Need amp suggestions for Hedlund Horns....

A few months ago, I heard a Cary 300b amp hooked up to some small monitors and was blown away... so the itch to upgrade started.

I just bought used a pair of Hedlund horns... came with it (free) was a diy homemade tube amp that does not sound adequate (based on what I heard these horns can do).

I’m in the market for a used amp that would be the ideal match for these Hedlunds. From what I read, I have several options such as 300b, 2A3, etc. but what would you recommend?  I've never had a low-power SET amp before.  

My room is 25’x 30’ with vaulted ceilings (large enough), wood floors, fairly open. I listen to everything from classic jazz, horns, classical, vocals, and the occasional rock. I would love to have some volume to feel the energy and texture of the song.

The following input is not based on knowledge of your particular speaker, but instead, reference to amps specifically designed for single driver and / or high efficiency designs.  In my opinion, all the company's listed below offer highly recognized, very good value, entry level amps, and higher end products; you will find many associated reviews on line. This is by no means an all inclusive list, just those that come to mind.
Good luck, hope you get many years of enjoyment from your new speakers.

Coincident Technologies


Sophia Electric (In Virgina)


Don Garber Fi

Triode Corporation

Triode Lab

Finale Audio

I am not familiar with  your horns or the drivers involved but you do have a big room. Since there is a popular play in 300B tubes manufactured today with many choices I would check a 300B with a stiff power supply for bass control.

There is a Border Patrol EXD powered amp. on the gon right now and with the EML 300B I predict you would be very happy if you can afford that quality. BP can and will drive some other speakers.

Best of Luck


Congratulations on acquiring your new horn speakers. Your speakers may be efficient and sensitive enough to be adequately driven with a 45 or 2A3 SET amplifier, how sensitive is the speaker?

I’m more familiar with 300b SET amplifiers and fortunately for you there are many High quality choices available. Gwalt mentioned the necessity of a "stiff"power supply and he’s correct. I would add that output transformer quality is a crucial factor. The Border Patrol amplifiers he cited and my Coincident Frankenstein MK II SET are two examples of very high quality 300b amplifiers, there are certainly other fine choices as well.

Do you have a specific budget? Be careful with lower priced SETs, there are good value amps to find as long as corners aren’t cut in regard to power supply and transformer quality. If you exercise some patience and do some reading and research you’ll find a very good match for your speakers. You're on the right pathway, a high quality 300b SET will provide you with superb music reproduction. 
Good luck,
In addition to the suggestions above, you might also want to consider the Allnic brand. They make some nice 300B amps and integrated 300B.

Yes the Allnic is , another fine choice. In the current market of 300b SET ampliifiers there is an abundance  of quality products.
I would certainly also recommend Deja Vu Audio, fantastic single ended amps using a mix of new and vintage parts, talk to Vu he's incredibly knowledgeable about amp/speaker matching and horns in particular. No affiliation just a very satisfied customer.

I agree with Charesdad if you know the efficiency of your horns and if the crossover is complex? I think you have to get that decided before you go forward with your tube power. Beware that the design of an SET amplifier is as important as the tube selection. Not all are created equal.

Best of luck,


I pulled the full range single driver and it is an AER MK1 which from what I read is (can be) a great speaker with the right enclosure/baffle (for $2500/pair it better be). Again these AERs are in a Hedlund Horn (feel free to search Google pics) so no crossover.

As far as efficiency, not sure how to measure this or where to find as the AER website has no specs- any help would be appreciated. If I had to guess it would be in the 102db range.

So what is a good 300b design? What makes a "stiff" power supply? What’s a good output transformer? What specs should I look for? None of the suggested 300b manufacturers mentioned share their circuit design nor parts list. Is it better to have one built to match specs for the AER speaker?

Hello Ramoneo14,
If your speakers sensitivity is in the vicinity of 102 db thats very impressive. With a 300b SET amplifier you’d hardly ever get outside of the 1 watt range of power usage. In reality you’d be using only small fractions of 1 watt. Your amplifier is coasting at this power level and the distortion is nearly unmeasurably low as well. Most 300b SETs have 6 to 10 watts of power thus the headroom factor is considerable.

Bradf posted a list of of companies that offer high quality amplifiers with established reputations, also the Allnic and Border Patrol amplifiers mentioned earlier. A few more quality brands are Thoress, Ocellia,Wavelength, Sophia Electric, Audion , Concert Fidelity, there are more. Certainly there are differences between various brands brands and their models.

