Tube Amp 2a3 or 300b

Otai ..plzzzzzzzzzzzzzz

300b by a mile.

What do you have in mind? I run two 300Bs

I use a 2a3 to drive 300b. 2a3 or 300b it's all depands on the sensitivity of your speaker. If 100db n above, go for 2a3. Below it should go for 300b.

brabusm wrote:300b by a mile.

What do you have in mind? I run two 300Bs

some people say 2a3 batter then 300b is it true ?

Personally speaking, I prefer 2A3. Btw, u aiming for which brand ?

2A3 Single-Ended amp produces 2.3Watt. 300b SE produces 7Watt. Having a high sensitivity >90+db speaker would make you appreciate a tube SE more.

I have a Yaqin 300b and a custom JE Labs 300B DIY. Both sounds great with the "proper" tubes. However, I have moth-balled the Yaqin 300B in favour of the DIY 300b.

I would akin the 300b is like a Shiraz, and the 2A3 like a Merlot.

2A3 produces 3.5Watt.

hasnul wrote:Personally speaking, I prefer 2A3. Btw, u aiming for which brand ?

maby 1st i try china shuaguang black tube . is it ok ?

Totally diff character from both types of tubes, watts aside 300B's are a mid oriented sound sounding tube, with most 300B's out there, ona general consensus ( don't quote me here) they sound a tad thick though very lush sounding. Perhaps the only 300B that don't sound like a 300B is the Shuguang Treasure series 300B-Z. Pretty delicate sounding and perhaps the only tube I can live with else I would not bother listening to a 300B ( my own opinion that is)

The 2A3 is tonally more lean and has quite balanced highs and extremely good in low registers, honestly if you have a speaker that is above the 95db sensitivity ( full range drivers bla bla bla) you'll be hard pressed to find a big diff in volume between 3.5W and 8W.

Most people are put off by the fact that below 5W is impossible but in a decent sized room (and most of our listening rooms here are decent in size I presume not giant big halls), they are able to punch out pretty loud volumes.

Hving said that I have to say given the multitude of diff low watt triodes out there, I too prefer the 2A3 ( 45 even more so!) than a 300B.

What brands of 2A3 tube that you would go for?

I try not to use the Shuguang tubes during the Chinese new years. else I am ok with it.

Why Chua55?? Tube also got 'Pantang' kah?

7810sam, u may try 2a3 EH gold for budget, shuguang treasures 2a3 for intermediate n Kr 2a3 for premium. I'm using EH gold 2a3 for my preamp n it's sounded superb.

chua55 wrote:I try not to use the Shuguang tubes during the Chinese new years. else I am ok with it.

I would rather not use at all! Still have to manage daily and monthly business risks!

[quote="noodle88"]Why Chua55?? Tube also got 'Pantang' kah?


why ..is the best from china 2a3 ....?

hi hazy

the pronounciations 'shuguang' is not very prosperous in chinese. so far it only applies to me and cham and definitely not noodle.

Anyone knows of speaker choices with a 98db sensitivity or better?

I know of a few horns with upto 105db sensitivity, but it would be on a DIY route.

hi mthoi.

consider this

http://www.gr-research.com/index.asp?PageAction=VIEWPROD&ProdID=120

heard this at Wong place and catches my attention much due to its sweet, open and transparent sound.

it is very cheap.

Bro, with 91db sensitivity, 300b SE amp can't drive it nicelly...
Forget about 2a3...

It is best that you seek at least > 100db speakers otherwise you won't be able to reproduce the entire range properly. Try to get a full range horn if possible.

The 300Bs sound very lush and tonally rich. Air and decay is excellent. The best I have listened to are the WE 300b. KR Audio sounds a tad modern and hi-Fi-ish to me. Not all 300b amps are build equall and they certainly do sound worlds apart despite the SET design. Best would be to go for those that are still built in the old fashion point to point wired ones. The Audio Note Kit One is a good beginner set and they come with WE 300b tubes as well. The Cary Audio 300B sei isn't too bad either as it is capable of producing some serious lows with a good pair of sensitive speakers. The bottom of your seat will vibrate with the lows from the cello and double bass.

