Valves, I think I'm starting to understand what the fuss is about.

[HighFidelityGuy]

Yesterday I took delivery of a WD KEL84 amp which I purchased off Martin (smurfbrain). Up until now I've never used a valve amp in my system other than a Chinese valve preamp which was a bit crap. I've heard some very nice valve amps in other systems and liked what I heard, so I decided the KEL84 seemed like a inexpensive but well respected amp to try out.

I wasn't really sure what to expect from the KEL84 in my system as my speakers are fairly difficult to drive and I listed to a lot of powerful, dynamic music. So in switching between my 550W solid state monoblocks to a tiny 15W valve amp I was at least expecting to have less bass punch and extension and less dynamics. I was quite wrong. In some ways the KEL84 seems to provide more punch and just as much bass extension. It does perhaps lack the level of dynamics that my monoblocks are capable of but there's not a huge difference if I'm honest.

I was half expecting the valves to improve the midrange over my monoblocks seen as this is one area that valve are supposed to excel. The KEL84 definitely provided a different tonal balance in the midrange, with male voices seeming more detailed and emotive. Stereo imaging in this department was also improved. There is however a little more warmth in the lower midrange which I'm not sure whether I like. This warmth reminds me of difference between my Alps Blue Velvet based passive attenuator and my LDR based attenuator. As I plan to use the KEL84 with my LDR attenuator I think that removing the volume control and input selector from the KEL84 will yield some improvements in the midrange.

As I hear a lot of people saying that valve amps sound less bright/harsh that solid state amps I was expecting the KEL84 to be more subdued in the treble department. This doesn't seem to be the case but the treble does seem to be slightly more airy and possibly less fatiguing, although I didn't really find my solid state amps fatiguing. The only negative in this area seems to be that the timing seems a little off on some fast sparkly cymbal passages. I have one track where every hi-hat tish constantly swaps from left to right on every hit. This channel swapping is very obvious with my monoblocks whereas the KEL84 seems to smear the effect. This is probably another area that will improve once the amp is converted to a power amp. If not I guess some better valves may help.

So in summary, I've found the KEL84 to be a very capable amp which can hold it's own against a pair of solid state monoblocks which are technically worth over three times as much based on rrp. While I've found the KEL84 to be slightly lacking in a couple of areas I feel this can be improved on with some very simple tweaks. The main eye opener for me has been that I do seem to be able to drive my speakers off a low powered valve amp with surprisingly good results, with the big surprise being that I actually seem to be getting a better bass sound which is completely opposite to what I expected.

So my first proper valve experience has been a good one and it's given me a taste of what valves have to offer. I like what I'm hearing and I want more. I think I might be a valve convert. Now look what you've gone and done.

Thanks again to Martin for packing the amp up so well.

[Ali Tait]

Yes, the KEL is a great little amp and a real giant killer. Has yours been modded?

[tubehunter]

Just a little

[John]

Welcome to the world of valves. A lot of us really like them

[HighFidelityGuy]

Yes, the KEL is a great little amp and a real giant killer. Has yours been modded?

I was going to say "I don't think so as Martin didn't mention it". However it seems Duncan (who built it) knows otherwise.

Just a little

Hi Duncan. Would you be able to list the mods you did please?

Welcome to the world of valves. A lot of us really like them

Cheers John. I think I'm starting to like them too. I need to do some better A/B testing between this amp and my solid state's. I think I'll get one of Stan's speaker switch boxes so I can do faster switching. That should then give me a more accurate idea of the areas where they differ. I can then find out if any extra mods or valve upgrades would be worthwhile. It should be an interesting project.

[SPS]

the kel84 is not a bad amp, most el84 based amps have that sound, its quite similar to the leak stereo 20 in many ways.. very nice

my view... is the valve amp is will be letting more of the finer detail through.

and in my view, that results in more of the harmonics being heard.. that tends to sweeten the sound and make it more musical, and can give more a room filling sound stage. What can sound like better seperation with the SS amp, could be due to the higher harmonics being missed, when they should bring the sounds together more.
in saying that, in most cases there should still be pinpoint seperation of all the sounds within the music, and a sense of space and air,

That in turn can change what you hear and how it sounds,
my 1st valve amp was a single ended el84 amp driving yam ns1000's

I quickly sold a 3 months old quite expensive SS pre/ power amp. and a few months later changed to higher effeciency speakers.

back then i used a swich box to change over the amps and speakers.. when i though 'that not right' i swapped the amp over.. the valve's won every time

Many modern solid state amps tend have a slight grey/ grainy sound , after that the valve amp tends to sound like there's something missing at first... until you get used to it.
When you do get used to it, I hard to believe why any one would want a SS amp.... but the strange thing is when one lives with it, its not heard. ...I've been there !

This point was demonstrated to mark grant the other week when he brought some kit round. your not too far away from me.. your very welcome to do the same.

its a slipery slope... and everyone has different tastes.
best of luck with it..