However what this list has in common is very good quality design, part quality (P. Supplies and output transformer) solid track records. Definitely lots of choices and it takes some time to sort thorough them and gain some degree of familiarity. The 300b SET amplifier niche is very alive and plentiful.
From what I could find online looks like your driver is over 100db efficiency and 16 ohms impedance so you should be able to drive it with virtually any good single ended amp even down to 1 watt or so. A stiff power supply means the power supply is robust and typically way over spec for the amp in question.
Since my speakers are VERY efficient, is the 300b still the "best" tube to use?  Is there anything "better" at 1 watt or so?  I want that warm bloom that I heard once, music just coming alive like I've never heard it.  300b vs 45 vs others?
16 ohms speaker impedance is ideal (generally speaking this means easier load for the amplifier to drive). I agree with Jond,  on paper this speaker "should " be an excellent match with the vast majority of SET amplifiers. 
That question has been debated since the invention of the DHT  tubes and is yet to be settled.  Each type of DHT  has its advocates and detractors.  Within the same family you'll hear very distinct differences of individual brands of tubes as well as different amptolifiers due to implementation etc. Want to do some interesting reading? Google 300b vs 2A3 vs 45 which sounds the best.  You'll be reading a long time 😁. All can be excellent sounding,  I'm a fan of the 300b for its tone,bloom liveliness and naturalness.  By no means will I knock the other terrific DHT tubes as it is a personal preference issue. My 300b amplifier took my listening enjoyment to a higher level when I bought it 7 years ago. 
I came across these following "6 Moons" reviews on Yamamoto 300B and 45 SET amps in my digital library. They include some pretty good detail of build quality and higher grade components. Should provoke some thought and give you something to contemplate.
....just started reading.  So much out there, so many opinions.  How do I decide?  (this is actually a self-diagnosed neurotic condition I have- I have a hard time deciding)  

There's also this latest review on the Triode Lab 2A3is that set me to drooling. Its sounds like it might be right up your alley. The article goes on to mention that if you call them and let them know what speaker you have, they can tailor it to the speaker and within your budget. 

All the best,

$5K yikes! Thats a lot of overtime.  Anything close 90% around the $1K mark??  (really being optimistic here)

How's this one on eBay?  I know buying stuff from the Far East is a gamble.  This guy is just two hours away from me.  How does the guts look?  

If you take a look at you'll find lots of tube amps in your price range. Some here as well. Finding the right one will be tough.

As to your query about that Far East gamble, Triode Lab's other business is fixing and upgrading and troubleshooting lesser quality tube amps. Their bills are very reasonable for the amount of work they do but they are amazed at what passes for QC in some of their repairs.

All the best,
This is why I inquired about price range in an earlier post as it's a major factor.if your budget is roughly 1500 USD  then virtually all of the amplifiers listed earlier will exceed that range by a substantial amount. 

The Sean Casper F2a amplifier could very possibly be a good one. The F2a isn't a DHT  (directly heated triode) but is a German Siemens Pentode type tube. Shindo used this tube in two of their power amplifiers(Shinhonia and Cortese).  This would suggest to me that it's a very good sounding tube. It is reputed to be a very durable and long life tube as well. 

I'd try to get in touch with Sean Casper to gain further information on his amplifiers. They’re American made and claim to use good parts and transformers. I believe that it's worth checking out. Any amp much less costly "may"compromise on parts and built quality. 
This might fit the bill for you and your budget no affiliation I know Charles and many other love Coincident gear.
Now that we know the budget the recommendations can be much more specific. The current available version is the Dynamo  MK II and is reported to be noticeably improved. Bigger and better  chassis,  power supply capacitance and better transformers. Worth the extra 200 dollars over the original version per reviewers. Runs the el 34 single ended for 8 watts. 
I totally agree, now that we know a price range it's a lot easier to make recommendations that are doable for Ramoneo14 ;-).

The impedance and efficiency make a lower powered OTL a good choice as well.
Spent some time (almost all night) reading and reading... and here are some of my findings please give me more insight. 

1. The Dynamo uses EL34 tubes with power at 8w.  As much as the price attracts me, it seems that my optimal power would be around 1-4w.  I currently have a homemade EL84 pentode/triode amp and at triode mode 1.9w (I think) it puts out a great amount of sound (but not glorious sound).  Will the EL34 tube give me the feeling of other tubes?

2.  2A3 tubes, single ended DHT circuit, NOT push/pull is my ideal sound/signature after hours of reading. The 45 tube would be second and 300b third but may have more 'power' than I need or want.  

