Hi,
So I am interested in having a hi-fi valve amp, but don't know that much particularly about the subject, I do have a couple of guitar valve amps and definitely appreciate the difference in the warmth of the sound they put out.
From what I can see hi-fi valve amps are very expensive. I am not opposed to a kit if it was significantly cheaper, I have built guitar effects pedals in the past so have some electronics construction abilities. I have never touched surface mount though, only through hole components, and cannot design circuits, just copy diagrams.
I've noticed some hybrid amps available that describe the valves being used as input buffers, what does this actually mean? I assume it's not that the preamp stage is valve like with many hybrid guitar amps? Would an amp with valve input buffers and the rest solid state still have a much warmer sound than an all solid state device?
Can anyone suggest any reasonably priced but good sounding amps/kits? I've seen some Chinese made valve amps that are very competitively priced, are these good amps or to be avoided, or are there any brands, models that are particularly good?
Anyway thanks in anticipation of any help that anyone can give me.
Cheers
Owen
So I am interested in having a hi-fi valve amp, but don't know that much particularly about the subject, I do have a couple of guitar valve amps and definitely appreciate the difference in the warmth of the sound they put out.
From what I can see hi-fi valve amps are very expensive. I am not opposed to a kit if it was significantly cheaper, I have built guitar effects pedals in the past so have some electronics construction abilities. I have never touched surface mount though, only through hole components, and cannot design circuits, just copy diagrams.
I've noticed some hybrid amps available that describe the valves being used as input buffers, what does this actually mean? I assume it's not that the preamp stage is valve like with many hybrid guitar amps? Would an amp with valve input buffers and the rest solid state still have a much warmer sound than an all solid state device?
Can anyone suggest any reasonably priced but good sounding amps/kits? I've seen some Chinese made valve amps that are very competitively priced, are these good amps or to be avoided, or are there any brands, models that are particularly good?
Anyway thanks in anticipation of any help that anyone can give me.
Cheers
Owen
If i were You i would get some british tube stuff. Look for used quad pre and power amp, leak radford are some british made that could be reasonable.
Imported stuff could also be found , dynaco ( make sure it's unmolested!), fisher scott
The ones mentioned here has schematics ans most spares available.
Imported stuff could also be found , dynaco ( make sure it's unmolested!), fisher scott
The ones mentioned here has schematics ans most spares available.
UK valve amp kits:
https://classic-sounds.co.uk/
http://www.world-designs.co.uk/integrated amplifiers.htm
These UK kits are "reasonably priced" in the arena of valve amplification. Don't expect Chinese valve kits to compete on quality.
https://classic-sounds.co.uk/
http://www.world-designs.co.uk/integrated amplifiers.htm
These UK kits are "reasonably priced" in the arena of valve amplification. Don't expect Chinese valve kits to compete on quality.
What speakers do you have? You want to build something that has enough power. The cheap Chinese tube amps are marginal in quality. Some of them aren't too bad but they generally don't perform very well and often require heavy modification to sound decent.
At the moment I've got some Mission floorstanders not sure on model number as bought a fair while back. I'd noticed that a lot of the valve amps are low output, but is it a bit like with guitar amps, my 30w laney amp is more than loud enough to use for playing a small venue, whereas a 50w solid state amp seems to have less power?
For one thing, guitar amps have much more efficient speakers compared to most hifi speakers. So will play much louder with less power.
What are the specs for your existing SS amp that's driving the Mission speakers, and does it play loud enough?
jeff
What are the specs for your existing SS amp that's driving the Mission speakers, and does it play loud enough?
jeff
It's a Cambridge Audio A1 that must be about 20 odd years old, bought when I first started working at 21. It's old but has served me well, it was a budget amp in its day , 30w per channel at 8 ohms. It's more than loud enough for my living room I find to be honest.
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Guitar amps are designed for Hi-fi frequency range, often have under-sized output transformers to increase low frequency distortion and that adds 'warmth'. A hi-fi valve amp has to work to lower frequencies and given that half of the power for music is 300Hz and below you'll need a different approach.
I think 15W is more than enough for a home hi-fi amp for casual living room listening (Keep a 100W solid state power amp under the sofa for parties).
My suggestion is to look at a push-pull amp based on EL84 output tubes as they produce useable power at good cost (I am collecting parts to build a ~12W Leben CS-300 clone but it's not a warm sounding amp). My perception is that there are many good designs out there for such amps.
