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2A3 SE or PP & Bottlehead or DIY?

sheltie dave said:
The quality of the iron is the most important thing in any 2A3 amp. The Bottlehead is good, but it has its limits due to economic necessity.
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Billfort said:
Agree with Dave - output iron is big-time important with these and Bottlehead is built to a price point.
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I was actually expecting more comments such as these as this is battle I've been having with myself for a long time. I'd love to build my own from scratch, all point to point without a PCB in sight using top-quality components but you've got to understand I'm a little scared as I don't want to destroy these 2A3s in the process plus I know that because I'm a good soldered I'm nearly guaranteed the Bottlehead kits will just 'work' without any risk or further fiddling about.

From what I've seen the SE circuits are pretty simple and I consider myself a fairly neat constructor so from that perspective I think I'll be fine however my pessimistic side just can't help but think that something's going to go wrong and I'll end up destroying hundreds of dollars worth of 2A3 goodness :tears: Then again, the thought of having two working SE monoblocks that I built myself from scratch is a pretty good incentive.

Ah! I have four tubes! Maybe I should do it both ways... start off with the Bottlehead kit (affordable, all inclusive convenience and basically guaranteed to work) then once I've discovered what the SE fuss is all about move onto building my own from scratch. This way I can learn and compare so I know the subtle differences between the two designs, methods & qualities. Hmmmm :scratch2:
 
Based on my experience with the Paramours (which feature laughably modest output iron -- 70V line matching transformers wired "backwards -- made possible only by the parallel-feed configuration), don't write off even Dan Schmalle's entry-level products too quickly. They do sound good.

paramours 112413 by mhardy6647, on Flickr

Having said that -- all the comments about the value of top-quality iron are true... and... the Bottlehead kits ain't the "value leaders" that they once were (i.e., they've gotten rather expensive).

You could DIY a "Simple 2A3" -- start with whatever SE iron you can afford, and upgrade later if and when you can; if and when you want to.

http://jelabsarch.blogspot.com/2012/06/je-labs-simple-452a3.html

Amp mit Westies by mhardy6647, on Flickr

This particular example was lovingly crafted by AK's Redboy...
http://www.audiokarma.org/forums/showthread.php?t=112767

... and give yourself permission to start with cheap, "cannon fodder" 2A3s if you're concerned about immolation due to "constructor error"!

DSC_0001 by icouldbeahero, on Flickr

--a cheap, generic Chinese 2A3 (branded "ValveArt", ca. 2000AD); they're not bad sounding tubes.

photo courtesy of my son, http://icouldbeahero.blogspot.com
 
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mhardy6647 said:
... some of the Fostex "fullrange" drivers (e.g., the FE-207E, no longer in production, at 95 dB per watt input at 1 meter)
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Although I don't have any fullrange speakers in my working system I have a few Corals in my 'to do' pile plus I've heard a couple of pairs of DIY versions based on drivers very similar to those Fostex and I think they're something I could very easily get used to :yes: They just seem to sound effortless & pure but of course only really enjoyable with certain types of music.
 
The more I listen to the new to me BH Stereomore ( this arrived this morning and it's been on since) the more I like. And the volume's been turned down. I had decided to buy a kit until this was offered on BT.
 
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You can make good headphones amp with 2A3. But in real life even 300B SET is barely sufficient for less than 100dB/W speakers. Push-pull 300B, or SE 845/211 is what necessary to get reasonably loud sound.
 
for_p1 said:
You can make good headphones amp with 2A3. But with real life speakers even 300B SET is barely sufficient for less than 100dB/W speakers. Push-pull 300B, or SE 845/211 is what necessary to get reasonably loud sound.
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True or not, I have many other Amps I already enjoy listening to at higher SPLs so I have that covered well enough at this stage. The 2A3 & associated high efficiency speakers would be dedicated to delicate listening sessions only. That has always been the plan.
 
for_p1 said:
You can make good headphones amp with 2A3. But with real life speakers even 300B SET is barely sufficient for less than 100dB/W speakers. Push-pull 300B, or SE 845/211 is what necessary to get reasonably loud sound.
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What's reasonably loud? 98db efficient speakers will get to 101db at 2 watts. OTOH I have my SE 2A3 amp running Khorns....:thmbsp:
 
nerdorama said:
Sorry everyone, but I vote for PP with a long tail pair driver like the Poindexter Music Machine. I've built one using 6B4G (6.3V version of 2A3). It's got great bass and is crystal clear. Very nice low level detail and still smooth as silk sounding.

http://www.6moons.com/audioreviews/audiotropic2/machine.html

http://www.diyaudio.com/forums/tube...ding-poindexters-6gk5-el34-music-machine.html

Have fun,
John
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I've heard John's amp a number of times and it is just excellent. John and a few other guys from the "Sound DIY" Club go up to Vancouver Island for the Planet10 Van Isle DIY Fest every year and the Canadian Guys "really liked" John's Push-Pull amp a lot! I believe that the amp has now become "a Keeper" in John's assortment of audio stuff!

