300B's vs. 2A3's

Paul Williams · 25-09-2005, 10:59 PM

300B vs. 2A3’s

OK as I’m hopelessly addicted to valves/tubes, now I’m looking at SE kits – fancy something a bit different, get some fun and experience with the soldering iron. As you can see from the title I’m thinking about these 2 classic output tubes, but I’ve never heard either. Being a kit amp I’m probably going to have to buy blind, but an initial trawl through cyberspace has elicited the following.

300B’s have a top-to-bottom consistency which can be unrivalled, provide an expansive sound-stage/depth; however, they can be considered a bit to the clinical side of the centre.
2A3’s have a (the best?) mid-band of any tube, but are uneven at the extremes, are (much) more to the musical/emotional side of the centre and lack the generous sound-stage.

Now, the above are of course dependent on the tube implementation (and the tube manufacturer) and are relative to no specific benchmark other than these seem to be the statements that are commonly floating around the ether, when both are compared together. Does anyone have experience of both of these tubes and what are your thoughts?

Why this type of kit? Well to be honest, they look simpler to build, and are less mainstream. I know whichever type of tube I settle on will produce minimal output (1 tube per channel) but that’s OK, I’m also thinking about trying out some full range single cone horns.

Like everything I do, I tend to take my time before I finally settle on a course of action, so I don’t expect to be placing and order for many months, so if anyone can point me in the direction of an interesting kit at about the £500 mark, please post the link.

Paul

**alexs2** · 26-09-2005, 6:12 AM

Hi....I'm sure you know what sort of output you're looking at...2-3W/channle from 2A3s and up to 9W/channel from 300B's,both run as SETs.

The various tubes do vary by quite an maount acroos the price range,and the TJ meshplate 2A3s and 300Bs seem to be the best price performance compromise currently,although this link may help you to decide.

http://www.enjoythemusic.com/magazin...ent/1201/300b/

There are a few other very useful bits of info on that site as well.

As to which kit....most will come in a bit above £500,although the Bottlehead amps from the US may just about fit in,as will the cheapest WAD 300B which comes in at £550 minus tubes.

I doubt that you'd be displeased with either tube in terms of midband,treble or overall sound,although SETs can be very speaker sensitive,so your choice of horns may be best overall with respect to efficiency and load matching.
Given that you're building kits,you also have the flexibility to build a relatively basic one now to save on costs,and upgrade things like the coupling caps,and internal wiring later as funds allow.
Upgrading the caps on mine made a huge difference to what was already a good set of 300b amps.

You could take a look at

http://www.worldaudiodesign.com/wadproducts/kit300.html

http://www.hificollective.co.uk/kits/300bseprice.html

http://www.bottlehead.com/et/adobesp...r/paramour.htm

The Bottleheads have unusual names etc but are well regarded.

Mine are a set of WAD 300B P/P amps and go very well with Quad ESLs,which is why I settled on PP rather than SET configurations.

The Audionote kits are OK,but perhaps a bit high in price,and a bit lower on finish and help,whereas the Glasshouse and WAD kits,being UK based,have very good backup,especially WAD,which offer a build and repair service.

Anything else....please ask

Paul Williams · 26-09-2005, 8:32 AM

Quote:

Originally Posted by alexs2

Hi....I'm sure you know what sort of output you're looking at...2-3W/channel from 2A3s and up to 9W/channel from 300B's,both run as SETs.

Hi alexs2

Between 2 to 9W/channel seems fine and I suspect even with my current 89db/w speaker I use at present will work OK initially. Used to have 100w mono-block and 80db/w speakers and could never use their potential, now have a 35w amp with the current speakers and 10 o'clock on the volume control is too loud for my 18' x 11' room.

At present the kit that is in top place is the Bottlehead Paramour. I recon these should come in at just under the £500 mark even with import duties. I like its non-traditional (Hi-Fi) looks and the flexibility for various finishing options and could always add a second pair for bi-amping the speakers. I did consider one of the cheaper WAD kits but really want to try something totally different from my current 6L6 PP amp and the Paramour is certainly that!

Paul

dynamic turtle · 26-09-2005, 10:07 AM

Hey Paul,

Long time no speak

Getting bored with the Romulus and fancy a change then? 300B's is it? If you're on a tight budget, China is the place to look. Whilst I cannot vouch for the sonic & build quality of these amps, on the face of it, they are catastophically cheap for what they offer. I'm very tempted to purchase the Consonance M100S myself (300B integrated, push-pull), or the Reference 5.0 (9wpc SET 300B integrated). £700 & £650 respectively!

