valve 'v' solid state power amps

[darron027]

Hi All!

My current system is listed in the sig below. I am happy with the overall performance. Im getting more and more into 2 channel music again. I do not have the option to have 2 separate systems. I am going to be looking into a number of ways to further enhance the 2 channel performance of the system.
After inital investigations Ive been informed by a number of pro sources that I should firstly look at the amp side of things.
Im going to start investigating a number of different power amp combinations with the view of improving 2 channel (CD/FM) playback without compromising the 5.1 AV side of things.

To get the ball rolling my first questions are:
What are the main pro's & cons with the hardware for either valve amplification or solid state amplification?
Secondly (although I understand this can be VERY subjective) what are the main 'sound' differences you would expect to find between the two types of amp?

Cheers,
Darron

 

[Cable Monkey]

Valves have not moved on. Many designs in use today are 30/40/50/60 years old. Unfortunately speaker design has moved on and the business of choosing speakers that will work well with your valves is an ongoing issue. With regards to sound, that is a non issue to me. SS can be made to sound valvy, valves can be every bit as clinical and analytical as SS.

 

[darron027]

I guess what your saying is that the majority of 'speakers' have moved on with time and matching a suitable valve amp to speaker setup is more difficult than adding a SS amp?

 

[alexs2]

I guess what your saying is that the majority of 'speakers' have moved on with time and matching a suitable valve amp to speaker setup is more difficult than adding a SS amp?

Speaker design has certainly moved on,and to a degree so has the design and implementation of many tubed designs,but S/s has progressed more as you would expect.

However,as CableMonkey has rightly said,it is very easy to make either type sound quite like the other,and whilst matching speakers to amplifiers is very important when considering a single ended triode amp,it is not critical with most others which are usually push-pull designs,and often tubed amps are a lot more stable into difficult loads,especially electrostatics.

One of the major factors has been that of power,with a lot of valve amps being quite low powered,but finding valve amps with 50W or a lot more is getting easier,and some of the most powerful amps around currently(costly as well of course) are tubed designs from VTL and Audio Research.

The other governing factor in tube amp design is that of the output transformers,as cost cutting here equates to poor performance,and there is a lot of truth in the saying that there is little substitute for weight,as this relates to the amount of iron in the transformers.....my little 11W 300B amp weighs in at over 25kgs,most of which is transformer.

The current chinese valve amps represent generally good value and construction,and there is little to compete in the sub£2k market currently.

 

[Mr_Sukebe]

A few thoughts:
- You've focused on purely the power amp side of things. My personal experiece with amps over the years has been that a lot of the real gains in SQ have been in the pre-amp area, with the power amp really adding control and adding headroom. Bit of a generalisation, but hopefully you get my gist. In short, if you look at a stereo amp, at least checkout the pre-amp side of it whilst you're at it. Based on your rig, it's clearly not rubbish, so you'll be looking at a reasonable level to get a serious improvement.
- As already mentioned, there's massive variance in valve amps (probably more so) than there is with SS amps. Some of the best amps I've ever heard were valve...but then also some of the worst. So trying to characterise them as all being better is just not the case, you need to have a listen.
- From having a quick google, I see that your Sonus are not exactly the least demanding speaker of all time. Chances are they need something with some serious grunt to sound good, that would seriously limit your valve amp choices (no 300b option or similar).
- Synergy really is so important between a speaker and amp. As mentioned, your speakers look quite demanding, meaning you'd need a pretty ballsy valve amp, thus pushing up the costs, complexity and thus influencing the reliability and long term running costs.

My personal view is that you should go have a listen to some valve based systems at places like Definitive audio, preferably taking your speakers with you. I'm guessing that you'd find valves working better with more efficient speakers, which is probably not what you want to hear.
If you intend to keep your speakers, then considering a better SS amp would be worth looking at. Sugden make class A SS amps, but again I really don't think that it's the correct route as the Sugdens are also notoriously lacking in outright grunt.
You then need to think about what you're finding missing with what you have right now. MF might be worth a look, and also some of the class D options. The better class D amps have a lot of the smoothness/clean sound of valves with power to spare.

