used SET amp under $1500 suggestion

As stated in another thread, I have problem of having too much gain in my system. I am considering buying a SET amp to drive a pair of Zu omen definition, and looking for suggestion. I have too options:

1) keeping my PrimaLuna Prologue 3 preamp and buy a SET power amp or mono block. I like the PrimaLuna sound, so, I prefer to keep it. However, in this case, my budge is under $1500. To work with the PrimaLuna, I need an amp with input impedance > 100k Ohm. And the PrimaLuna has a gain of 12 dB. My current McCormack has 30dB gain which is too loud. So .. likely, I prefer something not exceeding 20dB gain?

2) sell the PrimaLuan preamp, and replaced with an integrated SET amp. I prefer option 1 because I don't know if I will like the sound of the integrated. But if I get an integrated, my budget increase to $2500, and it seems it open up more choices.

I read the 6moons and other review, it seems the Almarro and Yamamoto are 2 highly recommended SET choices, but they are both quite expensive. Is there any other choices? Thanks in advance.
Almarro A318B. It's an increadable amp.
I would say it compaires to anything out there.
I am doing some research and come across a designer name Don Allen. It seems his SET amps are highly praised. But I try google and can't find his business nor any link to his product. Is there anyone who has his web site? Or a way to contact him?

He has a phone number and it has been noted on the SET forum at Audio Asylum a couple of times. You could try a search over there.

Good suggestions so far.
Also - Min Yang at Tube Audio Lab out of California can make you one heck of an amp for your budget.
This is just my opinion, but if you are going to go the SET route - do it right. Don't dip a toe half in, then declare it's not for you without truly giving it a try.

What does that mean? SET "musical presentation" is significantly different from other forms of amplification - in my opinion. It has unique characteristics and benefits, along with demands and shortcomings.

So, if you are adamant about using a preamp with a SET amp, be sure to use one that was designed for a SET system. I know, people will say the only design criterion for a preamp should be volume control and source selection, maybe impedance matching, too. So, any good preamp will be good in any system.

I'm not sure I buy that. The SET traits that are so valued by enthusiasts are so subtle and nuanced that they may easily be masked or lost if the amp designer isn't specifically using them in the process.

First off, most SET designers attempt to use the minimum amount of parts possible in the signal path. The same for crossovers in many/most SET-friendly speakers. Advocates claim that each extra part contributes a "veil" over the reproduction. Most SET amp designers take this same approach to their preamps, while designers for other forms of amplification tend to not concern themselves(as obsessively) with this purist approach.

Which is my long-winded way of saying that while your Prima-Luna preamp may be excellent, it may not be the most synergistic with a SET amp.

I'd try a SET integrated first to see if you like the approach. At least there you will know you are hearing exactly(or as close to) what the amp designer intended, instead of a mixture of two different approaches.

I have owned the afore-mentioned Almarro A318B integrated amp - it is excellent. And I mean this in an absolute sense, not just relative to it's price. It is a perfect first experience with SET amplification and still holds up with more experience. I happened to own it at the same time as two or three other highly regarded integrateds at much higher price points and it easily was on par. Be patient, they come up for sale used from time to time within your price range.
I like tubes myself and tend to agree there is a big difference between Push/pull and SET amps. The latter appear to have more, drive and transparency, but can suffer at the frequency extremes. I am not sure SET can be done cheaply, they do depend on good, large, quality output transformers, which are'nt cheap.
I would tend to agree that the Almarro 318B, is truly excellent at the price. The output tube on it runs very hot and according to the engineer I use, has a higher failure rate than some other tubes. He should know, he is a specialist in tube amps
like Zman I'm an Almarro fan....the 318B compares favorably to any price SET amp. Had the amp 4 years, never a tube failure, the big russian power tubes are only $40 each and if you bias correctly they run forever.
Mastersound makes wonderful amps. They come up for sale in your price range.
are you sure the problem lies with your pre or amp and not your source??? maybe your source has an unusually high output voltage??