3.  Price.  Since 300b's seem to the most popular of the bunch they seem to fetch the highest price which is another reason to go with the 2A3 or others.  A quick search on eB@y reveal makers like Dared, Douke, and others.  The Chinese one seem that they cut corners (PCBs, etc) so leaning away from it.  The Japan made ones (Hirata/Tango look promising so please let me know if this would be an ok amp.  

4.  Other selections.  What can you find that's under $2K that is the best value?  I'm all about value.   Don't want cheap as usually you get what you pay for but sometimes there are hidden gems to be found, especially used.  
**I actually prefer used, I give each used piece a name- after the person that I purchased it from.  That way the history/legacy lives on.  I do this with other gear like guitars-I'm a musician.  

Any and every suggestion is welcome.  I realize my ignorance in this topic and am very grateful to all your input.  
It's going to be hard to find a good 2a3 amp near $1K but here is a good looking used version for $1900 it's $4K new and the "little brother" of the Triode Labs amp in the 6moons review above:

Regarding the EL34 tube to me it combines some of the richness of the 300B with a bit more linearity and frequency range but less bloom and perhaps a touch less transparency. As always implementation means as much or more than tube type.
You could very well get along fine with a 2A3 SET given the characteristics of your Hedlund speakers. I don’t know how you determined that you prefer the sound signature of the 2A3 without hearing examples of these amplifier. As you’ve discovered there are many choices available in the DHT SET genre.

Somehow you need to find a way to hear a variety of SETs to get some idea of what differences exist among them. You heard the Cary 300b SET and were impressed with it, other brand 300b SETs will have different presentations. It can be somewhat challenging as there are multiple variables to account for.

2000 dollars can get you a good quality used 2A3 SET if you take your time, a similar quality 300b SET will likely cost you more money. I actually believe that the Sean Casper F2a amplifier could be a very good choice.

You asked can the el 34 tubes sound glorious? A talented designer/builder can extract good sound from most any tube. The El 34 isn’t a 300b which I believe is ultimately the better sounding tube (obviously just my opinion). Concerning the Coincident Dynamo several owners have posted their impressions on this site and are quite happy with it.
i have owned the exact driver and cabinet you just bought.  There are times I wish I never sold them.  Your driver is world class and will sound incredible with a quality 300b, 45 or 2a3 tube amp.  There transformers will make or break the sound.   I drove these speakers with a Air Tight 300b and a George Wright 2a3 amp.   Both sounded breathtakingly beautiful.  The Air Tight is above your budget but if you can find a used George Wright used jump on it.   I would also highly recommend Decware.  Their $1000 amp new will crush any Chinese amp near that price range.  Check them out!

Wow!  Ok, my search continues...  BTW I just updated my profile picture so you can see what the speakers look like.  

I believe you are beginning to appreciate the fact that a variety of power output tubes are capable of providing a very good sound. As Bobheinatz reiterated both amplifiers he cited have high quality output transformers. Based on his comments the Hedlund is an exceptional speaker that will reveal the quality of an amplifier (which is a good thing).

Are you still considering the Sean Casper F2a or the Dynamo MK II or are you determined to go with the DHT 2A3? You have interesting choices. 😊

I heard both 2a3 and a 45 on my Edgarhorn speakers and of the two preferred the 45. The caveat to all of this is the design quality of the amp....power transformers/coupling caps/power supplies etc. I also owned a top quality 300B but the 45 was at least an equal match in musicality with the 16 OHM/107 DB load.

You will notice little difference in power between 2a3/45 but I predict their are more 45 tubes out there to choose from the NOS tube days as they were used in tube radios of yesteryear. I owned the Yamamoto 45 and still own the Korneff 45 and prefer the Korneff for the sound you mention.......again same tube different design. Same ole story. My opinion is go with a used 45 if you can find one but quality of design matters a lot with either amp.

Hi Gwalt,
I always appreciate your impressions.  With a budget of 2000 dollars it would be easier to find a good quality 45 SET compared to the 3000b which are more expensive to produce. 


Thank you. I believe there is guy at Wu Audio that is building a Korneff Replica. All I know is he is from Asia and copied the design. I think he goes by Wu?

I had some trouble with 300B tubes being microphonic with the long plates into a high efficiency designed speaker. The 45 tube has it all in musicality with great bass control for its output. If I were Ramoneo I would go that route as there is also some great NOS 45 tubes still out there. I still own 2 pair of RCA Globes and they are sweet as can be.