Also, Mei-Xing has very competitively priced 300B/845 monoblocks:

http://www.meixingaudio.com/ENGLISH/...ts/mc-805a.htm £570 a pair

http://www.meixingaudio.com/ENGLISH/...ts/mc-300c.htm £650 a pair

http://www.meixingaudio.com/ENGLISH/...ts/mc845-c.htm £549 pair - apparently, these have "beautiful, vivid rythmiration"!!

Are you still using the EE minimax as pre-amp?

Rgds,

DT

Paul Williams · 26-09-2005, 12:46 PM

Hi DT

Still happy with the Romulus and aim to keep it, yes still using the Minimax Pre (just gets better). The cost restriction is so as to ensure that I don't waste to much money if the Kit idea falls flat. As for Consonance, did you know they also do kits? 300B mono-blocks, or 2A3/45/300B convertable direct heated triode single input amp and EL34/KT88/6550 Push-Pull 2 input unit. Just fancy a project for those long winter evenings.

Paul

dynamic turtle · 26-09-2005, 1:14 PM

Paul,

I doubt very much of they do kits. You could of course buy a ready-made one, take it apart, then put it back together! Ideal for even longer winter evenings!

Re kits, if it involves anything more than battery current, I steer well clear of it. Mains voltage isn't any fun, if you're the ditsy type like me

dynamic turtle · 26-09-2005, 1:19 PM

I got some revolvers btw - the R16's. Luuuuuuuurvely speakers for the money. Smooth as a baby's and totally fatigue-free. Very happy with them.

DT

Paul Williams · 26-09-2005, 4:08 PM

Quote:

Originally Posted by dynamic turtle

Paul,

I doubt very much of they do kits. You could of course buy a ready-made one, take it apart, then put it back together! Ideal for even longer winter evenings!

Ah, but they do, but it almost seems that Consonance might be providing made versions of the kits! Bit chicken & egg.

http://www.triode-systems.com/module...p?articleid=19

Glad you like the Revolvers. Their new HC range looks even more interesting.

Paul

dynamic turtle · 26-09-2005, 4:44 PM

ahhhhh, Interesting. I've heard nothing but positive reports about the LadyDay monos. Very good VFM byt the looks of it....

Nic Rhodes · 26-09-2005, 5:06 PM

Goody goody, my sort of thread, pity I am off on my travels again.

Sound quality wise I think the 2A3 is the better tube than the 300b (I use both) but I actually think a PX4 or PX25 are better again and worth considering (now also being remade). The 50 is another fine chouce but difficult to get now.

There are good stuff for all of these now. NOS 300B are a no no (unless you buy the substandard Cetron) but others are still available like RCA 2A3 etc. Ther eis as with all these tubes quite a variation even with the same number. The TJ Meshplates Alexs recs aare the best of current production unless you can afford WE.

Also have a think how you want to drive them. I woulkd look at transformer coupling with a choke input supply but most use 'Pi' supplies and are cap coupled. There is a HUGE difference. I like to keep it simple. The basic WE 91 amp is always an interesting one to make if you fancy tube rolling as it is quite versatile, try www.angela.com, for some down to earth stuff. Their 91a look alike I think used 6SJ7WGT but you could use the original, 6C6 etc etc, some great tubes at not silly money. Have 2a3 / 300b articles like the bendix if you are interested.

Paul Williams · 26-09-2005, 5:42 PM

Quote:

Originally Posted by Nic Rhodes

Also have a think how you want to drive them. I woulkd look at transformer coupling with a choke input supply but most use 'Pi' supplies and are cap coupled. There is a HUGE difference. I like to keep it simple. The basic WE 91 amp is always an interesting one to make if you fancy tube rolling as it is quite versatile, try www.angela.com, for some down to earth stuff. Their 91a look alike I think used 6SJ7WGT but you could use the original, 6C6 etc etc, some great tubes at not silly money. Have 2a3 / 300b articles like the bendix if you are interested.

Hi Nic

As I have no real technical knowledge in this area, I'll be getting a basic out of the box kit - the Bottlehead Paramour, seems most likely at this stage, even though they don't do a 230v transformer version. The idea is to build the basic unit, learn along the way and if I like the results, look into doing some changes/experiments.

Paul

Nic Rhodes · 26-09-2005, 5:50 PM

consonance seem pretty decent. AN kit work well but looks like a dogs dinner!! I like the idea of building an off the shelf kit using 6SL7GT / 6SN7GT / 300B personally but I am skint at the moment.