I had an issue with the output voltage of a source using a passive pre with a SET amp. the volume control could only be used for about clicks (stepped attenuator) before the volume became too loud.

had a passive custom made with step-DOWN transformers to reduce the voltage of the source before the amp. worked like a charm!

email me if you'd like more info

Very good thread and advice for some one new to SET amplifiers. Darkmoebius, you are so correct with your advice concerning preamps, choose carefully! A good SET amp is capable of extraodinary nuance,inner detail and purity of tone. The preamp must be clear,transparent and have a low noise floor, or the advantages of the SET amp will be lost. Pay much attention to power supply built/quality(very important)transformer quality and circuit(usally the simpler and with fewer parts and stages the better). With your stated budgetof 2500.00 you can find a good high quality intergrated SET, for example a used Audio Space 300b. Just remain patient and you`ll have a fine sounding SET to drive your Zu speakers.
Personally, I would skip the pentodes and tetrodes hooked up as triodes and move right to directly heated triodes. IMHO, this is where the magic lives. The Elekit 2A3 is a good example:

Alternately, if you like your current setup, but just have too much gain, an inexpensive, and effective, solution is the Rothwell in-line attenuators:

Good luck and happy listening.
05-01-11: Viridian
Personally, I would skip the pentodes and tetrodes hooked up as triodes and move right to directly heated triodes. IMHO, this is where the magic lives. The Elekit 2A3 is a good example:
While I agree with you 100% for experienced SET users , 45 and 2A3 are nearly unparalleled (although PX-25 ranks up there)... I just think the odds of a first-timer being totally satisfied with 2-3wpc are far less likely than 12-18wpc. Especially in the case where we do not know the OP's room size, musical tastes, and listening preferences.

Luckily, the Zu Omen Defs are 98dB/4-6ohm, so 2-3wpc could be satisfying in many situations, but not all. All depends on the robustness of the power supply.
As much as I enjoy SET amps (and I do!), I must agree with Jrinkerptdnet - moving to a SET amp for the reason you stated seems a little extreme to me. It might be easier to deal with the gain issue. But maybe your amp is just not a good match for your Omens.

But assuming that you want to move to SET for whatever reason, you have a lot of choices as you can see from the responses above. As the old saying goes, opinons are like... belly buttons. Everybody has one. There have been discussions and arguments ad nauseum on this and every other audio forum about the merits of DHT vs. PP vs. OTL vs. triode-mode pentode etc. In the end you are going to have to decide for yourself, in your room, with your gear and with your ears.

Without making any strict recommendations, please allow me to add some as of yet unmentioned, reasonably priced options that you might also consider:

Power Amps:
- Almarro A205A - a SEP, not a SET.
- Conrad Johnson Premier 11XS - An 11A wired in triode mode.
- Decware - reportedly an outstanding line of products
- Golden Tube Audio - the SE40 is a much maligned parallel SET amp. I have two, and I have never had an issue with either one. Outstanding value, and can be rebuilt quite reasonably if wanted or needed.
- Quicksilver - an entire line of great, fairly priced products, including a SET model.
- Sophia Baby

Integrated Amps:
- Audio Note OTO SE - IMHO the best value in a fully integrated SET amp
- Conrad Johnson CAV50 - a PP amp, but it looks and sounds great

Good luck!
I also feel that a DHT based amp is the ultimate in sound.The 45,2a3 and 300b(I`ve heard them all)can sound superb or merely average. Depends on implemetation and parts quality. The 300b(there`s many to choose from)can provide 8-10 watts in a SET design. For a 98db speaker this is a lot of power with plenty of headroom. With this speaker at reasonable listening levels(70-85db) you`re using 1/10to 1/100 of a watt!
Charles and Dark there's more to DHT land than 45, 2A3 and 300B. Give the 46 a try and if you can really live with low, low power, the 71A is unparalleled, and of course, the 6B4G is a nice DHT as well, more or less, a 6V 2A3.
not trying to talk him out of a SET amp, just not sure that will solve the problem of too much gain in the system. would be a shame to put $1500 into an amp and STILL have too much gain from the source allowing you a tiny range on the volume control