[anthonyTD]

hi Dave,
mono block amps whether valve or solid state will almost always give a better definition on right and left source recorded information than a stereo unit that shares the same power supply and chassis etc, other than that i think from what you have desribed, you have had a positive and pleasant surprise with your first adventure into Valve power amps.
Anthony,TD...

[Clive]

Hi Dave,

Our individual sensitivities help us define our views of the sounds and equipment we like or dislike. I'm unfortunately someone who greatly dislikes unnatural or over-emphasised sibilance. I find a great many solidstate amps are harsh in reproducing sibilance. There are other reasons for my liking valve amps but this harshness issue is a big reason for why I don't get on with many solidstate amps, I can hear the effect as soon as I enter a room with music playing. Of course you can get it wrong with valve amps too but that's harder to do.

[HighFidelityGuy]

my view... is the valve amp is will be letting more of the finer detail through.

and in my view, that results in more of the harmonics being heard.. that tends to sweeten the sound and make it more musical, and can give more a room filling sound stage. What can sound like better seperation with the SS amp, could be due to the higher harmonics being missed, when they should bring the sounds together more.
in saying that, in most cases there should still be pinpoint seperation of all the sounds within the music, and a sense of space and air,

I think you might be right about harmonics etc. I definitely got a sence that the harmonic content was different but I couldn't put my finger on the exact difference. I think I'll be able to tell better once I get the switch box and can switch between the amps quicker. I've heard that the harmonics that valve amps produce are mure musical sounding and more pleasing to the ear. So I guess to a certain extent I need to get used to this difference but at the same time I do like the sound I get from my solid-state's. I think I just need to pin down the differences and then decided which areas of each I prefer. I can then attempt to get the best of both through tweaking..

hi Dave,
mono block amps whether valve or solid state will almost always give a better definition on right and left source recorded information than a stereo unit that shares the same power supply and chassis etc, other than that i think from what you have desribed, you have had a positive and pleasant surprise with your first adventure into Valve power amps.
Anthony,TD...

I did suspect that. I do really like the extra channel seperation that monoblocks bring. I'm hoping that some tweaking will improve this area. It may not actual be a big issue, I've so far only noticed the smearing on one dubstep track that I only use for testing bass and chanel seperation. I don't have much music that will really highlight the weakness. So some extra chanel seperation and a wider stereo image would just be a bonus. I've seen some E80CF valves that are supposed to excel in this area, so I might try a pair of them. It's also another area where I think the power amp conversion may help as I think this will reduce crosstalk.

It's definitely been a pleasent supprise so far. I was expecting to have more issues that couldn't be solved without buying new speakers. That would have been a deal breaker as I love my speakers and I can't afford a bigger valve amp yet. Luckily it seems that the weak areas should be relatively easy and inexpensive to improve. So I'm felling quite positive about the whole thing.

Hi Dave,

Our individual sensitivities help us define our views of the sounds and equipment we like or dislike. I'm unfortunately someone who greatly dislikes unnatural or over-emphasised sibilance. I find a great many solidstate amps are harsh in reproducing sibilance. There are other reasons for my liking valve amps but this harshness issue is a big reason for why I don't get on with many solidstate amps, I can hear the effect as soon as I enter a room with music playing. Of course you can get it wrong with valve amps too but that's harder to do.

I know what you mean. I also dislike sibilance (although I suspect you are more sensitive to this than me), it gives me a headache. As does nasally or quacky sounding upper midrange and/or harsh treble. I've usually found speakers are to blame for this. Some PA speakers are intolerable in this respect. I guess solid state amps will emphasise this further.

My speakers have a seperate soft dome midrange driver that covers almost the entire vocal range and I find this helps as there's no crossover distortion in that important frequency band. Speakers with a crossover point around 3KHz tend to fall down in this area. That's not something your Bastanis will suffer from though.

[Clive]

I know what you mean. I also dislike sibilance (although I suspect you are more sensitive to this than me), it gives me a headache. As does nasally or quacky sounding upper midrange and/or harsh treble. I've usually found speakers are to blame for this. Some PA speakers are intolerable in this respect. I guess solid state amps will emphasise this further.

My speakers have a seperate soft dome midrange driver that covers almost the entire vocal range and I find this helps as there's no crossover distortion in that important frequency band. Speakers with a crossover point around 3KHz tend to fall down in this area. That's not something your Bastanis will suffer from though.

There are all sorts of ways of masking the effect, finding the source of it is important as masking isn't the best way. For sure it can be speakers, it's very often also CD players too - actually usually these are the worst culprits. As you say the Bastanis get around the xover are problem very well.

Sibilance annoys me the most when it invades the entire soundstage because it's totally over-blown. I don't get a headache but I do stop listening to music - which is probably why I don't get a headache!