Bare Knuckle Pickups Forum
Forum Ringside => Guitars, Amps and Effects => Topic started by: Twinfan on February 26, 2007, 10:34:35 AM
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I have a 50w Laney Klipp head and also a 100w version. Same model, similar age. I was doing some back-to-back comparisons yesterday and my 50w at 3/10 master volume is quite a bit louder than my 100w with exactly the same settings!
Both amps are working fine - no crackles/pops/hisses but the 100w is a lot more worn and has clearly been used more. Would this account for the volume difference i.e. the components in the 100w are "weaker"? Or are my power valves in the 100w on the verge of failing?
I'll have to get the 100w serviced to find out for sure I guess, but just wondered what the amp gurus on here thought?
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Maybe they use different pots (linear or audiotaper) for the volume.
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Ah - good point! I guess I need to try them cranked...
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i was going to say that wattage doesn't necessarily correlate to percieved volume, but since they're the exact same model (i.e. Klipps) i guess it should. Migh be worth checking the pots and the valves.
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Hi Twinfan,
Two points come immediately to mind, that seem to have already been hinted at.
1) wattage rating does not directly equal perceived output volume. I have a Fender 'The Twin' that can switch between 25w or 100w output. The actual difference in perceived volume sounds relatively modest, but the amount of clean headroom changes dramatically. On 25w, it still sounds almost as loud as the 100w option at most settings, but does not compress as early etc.
2) The output valves in your 100 watter may be starting to go "soft" with age. A set of 'spares' is always a good investment anyway.
Regards,
Derek. :D
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Cheers FF :D
The tubes in the 100w were relatively new (or so I was told by the seller) when I got the amp at the end of last year. They're EH EL34s.
The 50w has two unbranded EL34s in and the tone is loud and has quite a loose bass (which I don't like) so maybe it's just a difference between the valves that's causing the difference in volume and also tone.
The 100w is definitely not as loud but has a 'better' tone to my ears. I guess I'll not bother about it and use the 100w until something breaks.
Thanks guys!
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The slope on the volume pot vs power amp might be designed differently in the 100W vs the 50W version. Looser bass indicates less clean headroom. You would have to crank them both to max to confirm.
However, if the 100W sounds better and is loud enough, why even bother clarifying this issue?
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The difference in volume between 50w and 100w amps is not great and there are, as you have said, other factors at work here too.
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I personally find that valves make a huge difference to my amp.
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The 100w amp should be noticeably louder even accounting for the taper on the volume pots.
If the smoothing caps are the originals then it could be why the 100w amp is sounding weak. On an amp of that age, you really should get the smoothing caps replaced and a fresh set of valves in there to hear the amp at it's best.
:twisted:
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Cheers HTH :D
Smoothing caps are what, exactly??? The big blue things near the valves???
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Cheers HTH :D
Smoothing caps are what, exactly??? The big blue things near the valves???
yep, "the big things sticking up outside the amp chassis" is a good enough non-technical description for me :wink: :lol:
They run around £5 each depending on where you buy them and ideally need replacing every 10 years for optimum amp performance (although you will see 30 year old amps performing fine with their original caps - there are ALWAYS exceptions).
:twisted:
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Cheers matey - I'll bear that in mind when I next take it for a service.
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Well I've just bought another 100w Klipp that I pick up tomorrow, so it'll be interesting to see how the two compare...
:twisted:
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Amp power (watts) correlates to output (dBspl) in a logarithmic fashion, which is to say, twice the watts does not give twice the output.
A (relatively) simple equation can give us the difference in output level (in dB) for a given change in power (watts):
10 log(m/r)=dB
where "m" is measurement (new power rating in watts)
and "r" is reference (old power raing in watts)
and "dB" is the change in output level in decibels
Still with me? Let's put in some numbers and compare the output of a 50 watt amp with a 100 watt amp. So "r" will be 50 (watts) and "m"will be 100 (watts):
10 log(100/50)=3.01029995664
So a 100 watt amp feeding the same speaker as a 50 watt amp will only produce a signal that is 3dB louder. This is noticably louder but not a lot.
It's worth noting that a percieved doubling of volume equates to a change of about 10dB.
Lets try another, a 4 watt amp versus a 40 watt amp:
10 log(40/4)=10
So a 40 watt amp is 10dB louder than a 4 watt amp, which equates to a percieved doubling of volume, twice as loud.
So as a rule of thumb, doubling the power (watts) gives you 3dB more output volume (noticable but not great) and ten times the power (watts) gives you 10dB more output volume (twice as loud).
If you consider that every speaker has a specific sensitivity rating (how much output volume you get for a given wattage) then choice of speaker can also play a big role in overall loudness.
a 100 watt amp feeding a speaker rated 97dB @ 1w, 1m
- will be the same volume as -
a 50 watt amp feeding a speaker rated 100dB @ 1w, 1m
I hope that all made sense!
Leave a post if you want me to explain this better!
Cheers,
Spud
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Thanks Spud - but completely useless in explaining my case! I'm using the same cab and same amp model, just a 50w vs 100w. I think my current 100w needs a service as it's chucking out less power than 'Malcolms' DSL50 (as proven last night). Sounds beautiful and sweet though so I think I'll live with it until something breaks! :D
Looking forward to doing the back-to-backs with the two 100w heads tonight...
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Sorry,
Yeah I realise it's not really related to your problem, it's just something I found interesting when I learnt it at college. I was just trying to point out that the difference in level between 50w and 100w is not very large, which is something I think people don't generally expect. Differences in the speaker and valves etc. even if they're the same model, could easilly make up the 3dB difference you'd expect to find between the50 and 100w amps.
Cheers,
Spud.
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No probs Spud.
Well I tried the two 100w heads out and they sound pretty much the same volume - tone is a little different due to the different valves.
I think the 50w I have is a rogue freak...