I don't build from kits and have no experience of them to offer you but it does take a fair bit of time and effort to collect all the parts you need and a kit will make that a faster process. Secondly, chassis work usually means metal-work where you'll need tools and skills. A kit should include a ready cut chassis.
https://www.diyaudio.com/community/threads/recommendations-for-pp-el84-circuits.376189/
If you like valve amps and have a good budget, a good place to buy a push-pull output transformer is Sowter. A good transformer gives a solid foundation for an amplifier. Given all the time and effort required to build an amp I would suggest buying a good one - assuming you have the money, Sowter U064 might be a candidate. If budget is limited, look at Hammond transformers instead (low cost 125 Series are actually pretty good and perform above published spec. if you over-size).
I have a little experience with hybrid amps and the only approach that I think works there is having a tube gain stage feeding an open loop (no feedback) solid state class A push-pull follower (costs driven by heatsinks, power transformers etc.).
I think 15W is more than enough for a home hi-fi amp for casual living room listening (Keep a 100W solid state power amp under the sofa for parties).
My suggestion is to look at a push-pull amp based on EL84 output tubes as they produce useable power at good cost (I am collecting parts to build a ~12W Leben CS-300 clone but it's not a warm sounding amp). My perception is that there are many good designs out there for such amps.
I don't build from kits and have no experience of them to offer you but it does take a fair bit of time and effort to collect all the parts you need and a kit will make that a faster process. Secondly, chassis work usually means metal-work where you'll need tools and skills. A kit should include a ready cut chassis.
https://www.diyaudio.com/community/threads/recommendations-for-pp-el84-circuits.376189/
If you like valve amps and have a good budget, a good place to buy a push-pull output transformer is Sowter. A good transformer gives a solid foundation for an amplifier. Given all the time and effort required to build an amp I would suggest buying a good one - assuming you have the money, Sowter U064 might be a candidate. If budget is limited, look at Hammond transformers instead (low cost 125 Series are actually pretty good and perform above published spec. if you over-size).
I have a little experience with hybrid amps and the only approach that I think works there is having a tube gain stage feeding an open loop (no feedback) solid state class A push-pull follower (costs driven by heatsinks, power transformers etc.).
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Getting a cheap Chinese amp is still a good way of building you own. As it comes from the factory it will almost certainly be rubbish, but you get the enclosurse, iron and valves already mounted, so the hard work done for you. Strip out the circuit and rebuild a better one of your own inside, which won't be rubbish.
The above is true-
To avoid a large investment starting point, the chassis hardware starting point is paramount w/ a Chinese kit.
There are so, so many options hence forth to satisfy your curiosity as 'next level' by changing designs within that box.
At the High level- Cost no deterrent designs in current audiophile mags lay out that hybrids use tubes as drivers into SS output schema's...
Thats where the current market is- perhaps your intuition is already ahead
Jim
To avoid a large investment starting point, the chassis hardware starting point is paramount w/ a Chinese kit.
There are so, so many options hence forth to satisfy your curiosity as 'next level' by changing designs within that box.
At the High level- Cost no deterrent designs in current audiophile mags lay out that hybrids use tubes as drivers into SS output schema's...
Thats where the current market is- perhaps your intuition is already ahead
Jim
It means they are running a couple of tubes as cathode followers. This is just about the easiest way to insert a tube into a solid-state circuit without creating biasing/ageing/mismatching issues, and still be able to say the signal is "passing through the tubes". It's kind of a low-effort way to build a hybrid circuit, you're not really using the tubes for anything very useful or adding much 'tubey warmness', but most customers won't realise.
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The real benefit of a Chinese kit is that you have a working amp from the day it arrives and you can use it as-is. This allows you to enjoy listening to a tube amp and learning what they sound like and what is good and not good about a particular amp to your ears. You may find it sounds good enough to use until you are ready to build your own from scratch. It also avoids one of the major pitfalls in this hobby for ME which is losing interest in a project that takes too long to complete before it's ready to play.
If I were to buy a Chinese valve amp today I'd be asking myself if the output transformers were really that good and replacing them would mean spending money and then hacking into the chassis to accommodate different mounting holes. Then I'd want to replace all the valves. There are many other considerations that I might have (ground loop control, r.f. filters, fake parts) and in the end I'd likely conclude it's more trouble than its worth to modify it.