 

[Mad Mr H]

Hardware pro & cons

Valve amps seem to have more cons than solid state (SS), In my mind

• Large heat generated
• Sensitive Microphonic valves
• Many of todays valve amps are cheap China items sold for high value over here
• Second hand amps usually require valve replacement
• not child friendly

SS cons

• not sure of any

It is often mentioned how sweet the vocals sound from valve amps.

If I had valve amps again they would need to be on wall mounted shelves on a solid wall - not stud, OR best solution in another room. Valves are microphonic and NOT just when they are dead so best NOT to have them in the same room.

Now please don't think I'm anti valve amps I am not, its true I sold ALL my valve amps a few years ago, but I would consider them again I just think the maintenance is too high for me to enjoy them.

 

[Mad Mr H]

Often tubed amps are a lot more stable into difficult loads,especially electrostatics.

Excellent point , I used to have Quad ESL 63's

One of the major factors has been that of power,with a lot of valve amps being quite low powered,but finding valve amps with 50W or a lot more is getting easier,and some of the most powerful amps around currently(costly as well of course) are tubed designs from VTL and Audio Research.

My thoughts differ slightly here - I would prefer to buy an old valve amp with low power and run it with my Tannoy speakers. The issue I have is that with ago these amps (say Quad II's) will really need work to get back to factory spec and although "original KT88" valves are often available I believe that these are often past their life span.
I dont think that a high power valve amo built today will be as well built as an old low power - but the old ones have age issues I do actually want to try valves again.

The other governing factor in tube amp design is that of the output transformers,as cost cutting here equates to poor performance,and there is a lot of truth in the saying that there is little substitute for weight,as this relates to the amount of iron in the transformers.....my little 11W 300B amp weighs in at over 25kgs,most of which is transformer.

I agree the weight will be in the transformers a good amp will have up to five transformers - its the copper in the transformer that hold the high value, and the weight these days means high transportation costs.

The current chinese valve amps represent generally good value and construction,and there is little to compete in the sub£2k market currently.

I hate those, Sorry the likes of Music Angel, and other ebay amps are cheap builds sold at high prices in many hi fi stores - That I feel a con.

Its true to say that there are only a few valve amp designs and so by now people should be able to produce them well, as always it comes down to cost vs quality if the item is being sold at its true retail value and not some very over priced shop tag just because "its a valve amp" from some unknown brand.

Of course i've just been rather general in my statement but thats my general feeling.

I would say that I do still want to go back and try valves again, when I do I think it will be in the 15-40 watt area of maybe an old design - I am constantly teased with Quad II amps - I have not brought myself round to calling Quad to see if they would fully service a pair and at what rough cost. That might be too much tempting for me .

 

[Mad Mr H]

My personal view is that you should go have a listen to some valve based systems at places like Definitive audio, preferably taking your speakers with you.

If its possible I would get the amps brought to you .

 

[alexs2]

My thoughts differ slightly here - I would prefer to buy an old valve amp with low power and run it with my Tannoy speakers. The issue I have is that with ago these amps (say Quad II's) will really need work to get back to factory spec and although "original KT88" valves are often available I believe that these are often past their life span.
I dont think that a high power valve amo built today will be as well built as an old low power - but the old ones have age issues I do actually want to try valves again.

Have you looked at,heard or tried a few modern high powered tube amps such as from Audio Research or VTL....I think you'd be surprised.

I hate those, Sorry the likes of Music Angel, and other ebay amps are cheap builds sold at high prices in many hi fi stores - That I feel a con.

Its true to say that there are only a few valve amp designs and so by now people should be able to produce them well, as always it comes down to cost vs quality if the item is being sold at its true retail value and not some very over priced shop tag just because "its a valve amp" from some unknown brand.