The 2a3 are good in their own domain just that I personally prefer the richness of the 300Bs that's so natural and rich. There is always a conception that the 300Bs sound tonally rich for the mids and if it is properly setup, you will get the richness across the entire spectrum. It's beautiful to be enlightened.

Go for the older Audio Notes or the Cary Audios. They sound really analogue. Modern units like Zanden etc despite their price, really sound thin and are too hi-Fi sounding. The pace is way too fast but then it appeals to some as it is a matter of personal taste.

Good luck with your search. Follow your ears and forget what your eyes perceive. Make sure that you get proper speakers as 3.5w to 8w should be plenty.

I am wondering if there are any 300b DIY amps owners willing to share/exchange notes with me - especially on their design, components used (both passive components and tubes) in their DIY tube amps, etc. I currently own a Shuguang 300b using stock tubes, and a DIY JE Labs SE monoblocks using mid-range parts (Kiwame, Riken, Mundorf Silver Oil, Obbligato PSU). I would be embarking on a WE 91A design soon.

As a DIY, I am always curious about "sound" of different SE designs, tubes (especially 300b, 2A3 and 6A3) and passive components. Hopefully, if we can share notes, the experimentation would be less "costly"? Also, joint DIY projects would be great.

Pls PM me. Tx.

It's a fairly simple SET circuit. Try googling it.

mthoi wrote:I am wondering if there are any 300b DIY amps owners willing to share/exchange notes with me - especially on their design, components used (both passive components and tubes) in their DIY tube amps, etc. I currently own a Shuguang 300b using stock tubes, and a DIY JE Labs SE monoblocks using mid-range parts (Kiwame, Riken, Mundorf Silver Oil, Obbligato PSU). I would be embarking on a WE 91A design soon.

As a DIY, I am always curious about "sound" of different SE designs, tubes (especially 300b, 2A3 and 6A3) and passive components. Hopefully, if we can share notes, the experimentation would be less "costly"? Also, joint DIY projects would be great.

Pls PM me. Tx.

As many had said 2A3 have wide frequency band and 300B more emphasis on mid.

Anyway the driver tube also play quite important roles. That's why those who wish to have good driving power like 300B but sound charcteristic similar to 2A3 will try to use 2A3 as driver tube from a 300B.

Using power tube as driver tube can give 300B a better driving power and incurs some of the characteristic of the driver tube into the amp. Disadvantage is the cost is quite high.

Due to the same reason, i'm using 1626 as driver tube for my 300B SE.

As a result my 300B is not sounding like a conventional 300B. Some people say it is youngman 300B, some say it not sound like a 300B. But they all admit that it is one of the most punchy and dynamic 300B they heard so far.
Of course my friend's 300B (use similar circuit) but with V cap is even more punchy & dynamic.

So it is depend on what sound you want when you decide to diy a amp.

a 2A3 may also sound mellow if you use a lot warm sound component like jensen cap, mellow driver tube and so on.

Can Tumpang listen ? What amp his using ?

chua55 wrote:hi mthoi.

consider this

http://www.gr-research.com/index.asp?PageAction=VIEWPROD&ProdID=120

heard this at Wong place and catches my attention much due to its sweet, open and transparent sound.

it is very cheap.

Hasnul - Dr Wong is in Kuching and is a fellow DIY member. He is using a DIY First Watt F5 and recently completed a pair of Aleph J clone. (I gave him my extra pair of Aleph J clone PCB left-over from my project). His recent feedback was that he likes the AJ - maybe more than the F5(?).

He is currently building the speaker kit mentioned by Chua55 - I think Chua was refering to to his other open-baffle DIY speakers.

Hi mthoi,
Thanks for the alephj pcb and guidance during the build.
Indeed i like alephj over F5 in the mid and bass especially. I think F5 has cleaner high and maybe slightly wider soundstage.
My F5 is in the storeroom now !

