Tube Amp Advice: 2A3 or 300B or???

[tube fanatic]

Don't feel that you must go with DHTs to get wonderful triode sound. Triode strapped pentodes can also do an amazing job. Check out the offerings from Decware before you make any definite decisions.

I've never had much luck with triode strapped pentodes such as 6BQ5 without feedback. The sound was a accentuated sharp/shouty midrange to my ears.

I may have done something wrong being a rank amatuer, but I always had better luck using the 6BQ5 in pentode mode, with a dedicated screen supply or screen tap on the OPT, and some sort of feedback applied.

Directly heated triodes without feedback do have a bit of accentuation in the midrange, but not with a sharpish bite that a strapped 6BQ5 has...in my experience. I'd venture to say good single-ended pentode mode 6BQ5 circuit with proper feedback applied, can sound closer to a DHT amplifier than a triode strapped 6BQ5 circuit.

I dunno...there is this euphoria going with the sound of a directly heated triode such as a 2A3 or 45 that a indirectly heated 6BQ5 doesn't seem to quite do. To my ears.

Never tried triode strapped 6V6. With published curves in triode mode, it may be worth a shot.

Mike

The 6BQ5 does not make a good triode imo as it is hard to get the distortion down to an acceptable level with currently available output transformer impedances. That may account for the shouty midrange that you describe. As a pentode, as you mentioned, it functions much better. SEPs, with some voltage feedback at the ouput stage only, can mimic the midrange and top end smoothness of a triode while preserving the bottom end of pentodes. The 6V6 as a triode isn't bad, but you would do better to go with a 6L6 or 6Y6. They will provide a little more power with reasonably low distortion if the operating parameters are calculated correctly. Also, much depends on the output transformers used. Perhaps I'm strange, but I generally like the Hammond offerings. For triode operation, the 16--SEA series does a great job. For those on a tight budget, the 125 SE series also does a good job (better with pentodes than triodes imo). Some folks like the Edcor transformers, but I've never heard them.

[Panacea Engineering]

I'm in the process of building a WAD 300B PP amp, 28 Watts per channel. It was offered as a kit from World Audio Design years ago and has had some pretty rave reviews. If anyone is interested, I have a build thread going on audio-talk which is a European Forum. I have been researching this amp for the last six months and decided to make this my first venture into Valves. The transformers are still available from SP Wound and are made to order. There have been several mods and changes over the years and I am running an Excel spreadsheet with parts and sources. We will soon see what the Klipschorns sound like on tubes....!

Here is a link to the build thread: http://www.audio-talk.co.uk/phpBB2/viewtopic.php?t=3542&postdays=0&postorder=asc&start=0&sid=f370293d2a52f4b0adfc1877d5adb250

[Panacea Engineering]

Another pic

Pretty heavy in the Iron department seven transformers and the Mains is 35 pounds by itself.

[tinpan]

I would look at an Audio Note Kit 1 300b SET config. I have this one listed on Digital Pete's page

http://www.digitalpete.net/

You can buy the kit or for a modest price Pete can build it.

[Marvel]

If you are willing to build, I would have a look at the Jeff Lessard designed SETH, which is a P-P 2A3 amp. They use Magnequest iron. ALL the schematics and parts info is available on the Magnequest web site.

http://www.magnequest.com/diy2.htm

Bruce

[captmobley]

I listen to my LaScalas with Bottlehead Foreplay II and 2A3 Paramours and that is exactly how my last friend I had over described it-like having a huge set of headphones-it sounds great-almost better than my Moondog/Klipschorn "reference" system.

Part of the appeal is that system is at my cabin in the country and I can turn it up as loud and as long as i d*mn well please.

[juter22]

Hi, I'm also looking for tube amp to my Klipsch Heresy E, it was thinking about something on EL34 or EL84, some of my friends recommended me Radford STA 25 or Audio Innovations monobloks 1000 mkIII and also Dynaco SCA 35, could you help me? Mainly I listning rock music, now I'm using Bryston 4B st + Bryston BP20.

Thanks in advance for your help.

jt

[jannegard1]

hello i have woodside radford tube amp sounds good to my klipschorn

[jannegard1]

go for radford jutter22 that is a good sound radfords amp are a legend in sound i have woodside radford ma-100 and woodside sc26 preamp

[deafbykhorns]

I have a pair of DIY 2a3 driven by an Eimac tube. The Eimac tube gives you the flavor of a loftin-white or Fi X with the classic sound of a moondog.

Whatever you get, the iron is about 80% of the amp, the rest is design

[kentamcolin]

300B was too lush for me, not very exciting. 2A3 is very nice, but if you're looking for an amp that does not need to blow the roof off, my favorite would be a 45 SET. About 2 watts of tube magic. I used a Moth 45 SET with my Cornwalls and the sound was wonderful. Unfortunately for me, I more often want to blow the roof off and (regrettably) sold off the Moth. My favorite tube was the EML (Emission Labs) 45.

[thebes]

OK,. John, you've heard a lot of info on 2A3 and 300B, mostly about SET non-integrated, from what I can gather.

Let's reset and start with the basics. Price point, type of music, are you aware of the differences between push/pull and SET, why those two types of tubes, ie were you told to get those types or is because there are lot of other tube topologies out there. It's a nice discussion but perhaps not pertinent to your needs.