Best Regards,
TerryO
 
mhardy6647 said:
OSHA allows 2 hours/day of workplace exposure to 100 dB (A weighted). 100 dB is farking loud.
https://www.osha.gov/SLTC/noisehearingconservation/
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You need to count for dynamic headroom of at least 15 dB. So when you listen at 85 dB level, amplifier should be able to serve transient peaks reaching 100 dB. Otherwise sound will be effectively compressed - does not sound as bad as transistor amp clipping, but still not pleasant.
 
for_p1 said:
You need to count for dynamic headroom of at least 15 dB. So when you listen at 85 dB level, amplifier should be able to serve transient peaks reaching 100 dB. Otherwise sound will be effectively compressed - does not sound as bad as transistor amp clipping, but still not pleasant.
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Yes, that's the point. The value of an efficient speaker is not that it goes "loud" but that there is no dynamic compression. When the kick drum is given a good whack you hear the leading edge of the wave as tight, solid and powerful; you feel it hit your chest. That’s realistic dynamics and you are unlikely to experience it with low efficiency speakers unless you employ banks of transistors.

As I said, I enjoyed my time with the 93dB Tannoy coaxials. The sound was accurate and clean, but way too "polite;" the kick drum above would "thud" with the powerful leading edge missing. Maybe you need to hear the difference between a medium efficiency speaker and a high efficiency one to understand what dynamic compression sounds like. I enjoyed my time with the Tannoys, but when I went back to the Altecs I was immediately aware of what I had been missing.
 
As above 45 meshplates made my Tannoys sound poor; Farty bass, limited presence /dynamics. Not good at all.
Tannoys demand a current capable amplifier, invariably not a tube amp let alone an SE (big Heavy Cones)
Then they perform :-)

On a further note Bottlehead stuff does work, often well, but one has to buy and build the "kit' to comprehend just how inexpensive the components actually are.
Kit purchase price is imo Many multiples of the parts cost if one bought them retail.
Seriously consider accumulating your own parts for a DIY 'kit'.
Better bits less cost and even more enjoyable/prideful.
 
Bottlehead is not a non-profit organization last I checked, and I don't fault them for operating as a business with the intention if making money.

Their kits provide a midpoint between the cost of a commercially produced amplifier and a scratch built amplifier. Their products are intended for folks that want to build a kit, are likely not experienced builders and therefore they provide lifetime support via their forum. In my opinion there is a considerable amount of value there that is being overlooked. Their products also happen to sound very good, even if they aren't built with boutique parts.

Yes, their kits are built to a price point, but that's the point. They offer products at several price points to offer options to buyers at different budgets.
 
marantzfan said:
Bottlehead is not a non-profit organization last I checked, and I don't fault them for operating as a business with the intention if making money.

Their kits provide a midpoint between the cost of a commercially produced amplifier and a scratch built amplifier. Their products are intended for folks that want to build a kit, are likely not experienced builders and therefore they provide lifetime support via their forum. In my opinion there is a considerable amount of value there that is being overlooked. Their products also happen to sound very good, even if they aren't built with boutique parts.

Yes, their kits are built to a price point, but that's the point. They offer products at several price points to offer options to buyers at different budgets.
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I agree completely! Dan has gotten a lot of people started building their own gear with the experience they gained with their Bottlehead kit construction!

BTW: If people think that Bottlehead is ripping people off, why don't they start their own company and show us how it's supposed to be done!
:banana:

Best Regards,
TerryO
 
SteveAndBell said:
Hi.

I'm lucky enough have been given 4 x NOS RCA 2A3 Tubes still in their boxes and want to build an amp around them.
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Store them in a safe place as an investment and build your amp around some Shuguang 2a3's.

After you get the setup up and running with the Shuguang's then and only then try them as a swap to see if there is a substantial enough difference to justify run NOS 2A3's. Especially if they are globe types.

Just my opinion.

Steve
 
targeteye said:
Store them in a safe place as an investment and build your amp around some Shuguang 2a3's.

After you get the setup up and running with the Shuguang's then and only then try them as a swap to see if there is a substantial enough difference to justify run NOS 2A3's. Especially if they are globe types.

Just my opinion.

Steve
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FWIW I prefer the Shuguangs over my RCA 2a3's.
 
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