Both amps have more than enough power to give bass that results in vibration of the window panes.
My room is about 200 sq ft only.
The link posted by Chua is my present sepaker ---OB5
regards
kp93300

[quote="sswong3374"]As many had said 2A3 have wide frequency band and 300B more emphasis on mid.

Anyway the driver tube also play quite important roles. That's why those who wish to have good driving power like 300B but sound charcteristic similar to 2A3 will try to use 2A3 as driver tube from a 300B.

Using power tube as driver tube can give 300B a better driving power and incurs some of the characteristic of the driver tube into the amp. Disadvantage is the cost is quite high.

Due to the same reason, i'm using 1626 as driver tube for my 300B SE.

As a result my 300B is not sounding like a conventional 300B. Some people say it is youngman 300B, some say it not sound like a 300B. But they all admit that it is one of the most punchy and dynamic 300B they heard so far.
Of course my friend's 300B (use similar circuit) but with V cap is even more punchy & dynamic.

So it is depend on what sound you want when you decide to diy a amp.

a 2A3 may also sound mellow if you use a lot warm sound component like jensen cap, mellow driver tube and so on.




Another thing that will make a 300B not sound like a 300B is the type of 300B tube you run, the Shuguang 300B-Z tubes are very dynamic and tight sounding, leaner than your typical 300B's ( including the KR 300B) where its mid is too thick for me..

most important is still driver position.. you want full scale dynamics, then a pentode driver unit like the WE 310A driver is pretty awesome sounding la....

I agree that Pentodes are nice and smooth sounding. I got one channel of my DIY WE91a working with Philips-JAN 6SJ7 pentode driving a JJ 300b - sounded excellent. And tube rolling with GE 5693 Red tubes (6SJ7 equivalent) further confirms.

WE310A NOS original WE are priced way too high. Shuguang has a new 310A, or Russian. Anyone have a pair of 310A to swap/let-go? I have a few pairs of GE5693 Red tubes to swap.

Me too find out the shuguang 300b -z sounded very good in my poweramp( better than kr300b we copy). For those who use power as driver tube, u may want to try interstage transfomer, it's really worth the effort .

Cheers,

Dont forget output transformer. The quality and characteristics of the OPT plays a significant part in the characteristics of the tube amp. I have changed OPT for my 300b amp from hammond to hashimoto - after 60hrs, the hashimoto seems better in mids and upper frequency, but not as deep in bass as compared to hammond.

There is a following of Loftin-White SE design that do away with interstage transformers and coupling capacitors - anyone with an amp using this design?

Can't agree more.

Previously I was using a pair of 6SN7 as the driver tube to support the 300B output tubes. It sounded fantasticly lush and warm.

Now, I am trying out the following: 6SN7 as input, 300B as driver and 845 as the output tube. The sound is out of this world.


[quote="dixchen"]

sswong3374 wrote:As many had said 2A3 have wide frequency band and 300B more emphasis on mid.

Anyway the driver tube also play quite important roles. That's why those who wish to have good driving power like 300B but sound charcteristic similar to 2A3 will try to use 2A3 as driver tube from a 300B.

Using power tube as driver tube can give 300B a better driving power and incurs some of the characteristic of the driver tube into the amp. Disadvantage is the cost is quite high.

Due to the same reason, i'm using 1626 as driver tube for my 300B SE.

As a result my 300B is not sounding like a conventional 300B. Some people say it is youngman 300B, some say it not sound like a 300B. But they all admit that it is one of the most punchy and dynamic 300B they heard so far.
Of course my friend's 300B (use similar circuit) but with V cap is even more punchy & dynamic.

So it is depend on what sound you want when you decide to diy a amp.

a 2A3 may also sound mellow if you use a lot warm sound component like jensen cap, mellow driver tube and so on.




Another thing that will make a 300B not sound like a 300B is the type of 300B tube you run, the Shuguang 300B-Z tubes are very dynamic and tight sounding, leaner than your typical 300B's ( including the KR 300B) where its mid is too thick for me..

most important is still driver position.. you want full scale dynamics, then a pentode driver unit like the WE 310A driver is pretty awesome sounding la....