I can find out the builder if Mr. Ramoneo wants to know as I had a friend who had one built.

Willard Vincent in Idaho makes fabulous sounding SET as well as push-pull amps based on 45 tubes. I have been using a push pull for 5 years with no problems. (Amp is on everyday). His prices are close to your budget. He goes by autospec. Or google will Vincent amps.
Hi, ramoneo14
Your original question stated that you wanted suggestions for a good amp. Is this the case, and if so what pre-amp do you have or plan to get, or are you looking for an integrated amp?
Also did you come too realize that $1000.00 may not be able to obtain you the amp/preamp/integrated your seeking and you have since increased your budget to $2K.
Knowing the above would help in making more accurate suggestions with regard to possible candidates.
Another suggestion would be to research audio clubs/organizations in your area; there may be members willing to share or demonstrate there amps/integrated for you, there by taking some of the guess work out if for you.

@gwalt Min at Tube Audio Labs is building Korneff45 clones not sure who else is building them.


That is it then. Thanks Jond. My memory sucks but I did have a friend who had both a Korneff 45 built by Jeff and a Min one and liked them both. He bought the Min one after selling the Korneff and wanted another Korneff and Jeff had stopped making them.


@charles1dad , @gwalt , @powder1 : I am certainly open to the 45 tube variety- low power, reputable sound quality, availability, and if prices are low that is the ticket.

@bradf : I now realize that $1K is a bit low to spend on a quality integrated so I am open to go $2K if the value is there.  I have a VTL Dual Mono tube preamp (may not be a good match, not sure).  I'd rather go integrated for matching and simplicity. 

@jond There is a Tube Audio Labs 300b amp on Audiogon right now for $1900. Is that a good unit? If so, how good and would you advise that option over the 45 version?  Also there is another Tube Audio Labs 2A3 amp for a good price.  Your opinions?  
This looks like a very good option.  I looked at their parts selection list on that site and there are some really good choices offered. You are given an opportunity to upgrade/customize the amplifier to a significant degree if desired. Really nice transformers are available. 
Go back and check out the link that bradf provided for Finale Audio. They are the French flip side to Triode Lab (same people) and there are a few amps, in your new budget, that use high quality parts and exacting build standards. 

Even better, give them a call (don't feel obligated) and see what they recommend for your speakers.
If I ever luck out and get a better and bigger place, and still have my Tonian Labs TL-D1s, they'd be the first place I'd look into.

All the best,
The following is not a recommendation, but rather an integrated found while searching for an good quality 2A3  at approx. $1,000.00

I think Charles 1 dad, jond, gwalt, powder1, and the other members addressing this issue, are more exposed , educated, and familiar with the SET variety then I am, or ever hope to be.
They would have much better advice then I would be able to provide you regarding this integrated.
Audiogon Triode Labs 2A3 integrated listing

Reference to various 2A# tube pairs

6 Moons review of Triode labs 2A3 integrated

Here’s my take, the 2A3 integrated amplifier for1000 dollars is a good value choice from a reputable company. The Triode Lab Signature 2A3 SET for 1900 (4000 dollars retail) is a better long term choice, it has higher quality transformers, capacitors and power supply. This better amplifier would be exploited by the Hedlund speakers. I’d spend more for the higher quality SET.
I have to agree with Charles better to spend more money now and get it right trust me its cheaper in the long run (speaking from experience). Transformer quality doesn't come cheap and makes a huge difference with SET amps, PP amps to for that matter.  I can't imagine what my own amp would sound like without its huge overspec'd 60s vintage transformer. That Triode Lab Sig 2a3 for $1900 looks like the real deal, a well executed amp that uses high quality parts.
charles 1 dad
I would have to agree with you on both topics; but as you point out,  the overall better choice would be to opt for the 2A3 Signature.
By the way, you have brought a lot of info to this discussion which I have found beneficial / educational. Thanks
Thanks for your kind comments.  Jond, Yes it is wiser to get the best you can afford the first time,  it is definitely cheaper in the long run. I made that decision 7 years ago when I purchased my SET amplifier  (Coincident Frankenstein MK II). There's been no second guessing,  just pure musical joy. 
charles 1 dad

What pre-amp are you using with your Coincident Monos (BTW, nice choice). or pre-amp recommendation for the Frankenstein 300B
Hello Brad,
I use the Coincident Statement Line Stage.  My system is posted in  the virtual system section of audiogon.  My system is titled "SET Bliss".
Linear tube audio microzotl2.0 Deluxe (David Berning design)