just my 2 cents

Your point is understood, but in the context of an initial step into the DHT-SET world They`re many choices available with the much more commonly used(easy to find)tubes that still offer excellent sound.
05-01-11: Viridian
Charles and Dark there's more to DHT land than 45, 2A3 and 300B. Give the 46 a try and if you can really live with low, low power, the 71A is unparalleled, and of course, the 6B4G is a nice DHT as well, more or less, a 6V 2A3.
All valid points, but as of yet, we know nothing of the OP's preferences. Under-powered systems can led to some pretty negative generalizations about SET overall. Better to start out in the higher power regions and work one's way down, than vice versa.
At the $2500 budgetary max for an integrated I'd acquire a Grant Fidelity A534B, a 9 watt 300B Class A SET design maxed out with premium black treasure tubes, both 300b and 6CA7's, and psvane 12ax7 drivers, and still have a bit left over for vinyl or cd. Complete with remote!

I've owned Prima Luna, BAT, VTL, Plinius, some decent gear over the years, but for my ears nothing tops the A534B juiced up on black treasure tubes...that combo is my reference now. But don't let the 9 watts of the design fool you, it pushes electostats with ease, and for the average person it would be the only amp they'd ever need.
That`s a very good suggestion, I`ve read and have heard nothing but excellent comments on that amplifier. I use the Black Treasure Series 300b in my amp and it`s superb! That amp would coast driving the Zu 98db speaker.
Charles1dad, for sure it would coast driving Zu's or any other higher sensitivity rated speaker. But I was truly amazed that the amp was capable of driving a pair of electrostats that commonly dip below 2 ohms. This modestly priced integ loaded with black treasures encouraged me to sell off far more expensive gear. It's a very impressive amp and I'm surprised more listeners aren't beating a path to Grant Fidelity's door in an attempt to land one.

Get this, my former VK300XSE clipped out at 85dB driving a pair of cls iiz's but this modestly priced lower power 300B just chugged along as if it was pushing a pair of ZU's - that's sum trick.
The Grant Fidelity Shuguang 300B integrated is kick ass also.....I sold mine a few months ago and it is 90% as good as my now much more expensive system.

I would recommend:
Decware torii
GF Shuguang 300
Almarro 318
Quad KT-66 amp ( and there is one on Audiogon that I heard and loved with Superfly's)
Melody 2A3 Monoblocks (used). Ask Sam HiFi on Audiocircle about this one.....he loves it with his Defs ( he has the integrated version).

I have the Omen Defs and have heard all of the above except the Almarro....and all are fantastic.

I would agree with a few posters though.....the Zu's are so transparent that you must have every piece working together to get a great sound......and just one piece off upstream will degrade the entire system. I would suspect the McCormack should sound pretty good with your Defs.

What is your source?
Yes, I think the McCormack sounds very good. However, I don't have others to compare to. The only problem is the gain. When I have to keep the volume low, it doesn't sound good. But when I turn it up a bit at about 9 o'clock, it sounds very good IMO. So, I don't really know if I should change it. It seems most of the SS amp has very high gain. For example, some ppl recommend the red wine audio sig 30.2. I did a calculation, it has aboutn 30dB gain as well. The Pass XA 30.5 has 26dB. It seems the only way to have lower gain is to with the SET.
I think the only way to know is to buy a SET amp and give it a try! There is a used GF 300 with upgraded tubes for sale used right now. Assuming the tubes are A Grade matched, that is a bargain as rhe tubes alone are $500-600. That would be a good starting match for you to get the flavor of set with little risk as you could resell it easily. That's the key here.....finding synergy while not losing money in the process! At least that's what I have done and it has been worth the time and effort as now I am loving my system!
I spot a Cary / AES SE-1 300B with 7 watt on local craigslist for $800. Do you think it will be a good match with the Omen Defn? Does anyone has experience with this unit? It has no negative feed back and the output impedance is 3.2 Ohm. The comment from the review says high output impedance results in lack of bass "tightness". Any comment on this?

If you decide to sell the Prima and can move to the $2500 level you may want to look at the Tri (Try??) 845C integrated. I've heard one locally and it's awfully nice. Driving a pair of B&W 802 Diamonds...nice stuff indeedly. And cool as hell to look at as well.