I nearly went for that combination till this configuration came along 6sn7 --> 45 --> 845 in only 6W output since B+ is only at about 450V, harnessing the musicality of the 45 tube with more ' balls ' via the 845 tube.. the combination in SET amps are infinite

dixchen,

Your pace really fast and never ending toys with you.

To 45 is a prefered driver tube to 2A3, 300B as a driver tube a bit waste and costly.

I prefer using power triode as driver than pentode.

For low cost, 1626 is a good choice, higher cost 45 will be my choice.

what brand of 845 you all use?

Full exploration into all types of tubes ma...LOL!

Listening to one type of valves only is not sufficient sometimes, they all excel at diff areas altogether

Am using a pair of now no longer available 845M's made bout 5 or 6 years ago. They are made by Shuguang but with its metal plate material sourced for them by another company. The advantages of this tube? Excellent dynamics and micro details but power dissipation is lesser than your average 845's but for 6W or so like my application, more than enough la.

mthoi,

Which model of the hashimoto you used? how much for a pair?

Frankly speaking, hammond's bass relly not bad but just not musical.

sss333,

I bought the Hashimoto H-20-3.5U from e-bay for around RM 2,000 per pair incl. shipping. It is a 20W rating and comes with a dual 2.5k/3.5k primary tappings - very nice potted OPT. absolutely no complain.

The Hammonds are OK but perhaps not as musical in the mid-range.

Have anyone experienced any other brands of OPT? Any experience with Promitheus Audio's OPT? They are local.

mthoi,

I'm using SAC currently, quite musical with lower price.
The guy who make SAC opt is agent/distributor of Audionote in Thailand if not mistaken. He use tango & audionote opt as reference when make the OPT. Thus the sound direction/characteristic is close to the above.

You already got hashimoto, that should be good enough.

mthoi wrote:sss333,

I bought the Hashimoto H-20-3.5U from e-bay for around RM 2,000 per pair incl. shipping. It is a 20W rating and comes with a dual 2.5k/3.5k primary tappings - very nice potted OPT. absolutely no complain.

The Hammonds are OK but perhaps not as musical in the mid-range.

Have anyone experienced any other brands of OPT? Any experience with Promitheus Audio's OPT? They are local.

sss333 & mthoi

me using lundahl 1663se thus "emancipated" from hammonditis
good sonic body across the frequency spectrum with bass going effortlessly below 40hz & high frequencies are well blended within any given harmonic structure offering natural highs alas many people claimed insufficiency as they probably wanted highs which stand out or hearing response has curtailed... i guess




regards
tlkoo

tlkoo - At my age, I am happy that I can still hear (reasonably) well - or at least to what I want to selectively hear (from the wife!). LOL, but seriously, having a pair of horn-based speakers seems to present the upper frequencies in a new "high". Wind and string instruments seems more realistic.

Lundhal have loads of positive reviews in the diyAudio community. I have a pair of PP lundahl from Wikin which I intend to build a 2A3 PP in the near future.

I understand from Nicholas - Promitheus Audio that the power transformers and inductors also contribute to the overall sonic qualities in the amp. Previously I have only used made-to-order transformers and inductors from Pasar-road, but have recently ordered a pair of power transformers and inductors for that purpose.

We shall see whether I hear any sonic improvements (with my "selective" hearing)when they arrives.

mthoi wrote:tlkoo - At my age, I am happy that I can still hear (reasonably) well - or at least to what I want to selectively hear (from the wife!). LOL, but seriously, having a pair of horn-based speakers seems to present the upper frequencies in a new "high". Wind and string instruments seems more realistic.

Lundhal have loads of positive reviews in the diyAudio community. I have a pair of PP lundahl from Wikin which I intend to build a 2A3 PP in the near future.

I understand from Nicholas - Promitheus Audio that the power transformers and inductors also contribute to the overall sonic qualities in the amp. Previously I have only used made-to-order transformers and inductors from Pasar-road, but have recently ordered a pair of power transformers and inductors for that purpose.