Of course i've just been rather general in my statement but thats my general feeling.

I would say that I do still want to go back and try valves again, when I do I think it will be in the 15-40 watt area of maybe an old design - I am constantly teased with Quad II amps - I have not brought myself round to calling Quad to see if they would fully service a pair and at what rough cost. That might be too much tempting for me .

Quad do still service them,and at reasonable prices....I have a set of these.

Just don't buy a restored pair that hasnt been restored to original status,there are plenty of nasty ones around.

It's the KT66 you would need for the Quad II,and NOS KT66's are still available,but the Golden Dragon KT66 replica,is actually very close sonically and at a fraction of the price.

As to the chinese amps...love them or hate them,they are here,and some are actually pretty good but as with everything cheap,you do have to choose carefully.

 

[karkus30]

FWIW........I have heard good valve amps and good transistor amps. Generally valves are more expensive and can be problematic.... Years ago, it was easy to pick a valve amp over the newer Transistor designs because of the generally poor design of the transistors. Transistors were generally used as a switch and were made to work in an amplifier circuit, where valves had been used for a long time in audio and transmission amplifiers.

These days transistor design and implementation is fantastic, its also virtually problem free and far cheaper than the equivalent valve amp. They can also have far greater headroom so will drive virtually any speaker load for a budget price.

Valves look classy and have nicer distortion at high levels, hence there use in guitar amplifiers. When it comes down to creating high power, robust and economic amplification that equals and in many cases surpasses valves it is hard to argue with transistors.

A nice option is to try a valve preamp and a solid state power. The character of the valves is pretty clear. A Copland CTA 405 is an integrated doing just that.

 

[darron027]

Hi All,
Wow - so many very helpful and very informative information.
A Big thanks guys for all this invaluble info. GREATLY appreciated.
Its given me a lot of food for thought.

Ive read through all the above posts a couple of times to try and take it all in at his early hour in the day.

I will be booking a mass of demos sometime in the next few weeks ahead. I havn't ruled out valve amplification however at this time I'm leaning towards the more 'trouble-free' SS amps. Obviously I will still be demoing both types but at this early stage SS has more ticks in the box than valves.
At a 'best guestimate' my budget next month for this area of upgrade will be £3-4K.

The long-term project of my system is to further improve the 2 channel performance from its current state (which is already pretty good; but you know what its like we all tend to think it can be even better.....)

My current 'sound' improvement project is to the actual room itself. Ive trialed and ordered a number of room acoustic treatment products (bass traps / reflection point wall panels). These will hopefully begin to arrive next week. I'm doing this in two stages and this initial order is the first stage to get me going. Stage two which involves a further large wall panel and 'something' to stand in front of a large patio door is currently under investigation. Once all these are in place I will reavaluate the current sound quality of the system.

Tricky question here for my future 2 channel pre-pro investigations (so I hope I explain it well guys):
As per the sig below, I'm feeding my pair of sonus faber speakers from the AV9+P7 combo for both 2 and multichannel. I can not add any more speakers.
If I also had a seperate designated 2 channel pre-pro combo system (valve or SS). How could I set up the system so that I could feed the pair of SF speakers either a signal from the AV9 or a signal from a designated 2 channel processor without having to swop over cables each time? Hope that makes sense.

Thanks,
Darron

 

[Mark.Yudkin]

You've mentioned room treatment, which is probably where the greatest improvement is to be found.

To be honest, I don't think you're going to get very far from where you are on the equipment side. The AV9 + P7 is a great combination for stereo (I couldn't fit the P7 due to its depth). I also rather doubt that your Sonus Faber are going to like valves. A pair (or quadruple) of P1's may well be the best power upgrade.

OTOH, you seem to be using your DV139 as a CD source and I rather suspect that the CD37 would make a much better upgrade for 2 channel than anything you'll achieve with amplification.

