300B Tube Amps with 15/16 Watts Per Channel?

@vthokie83 Interesting.  If you do get the chance then please post your impressions!

@debjit_g  There is an old customer of mine who has a prototype pair of the design used for the Blackbird amps that Spatial audio is producing.  PP300b and they produce about 24 watts/ch.   He has one of the Cube speakers as I recall and the amps drive them with ease.  So I am sure a well designed and preferably fully balanced PP 300b would have no problem.  

@dietrdeb 

I wasn't really suggesting you buy the Blackbirds, just that if you do the 300b route I really think PP is best IMHO.  My system is fully balanced from Pacific 2 through to the amp speaker terminals.  It is so quiet that I cannot even tell it is on when idling away.  So I like balanced with transformer coupling, but we all have our taste and needs.   

@vthokie83 Yes, the Blackbirds measure out at about 24 wpc. I know Aric and he builds seriously good tube gear. He is a master craftsman. That said, I wish you could hear the Blackbirds with the matching Raven preamp:) It would be a different experience and I would be very interested in your take on the comparison...

@vthokie83 Just curious.  What speakers is your friend driving with the Blackbird 300b amps?  Just another data point!

Or you can simply use speakers that will run happily on 10 watts and build a very simple (well not that simple actually if you consider power supplies and transformers, etc..)  push pull amp with no feedback that is flat from 20-20K with very low distortion to drive them and be happy:)  Using  DHTs...  to each their own.  The problem lies in supporting people that need more than 20-25 watts/ch.  If they have made that speaker choice so be it.   We all have our paths to audio nirvana....

We all have different views as manufacturers and that is as it should be.  I don't give detailed advice because some of my views will clash with others and that is not what I really want to do on a public forum.  I will say from years of experience, that in general, the larger the plate on the tube, the better it sounds to ME, but that is not everyone's view.  I will also say, that if you know what you are doing, directly heated tubes are the way to go, but there are problems to solve and therefore they are not for everyone.  I will also say that I prefer amps with zero feedback, but @atmasphere and I will diverge there, and that is just fine.  I respect his opinion for what he builds.  I do agree with him that the 6DJ8 family isn't all that good sounding a tube.  Neither is the 12au7 and I never understood why people used them.  But we all have our taste.  I would still take a well designed push pull amp over a single ended one every day of the week, but again, that is my opinion and take it or leave it.  I also favor completely regulated supplies, but others differ in opinion.  

I am sure if you buy an amplifier you can modify it to improve it, unless you are buying a very expensive and well designed amp that someone has put a lot of time and effort into.  One that was designed without the usual budgetary constraints.  As a modifier of more cost effective gear you can certainly remove some of those constraints.   If there are coupling caps then those are generally modified for personal taste.  There are certainly things  you can do to power supplies on cheaper gear to improve them, but it depends on whether there is room.  Often just bypassing a power supply electrolytic cap with a small film cap of sufficient voltage rating can make a subtle improvement for a few dollars.  We used to do all sorts of things to improve vintage gear when rebuilding it.

I read something years ago that stuck with my and I have always tried to heed.  A really good tube amp is the sum of three things.  How good is the circuit, how good is the power supply, and how good is the iron (transformers).  Those who favour OTL designs can ignore the iron.  Of course there are other factors at play such as how much distortion there is in the tubes chosen, but if you use decent tubes and pay serious attention to the main three points, you should end up with a very nice amplifier.

I rebuilt hundreds upon hundreds of vintage tube amps and preamps before I started making my own.  You could tell the good ones before you even started.  If there were serious compromises in power supplies or transformers, then no amount of replacing old parts with better modern ones would ever make them great amps.  You could tell the great amps from the schematic and quality of parts used.

So my advice is the build the best power supply you can, use the best iron you can, and find a good circuit.  I exclusively build push pull amps.  I don't build single ended or parallel single ended circuits.  I understand there are those who favour such designs.  I only use regulated supplies, and I also only use tubes with larger plates, and as many directly heated tubes as I can.  Those are my choices based on the main rules above, and moving beyond the "conventional" designs I built for years.  The conventional amps I built are very nice, but the latest full balanced circuits are far superior to my ear, and more costly to build.

So my advice on a good 15-20 watt 300b or other amp, is to heed the three main rules, and build a good push pull one.  If you can DIY you will save lots of money.  There are many great parts from companies like Neurochrome, the Rod Coleman regulators favoured by a pretty large camp, read Barola valves site for some great info...particularly on drivers.  There are lots of places you can check out for a DIY 300b project.

Hit post too soon..  Great iron, not just good iron.  The kind of transformers that give you goosebumps if used in the right circuit.   If you use a Hammond, you will never hear what the circuit can do....

@atmasphere I agree on the vintage amp transformers.  The citation II amps were legendary and would be flat down to about 8 or 9 Hz at full power.  The Sherwoods were generally pretty good as well as the Scotts and Fishers.  The Eico stuff can vary.  They were definitely built to a price point.   The best little EL84 amp I ever heard was the Sherwood.  If 10-12 watts/ch was enough, the little Sherwood integrated amp was quite enjoyable to listen to.  The Macs and Marantz amps also had very good iron.   The little Eicos, Heathkit, and others of that ilk were all over the map for quality of iron.  Honestly there are fabulous transformers wound today if you want to work with a winder and spend the money.  If you buy an off shelf Hammond, or Edcor or whatever you can certainly build a decent amp, but you will not the get the inner detail you will from a more expensive transformer.   You get what you pay for.   That is why Chinese amps for $1500-2000 are decent, but not great.  Good iron is over $1000 for a stereo amp....

I used to fix guitar amps for musician friends.  They are pretty simple.... (the amps, not the guitarists!)...  except Marshalls, which have many small pcbs and jumpers and inevitably it would be a failed bias pot on the board buried the deepest in the amp.  A 3 minute repair that took an hour to get to.   The thing was, I could always improve the amps, but they wouldn't want you to.  They WANT distortion.   So you just replace all the bad lytic caps, and make sure the operating points are where they should be, and put k40 oil caps in where old oil caps have failed, etc..  You can get away with making the power supply a bit stiffer, but that is it.  Otherwise the amp is too "clean" for a lot of guys....   So yeah, a Hammond is just fine for a guitar amp....