We shall see whether I hear any sonic improvements (with my "selective" hearing)when they arrives.

you like highs that stand out? what drivers deployed in your horns? backloaded, frontloaded, hybrid or hedlund or something else? i may have to revisit horns since i failed to be happy back then

so happened that i'm stiill using power trans promitheus helped to source, not sure if it was wound by someone else





regards

tlkoo - I am using a pair of Tyler Acoustic PD15's Horn speakers. It comes with Eminence-pro horn and 15" woofers and measures 95db/1m sensitivity. American pro-sound.

At present, I am also trying to build a pair of Altec Lansing-based horn speaker. I was previously looking for a pair of Altec A-5 Voice Of Theater or an Altec Model 19 speakers, but resigned to the fact that they are rare commodity in Malaysia. The alternative was to import them from USA but the shipping cost are high (each box weighs over 150ib) and the quality of the items (upto 30+ years old) may be an issue.

I have started gathering parts - first stop was a pair of Altec Lansing 288-8L compression drivers that I purchased through e-bay. But I think this project would be long-termed to get-done.

If you know of anyone selling Altec Lansing vintage parts - PM me.

MTHOI,

What's the spec of power trans you order from promitheus and what the price?

tlkoo,
Lundahl is quite famous but i never have the chance to test it.

I migh be wrong, but i think asia OPT is more emphasis on the mid n HF refinement, western opt more on LF. that's why western OPT tend have have much higher inductant for OPT.

Hi,

I'm using a pair of Tango interstage (NC20) n Tango output trans for my 300b amp with a 2a3 as driver tube.

For me every component in the amp also very important because they do contribute to it's sound, it's depend how u want to voice your amp.

Good luck n enjoy

Dear Noodles,

Admire! Tango is my dream iron....

To me use 2A3/ 45 to drive 300B is once of the best combination.

Sss333,

The beaute is the interstage. It's way better than any best cap in this world because interstage don't store energy like cap do.

That is the beauty of tube amps designs - simple yet so complicated.

Interstage vs capacitors vs none-of-the-above (i.e. Loftin-White design). So many designs with so many different operating voltage points, driver tubes, output transformers, resistors, etc. So many permutations, but they all sounds good!

We should all get-together and have a tube-amp fest.

noodle88 wrote:Sss333,

The beaute is the interstage. It's way better than any best cap in this world because interstage don't store energy like cap do.

Storing energy is not necessary a bad thing in RC circuits not to mention the so called ' phase shifts ' that coupling caps are condemned most of the time. I think the decision between interstage coupling or capacitor coupling is more of a personal taste. At the hands of a good SET amp builder, an RC circuit can be made to sound really good. So some like it and some don't like it. Depends who builds the amps..A lot of the commercial made SET amps today sounds rather ordinary anyway thus lots of generalization on why RC sounds bad..

No offence ya Noodle, just a comment for general discussion only...

If someone asked me again I would say I fancy NEITHER the 300B or the 2A3..many other triodes do sound much better than them IMHO...for ex. the superb RS 241's made only by Telefunken in the 1930's..

I also feel that each type of circuit have their strength and weakness, so whether using interstage, cap coupling or direct coupling is depend on individual taste.

Dixchen,

u r right, they are many better power tube out there, but for beginner 300B is always prefered as easier to obtain the schematic as reference, drive power at 5-10w can be achieve and more choice of speaker. I also wont use 300B once my current 300B tube die... : )

DHT tubes don't die so easily wan la... so better make it happen earlier... hahahaha..

Jokes aside, yes agreed that the 8W 300B can be made to drive even lower sensitivity speakers such as my previous Harbeth Compact 7's, speaker choice was difficult then when going low watts but as soon as I went full range with 99db/w, 1.5W was all needed to achieve big scale dynamics...

Dixchen,

even though the AN SUPER CAST 12" on paper is 99dB, but from listening seems not really that high, seems like ~95-96db

Well I agree cause there are limitations to what a full range can do but even at 95 - 96 its plenty la... all depends on room size...my 1.8W 45 amp plays awesomely loud on it though