Your P7 is a THX Ultra 2 amp; it has a fixed 29dB gain. You would need a power amp with 29dB gain, this is rather uncommon with stereo amps. (You can probably balance using the AV9 though).

I was very impressed with a pair of Quad II 40s driving a pair of ESL 2805's, but didn't really accept the concept of a set of valve monoblocks in my lounge.

 

[darron027]

Hi Mark,
thanks for the reply.

Yep - Im hoping the room treatment will be a good upgrade. Will take me about another 4 weeks to complete.

Havnt tried the CD37 yet but did try the CD36 on home loan on a number of occasions, but at the time I could tell almost zero difference between the 139 and 36. Maybe the new 37 will be much better.

I do agree that the AV9 and P7 are excellent (thats why I bought them). Wishing to keep my options open for future/further improvements.

Having spoke to a number of audio pro's/engineers (not dealers) all had said that if I wanted to 'further' improve two channel quality I should next look at the power side and not the source side.

 

[Mr_Sukebe]

If you were to add in a dedicated stereo integrated or pre-power combo, then you could do the following:

Music: CD > New stereo amp > speakers (SFs)
AV: DVD player > AV9 > (pre-outs) > New stereo amp > front stereo speakers

That would prevent a requirement to fiddle with wires, but would mean that you'd be using a different power amp to what you're presently driving the SFs with. It might not matter, but could result in a mismatch of sound presentation on 5.1.


I'm guessing that different people will give different advice on how well the AV9 performs with music against a dedicated stereo unit. Frankly I'd suggest you ignore all comments either on here or from others and go prove it to yourself with a dem. If possible, borrow some good stereo units for a home dem and compare with your AV9 combo.

 

[darron027]

Thanks for the above further info, especially regarding the way to cable up.
Further to your welcomed info; are there 2 channel power amps that have 2xpairs of inputs? Reason for asking this is that it would be nice to have just the one processor to control 'all' the amps volume for mulitchannel and one processor for 2 channel.
If Ive made the correct assumption here although I think I'm just getting 'my knickers in a twist', what Im trying to say (and probably not very well), is that if the 2 channel system side of things had its own processor/volume and also the multichannel (AV9) processor had its own volume control; when using the pair of SF speakers in souround mode could this cause balancing the correct volume issues. OR which I think is probably more correct, the 2 channel power amp should have more than one pair of inputs so that one pair can be plugged into the AV9 and the other pair can be plugged into a 2channel pre-amp?
Thus I guess that the separate pre-pro would be better than an integrated unit for these reasons?
Sorry for mummbling guys having a mentally challenging day at work today....

If I did decide to go for a new 2 channel amp (pre-pro/integrated). I would more than likely look to also swap out the P7 (as I would only be using 3 of its 7 channels) and add a further 3 channel amp for center and surrounds (to best match the stereo amp & speakers)

Again I agree that demos are an absolute must. I plan to start this at the dealers and then get a shortlist for home demo. If I can not get the home demo I will not buy as Ive always noticed differences in demo room and home environments.

Once again many thanks.
Darron

 

[Mr_Sukebe]

I'm not familiar with power amps with multiple inputs, but I would be surprised if none existed. What you might be able to find is a power amp that accepted say both RCA/phono and balanced connections, giving you the option of switching between the two if your dedicated stereo pre-amp had balanced outputs.

Having said all of that, there is a fairly easy work around for AV. Many of the newer pre-amps and integrateds have "unity gain" or similar bypass facility on one of their inputs, which bypasses the volume control, meaning that your AV9 would be the only element controlling volume. Failing that, simply select an obvious sensible(ish) volume on even a non-unity gain pre-amp that you can easily switch to on a consistent basis and you avoid the issue.
For example, my integrated amp has a default volume setting for individual channels, so when I switch the input to AV, it'll be at a preset volume, making it very easy to integrate with my AV amp.