x12 valve combo for his band in the late 50s (as they did back then) and it had a hard life of regular use for many years (handling two guitars and the vocals mike!). It then sat in his shed since the late 60s, nice and damp (mouldy speaker cloth etc). We dug it out a few weeks back but started up first time and sounded great (despite very noisy pots etc). Got used by my lad's band for guitar but, not surprisingly, packed up. Not a valve but a capacitor! Valves are all original, filthy dirty, when I approached someone to repair it he made no suggestion of replacing the valves, will put the original ones back in.

Your amp will come with instructions, just keep to them.

The amp Class is nothing to do with quality of components, just the way it operates electronically. Class A amplifies the entire sound wave (or cycle) (like an ac power supply) but are notoriously inefficient (~20% of the electrical energy is turned to sound) and so are power hungry and so get hot. They're not necessarily the best, just simple.

The Old amp in the Father In Law's combo is Class B, or Push-Pull, where it amplifies one side of the wave and the other as a pair (rather like 2 dc supplies added together). Its more efficient (~50%) but things get awkward when the two halves are re-joined as they need to be linear - hence the amps name 'Linear'!).

Class D are very complicated but operate with high efficiency and so are suitable for the examples given in a previous post, ie cars and loud hailers, where the power supplies are limited.

With regard to changing valves because they are made in China or Russia, well, that's up to individual choice, but I would suggest many people will hear no difference (especially in a band mix) but there are plenty of sites with all sorts of info. Most of these will tell you what slight differences in sound to expect and so you might choose a valve which happens to be made in China for its middly sound, for example. If you find a make that proves to be poor in reliability or to have a particular sonic character, then let us know.

[Lfalex v1.1]

[quote name='Dave_MuadDib' post='885746' date='Jul 4 2010, 07:54 PM']It's the only book in the series that i haven't read - I've even read the Dune Encyclopedia! As much as I really did like the new dune novels, i'm not entirely sure that i can forgive the authors for crowbarring their robot characters into the series finale as marty and daniel - who were very clearly described as face dancers in chapterhouse! - and then quite literally dropping a deus ex machina final ending on us :-/ How are you finding Paul so far? I will have to give it a read at some point...[/quote]

It's okay, pretty much in keeping with the other Herbert/ Anderson novels. There's another one out, too- it's set between "Paul" and "Dune Messiah".
I think I liked the Prequels (Houses Atreides/Harkonnen/Corrino) best of the new stuff. The Butlerian Jihad ones were alright, too.

[quote name='DaveMuadDib' post='885887' date='Jul 4 2010, 10:14 PM']I once read here (I think) that tubes start to degrade almost immediately, but I don't know if this was after production or after they're installed.

Children of Dune is a great novel, a fantastic end to the trilogy. Admittedly, God Emperor of Dune is a little bit long-winded, and this is where most people get lost and give up. But stick with it, it gets good towards the end, and it all makes sense with Heretics of Dune after that (my favourite book in the entire series, if not EVER) and Chapter House Dune is excellent too. Apparently they ARE making a new movie, but I'm not holding my breath for it to be any good. I love the Lynch movie so much, even if it is a bit :wacko:[/quote]

I like "God Emperor of Dune". Heavy going, but the whole Leto II / Idaho ghola piece is good. I like the Lynch movie, even if it does take a few liberties. It's stylistically, visually and musically excellent (thanks to Toto and Brian Eno, IIRC)

[GarethFlatlands]

[quote name='Lfalex v1.1' post='887512' date='Jul 6 2010, 04:52 PM']I like the Lynch movie, even if it does take a few liberties. It's stylistically, visually and musically excellent (thanks to Toto and Brian Eno, IIRC)[/quote]

I liked it too but it's utterley impenetrable to anyone who hasn't read the book. It's dated a little too.