Valve power amp newbie - Audio Note P1

dunkyboy

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I've just secured an Audio Note P1 power amp (via this very wigwam) and, having never owned a valve power amp, and not finding much about this particular amp online, was wondering if there's anything I should know about it?

I've read about bias being "a thing", but not sure if it applies to the P1 or if anyone has any tips about setting it?

I presume people only switch them on when they use them (for power usage if nothing else)..? 30-60 mins to warm up?

I'll be using it with a pair of AN-Es, the 98dB hemp-cone ones. Any advice about which taps to use (4-ohm or 8-ohm) with these? Any requirements for speaker cable (eg. low-capacitance)? Will probably end up just using whatever cables I have lying around...

Generally just hoping for folk's experience with this amp, and with valve power amps generally... I'll be using it with an AN M2 pre.

Cheers!

Dunc

 

bmtell

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You don't need to worry about biasing. But buy matched quads of EL84's when they power valves need replacing.

10 mins or so warm up should do you.

Try both output taps and use the one you like best.

Use whatever cables you like.

 

dunkyboy

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You don't need to worry about biasing. But buy matched quads of EL84's when they power valves need replacing.10 mins or so warm up should do you.

Try both output taps and use the one you like best.

Use whatever cables you like.
Sounds good, thanks. :)

Dunc

 

robin

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Iirc the P1 uses the power amp bit of and Otto. Is yours the push-pull or single ended version?

There are plenty of Otto users on here than could advise you on cables and settings and stuff.

There is even one that could advise you how to transform it, with the aid of some select mods, into an unreliable pile of scrap. :whistle:
chris"s oto is now in tip top condition,and never sounded better,i know because he told me so :whistle:

 

dunkyboy

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It's the PP (push-pull) version. Not actually sure what that means - two valves per channel for more power but less sweetness? Or along those lines..?

Anyone compared the PP and SE versions?

Dunc

 

dunkyboy

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Installed it and the Es over the weekend, and fired it all up. Sounds bloody magnificent! Match made in heaven. Rich, full tonal colours, wide open soundstage, generous, effortless sound - but not over-warm or rolled-off or muddy at all, and with great groove and snap, and micro/macro-dynamics. Love it.

It’s a little softer than I’m used to with my ATC actives (e.g. dynamic hits like a well-recorded drum set) and it errs on the side of politeness (never quite gets really loud or brash or nasty, even if the music demands it), but these are faults I’m happy to live with for now. I’ve only tried the 8-ohm taps, so need to compare the 4-ohms. And I’m happy to cut this amp a break – it’s AN’s entry-level power, and these speakers won’t be embarrassed by amps costing many times what this cost me!

In valve heaven. :D

Cheers,

Dunc

 

Valvebloke

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One thing I'll mention just in case, as a relative newcomer to things thermionic, you've never come across it before - it's risky to run valve amps without speakers (or a resistive dummy load, but few people have those) connected. Unlike almost all solid-state amps valve amps have output transformers which feed the speakers. With no speakers attached the transformers becomes inductors and the energy that's stored in them becomes available to do damage, usually to the transformers. You might get away with it if there's no music playing and if you don't make any switching/plugging noises with the pre. You might also get away with it if the transformers are robust enough or if the output valves are sufficiently low powered. But you might not. So it's best not to risk it.

VB

 

pmac

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One thing I'll mention just in case, as a relative newcomer to things thermionic, you've never come across it before - it's risky to run valve amps without speakers (or a resistive dummy load, but few people have those) connected. Unlike almost all solid-state amps valve amps have output transformers which feed the speakers. With no speakers attached the transformers becomes inductors and the energy that's stored in them becomes available to do damage, usually to the transformers. You might get away with it if there's no music playing and if you don't make any switching/plugging noises with the pre. You might also get away with it if the transformers are robust enough or if the output valves are sufficiently low powered. But you might not. So it's best not to risk it.VB
Is it not the case that there is no risk if there is no source connected to the amp?

Very interested in your opinion on this :^

 

hearingisbelieving

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Is it not the case that there is no risk if there is no source connected to the amp? Very interested in your opinion on this :^
yes also curious as I have heard this as well. I always use a dummy load or expendable speakers just in case but still curious

 
G

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Is it not the case that there is no risk if there is no source connected to the amp? Very interested in your opinion on this :^
whether there is a source connected to the input(s) of a valve amp or not doesn't do anything to the O/P transformers' behaviour, which is that they must always be loaded with a speaker or a big enough (TMBK preferably around 8Ohms/10W) dummy load, just as Valvebloke described it above

 

Valvebloke

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Is it not the case that there is no risk if there is no source connected to the amp? Very interested in your opinion on this :^
Well there's much less risk if there's no source connected. But there's always the chance of a click or a pop or a taxi driver finding its way into the system. Whether this is sufficient to do any harm depends on whether the click/pop/taximan is loud enough, the output stage powerful enough, the output transformer inductive enough and the weak point in the circuit (wherever it is) weak enough. I'm usually prepared to risk it with my own hifi amps, but it would be unprofessional of me to encourage others to. I certainly wouldn't risk it with a big guitar amp, say. They tend to run much closer to the edge in any case. And it's pretty rare that I switch a power amp on without having a source connected, so the question doesn't often arise to be honest.

VB

 

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